+++ /dev/null
-This is doc/gccint.info, produced by makeinfo version 4.13 from
-/home/jingyu/projects/gcc/android-toolchainsrc/build/../gcc/gcc-4.4.3/gcc/doc/gccint.texi.
-
-Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free
-Software Foundation, Inc.
-
- Permission is granted to copy, distribute and/or modify this document
-under the terms of the GNU Free Documentation License, Version 1.2 or
-any later version published by the Free Software Foundation; with the
-Invariant Sections being "Funding Free Software", the Front-Cover Texts
-being (a) (see below), and with the Back-Cover Texts being (b) (see
-below). A copy of the license is included in the section entitled "GNU
-Free Documentation License".
-
- (a) The FSF's Front-Cover Text is:
-
- A GNU Manual
-
- (b) The FSF's Back-Cover Text is:
-
- You have freedom to copy and modify this GNU Manual, like GNU
-software. Copies published by the Free Software Foundation raise
-funds for GNU development.
-
-INFO-DIR-SECTION Software development
-START-INFO-DIR-ENTRY
-* gccint: (gccint). Internals of the GNU Compiler Collection.
-END-INFO-DIR-ENTRY
- This file documents the internals of the GNU compilers.
-
- Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free
-Software Foundation, Inc.
-
- Permission is granted to copy, distribute and/or modify this document
-under the terms of the GNU Free Documentation License, Version 1.2 or
-any later version published by the Free Software Foundation; with the
-Invariant Sections being "Funding Free Software", the Front-Cover Texts
-being (a) (see below), and with the Back-Cover Texts being (b) (see
-below). A copy of the license is included in the section entitled "GNU
-Free Documentation License".
-
- (a) The FSF's Front-Cover Text is:
-
- A GNU Manual
-
- (b) The FSF's Back-Cover Text is:
-
- You have freedom to copy and modify this GNU Manual, like GNU
-software. Copies published by the Free Software Foundation raise
-funds for GNU development.
-
-
-\1f
-File: gccint.info, Node: Top, Next: Contributing, Up: (DIR)
-
-Introduction
-************
-
-This manual documents the internals of the GNU compilers, including how
-to port them to new targets and some information about how to write
-front ends for new languages. It corresponds to the compilers
-(GCC) version 4.4.3. The use of the GNU compilers is documented in a
-separate manual. *Note Introduction: (gcc)Top.
-
- This manual is mainly a reference manual rather than a tutorial. It
-discusses how to contribute to GCC (*note Contributing::), the
-characteristics of the machines supported by GCC as hosts and targets
-(*note Portability::), how GCC relates to the ABIs on such systems
-(*note Interface::), and the characteristics of the languages for which
-GCC front ends are written (*note Languages::). It then describes the
-GCC source tree structure and build system, some of the interfaces to
-GCC front ends, and how support for a target system is implemented in
-GCC.
-
- Additional tutorial information is linked to from
-`http://gcc.gnu.org/readings.html'.
-
-* Menu:
-
-* Contributing:: How to contribute to testing and developing GCC.
-* Portability:: Goals of GCC's portability features.
-* Interface:: Function-call interface of GCC output.
-* Libgcc:: Low-level runtime library used by GCC.
-* Languages:: Languages for which GCC front ends are written.
-* Source Tree:: GCC source tree structure and build system.
-* Options:: Option specification files.
-* Passes:: Order of passes, what they do, and what each file is for.
-* Trees:: The source representation used by the C and C++ front ends.
-* GENERIC:: Language-independent representation generated by Front Ends
-* GIMPLE:: Tuple representation used by Tree SSA optimizers
-* Tree SSA:: Analysis and optimization of GIMPLE
-* RTL:: Machine-dependent low-level intermediate representation.
-* Control Flow:: Maintaining and manipulating the control flow graph.
-* Loop Analysis and Representation:: Analysis and representation of loops
-* Machine Desc:: How to write machine description instruction patterns.
-* Target Macros:: How to write the machine description C macros and functions.
-* Host Config:: Writing the `xm-MACHINE.h' file.
-* Fragments:: Writing the `t-TARGET' and `x-HOST' files.
-* Collect2:: How `collect2' works; how it finds `ld'.
-* Header Dirs:: Understanding the standard header file directories.
-* Type Information:: GCC's memory management; generating type information.
-* Plugins:: Extending the compiler with plugins.
-
-* Funding:: How to help assure funding for free software.
-* GNU Project:: The GNU Project and GNU/Linux.
-
-* Copying:: GNU General Public License says
- how you can copy and share GCC.
-* GNU Free Documentation License:: How you can copy and share this manual.
-* Contributors:: People who have contributed to GCC.
-
-* Option Index:: Index to command line options.
-* Concept Index:: Index of concepts and symbol names.
-
-\1f
-File: gccint.info, Node: Contributing, Next: Portability, Prev: Top, Up: Top
-
-1 Contributing to GCC Development
-*********************************
-
-If you would like to help pretest GCC releases to assure they work well,
-current development sources are available by SVN (see
-`http://gcc.gnu.org/svn.html'). Source and binary snapshots are also
-available for FTP; see `http://gcc.gnu.org/snapshots.html'.
-
- If you would like to work on improvements to GCC, please read the
-advice at these URLs:
-
- `http://gcc.gnu.org/contribute.html'
- `http://gcc.gnu.org/contributewhy.html'
-
-for information on how to make useful contributions and avoid
-duplication of effort. Suggested projects are listed at
-`http://gcc.gnu.org/projects/'.
-
-\1f
-File: gccint.info, Node: Portability, Next: Interface, Prev: Contributing, Up: Top
-
-2 GCC and Portability
-*********************
-
-GCC itself aims to be portable to any machine where `int' is at least a
-32-bit type. It aims to target machines with a flat (non-segmented)
-byte addressed data address space (the code address space can be
-separate). Target ABIs may have 8, 16, 32 or 64-bit `int' type. `char'
-can be wider than 8 bits.
-
- GCC gets most of the information about the target machine from a
-machine description which gives an algebraic formula for each of the
-machine's instructions. This is a very clean way to describe the
-target. But when the compiler needs information that is difficult to
-express in this fashion, ad-hoc parameters have been defined for
-machine descriptions. The purpose of portability is to reduce the
-total work needed on the compiler; it was not of interest for its own
-sake.
-
- GCC does not contain machine dependent code, but it does contain code
-that depends on machine parameters such as endianness (whether the most
-significant byte has the highest or lowest address of the bytes in a
-word) and the availability of autoincrement addressing. In the
-RTL-generation pass, it is often necessary to have multiple strategies
-for generating code for a particular kind of syntax tree, strategies
-that are usable for different combinations of parameters. Often, not
-all possible cases have been addressed, but only the common ones or
-only the ones that have been encountered. As a result, a new target
-may require additional strategies. You will know if this happens
-because the compiler will call `abort'. Fortunately, the new
-strategies can be added in a machine-independent fashion, and will
-affect only the target machines that need them.
-
-\1f
-File: gccint.info, Node: Interface, Next: Libgcc, Prev: Portability, Up: Top
-
-3 Interfacing to GCC Output
-***************************
-
-GCC is normally configured to use the same function calling convention
-normally in use on the target system. This is done with the
-machine-description macros described (*note Target Macros::).
-
- However, returning of structure and union values is done differently on
-some target machines. As a result, functions compiled with PCC
-returning such types cannot be called from code compiled with GCC, and
-vice versa. This does not cause trouble often because few Unix library
-routines return structures or unions.
-
- GCC code returns structures and unions that are 1, 2, 4 or 8 bytes
-long in the same registers used for `int' or `double' return values.
-(GCC typically allocates variables of such types in registers also.)
-Structures and unions of other sizes are returned by storing them into
-an address passed by the caller (usually in a register). The target
-hook `TARGET_STRUCT_VALUE_RTX' tells GCC where to pass this address.
-
- By contrast, PCC on most target machines returns structures and unions
-of any size by copying the data into an area of static storage, and then
-returning the address of that storage as if it were a pointer value.
-The caller must copy the data from that memory area to the place where
-the value is wanted. This is slower than the method used by GCC, and
-fails to be reentrant.
-
- On some target machines, such as RISC machines and the 80386, the
-standard system convention is to pass to the subroutine the address of
-where to return the value. On these machines, GCC has been configured
-to be compatible with the standard compiler, when this method is used.
-It may not be compatible for structures of 1, 2, 4 or 8 bytes.
-
- GCC uses the system's standard convention for passing arguments. On
-some machines, the first few arguments are passed in registers; in
-others, all are passed on the stack. It would be possible to use
-registers for argument passing on any machine, and this would probably
-result in a significant speedup. But the result would be complete
-incompatibility with code that follows the standard convention. So this
-change is practical only if you are switching to GCC as the sole C
-compiler for the system. We may implement register argument passing on
-certain machines once we have a complete GNU system so that we can
-compile the libraries with GCC.
-
- On some machines (particularly the SPARC), certain types of arguments
-are passed "by invisible reference". This means that the value is
-stored in memory, and the address of the memory location is passed to
-the subroutine.
-
- If you use `longjmp', beware of automatic variables. ISO C says that
-automatic variables that are not declared `volatile' have undefined
-values after a `longjmp'. And this is all GCC promises to do, because
-it is very difficult to restore register variables correctly, and one
-of GCC's features is that it can put variables in registers without
-your asking it to.
-
-\1f
-File: gccint.info, Node: Libgcc, Next: Languages, Prev: Interface, Up: Top
-
-4 The GCC low-level runtime library
-***********************************
-
-GCC provides a low-level runtime library, `libgcc.a' or `libgcc_s.so.1'
-on some platforms. GCC generates calls to routines in this library
-automatically, whenever it needs to perform some operation that is too
-complicated to emit inline code for.
-
- Most of the routines in `libgcc' handle arithmetic operations that the
-target processor cannot perform directly. This includes integer
-multiply and divide on some machines, and all floating-point and
-fixed-point operations on other machines. `libgcc' also includes
-routines for exception handling, and a handful of miscellaneous
-operations.
-
- Some of these routines can be defined in mostly machine-independent C.
-Others must be hand-written in assembly language for each processor
-that needs them.
-
- GCC will also generate calls to C library routines, such as `memcpy'
-and `memset', in some cases. The set of routines that GCC may possibly
-use is documented in *note Other Builtins: (gcc)Other Builtins.
-
- These routines take arguments and return values of a specific machine
-mode, not a specific C type. *Note Machine Modes::, for an explanation
-of this concept. For illustrative purposes, in this chapter the
-floating point type `float' is assumed to correspond to `SFmode';
-`double' to `DFmode'; and `long double' to both `TFmode' and `XFmode'.
-Similarly, the integer types `int' and `unsigned int' correspond to
-`SImode'; `long' and `unsigned long' to `DImode'; and `long long' and
-`unsigned long long' to `TImode'.
-
-* Menu:
-
-* Integer library routines::
-* Soft float library routines::
-* Decimal float library routines::
-* Fixed-point fractional library routines::
-* Exception handling routines::
-* Miscellaneous routines::
-
-\1f
-File: gccint.info, Node: Integer library routines, Next: Soft float library routines, Up: Libgcc
-
-4.1 Routines for integer arithmetic
-===================================
-
-The integer arithmetic routines are used on platforms that don't provide
-hardware support for arithmetic operations on some modes.
-
-4.1.1 Arithmetic functions
---------------------------
-
- -- Runtime Function: int __ashlsi3 (int A, int B)
- -- Runtime Function: long __ashldi3 (long A, int B)
- -- Runtime Function: long long __ashlti3 (long long A, int B)
- These functions return the result of shifting A left by B bits.
-
- -- Runtime Function: int __ashrsi3 (int A, int B)
- -- Runtime Function: long __ashrdi3 (long A, int B)
- -- Runtime Function: long long __ashrti3 (long long A, int B)
- These functions return the result of arithmetically shifting A
- right by B bits.
-
- -- Runtime Function: int __divsi3 (int A, int B)
- -- Runtime Function: long __divdi3 (long A, long B)
- -- Runtime Function: long long __divti3 (long long A, long long B)
- These functions return the quotient of the signed division of A and
- B.
-
- -- Runtime Function: int __lshrsi3 (int A, int B)
- -- Runtime Function: long __lshrdi3 (long A, int B)
- -- Runtime Function: long long __lshrti3 (long long A, int B)
- These functions return the result of logically shifting A right by
- B bits.
-
- -- Runtime Function: int __modsi3 (int A, int B)
- -- Runtime Function: long __moddi3 (long A, long B)
- -- Runtime Function: long long __modti3 (long long A, long long B)
- These functions return the remainder of the signed division of A
- and B.
-
- -- Runtime Function: int __mulsi3 (int A, int B)
- -- Runtime Function: long __muldi3 (long A, long B)
- -- Runtime Function: long long __multi3 (long long A, long long B)
- These functions return the product of A and B.
-
- -- Runtime Function: long __negdi2 (long A)
- -- Runtime Function: long long __negti2 (long long A)
- These functions return the negation of A.
-
- -- Runtime Function: unsigned int __udivsi3 (unsigned int A, unsigned
- int B)
- -- Runtime Function: unsigned long __udivdi3 (unsigned long A,
- unsigned long B)
- -- Runtime Function: unsigned long long __udivti3 (unsigned long long
- A, unsigned long long B)
- These functions return the quotient of the unsigned division of A
- and B.
-
- -- Runtime Function: unsigned long __udivmoddi3 (unsigned long A,
- unsigned long B, unsigned long *C)
- -- Runtime Function: unsigned long long __udivti3 (unsigned long long
- A, unsigned long long B, unsigned long long *C)
- These functions calculate both the quotient and remainder of the
- unsigned division of A and B. The return value is the quotient,
- and the remainder is placed in variable pointed to by C.
-
- -- Runtime Function: unsigned int __umodsi3 (unsigned int A, unsigned
- int B)
- -- Runtime Function: unsigned long __umoddi3 (unsigned long A,
- unsigned long B)
- -- Runtime Function: unsigned long long __umodti3 (unsigned long long
- A, unsigned long long B)
- These functions return the remainder of the unsigned division of A
- and B.
-
-4.1.2 Comparison functions
---------------------------
-
-The following functions implement integral comparisons. These functions
-implement a low-level compare, upon which the higher level comparison
-operators (such as less than and greater than or equal to) can be
-constructed. The returned values lie in the range zero to two, to allow
-the high-level operators to be implemented by testing the returned
-result using either signed or unsigned comparison.
-
- -- Runtime Function: int __cmpdi2 (long A, long B)
- -- Runtime Function: int __cmpti2 (long long A, long long B)
- These functions perform a signed comparison of A and B. If A is
- less than B, they return 0; if A is greater than B, they return 2;
- and if A and B are equal they return 1.
-
- -- Runtime Function: int __ucmpdi2 (unsigned long A, unsigned long B)
- -- Runtime Function: int __ucmpti2 (unsigned long long A, unsigned
- long long B)
- These functions perform an unsigned comparison of A and B. If A
- is less than B, they return 0; if A is greater than B, they return
- 2; and if A and B are equal they return 1.
-
-4.1.3 Trapping arithmetic functions
------------------------------------
-
-The following functions implement trapping arithmetic. These functions
-call the libc function `abort' upon signed arithmetic overflow.
-
- -- Runtime Function: int __absvsi2 (int A)
- -- Runtime Function: long __absvdi2 (long A)
- These functions return the absolute value of A.
-
- -- Runtime Function: int __addvsi3 (int A, int B)
- -- Runtime Function: long __addvdi3 (long A, long B)
- These functions return the sum of A and B; that is `A + B'.
-
- -- Runtime Function: int __mulvsi3 (int A, int B)
- -- Runtime Function: long __mulvdi3 (long A, long B)
- The functions return the product of A and B; that is `A * B'.
-
- -- Runtime Function: int __negvsi2 (int A)
- -- Runtime Function: long __negvdi2 (long A)
- These functions return the negation of A; that is `-A'.
-
- -- Runtime Function: int __subvsi3 (int A, int B)
- -- Runtime Function: long __subvdi3 (long A, long B)
- These functions return the difference between B and A; that is `A
- - B'.
-
-4.1.4 Bit operations
---------------------
-
- -- Runtime Function: int __clzsi2 (int A)
- -- Runtime Function: int __clzdi2 (long A)
- -- Runtime Function: int __clzti2 (long long A)
- These functions return the number of leading 0-bits in A, starting
- at the most significant bit position. If A is zero, the result is
- undefined.
-
- -- Runtime Function: int __ctzsi2 (int A)
- -- Runtime Function: int __ctzdi2 (long A)
- -- Runtime Function: int __ctzti2 (long long A)
- These functions return the number of trailing 0-bits in A, starting
- at the least significant bit position. If A is zero, the result is
- undefined.
-
- -- Runtime Function: int __ffsdi2 (long A)
- -- Runtime Function: int __ffsti2 (long long A)
- These functions return the index of the least significant 1-bit in
- A, or the value zero if A is zero. The least significant bit is
- index one.
-
- -- Runtime Function: int __paritysi2 (int A)
- -- Runtime Function: int __paritydi2 (long A)
- -- Runtime Function: int __parityti2 (long long A)
- These functions return the value zero if the number of bits set in
- A is even, and the value one otherwise.
-
- -- Runtime Function: int __popcountsi2 (int A)
- -- Runtime Function: int __popcountdi2 (long A)
- -- Runtime Function: int __popcountti2 (long long A)
- These functions return the number of bits set in A.
-
- -- Runtime Function: int32_t __bswapsi2 (int32_t A)
- -- Runtime Function: int64_t __bswapdi2 (int64_t A)
- These functions return the A byteswapped.
-
-\1f
-File: gccint.info, Node: Soft float library routines, Next: Decimal float library routines, Prev: Integer library routines, Up: Libgcc
-
-4.2 Routines for floating point emulation
-=========================================
-
-The software floating point library is used on machines which do not
-have hardware support for floating point. It is also used whenever
-`-msoft-float' is used to disable generation of floating point
-instructions. (Not all targets support this switch.)
-
- For compatibility with other compilers, the floating point emulation
-routines can be renamed with the `DECLARE_LIBRARY_RENAMES' macro (*note
-Library Calls::). In this section, the default names are used.
-
- Presently the library does not support `XFmode', which is used for
-`long double' on some architectures.
-
-4.2.1 Arithmetic functions
---------------------------
-
- -- Runtime Function: float __addsf3 (float A, float B)
- -- Runtime Function: double __adddf3 (double A, double B)
- -- Runtime Function: long double __addtf3 (long double A, long double
- B)
- -- Runtime Function: long double __addxf3 (long double A, long double
- B)
- These functions return the sum of A and B.
-
- -- Runtime Function: float __subsf3 (float A, float B)
- -- Runtime Function: double __subdf3 (double A, double B)
- -- Runtime Function: long double __subtf3 (long double A, long double
- B)
- -- Runtime Function: long double __subxf3 (long double A, long double
- B)
- These functions return the difference between B and A; that is,
- A - B.
-
- -- Runtime Function: float __mulsf3 (float A, float B)
- -- Runtime Function: double __muldf3 (double A, double B)
- -- Runtime Function: long double __multf3 (long double A, long double
- B)
- -- Runtime Function: long double __mulxf3 (long double A, long double
- B)
- These functions return the product of A and B.
-
- -- Runtime Function: float __divsf3 (float A, float B)
- -- Runtime Function: double __divdf3 (double A, double B)
- -- Runtime Function: long double __divtf3 (long double A, long double
- B)
- -- Runtime Function: long double __divxf3 (long double A, long double
- B)
- These functions return the quotient of A and B; that is, A / B.
-
- -- Runtime Function: float __negsf2 (float A)
- -- Runtime Function: double __negdf2 (double A)
- -- Runtime Function: long double __negtf2 (long double A)
- -- Runtime Function: long double __negxf2 (long double A)
- These functions return the negation of A. They simply flip the
- sign bit, so they can produce negative zero and negative NaN.
-
-4.2.2 Conversion functions
---------------------------
-
- -- Runtime Function: double __extendsfdf2 (float A)
- -- Runtime Function: long double __extendsftf2 (float A)
- -- Runtime Function: long double __extendsfxf2 (float A)
- -- Runtime Function: long double __extenddftf2 (double A)
- -- Runtime Function: long double __extenddfxf2 (double A)
- These functions extend A to the wider mode of their return type.
-
- -- Runtime Function: double __truncxfdf2 (long double A)
- -- Runtime Function: double __trunctfdf2 (long double A)
- -- Runtime Function: float __truncxfsf2 (long double A)
- -- Runtime Function: float __trunctfsf2 (long double A)
- -- Runtime Function: float __truncdfsf2 (double A)
- These functions truncate A to the narrower mode of their return
- type, rounding toward zero.
-
- -- Runtime Function: int __fixsfsi (float A)
- -- Runtime Function: int __fixdfsi (double A)
- -- Runtime Function: int __fixtfsi (long double A)
- -- Runtime Function: int __fixxfsi (long double A)
- These functions convert A to a signed integer, rounding toward
- zero.
-
- -- Runtime Function: long __fixsfdi (float A)
- -- Runtime Function: long __fixdfdi (double A)
- -- Runtime Function: long __fixtfdi (long double A)
- -- Runtime Function: long __fixxfdi (long double A)
- These functions convert A to a signed long, rounding toward zero.
-
- -- Runtime Function: long long __fixsfti (float A)
- -- Runtime Function: long long __fixdfti (double A)
- -- Runtime Function: long long __fixtfti (long double A)
- -- Runtime Function: long long __fixxfti (long double A)
- These functions convert A to a signed long long, rounding toward
- zero.
-
- -- Runtime Function: unsigned int __fixunssfsi (float A)
- -- Runtime Function: unsigned int __fixunsdfsi (double A)
- -- Runtime Function: unsigned int __fixunstfsi (long double A)
- -- Runtime Function: unsigned int __fixunsxfsi (long double A)
- These functions convert A to an unsigned integer, rounding toward
- zero. Negative values all become zero.
-
- -- Runtime Function: unsigned long __fixunssfdi (float A)
- -- Runtime Function: unsigned long __fixunsdfdi (double A)
- -- Runtime Function: unsigned long __fixunstfdi (long double A)
- -- Runtime Function: unsigned long __fixunsxfdi (long double A)
- These functions convert A to an unsigned long, rounding toward
- zero. Negative values all become zero.
-
- -- Runtime Function: unsigned long long __fixunssfti (float A)
- -- Runtime Function: unsigned long long __fixunsdfti (double A)
- -- Runtime Function: unsigned long long __fixunstfti (long double A)
- -- Runtime Function: unsigned long long __fixunsxfti (long double A)
- These functions convert A to an unsigned long long, rounding
- toward zero. Negative values all become zero.
-
- -- Runtime Function: float __floatsisf (int I)
- -- Runtime Function: double __floatsidf (int I)
- -- Runtime Function: long double __floatsitf (int I)
- -- Runtime Function: long double __floatsixf (int I)
- These functions convert I, a signed integer, to floating point.
-
- -- Runtime Function: float __floatdisf (long I)
- -- Runtime Function: double __floatdidf (long I)
- -- Runtime Function: long double __floatditf (long I)
- -- Runtime Function: long double __floatdixf (long I)
- These functions convert I, a signed long, to floating point.
-
- -- Runtime Function: float __floattisf (long long I)
- -- Runtime Function: double __floattidf (long long I)
- -- Runtime Function: long double __floattitf (long long I)
- -- Runtime Function: long double __floattixf (long long I)
- These functions convert I, a signed long long, to floating point.
-
- -- Runtime Function: float __floatunsisf (unsigned int I)
- -- Runtime Function: double __floatunsidf (unsigned int I)
- -- Runtime Function: long double __floatunsitf (unsigned int I)
- -- Runtime Function: long double __floatunsixf (unsigned int I)
- These functions convert I, an unsigned integer, to floating point.
-
- -- Runtime Function: float __floatundisf (unsigned long I)
- -- Runtime Function: double __floatundidf (unsigned long I)
- -- Runtime Function: long double __floatunditf (unsigned long I)
- -- Runtime Function: long double __floatundixf (unsigned long I)
- These functions convert I, an unsigned long, to floating point.
-
- -- Runtime Function: float __floatuntisf (unsigned long long I)
- -- Runtime Function: double __floatuntidf (unsigned long long I)
- -- Runtime Function: long double __floatuntitf (unsigned long long I)
- -- Runtime Function: long double __floatuntixf (unsigned long long I)
- These functions convert I, an unsigned long long, to floating
- point.
-
-4.2.3 Comparison functions
---------------------------
-
-There are two sets of basic comparison functions.
-
- -- Runtime Function: int __cmpsf2 (float A, float B)
- -- Runtime Function: int __cmpdf2 (double A, double B)
- -- Runtime Function: int __cmptf2 (long double A, long double B)
- These functions calculate a <=> b. That is, if A is less than B,
- they return -1; if A is greater than B, they return 1; and if A
- and B are equal they return 0. If either argument is NaN they
- return 1, but you should not rely on this; if NaN is a
- possibility, use one of the higher-level comparison functions.
-
- -- Runtime Function: int __unordsf2 (float A, float B)
- -- Runtime Function: int __unorddf2 (double A, double B)
- -- Runtime Function: int __unordtf2 (long double A, long double B)
- These functions return a nonzero value if either argument is NaN,
- otherwise 0.
-
- There is also a complete group of higher level functions which
-correspond directly to comparison operators. They implement the ISO C
-semantics for floating-point comparisons, taking NaN into account. Pay
-careful attention to the return values defined for each set. Under the
-hood, all of these routines are implemented as
-
- if (__unordXf2 (a, b))
- return E;
- return __cmpXf2 (a, b);
-
-where E is a constant chosen to give the proper behavior for NaN.
-Thus, the meaning of the return value is different for each set. Do
-not rely on this implementation; only the semantics documented below
-are guaranteed.
-
- -- Runtime Function: int __eqsf2 (float A, float B)
- -- Runtime Function: int __eqdf2 (double A, double B)
- -- Runtime Function: int __eqtf2 (long double A, long double B)
- These functions return zero if neither argument is NaN, and A and
- B are equal.
-
- -- Runtime Function: int __nesf2 (float A, float B)
- -- Runtime Function: int __nedf2 (double A, double B)
- -- Runtime Function: int __netf2 (long double A, long double B)
- These functions return a nonzero value if either argument is NaN,
- or if A and B are unequal.
-
- -- Runtime Function: int __gesf2 (float A, float B)
- -- Runtime Function: int __gedf2 (double A, double B)
- -- Runtime Function: int __getf2 (long double A, long double B)
- These functions return a value greater than or equal to zero if
- neither argument is NaN, and A is greater than or equal to B.
-
- -- Runtime Function: int __ltsf2 (float A, float B)
- -- Runtime Function: int __ltdf2 (double A, double B)
- -- Runtime Function: int __lttf2 (long double A, long double B)
- These functions return a value less than zero if neither argument
- is NaN, and A is strictly less than B.
-
- -- Runtime Function: int __lesf2 (float A, float B)
- -- Runtime Function: int __ledf2 (double A, double B)
- -- Runtime Function: int __letf2 (long double A, long double B)
- These functions return a value less than or equal to zero if
- neither argument is NaN, and A is less than or equal to B.
-
- -- Runtime Function: int __gtsf2 (float A, float B)
- -- Runtime Function: int __gtdf2 (double A, double B)
- -- Runtime Function: int __gttf2 (long double A, long double B)
- These functions return a value greater than zero if neither
- argument is NaN, and A is strictly greater than B.
-
-4.2.4 Other floating-point functions
-------------------------------------
-
- -- Runtime Function: float __powisf2 (float A, int B)
- -- Runtime Function: double __powidf2 (double A, int B)
- -- Runtime Function: long double __powitf2 (long double A, int B)
- -- Runtime Function: long double __powixf2 (long double A, int B)
- These functions convert raise A to the power B.
-
- -- Runtime Function: complex float __mulsc3 (float A, float B, float
- C, float D)
- -- Runtime Function: complex double __muldc3 (double A, double B,
- double C, double D)
- -- Runtime Function: complex long double __multc3 (long double A, long
- double B, long double C, long double D)
- -- Runtime Function: complex long double __mulxc3 (long double A, long
- double B, long double C, long double D)
- These functions return the product of A + iB and C + iD, following
- the rules of C99 Annex G.
-
- -- Runtime Function: complex float __divsc3 (float A, float B, float
- C, float D)
- -- Runtime Function: complex double __divdc3 (double A, double B,
- double C, double D)
- -- Runtime Function: complex long double __divtc3 (long double A, long
- double B, long double C, long double D)
- -- Runtime Function: complex long double __divxc3 (long double A, long
- double B, long double C, long double D)
- These functions return the quotient of A + iB and C + iD (i.e., (A
- + iB) / (C + iD)), following the rules of C99 Annex G.
-
-\1f
-File: gccint.info, Node: Decimal float library routines, Next: Fixed-point fractional library routines, Prev: Soft float library routines, Up: Libgcc
-
-4.3 Routines for decimal floating point emulation
-=================================================
-
-The software decimal floating point library implements IEEE 754-2008
-decimal floating point arithmetic and is only activated on selected
-targets.
-
- The software decimal floating point library supports either DPD
-(Densely Packed Decimal) or BID (Binary Integer Decimal) encoding as
-selected at configure time.
-
-4.3.1 Arithmetic functions
---------------------------
-
- -- Runtime Function: _Decimal32 __dpd_addsd3 (_Decimal32 A, _Decimal32
- B)
- -- Runtime Function: _Decimal32 __bid_addsd3 (_Decimal32 A, _Decimal32
- B)
- -- Runtime Function: _Decimal64 __dpd_adddd3 (_Decimal64 A, _Decimal64
- B)
- -- Runtime Function: _Decimal64 __bid_adddd3 (_Decimal64 A, _Decimal64
- B)
- -- Runtime Function: _Decimal128 __dpd_addtd3 (_Decimal128 A,
- _Decimal128 B)
- -- Runtime Function: _Decimal128 __bid_addtd3 (_Decimal128 A,
- _Decimal128 B)
- These functions return the sum of A and B.
-
- -- Runtime Function: _Decimal32 __dpd_subsd3 (_Decimal32 A, _Decimal32
- B)
- -- Runtime Function: _Decimal32 __bid_subsd3 (_Decimal32 A, _Decimal32
- B)
- -- Runtime Function: _Decimal64 __dpd_subdd3 (_Decimal64 A, _Decimal64
- B)
- -- Runtime Function: _Decimal64 __bid_subdd3 (_Decimal64 A, _Decimal64
- B)
- -- Runtime Function: _Decimal128 __dpd_subtd3 (_Decimal128 A,
- _Decimal128 B)
- -- Runtime Function: _Decimal128 __bid_subtd3 (_Decimal128 A,
- _Decimal128 B)
- These functions return the difference between B and A; that is,
- A - B.
-
- -- Runtime Function: _Decimal32 __dpd_mulsd3 (_Decimal32 A, _Decimal32
- B)
- -- Runtime Function: _Decimal32 __bid_mulsd3 (_Decimal32 A, _Decimal32
- B)
- -- Runtime Function: _Decimal64 __dpd_muldd3 (_Decimal64 A, _Decimal64
- B)
- -- Runtime Function: _Decimal64 __bid_muldd3 (_Decimal64 A, _Decimal64
- B)
- -- Runtime Function: _Decimal128 __dpd_multd3 (_Decimal128 A,
- _Decimal128 B)
- -- Runtime Function: _Decimal128 __bid_multd3 (_Decimal128 A,
- _Decimal128 B)
- These functions return the product of A and B.
-
- -- Runtime Function: _Decimal32 __dpd_divsd3 (_Decimal32 A, _Decimal32
- B)
- -- Runtime Function: _Decimal32 __bid_divsd3 (_Decimal32 A, _Decimal32
- B)
- -- Runtime Function: _Decimal64 __dpd_divdd3 (_Decimal64 A, _Decimal64
- B)
- -- Runtime Function: _Decimal64 __bid_divdd3 (_Decimal64 A, _Decimal64
- B)
- -- Runtime Function: _Decimal128 __dpd_divtd3 (_Decimal128 A,
- _Decimal128 B)
- -- Runtime Function: _Decimal128 __bid_divtd3 (_Decimal128 A,
- _Decimal128 B)
- These functions return the quotient of A and B; that is, A / B.
-
- -- Runtime Function: _Decimal32 __dpd_negsd2 (_Decimal32 A)
- -- Runtime Function: _Decimal32 __bid_negsd2 (_Decimal32 A)
- -- Runtime Function: _Decimal64 __dpd_negdd2 (_Decimal64 A)
- -- Runtime Function: _Decimal64 __bid_negdd2 (_Decimal64 A)
- -- Runtime Function: _Decimal128 __dpd_negtd2 (_Decimal128 A)
- -- Runtime Function: _Decimal128 __bid_negtd2 (_Decimal128 A)
- These functions return the negation of A. They simply flip the
- sign bit, so they can produce negative zero and negative NaN.
-
-4.3.2 Conversion functions
---------------------------
-
- -- Runtime Function: _Decimal64 __dpd_extendsddd2 (_Decimal32 A)
- -- Runtime Function: _Decimal64 __bid_extendsddd2 (_Decimal32 A)
- -- Runtime Function: _Decimal128 __dpd_extendsdtd2 (_Decimal32 A)
- -- Runtime Function: _Decimal128 __bid_extendsdtd2 (_Decimal32 A)
- -- Runtime Function: _Decimal128 __dpd_extendddtd2 (_Decimal64 A)
- -- Runtime Function: _Decimal128 __bid_extendddtd2 (_Decimal64 A)
- -- Runtime Function: _Decimal32 __dpd_truncddsd2 (_Decimal64 A)
- -- Runtime Function: _Decimal32 __bid_truncddsd2 (_Decimal64 A)
- -- Runtime Function: _Decimal32 __dpd_trunctdsd2 (_Decimal128 A)
- -- Runtime Function: _Decimal32 __bid_trunctdsd2 (_Decimal128 A)
- -- Runtime Function: _Decimal64 __dpd_trunctddd2 (_Decimal128 A)
- -- Runtime Function: _Decimal64 __bid_trunctddd2 (_Decimal128 A)
- These functions convert the value A from one decimal floating type
- to another.
-
- -- Runtime Function: _Decimal64 __dpd_extendsfdd (float A)
- -- Runtime Function: _Decimal64 __bid_extendsfdd (float A)
- -- Runtime Function: _Decimal128 __dpd_extendsftd (float A)
- -- Runtime Function: _Decimal128 __bid_extendsftd (float A)
- -- Runtime Function: _Decimal128 __dpd_extenddftd (double A)
- -- Runtime Function: _Decimal128 __bid_extenddftd (double A)
- -- Runtime Function: _Decimal128 __dpd_extendxftd (long double A)
- -- Runtime Function: _Decimal128 __bid_extendxftd (long double A)
- -- Runtime Function: _Decimal32 __dpd_truncdfsd (double A)
- -- Runtime Function: _Decimal32 __bid_truncdfsd (double A)
- -- Runtime Function: _Decimal32 __dpd_truncxfsd (long double A)
- -- Runtime Function: _Decimal32 __bid_truncxfsd (long double A)
- -- Runtime Function: _Decimal32 __dpd_trunctfsd (long double A)
- -- Runtime Function: _Decimal32 __bid_trunctfsd (long double A)
- -- Runtime Function: _Decimal64 __dpd_truncxfdd (long double A)
- -- Runtime Function: _Decimal64 __bid_truncxfdd (long double A)
- -- Runtime Function: _Decimal64 __dpd_trunctfdd (long double A)
- -- Runtime Function: _Decimal64 __bid_trunctfdd (long double A)
- These functions convert the value of A from a binary floating type
- to a decimal floating type of a different size.
-
- -- Runtime Function: float __dpd_truncddsf (_Decimal64 A)
- -- Runtime Function: float __bid_truncddsf (_Decimal64 A)
- -- Runtime Function: float __dpd_trunctdsf (_Decimal128 A)
- -- Runtime Function: float __bid_trunctdsf (_Decimal128 A)
- -- Runtime Function: double __dpd_extendsddf (_Decimal32 A)
- -- Runtime Function: double __bid_extendsddf (_Decimal32 A)
- -- Runtime Function: double __dpd_trunctddf (_Decimal128 A)
- -- Runtime Function: double __bid_trunctddf (_Decimal128 A)
- -- Runtime Function: long double __dpd_extendsdxf (_Decimal32 A)
- -- Runtime Function: long double __bid_extendsdxf (_Decimal32 A)
- -- Runtime Function: long double __dpd_extendddxf (_Decimal64 A)
- -- Runtime Function: long double __bid_extendddxf (_Decimal64 A)
- -- Runtime Function: long double __dpd_trunctdxf (_Decimal128 A)
- -- Runtime Function: long double __bid_trunctdxf (_Decimal128 A)
- -- Runtime Function: long double __dpd_extendsdtf (_Decimal32 A)
- -- Runtime Function: long double __bid_extendsdtf (_Decimal32 A)
- -- Runtime Function: long double __dpd_extendddtf (_Decimal64 A)
- -- Runtime Function: long double __bid_extendddtf (_Decimal64 A)
- These functions convert the value of A from a decimal floating type
- to a binary floating type of a different size.
-
- -- Runtime Function: _Decimal32 __dpd_extendsfsd (float A)
- -- Runtime Function: _Decimal32 __bid_extendsfsd (float A)
- -- Runtime Function: _Decimal64 __dpd_extenddfdd (double A)
- -- Runtime Function: _Decimal64 __bid_extenddfdd (double A)
- -- Runtime Function: _Decimal128 __dpd_extendtftd (long double A)
- -- Runtime Function: _Decimal128 __bid_extendtftd (long double A)
- -- Runtime Function: float __dpd_truncsdsf (_Decimal32 A)
- -- Runtime Function: float __bid_truncsdsf (_Decimal32 A)
- -- Runtime Function: double __dpd_truncdddf (_Decimal64 A)
- -- Runtime Function: double __bid_truncdddf (_Decimal64 A)
- -- Runtime Function: long double __dpd_trunctdtf (_Decimal128 A)
- -- Runtime Function: long double __bid_trunctdtf (_Decimal128 A)
- These functions convert the value of A between decimal and binary
- floating types of the same size.
-
- -- Runtime Function: int __dpd_fixsdsi (_Decimal32 A)
- -- Runtime Function: int __bid_fixsdsi (_Decimal32 A)
- -- Runtime Function: int __dpd_fixddsi (_Decimal64 A)
- -- Runtime Function: int __bid_fixddsi (_Decimal64 A)
- -- Runtime Function: int __dpd_fixtdsi (_Decimal128 A)
- -- Runtime Function: int __bid_fixtdsi (_Decimal128 A)
- These functions convert A to a signed integer.
-
- -- Runtime Function: long __dpd_fixsddi (_Decimal32 A)
- -- Runtime Function: long __bid_fixsddi (_Decimal32 A)
- -- Runtime Function: long __dpd_fixdddi (_Decimal64 A)
- -- Runtime Function: long __bid_fixdddi (_Decimal64 A)
- -- Runtime Function: long __dpd_fixtddi (_Decimal128 A)
- -- Runtime Function: long __bid_fixtddi (_Decimal128 A)
- These functions convert A to a signed long.
-
- -- Runtime Function: unsigned int __dpd_fixunssdsi (_Decimal32 A)
- -- Runtime Function: unsigned int __bid_fixunssdsi (_Decimal32 A)
- -- Runtime Function: unsigned int __dpd_fixunsddsi (_Decimal64 A)
- -- Runtime Function: unsigned int __bid_fixunsddsi (_Decimal64 A)
- -- Runtime Function: unsigned int __dpd_fixunstdsi (_Decimal128 A)
- -- Runtime Function: unsigned int __bid_fixunstdsi (_Decimal128 A)
- These functions convert A to an unsigned integer. Negative values
- all become zero.
-
- -- Runtime Function: unsigned long __dpd_fixunssddi (_Decimal32 A)
- -- Runtime Function: unsigned long __bid_fixunssddi (_Decimal32 A)
- -- Runtime Function: unsigned long __dpd_fixunsdddi (_Decimal64 A)
- -- Runtime Function: unsigned long __bid_fixunsdddi (_Decimal64 A)
- -- Runtime Function: unsigned long __dpd_fixunstddi (_Decimal128 A)
- -- Runtime Function: unsigned long __bid_fixunstddi (_Decimal128 A)
- These functions convert A to an unsigned long. Negative values
- all become zero.
-
- -- Runtime Function: _Decimal32 __dpd_floatsisd (int I)
- -- Runtime Function: _Decimal32 __bid_floatsisd (int I)
- -- Runtime Function: _Decimal64 __dpd_floatsidd (int I)
- -- Runtime Function: _Decimal64 __bid_floatsidd (int I)
- -- Runtime Function: _Decimal128 __dpd_floatsitd (int I)
- -- Runtime Function: _Decimal128 __bid_floatsitd (int I)
- These functions convert I, a signed integer, to decimal floating
- point.
-
- -- Runtime Function: _Decimal32 __dpd_floatdisd (long I)
- -- Runtime Function: _Decimal32 __bid_floatdisd (long I)
- -- Runtime Function: _Decimal64 __dpd_floatdidd (long I)
- -- Runtime Function: _Decimal64 __bid_floatdidd (long I)
- -- Runtime Function: _Decimal128 __dpd_floatditd (long I)
- -- Runtime Function: _Decimal128 __bid_floatditd (long I)
- These functions convert I, a signed long, to decimal floating
- point.
-
- -- Runtime Function: _Decimal32 __dpd_floatunssisd (unsigned int I)
- -- Runtime Function: _Decimal32 __bid_floatunssisd (unsigned int I)
- -- Runtime Function: _Decimal64 __dpd_floatunssidd (unsigned int I)
- -- Runtime Function: _Decimal64 __bid_floatunssidd (unsigned int I)
- -- Runtime Function: _Decimal128 __dpd_floatunssitd (unsigned int I)
- -- Runtime Function: _Decimal128 __bid_floatunssitd (unsigned int I)
- These functions convert I, an unsigned integer, to decimal
- floating point.
-
- -- Runtime Function: _Decimal32 __dpd_floatunsdisd (unsigned long I)
- -- Runtime Function: _Decimal32 __bid_floatunsdisd (unsigned long I)
- -- Runtime Function: _Decimal64 __dpd_floatunsdidd (unsigned long I)
- -- Runtime Function: _Decimal64 __bid_floatunsdidd (unsigned long I)
- -- Runtime Function: _Decimal128 __dpd_floatunsditd (unsigned long I)
- -- Runtime Function: _Decimal128 __bid_floatunsditd (unsigned long I)
- These functions convert I, an unsigned long, to decimal floating
- point.
-
-4.3.3 Comparison functions
---------------------------
-
- -- Runtime Function: int __dpd_unordsd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __bid_unordsd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __dpd_unorddd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __bid_unorddd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __dpd_unordtd2 (_Decimal128 A, _Decimal128 B)
- -- Runtime Function: int __bid_unordtd2 (_Decimal128 A, _Decimal128 B)
- These functions return a nonzero value if either argument is NaN,
- otherwise 0.
-
- There is also a complete group of higher level functions which
-correspond directly to comparison operators. They implement the ISO C
-semantics for floating-point comparisons, taking NaN into account. Pay
-careful attention to the return values defined for each set. Under the
-hood, all of these routines are implemented as
-
- if (__bid_unordXd2 (a, b))
- return E;
- return __bid_cmpXd2 (a, b);
-
-where E is a constant chosen to give the proper behavior for NaN.
-Thus, the meaning of the return value is different for each set. Do
-not rely on this implementation; only the semantics documented below
-are guaranteed.
-
- -- Runtime Function: int __dpd_eqsd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __bid_eqsd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __dpd_eqdd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __bid_eqdd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __dpd_eqtd2 (_Decimal128 A, _Decimal128 B)
- -- Runtime Function: int __bid_eqtd2 (_Decimal128 A, _Decimal128 B)
- These functions return zero if neither argument is NaN, and A and
- B are equal.
-
- -- Runtime Function: int __dpd_nesd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __bid_nesd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __dpd_nedd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __bid_nedd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __dpd_netd2 (_Decimal128 A, _Decimal128 B)
- -- Runtime Function: int __bid_netd2 (_Decimal128 A, _Decimal128 B)
- These functions return a nonzero value if either argument is NaN,
- or if A and B are unequal.
-
- -- Runtime Function: int __dpd_gesd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __bid_gesd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __dpd_gedd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __bid_gedd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __dpd_getd2 (_Decimal128 A, _Decimal128 B)
- -- Runtime Function: int __bid_getd2 (_Decimal128 A, _Decimal128 B)
- These functions return a value greater than or equal to zero if
- neither argument is NaN, and A is greater than or equal to B.
-
- -- Runtime Function: int __dpd_ltsd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __bid_ltsd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __dpd_ltdd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __bid_ltdd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __dpd_lttd2 (_Decimal128 A, _Decimal128 B)
- -- Runtime Function: int __bid_lttd2 (_Decimal128 A, _Decimal128 B)
- These functions return a value less than zero if neither argument
- is NaN, and A is strictly less than B.
-
- -- Runtime Function: int __dpd_lesd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __bid_lesd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __dpd_ledd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __bid_ledd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __dpd_letd2 (_Decimal128 A, _Decimal128 B)
- -- Runtime Function: int __bid_letd2 (_Decimal128 A, _Decimal128 B)
- These functions return a value less than or equal to zero if
- neither argument is NaN, and A is less than or equal to B.
-
- -- Runtime Function: int __dpd_gtsd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __bid_gtsd2 (_Decimal32 A, _Decimal32 B)
- -- Runtime Function: int __dpd_gtdd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __bid_gtdd2 (_Decimal64 A, _Decimal64 B)
- -- Runtime Function: int __dpd_gttd2 (_Decimal128 A, _Decimal128 B)
- -- Runtime Function: int __bid_gttd2 (_Decimal128 A, _Decimal128 B)
- These functions return a value greater than zero if neither
- argument is NaN, and A is strictly greater than B.
-
-\1f
-File: gccint.info, Node: Fixed-point fractional library routines, Next: Exception handling routines, Prev: Decimal float library routines, Up: Libgcc
-
-4.4 Routines for fixed-point fractional emulation
-=================================================
-
-The software fixed-point library implements fixed-point fractional
-arithmetic, and is only activated on selected targets.
-
- For ease of comprehension `fract' is an alias for the `_Fract' type,
-`accum' an alias for `_Accum', and `sat' an alias for `_Sat'.
-
- For illustrative purposes, in this section the fixed-point fractional
-type `short fract' is assumed to correspond to machine mode `QQmode';
-`unsigned short fract' to `UQQmode'; `fract' to `HQmode';
-`unsigned fract' to `UHQmode'; `long fract' to `SQmode';
-`unsigned long fract' to `USQmode'; `long long fract' to `DQmode'; and
-`unsigned long long fract' to `UDQmode'. Similarly the fixed-point
-accumulator type `short accum' corresponds to `HAmode';
-`unsigned short accum' to `UHAmode'; `accum' to `SAmode';
-`unsigned accum' to `USAmode'; `long accum' to `DAmode';
-`unsigned long accum' to `UDAmode'; `long long accum' to `TAmode'; and
-`unsigned long long accum' to `UTAmode'.
-
-4.4.1 Arithmetic functions
---------------------------
-
- -- Runtime Function: short fract __addqq3 (short fract A, short fract
- B)
- -- Runtime Function: fract __addhq3 (fract A, fract B)
- -- Runtime Function: long fract __addsq3 (long fract A, long fract B)
- -- Runtime Function: long long fract __adddq3 (long long fract A, long
- long fract B)
- -- Runtime Function: unsigned short fract __adduqq3 (unsigned short
- fract A, unsigned short fract B)
- -- Runtime Function: unsigned fract __adduhq3 (unsigned fract A,
- unsigned fract B)
- -- Runtime Function: unsigned long fract __addusq3 (unsigned long
- fract A, unsigned long fract B)
- -- Runtime Function: unsigned long long fract __addudq3 (unsigned long
- long fract A, unsigned long long fract B)
- -- Runtime Function: short accum __addha3 (short accum A, short accum
- B)
- -- Runtime Function: accum __addsa3 (accum A, accum B)
- -- Runtime Function: long accum __addda3 (long accum A, long accum B)
- -- Runtime Function: long long accum __addta3 (long long accum A, long
- long accum B)
- -- Runtime Function: unsigned short accum __adduha3 (unsigned short
- accum A, unsigned short accum B)
- -- Runtime Function: unsigned accum __addusa3 (unsigned accum A,
- unsigned accum B)
- -- Runtime Function: unsigned long accum __adduda3 (unsigned long
- accum A, unsigned long accum B)
- -- Runtime Function: unsigned long long accum __adduta3 (unsigned long
- long accum A, unsigned long long accum B)
- These functions return the sum of A and B.
-
- -- Runtime Function: short fract __ssaddqq3 (short fract A, short
- fract B)
- -- Runtime Function: fract __ssaddhq3 (fract A, fract B)
- -- Runtime Function: long fract __ssaddsq3 (long fract A, long fract B)
- -- Runtime Function: long long fract __ssadddq3 (long long fract A,
- long long fract B)
- -- Runtime Function: short accum __ssaddha3 (short accum A, short
- accum B)
- -- Runtime Function: accum __ssaddsa3 (accum A, accum B)
- -- Runtime Function: long accum __ssaddda3 (long accum A, long accum B)
- -- Runtime Function: long long accum __ssaddta3 (long long accum A,
- long long accum B)
- These functions return the sum of A and B with signed saturation.
-
- -- Runtime Function: unsigned short fract __usadduqq3 (unsigned short
- fract A, unsigned short fract B)
- -- Runtime Function: unsigned fract __usadduhq3 (unsigned fract A,
- unsigned fract B)
- -- Runtime Function: unsigned long fract __usaddusq3 (unsigned long
- fract A, unsigned long fract B)
- -- Runtime Function: unsigned long long fract __usaddudq3 (unsigned
- long long fract A, unsigned long long fract B)
- -- Runtime Function: unsigned short accum __usadduha3 (unsigned short
- accum A, unsigned short accum B)
- -- Runtime Function: unsigned accum __usaddusa3 (unsigned accum A,
- unsigned accum B)
- -- Runtime Function: unsigned long accum __usadduda3 (unsigned long
- accum A, unsigned long accum B)
- -- Runtime Function: unsigned long long accum __usadduta3 (unsigned
- long long accum A, unsigned long long accum B)
- These functions return the sum of A and B with unsigned saturation.
-
- -- Runtime Function: short fract __subqq3 (short fract A, short fract
- B)
- -- Runtime Function: fract __subhq3 (fract A, fract B)
- -- Runtime Function: long fract __subsq3 (long fract A, long fract B)
- -- Runtime Function: long long fract __subdq3 (long long fract A, long
- long fract B)
- -- Runtime Function: unsigned short fract __subuqq3 (unsigned short
- fract A, unsigned short fract B)
- -- Runtime Function: unsigned fract __subuhq3 (unsigned fract A,
- unsigned fract B)
- -- Runtime Function: unsigned long fract __subusq3 (unsigned long
- fract A, unsigned long fract B)
- -- Runtime Function: unsigned long long fract __subudq3 (unsigned long
- long fract A, unsigned long long fract B)
- -- Runtime Function: short accum __subha3 (short accum A, short accum
- B)
- -- Runtime Function: accum __subsa3 (accum A, accum B)
- -- Runtime Function: long accum __subda3 (long accum A, long accum B)
- -- Runtime Function: long long accum __subta3 (long long accum A, long
- long accum B)
- -- Runtime Function: unsigned short accum __subuha3 (unsigned short
- accum A, unsigned short accum B)
- -- Runtime Function: unsigned accum __subusa3 (unsigned accum A,
- unsigned accum B)
- -- Runtime Function: unsigned long accum __subuda3 (unsigned long
- accum A, unsigned long accum B)
- -- Runtime Function: unsigned long long accum __subuta3 (unsigned long
- long accum A, unsigned long long accum B)
- These functions return the difference of A and B; that is, `A - B'.
-
- -- Runtime Function: short fract __sssubqq3 (short fract A, short
- fract B)
- -- Runtime Function: fract __sssubhq3 (fract A, fract B)
- -- Runtime Function: long fract __sssubsq3 (long fract A, long fract B)
- -- Runtime Function: long long fract __sssubdq3 (long long fract A,
- long long fract B)
- -- Runtime Function: short accum __sssubha3 (short accum A, short
- accum B)
- -- Runtime Function: accum __sssubsa3 (accum A, accum B)
- -- Runtime Function: long accum __sssubda3 (long accum A, long accum B)
- -- Runtime Function: long long accum __sssubta3 (long long accum A,
- long long accum B)
- These functions return the difference of A and B with signed
- saturation; that is, `A - B'.
-
- -- Runtime Function: unsigned short fract __ussubuqq3 (unsigned short
- fract A, unsigned short fract B)
- -- Runtime Function: unsigned fract __ussubuhq3 (unsigned fract A,
- unsigned fract B)
- -- Runtime Function: unsigned long fract __ussubusq3 (unsigned long
- fract A, unsigned long fract B)
- -- Runtime Function: unsigned long long fract __ussubudq3 (unsigned
- long long fract A, unsigned long long fract B)
- -- Runtime Function: unsigned short accum __ussubuha3 (unsigned short
- accum A, unsigned short accum B)
- -- Runtime Function: unsigned accum __ussubusa3 (unsigned accum A,
- unsigned accum B)
- -- Runtime Function: unsigned long accum __ussubuda3 (unsigned long
- accum A, unsigned long accum B)
- -- Runtime Function: unsigned long long accum __ussubuta3 (unsigned
- long long accum A, unsigned long long accum B)
- These functions return the difference of A and B with unsigned
- saturation; that is, `A - B'.
-
- -- Runtime Function: short fract __mulqq3 (short fract A, short fract
- B)
- -- Runtime Function: fract __mulhq3 (fract A, fract B)
- -- Runtime Function: long fract __mulsq3 (long fract A, long fract B)
- -- Runtime Function: long long fract __muldq3 (long long fract A, long
- long fract B)
- -- Runtime Function: unsigned short fract __muluqq3 (unsigned short
- fract A, unsigned short fract B)
- -- Runtime Function: unsigned fract __muluhq3 (unsigned fract A,
- unsigned fract B)
- -- Runtime Function: unsigned long fract __mulusq3 (unsigned long
- fract A, unsigned long fract B)
- -- Runtime Function: unsigned long long fract __muludq3 (unsigned long
- long fract A, unsigned long long fract B)
- -- Runtime Function: short accum __mulha3 (short accum A, short accum
- B)
- -- Runtime Function: accum __mulsa3 (accum A, accum B)
- -- Runtime Function: long accum __mulda3 (long accum A, long accum B)
- -- Runtime Function: long long accum __multa3 (long long accum A, long
- long accum B)
- -- Runtime Function: unsigned short accum __muluha3 (unsigned short
- accum A, unsigned short accum B)
- -- Runtime Function: unsigned accum __mulusa3 (unsigned accum A,
- unsigned accum B)
- -- Runtime Function: unsigned long accum __muluda3 (unsigned long
- accum A, unsigned long accum B)
- -- Runtime Function: unsigned long long accum __muluta3 (unsigned long
- long accum A, unsigned long long accum B)
- These functions return the product of A and B.
-
- -- Runtime Function: short fract __ssmulqq3 (short fract A, short
- fract B)
- -- Runtime Function: fract __ssmulhq3 (fract A, fract B)
- -- Runtime Function: long fract __ssmulsq3 (long fract A, long fract B)
- -- Runtime Function: long long fract __ssmuldq3 (long long fract A,
- long long fract B)
- -- Runtime Function: short accum __ssmulha3 (short accum A, short
- accum B)
- -- Runtime Function: accum __ssmulsa3 (accum A, accum B)
- -- Runtime Function: long accum __ssmulda3 (long accum A, long accum B)
- -- Runtime Function: long long accum __ssmulta3 (long long accum A,
- long long accum B)
- These functions return the product of A and B with signed
- saturation.
-
- -- Runtime Function: unsigned short fract __usmuluqq3 (unsigned short
- fract A, unsigned short fract B)
- -- Runtime Function: unsigned fract __usmuluhq3 (unsigned fract A,
- unsigned fract B)
- -- Runtime Function: unsigned long fract __usmulusq3 (unsigned long
- fract A, unsigned long fract B)
- -- Runtime Function: unsigned long long fract __usmuludq3 (unsigned
- long long fract A, unsigned long long fract B)
- -- Runtime Function: unsigned short accum __usmuluha3 (unsigned short
- accum A, unsigned short accum B)
- -- Runtime Function: unsigned accum __usmulusa3 (unsigned accum A,
- unsigned accum B)
- -- Runtime Function: unsigned long accum __usmuluda3 (unsigned long
- accum A, unsigned long accum B)
- -- Runtime Function: unsigned long long accum __usmuluta3 (unsigned
- long long accum A, unsigned long long accum B)
- These functions return the product of A and B with unsigned
- saturation.
-
- -- Runtime Function: short fract __divqq3 (short fract A, short fract
- B)
- -- Runtime Function: fract __divhq3 (fract A, fract B)
- -- Runtime Function: long fract __divsq3 (long fract A, long fract B)
- -- Runtime Function: long long fract __divdq3 (long long fract A, long
- long fract B)
- -- Runtime Function: short accum __divha3 (short accum A, short accum
- B)
- -- Runtime Function: accum __divsa3 (accum A, accum B)
- -- Runtime Function: long accum __divda3 (long accum A, long accum B)
- -- Runtime Function: long long accum __divta3 (long long accum A, long
- long accum B)
- These functions return the quotient of the signed division of A
- and B.
-
- -- Runtime Function: unsigned short fract __udivuqq3 (unsigned short
- fract A, unsigned short fract B)
- -- Runtime Function: unsigned fract __udivuhq3 (unsigned fract A,
- unsigned fract B)
- -- Runtime Function: unsigned long fract __udivusq3 (unsigned long
- fract A, unsigned long fract B)
- -- Runtime Function: unsigned long long fract __udivudq3 (unsigned
- long long fract A, unsigned long long fract B)
- -- Runtime Function: unsigned short accum __udivuha3 (unsigned short
- accum A, unsigned short accum B)
- -- Runtime Function: unsigned accum __udivusa3 (unsigned accum A,
- unsigned accum B)
- -- Runtime Function: unsigned long accum __udivuda3 (unsigned long
- accum A, unsigned long accum B)
- -- Runtime Function: unsigned long long accum __udivuta3 (unsigned
- long long accum A, unsigned long long accum B)
- These functions return the quotient of the unsigned division of A
- and B.
-
- -- Runtime Function: short fract __ssdivqq3 (short fract A, short
- fract B)
- -- Runtime Function: fract __ssdivhq3 (fract A, fract B)
- -- Runtime Function: long fract __ssdivsq3 (long fract A, long fract B)
- -- Runtime Function: long long fract __ssdivdq3 (long long fract A,
- long long fract B)
- -- Runtime Function: short accum __ssdivha3 (short accum A, short
- accum B)
- -- Runtime Function: accum __ssdivsa3 (accum A, accum B)
- -- Runtime Function: long accum __ssdivda3 (long accum A, long accum B)
- -- Runtime Function: long long accum __ssdivta3 (long long accum A,
- long long accum B)
- These functions return the quotient of the signed division of A
- and B with signed saturation.
-
- -- Runtime Function: unsigned short fract __usdivuqq3 (unsigned short
- fract A, unsigned short fract B)
- -- Runtime Function: unsigned fract __usdivuhq3 (unsigned fract A,
- unsigned fract B)
- -- Runtime Function: unsigned long fract __usdivusq3 (unsigned long
- fract A, unsigned long fract B)
- -- Runtime Function: unsigned long long fract __usdivudq3 (unsigned
- long long fract A, unsigned long long fract B)
- -- Runtime Function: unsigned short accum __usdivuha3 (unsigned short
- accum A, unsigned short accum B)
- -- Runtime Function: unsigned accum __usdivusa3 (unsigned accum A,
- unsigned accum B)
- -- Runtime Function: unsigned long accum __usdivuda3 (unsigned long
- accum A, unsigned long accum B)
- -- Runtime Function: unsigned long long accum __usdivuta3 (unsigned
- long long accum A, unsigned long long accum B)
- These functions return the quotient of the unsigned division of A
- and B with unsigned saturation.
-
- -- Runtime Function: short fract __negqq2 (short fract A)
- -- Runtime Function: fract __neghq2 (fract A)
- -- Runtime Function: long fract __negsq2 (long fract A)
- -- Runtime Function: long long fract __negdq2 (long long fract A)
- -- Runtime Function: unsigned short fract __neguqq2 (unsigned short
- fract A)
- -- Runtime Function: unsigned fract __neguhq2 (unsigned fract A)
- -- Runtime Function: unsigned long fract __negusq2 (unsigned long
- fract A)
- -- Runtime Function: unsigned long long fract __negudq2 (unsigned long
- long fract A)
- -- Runtime Function: short accum __negha2 (short accum A)
- -- Runtime Function: accum __negsa2 (accum A)
- -- Runtime Function: long accum __negda2 (long accum A)
- -- Runtime Function: long long accum __negta2 (long long accum A)
- -- Runtime Function: unsigned short accum __neguha2 (unsigned short
- accum A)
- -- Runtime Function: unsigned accum __negusa2 (unsigned accum A)
- -- Runtime Function: unsigned long accum __neguda2 (unsigned long
- accum A)
- -- Runtime Function: unsigned long long accum __neguta2 (unsigned long
- long accum A)
- These functions return the negation of A.
-
- -- Runtime Function: short fract __ssnegqq2 (short fract A)
- -- Runtime Function: fract __ssneghq2 (fract A)
- -- Runtime Function: long fract __ssnegsq2 (long fract A)
- -- Runtime Function: long long fract __ssnegdq2 (long long fract A)
- -- Runtime Function: short accum __ssnegha2 (short accum A)
- -- Runtime Function: accum __ssnegsa2 (accum A)
- -- Runtime Function: long accum __ssnegda2 (long accum A)
- -- Runtime Function: long long accum __ssnegta2 (long long accum A)
- These functions return the negation of A with signed saturation.
-
- -- Runtime Function: unsigned short fract __usneguqq2 (unsigned short
- fract A)
- -- Runtime Function: unsigned fract __usneguhq2 (unsigned fract A)
- -- Runtime Function: unsigned long fract __usnegusq2 (unsigned long
- fract A)
- -- Runtime Function: unsigned long long fract __usnegudq2 (unsigned
- long long fract A)
- -- Runtime Function: unsigned short accum __usneguha2 (unsigned short
- accum A)
- -- Runtime Function: unsigned accum __usnegusa2 (unsigned accum A)
- -- Runtime Function: unsigned long accum __usneguda2 (unsigned long
- accum A)
- -- Runtime Function: unsigned long long accum __usneguta2 (unsigned
- long long accum A)
- These functions return the negation of A with unsigned saturation.
-
- -- Runtime Function: short fract __ashlqq3 (short fract A, int B)
- -- Runtime Function: fract __ashlhq3 (fract A, int B)
- -- Runtime Function: long fract __ashlsq3 (long fract A, int B)
- -- Runtime Function: long long fract __ashldq3 (long long fract A, int
- B)
- -- Runtime Function: unsigned short fract __ashluqq3 (unsigned short
- fract A, int B)
- -- Runtime Function: unsigned fract __ashluhq3 (unsigned fract A, int
- B)
- -- Runtime Function: unsigned long fract __ashlusq3 (unsigned long
- fract A, int B)
- -- Runtime Function: unsigned long long fract __ashludq3 (unsigned
- long long fract A, int B)
- -- Runtime Function: short accum __ashlha3 (short accum A, int B)
- -- Runtime Function: accum __ashlsa3 (accum A, int B)
- -- Runtime Function: long accum __ashlda3 (long accum A, int B)
- -- Runtime Function: long long accum __ashlta3 (long long accum A, int
- B)
- -- Runtime Function: unsigned short accum __ashluha3 (unsigned short
- accum A, int B)
- -- Runtime Function: unsigned accum __ashlusa3 (unsigned accum A, int
- B)
- -- Runtime Function: unsigned long accum __ashluda3 (unsigned long
- accum A, int B)
- -- Runtime Function: unsigned long long accum __ashluta3 (unsigned
- long long accum A, int B)
- These functions return the result of shifting A left by B bits.
-
- -- Runtime Function: short fract __ashrqq3 (short fract A, int B)
- -- Runtime Function: fract __ashrhq3 (fract A, int B)
- -- Runtime Function: long fract __ashrsq3 (long fract A, int B)
- -- Runtime Function: long long fract __ashrdq3 (long long fract A, int
- B)
- -- Runtime Function: short accum __ashrha3 (short accum A, int B)
- -- Runtime Function: accum __ashrsa3 (accum A, int B)
- -- Runtime Function: long accum __ashrda3 (long accum A, int B)
- -- Runtime Function: long long accum __ashrta3 (long long accum A, int
- B)
- These functions return the result of arithmetically shifting A
- right by B bits.
-
- -- Runtime Function: unsigned short fract __lshruqq3 (unsigned short
- fract A, int B)
- -- Runtime Function: unsigned fract __lshruhq3 (unsigned fract A, int
- B)
- -- Runtime Function: unsigned long fract __lshrusq3 (unsigned long
- fract A, int B)
- -- Runtime Function: unsigned long long fract __lshrudq3 (unsigned
- long long fract A, int B)
- -- Runtime Function: unsigned short accum __lshruha3 (unsigned short
- accum A, int B)
- -- Runtime Function: unsigned accum __lshrusa3 (unsigned accum A, int
- B)
- -- Runtime Function: unsigned long accum __lshruda3 (unsigned long
- accum A, int B)
- -- Runtime Function: unsigned long long accum __lshruta3 (unsigned
- long long accum A, int B)
- These functions return the result of logically shifting A right by
- B bits.
-
- -- Runtime Function: fract __ssashlhq3 (fract A, int B)
- -- Runtime Function: long fract __ssashlsq3 (long fract A, int B)
- -- Runtime Function: long long fract __ssashldq3 (long long fract A,
- int B)
- -- Runtime Function: short accum __ssashlha3 (short accum A, int B)
- -- Runtime Function: accum __ssashlsa3 (accum A, int B)
- -- Runtime Function: long accum __ssashlda3 (long accum A, int B)
- -- Runtime Function: long long accum __ssashlta3 (long long accum A,
- int B)
- These functions return the result of shifting A left by B bits
- with signed saturation.
-
- -- Runtime Function: unsigned short fract __usashluqq3 (unsigned short
- fract A, int B)
- -- Runtime Function: unsigned fract __usashluhq3 (unsigned fract A,
- int B)
- -- Runtime Function: unsigned long fract __usashlusq3 (unsigned long
- fract A, int B)
- -- Runtime Function: unsigned long long fract __usashludq3 (unsigned
- long long fract A, int B)
- -- Runtime Function: unsigned short accum __usashluha3 (unsigned short
- accum A, int B)
- -- Runtime Function: unsigned accum __usashlusa3 (unsigned accum A,
- int B)
- -- Runtime Function: unsigned long accum __usashluda3 (unsigned long
- accum A, int B)
- -- Runtime Function: unsigned long long accum __usashluta3 (unsigned
- long long accum A, int B)
- These functions return the result of shifting A left by B bits
- with unsigned saturation.
-
-4.4.2 Comparison functions
---------------------------
-
-The following functions implement fixed-point comparisons. These
-functions implement a low-level compare, upon which the higher level
-comparison operators (such as less than and greater than or equal to)
-can be constructed. The returned values lie in the range zero to two,
-to allow the high-level operators to be implemented by testing the
-returned result using either signed or unsigned comparison.
-
- -- Runtime Function: int __cmpqq2 (short fract A, short fract B)
- -- Runtime Function: int __cmphq2 (fract A, fract B)
- -- Runtime Function: int __cmpsq2 (long fract A, long fract B)
- -- Runtime Function: int __cmpdq2 (long long fract A, long long fract
- B)
- -- Runtime Function: int __cmpuqq2 (unsigned short fract A, unsigned
- short fract B)
- -- Runtime Function: int __cmpuhq2 (unsigned fract A, unsigned fract B)
- -- Runtime Function: int __cmpusq2 (unsigned long fract A, unsigned
- long fract B)
- -- Runtime Function: int __cmpudq2 (unsigned long long fract A,
- unsigned long long fract B)
- -- Runtime Function: int __cmpha2 (short accum A, short accum B)
- -- Runtime Function: int __cmpsa2 (accum A, accum B)
- -- Runtime Function: int __cmpda2 (long accum A, long accum B)
- -- Runtime Function: int __cmpta2 (long long accum A, long long accum
- B)
- -- Runtime Function: int __cmpuha2 (unsigned short accum A, unsigned
- short accum B)
- -- Runtime Function: int __cmpusa2 (unsigned accum A, unsigned accum B)
- -- Runtime Function: int __cmpuda2 (unsigned long accum A, unsigned
- long accum B)
- -- Runtime Function: int __cmputa2 (unsigned long long accum A,
- unsigned long long accum B)
- These functions perform a signed or unsigned comparison of A and B
- (depending on the selected machine mode). If A is less than B,
- they return 0; if A is greater than B, they return 2; and if A and
- B are equal they return 1.
-
-4.4.3 Conversion functions
---------------------------
-
- -- Runtime Function: fract __fractqqhq2 (short fract A)
- -- Runtime Function: long fract __fractqqsq2 (short fract A)
- -- Runtime Function: long long fract __fractqqdq2 (short fract A)
- -- Runtime Function: short accum __fractqqha (short fract A)
- -- Runtime Function: accum __fractqqsa (short fract A)
- -- Runtime Function: long accum __fractqqda (short fract A)
- -- Runtime Function: long long accum __fractqqta (short fract A)
- -- Runtime Function: unsigned short fract __fractqquqq (short fract A)
- -- Runtime Function: unsigned fract __fractqquhq (short fract A)
- -- Runtime Function: unsigned long fract __fractqqusq (short fract A)
- -- Runtime Function: unsigned long long fract __fractqqudq (short
- fract A)
- -- Runtime Function: unsigned short accum __fractqquha (short fract A)
- -- Runtime Function: unsigned accum __fractqqusa (short fract A)
- -- Runtime Function: unsigned long accum __fractqquda (short fract A)
- -- Runtime Function: unsigned long long accum __fractqquta (short
- fract A)
- -- Runtime Function: signed char __fractqqqi (short fract A)
- -- Runtime Function: short __fractqqhi (short fract A)
- -- Runtime Function: int __fractqqsi (short fract A)
- -- Runtime Function: long __fractqqdi (short fract A)
- -- Runtime Function: long long __fractqqti (short fract A)
- -- Runtime Function: float __fractqqsf (short fract A)
- -- Runtime Function: double __fractqqdf (short fract A)
- -- Runtime Function: short fract __fracthqqq2 (fract A)
- -- Runtime Function: long fract __fracthqsq2 (fract A)
- -- Runtime Function: long long fract __fracthqdq2 (fract A)
- -- Runtime Function: short accum __fracthqha (fract A)
- -- Runtime Function: accum __fracthqsa (fract A)
- -- Runtime Function: long accum __fracthqda (fract A)
- -- Runtime Function: long long accum __fracthqta (fract A)
- -- Runtime Function: unsigned short fract __fracthquqq (fract A)
- -- Runtime Function: unsigned fract __fracthquhq (fract A)
- -- Runtime Function: unsigned long fract __fracthqusq (fract A)
- -- Runtime Function: unsigned long long fract __fracthqudq (fract A)
- -- Runtime Function: unsigned short accum __fracthquha (fract A)
- -- Runtime Function: unsigned accum __fracthqusa (fract A)
- -- Runtime Function: unsigned long accum __fracthquda (fract A)
- -- Runtime Function: unsigned long long accum __fracthquta (fract A)
- -- Runtime Function: signed char __fracthqqi (fract A)
- -- Runtime Function: short __fracthqhi (fract A)
- -- Runtime Function: int __fracthqsi (fract A)
- -- Runtime Function: long __fracthqdi (fract A)
- -- Runtime Function: long long __fracthqti (fract A)
- -- Runtime Function: float __fracthqsf (fract A)
- -- Runtime Function: double __fracthqdf (fract A)
- -- Runtime Function: short fract __fractsqqq2 (long fract A)
- -- Runtime Function: fract __fractsqhq2 (long fract A)
- -- Runtime Function: long long fract __fractsqdq2 (long fract A)
- -- Runtime Function: short accum __fractsqha (long fract A)
- -- Runtime Function: accum __fractsqsa (long fract A)
- -- Runtime Function: long accum __fractsqda (long fract A)
- -- Runtime Function: long long accum __fractsqta (long fract A)
- -- Runtime Function: unsigned short fract __fractsquqq (long fract A)
- -- Runtime Function: unsigned fract __fractsquhq (long fract A)
- -- Runtime Function: unsigned long fract __fractsqusq (long fract A)
- -- Runtime Function: unsigned long long fract __fractsqudq (long fract
- A)
- -- Runtime Function: unsigned short accum __fractsquha (long fract A)
- -- Runtime Function: unsigned accum __fractsqusa (long fract A)
- -- Runtime Function: unsigned long accum __fractsquda (long fract A)
- -- Runtime Function: unsigned long long accum __fractsquta (long fract
- A)
- -- Runtime Function: signed char __fractsqqi (long fract A)
- -- Runtime Function: short __fractsqhi (long fract A)
- -- Runtime Function: int __fractsqsi (long fract A)
- -- Runtime Function: long __fractsqdi (long fract A)
- -- Runtime Function: long long __fractsqti (long fract A)
- -- Runtime Function: float __fractsqsf (long fract A)
- -- Runtime Function: double __fractsqdf (long fract A)
- -- Runtime Function: short fract __fractdqqq2 (long long fract A)
- -- Runtime Function: fract __fractdqhq2 (long long fract A)
- -- Runtime Function: long fract __fractdqsq2 (long long fract A)
- -- Runtime Function: short accum __fractdqha (long long fract A)
- -- Runtime Function: accum __fractdqsa (long long fract A)
- -- Runtime Function: long accum __fractdqda (long long fract A)
- -- Runtime Function: long long accum __fractdqta (long long fract A)
- -- Runtime Function: unsigned short fract __fractdquqq (long long
- fract A)
- -- Runtime Function: unsigned fract __fractdquhq (long long fract A)
- -- Runtime Function: unsigned long fract __fractdqusq (long long fract
- A)
- -- Runtime Function: unsigned long long fract __fractdqudq (long long
- fract A)
- -- Runtime Function: unsigned short accum __fractdquha (long long
- fract A)
- -- Runtime Function: unsigned accum __fractdqusa (long long fract A)
- -- Runtime Function: unsigned long accum __fractdquda (long long fract
- A)
- -- Runtime Function: unsigned long long accum __fractdquta (long long
- fract A)
- -- Runtime Function: signed char __fractdqqi (long long fract A)
- -- Runtime Function: short __fractdqhi (long long fract A)
- -- Runtime Function: int __fractdqsi (long long fract A)
- -- Runtime Function: long __fractdqdi (long long fract A)
- -- Runtime Function: long long __fractdqti (long long fract A)
- -- Runtime Function: float __fractdqsf (long long fract A)
- -- Runtime Function: double __fractdqdf (long long fract A)
- -- Runtime Function: short fract __fracthaqq (short accum A)
- -- Runtime Function: fract __fracthahq (short accum A)
- -- Runtime Function: long fract __fracthasq (short accum A)
- -- Runtime Function: long long fract __fracthadq (short accum A)
- -- Runtime Function: accum __fracthasa2 (short accum A)
- -- Runtime Function: long accum __fracthada2 (short accum A)
- -- Runtime Function: long long accum __fracthata2 (short accum A)
- -- Runtime Function: unsigned short fract __fracthauqq (short accum A)
- -- Runtime Function: unsigned fract __fracthauhq (short accum A)
- -- Runtime Function: unsigned long fract __fracthausq (short accum A)
- -- Runtime Function: unsigned long long fract __fracthaudq (short
- accum A)
- -- Runtime Function: unsigned short accum __fracthauha (short accum A)
- -- Runtime Function: unsigned accum __fracthausa (short accum A)
- -- Runtime Function: unsigned long accum __fracthauda (short accum A)
- -- Runtime Function: unsigned long long accum __fracthauta (short
- accum A)
- -- Runtime Function: signed char __fracthaqi (short accum A)
- -- Runtime Function: short __fracthahi (short accum A)
- -- Runtime Function: int __fracthasi (short accum A)
- -- Runtime Function: long __fracthadi (short accum A)
- -- Runtime Function: long long __fracthati (short accum A)
- -- Runtime Function: float __fracthasf (short accum A)
- -- Runtime Function: double __fracthadf (short accum A)
- -- Runtime Function: short fract __fractsaqq (accum A)
- -- Runtime Function: fract __fractsahq (accum A)
- -- Runtime Function: long fract __fractsasq (accum A)
- -- Runtime Function: long long fract __fractsadq (accum A)
- -- Runtime Function: short accum __fractsaha2 (accum A)
- -- Runtime Function: long accum __fractsada2 (accum A)
- -- Runtime Function: long long accum __fractsata2 (accum A)
- -- Runtime Function: unsigned short fract __fractsauqq (accum A)
- -- Runtime Function: unsigned fract __fractsauhq (accum A)
- -- Runtime Function: unsigned long fract __fractsausq (accum A)
- -- Runtime Function: unsigned long long fract __fractsaudq (accum A)
- -- Runtime Function: unsigned short accum __fractsauha (accum A)
- -- Runtime Function: unsigned accum __fractsausa (accum A)
- -- Runtime Function: unsigned long accum __fractsauda (accum A)
- -- Runtime Function: unsigned long long accum __fractsauta (accum A)
- -- Runtime Function: signed char __fractsaqi (accum A)
- -- Runtime Function: short __fractsahi (accum A)
- -- Runtime Function: int __fractsasi (accum A)
- -- Runtime Function: long __fractsadi (accum A)
- -- Runtime Function: long long __fractsati (accum A)
- -- Runtime Function: float __fractsasf (accum A)
- -- Runtime Function: double __fractsadf (accum A)
- -- Runtime Function: short fract __fractdaqq (long accum A)
- -- Runtime Function: fract __fractdahq (long accum A)
- -- Runtime Function: long fract __fractdasq (long accum A)
- -- Runtime Function: long long fract __fractdadq (long accum A)
- -- Runtime Function: short accum __fractdaha2 (long accum A)
- -- Runtime Function: accum __fractdasa2 (long accum A)
- -- Runtime Function: long long accum __fractdata2 (long accum A)
- -- Runtime Function: unsigned short fract __fractdauqq (long accum A)
- -- Runtime Function: unsigned fract __fractdauhq (long accum A)
- -- Runtime Function: unsigned long fract __fractdausq (long accum A)
- -- Runtime Function: unsigned long long fract __fractdaudq (long accum
- A)
- -- Runtime Function: unsigned short accum __fractdauha (long accum A)
- -- Runtime Function: unsigned accum __fractdausa (long accum A)
- -- Runtime Function: unsigned long accum __fractdauda (long accum A)
- -- Runtime Function: unsigned long long accum __fractdauta (long accum
- A)
- -- Runtime Function: signed char __fractdaqi (long accum A)
- -- Runtime Function: short __fractdahi (long accum A)
- -- Runtime Function: int __fractdasi (long accum A)
- -- Runtime Function: long __fractdadi (long accum A)
- -- Runtime Function: long long __fractdati (long accum A)
- -- Runtime Function: float __fractdasf (long accum A)
- -- Runtime Function: double __fractdadf (long accum A)
- -- Runtime Function: short fract __fracttaqq (long long accum A)
- -- Runtime Function: fract __fracttahq (long long accum A)
- -- Runtime Function: long fract __fracttasq (long long accum A)
- -- Runtime Function: long long fract __fracttadq (long long accum A)
- -- Runtime Function: short accum __fracttaha2 (long long accum A)
- -- Runtime Function: accum __fracttasa2 (long long accum A)
- -- Runtime Function: long accum __fracttada2 (long long accum A)
- -- Runtime Function: unsigned short fract __fracttauqq (long long
- accum A)
- -- Runtime Function: unsigned fract __fracttauhq (long long accum A)
- -- Runtime Function: unsigned long fract __fracttausq (long long accum
- A)
- -- Runtime Function: unsigned long long fract __fracttaudq (long long
- accum A)
- -- Runtime Function: unsigned short accum __fracttauha (long long
- accum A)
- -- Runtime Function: unsigned accum __fracttausa (long long accum A)
- -- Runtime Function: unsigned long accum __fracttauda (long long accum
- A)
- -- Runtime Function: unsigned long long accum __fracttauta (long long
- accum A)
- -- Runtime Function: signed char __fracttaqi (long long accum A)
- -- Runtime Function: short __fracttahi (long long accum A)
- -- Runtime Function: int __fracttasi (long long accum A)
- -- Runtime Function: long __fracttadi (long long accum A)
- -- Runtime Function: long long __fracttati (long long accum A)
- -- Runtime Function: float __fracttasf (long long accum A)
- -- Runtime Function: double __fracttadf (long long accum A)
- -- Runtime Function: short fract __fractuqqqq (unsigned short fract A)
- -- Runtime Function: fract __fractuqqhq (unsigned short fract A)
- -- Runtime Function: long fract __fractuqqsq (unsigned short fract A)
- -- Runtime Function: long long fract __fractuqqdq (unsigned short
- fract A)
- -- Runtime Function: short accum __fractuqqha (unsigned short fract A)
- -- Runtime Function: accum __fractuqqsa (unsigned short fract A)
- -- Runtime Function: long accum __fractuqqda (unsigned short fract A)
- -- Runtime Function: long long accum __fractuqqta (unsigned short
- fract A)
- -- Runtime Function: unsigned fract __fractuqquhq2 (unsigned short
- fract A)
- -- Runtime Function: unsigned long fract __fractuqqusq2 (unsigned
- short fract A)
- -- Runtime Function: unsigned long long fract __fractuqqudq2 (unsigned
- short fract A)
- -- Runtime Function: unsigned short accum __fractuqquha (unsigned
- short fract A)
- -- Runtime Function: unsigned accum __fractuqqusa (unsigned short
- fract A)
- -- Runtime Function: unsigned long accum __fractuqquda (unsigned short
- fract A)
- -- Runtime Function: unsigned long long accum __fractuqquta (unsigned
- short fract A)
- -- Runtime Function: signed char __fractuqqqi (unsigned short fract A)
- -- Runtime Function: short __fractuqqhi (unsigned short fract A)
- -- Runtime Function: int __fractuqqsi (unsigned short fract A)
- -- Runtime Function: long __fractuqqdi (unsigned short fract A)
- -- Runtime Function: long long __fractuqqti (unsigned short fract A)
- -- Runtime Function: float __fractuqqsf (unsigned short fract A)
- -- Runtime Function: double __fractuqqdf (unsigned short fract A)
- -- Runtime Function: short fract __fractuhqqq (unsigned fract A)
- -- Runtime Function: fract __fractuhqhq (unsigned fract A)
- -- Runtime Function: long fract __fractuhqsq (unsigned fract A)
- -- Runtime Function: long long fract __fractuhqdq (unsigned fract A)
- -- Runtime Function: short accum __fractuhqha (unsigned fract A)
- -- Runtime Function: accum __fractuhqsa (unsigned fract A)
- -- Runtime Function: long accum __fractuhqda (unsigned fract A)
- -- Runtime Function: long long accum __fractuhqta (unsigned fract A)
- -- Runtime Function: unsigned short fract __fractuhquqq2 (unsigned
- fract A)
- -- Runtime Function: unsigned long fract __fractuhqusq2 (unsigned
- fract A)
- -- Runtime Function: unsigned long long fract __fractuhqudq2 (unsigned
- fract A)
- -- Runtime Function: unsigned short accum __fractuhquha (unsigned
- fract A)
- -- Runtime Function: unsigned accum __fractuhqusa (unsigned fract A)
- -- Runtime Function: unsigned long accum __fractuhquda (unsigned fract
- A)
- -- Runtime Function: unsigned long long accum __fractuhquta (unsigned
- fract A)
- -- Runtime Function: signed char __fractuhqqi (unsigned fract A)
- -- Runtime Function: short __fractuhqhi (unsigned fract A)
- -- Runtime Function: int __fractuhqsi (unsigned fract A)
- -- Runtime Function: long __fractuhqdi (unsigned fract A)
- -- Runtime Function: long long __fractuhqti (unsigned fract A)
- -- Runtime Function: float __fractuhqsf (unsigned fract A)
- -- Runtime Function: double __fractuhqdf (unsigned fract A)
- -- Runtime Function: short fract __fractusqqq (unsigned long fract A)
- -- Runtime Function: fract __fractusqhq (unsigned long fract A)
- -- Runtime Function: long fract __fractusqsq (unsigned long fract A)
- -- Runtime Function: long long fract __fractusqdq (unsigned long fract
- A)
- -- Runtime Function: short accum __fractusqha (unsigned long fract A)
- -- Runtime Function: accum __fractusqsa (unsigned long fract A)
- -- Runtime Function: long accum __fractusqda (unsigned long fract A)
- -- Runtime Function: long long accum __fractusqta (unsigned long fract
- A)
- -- Runtime Function: unsigned short fract __fractusquqq2 (unsigned
- long fract A)
- -- Runtime Function: unsigned fract __fractusquhq2 (unsigned long
- fract A)
- -- Runtime Function: unsigned long long fract __fractusqudq2 (unsigned
- long fract A)
- -- Runtime Function: unsigned short accum __fractusquha (unsigned long
- fract A)
- -- Runtime Function: unsigned accum __fractusqusa (unsigned long fract
- A)
- -- Runtime Function: unsigned long accum __fractusquda (unsigned long
- fract A)
- -- Runtime Function: unsigned long long accum __fractusquta (unsigned
- long fract A)
- -- Runtime Function: signed char __fractusqqi (unsigned long fract A)
- -- Runtime Function: short __fractusqhi (unsigned long fract A)
- -- Runtime Function: int __fractusqsi (unsigned long fract A)
- -- Runtime Function: long __fractusqdi (unsigned long fract A)
- -- Runtime Function: long long __fractusqti (unsigned long fract A)
- -- Runtime Function: float __fractusqsf (unsigned long fract A)
- -- Runtime Function: double __fractusqdf (unsigned long fract A)
- -- Runtime Function: short fract __fractudqqq (unsigned long long
- fract A)
- -- Runtime Function: fract __fractudqhq (unsigned long long fract A)
- -- Runtime Function: long fract __fractudqsq (unsigned long long fract
- A)
- -- Runtime Function: long long fract __fractudqdq (unsigned long long
- fract A)
- -- Runtime Function: short accum __fractudqha (unsigned long long
- fract A)
- -- Runtime Function: accum __fractudqsa (unsigned long long fract A)
- -- Runtime Function: long accum __fractudqda (unsigned long long fract
- A)
- -- Runtime Function: long long accum __fractudqta (unsigned long long
- fract A)
- -- Runtime Function: unsigned short fract __fractudquqq2 (unsigned
- long long fract A)
- -- Runtime Function: unsigned fract __fractudquhq2 (unsigned long long
- fract A)
- -- Runtime Function: unsigned long fract __fractudqusq2 (unsigned long
- long fract A)
- -- Runtime Function: unsigned short accum __fractudquha (unsigned long
- long fract A)
- -- Runtime Function: unsigned accum __fractudqusa (unsigned long long
- fract A)
- -- Runtime Function: unsigned long accum __fractudquda (unsigned long
- long fract A)
- -- Runtime Function: unsigned long long accum __fractudquta (unsigned
- long long fract A)
- -- Runtime Function: signed char __fractudqqi (unsigned long long
- fract A)
- -- Runtime Function: short __fractudqhi (unsigned long long fract A)
- -- Runtime Function: int __fractudqsi (unsigned long long fract A)
- -- Runtime Function: long __fractudqdi (unsigned long long fract A)
- -- Runtime Function: long long __fractudqti (unsigned long long fract
- A)
- -- Runtime Function: float __fractudqsf (unsigned long long fract A)
- -- Runtime Function: double __fractudqdf (unsigned long long fract A)
- -- Runtime Function: short fract __fractuhaqq (unsigned short accum A)
- -- Runtime Function: fract __fractuhahq (unsigned short accum A)
- -- Runtime Function: long fract __fractuhasq (unsigned short accum A)
- -- Runtime Function: long long fract __fractuhadq (unsigned short
- accum A)
- -- Runtime Function: short accum __fractuhaha (unsigned short accum A)
- -- Runtime Function: accum __fractuhasa (unsigned short accum A)
- -- Runtime Function: long accum __fractuhada (unsigned short accum A)
- -- Runtime Function: long long accum __fractuhata (unsigned short
- accum A)
- -- Runtime Function: unsigned short fract __fractuhauqq (unsigned
- short accum A)
- -- Runtime Function: unsigned fract __fractuhauhq (unsigned short
- accum A)
- -- Runtime Function: unsigned long fract __fractuhausq (unsigned short
- accum A)
- -- Runtime Function: unsigned long long fract __fractuhaudq (unsigned
- short accum A)
- -- Runtime Function: unsigned accum __fractuhausa2 (unsigned short
- accum A)
- -- Runtime Function: unsigned long accum __fractuhauda2 (unsigned
- short accum A)
- -- Runtime Function: unsigned long long accum __fractuhauta2 (unsigned
- short accum A)
- -- Runtime Function: signed char __fractuhaqi (unsigned short accum A)
- -- Runtime Function: short __fractuhahi (unsigned short accum A)
- -- Runtime Function: int __fractuhasi (unsigned short accum A)
- -- Runtime Function: long __fractuhadi (unsigned short accum A)
- -- Runtime Function: long long __fractuhati (unsigned short accum A)
- -- Runtime Function: float __fractuhasf (unsigned short accum A)
- -- Runtime Function: double __fractuhadf (unsigned short accum A)
- -- Runtime Function: short fract __fractusaqq (unsigned accum A)
- -- Runtime Function: fract __fractusahq (unsigned accum A)
- -- Runtime Function: long fract __fractusasq (unsigned accum A)
- -- Runtime Function: long long fract __fractusadq (unsigned accum A)
- -- Runtime Function: short accum __fractusaha (unsigned accum A)
- -- Runtime Function: accum __fractusasa (unsigned accum A)
- -- Runtime Function: long accum __fractusada (unsigned accum A)
- -- Runtime Function: long long accum __fractusata (unsigned accum A)
- -- Runtime Function: unsigned short fract __fractusauqq (unsigned
- accum A)
- -- Runtime Function: unsigned fract __fractusauhq (unsigned accum A)
- -- Runtime Function: unsigned long fract __fractusausq (unsigned accum
- A)
- -- Runtime Function: unsigned long long fract __fractusaudq (unsigned
- accum A)
- -- Runtime Function: unsigned short accum __fractusauha2 (unsigned
- accum A)
- -- Runtime Function: unsigned long accum __fractusauda2 (unsigned
- accum A)
- -- Runtime Function: unsigned long long accum __fractusauta2 (unsigned
- accum A)
- -- Runtime Function: signed char __fractusaqi (unsigned accum A)
- -- Runtime Function: short __fractusahi (unsigned accum A)
- -- Runtime Function: int __fractusasi (unsigned accum A)
- -- Runtime Function: long __fractusadi (unsigned accum A)
- -- Runtime Function: long long __fractusati (unsigned accum A)
- -- Runtime Function: float __fractusasf (unsigned accum A)
- -- Runtime Function: double __fractusadf (unsigned accum A)
- -- Runtime Function: short fract __fractudaqq (unsigned long accum A)
- -- Runtime Function: fract __fractudahq (unsigned long accum A)
- -- Runtime Function: long fract __fractudasq (unsigned long accum A)
- -- Runtime Function: long long fract __fractudadq (unsigned long accum
- A)
- -- Runtime Function: short accum __fractudaha (unsigned long accum A)
- -- Runtime Function: accum __fractudasa (unsigned long accum A)
- -- Runtime Function: long accum __fractudada (unsigned long accum A)
- -- Runtime Function: long long accum __fractudata (unsigned long accum
- A)
- -- Runtime Function: unsigned short fract __fractudauqq (unsigned long
- accum A)
- -- Runtime Function: unsigned fract __fractudauhq (unsigned long accum
- A)
- -- Runtime Function: unsigned long fract __fractudausq (unsigned long
- accum A)
- -- Runtime Function: unsigned long long fract __fractudaudq (unsigned
- long accum A)
- -- Runtime Function: unsigned short accum __fractudauha2 (unsigned
- long accum A)
- -- Runtime Function: unsigned accum __fractudausa2 (unsigned long
- accum A)
- -- Runtime Function: unsigned long long accum __fractudauta2 (unsigned
- long accum A)
- -- Runtime Function: signed char __fractudaqi (unsigned long accum A)
- -- Runtime Function: short __fractudahi (unsigned long accum A)
- -- Runtime Function: int __fractudasi (unsigned long accum A)
- -- Runtime Function: long __fractudadi (unsigned long accum A)
- -- Runtime Function: long long __fractudati (unsigned long accum A)
- -- Runtime Function: float __fractudasf (unsigned long accum A)
- -- Runtime Function: double __fractudadf (unsigned long accum A)
- -- Runtime Function: short fract __fractutaqq (unsigned long long
- accum A)
- -- Runtime Function: fract __fractutahq (unsigned long long accum A)
- -- Runtime Function: long fract __fractutasq (unsigned long long accum
- A)
- -- Runtime Function: long long fract __fractutadq (unsigned long long
- accum A)
- -- Runtime Function: short accum __fractutaha (unsigned long long
- accum A)
- -- Runtime Function: accum __fractutasa (unsigned long long accum A)
- -- Runtime Function: long accum __fractutada (unsigned long long accum
- A)
- -- Runtime Function: long long accum __fractutata (unsigned long long
- accum A)
- -- Runtime Function: unsigned short fract __fractutauqq (unsigned long
- long accum A)
- -- Runtime Function: unsigned fract __fractutauhq (unsigned long long
- accum A)
- -- Runtime Function: unsigned long fract __fractutausq (unsigned long
- long accum A)
- -- Runtime Function: unsigned long long fract __fractutaudq (unsigned
- long long accum A)
- -- Runtime Function: unsigned short accum __fractutauha2 (unsigned
- long long accum A)
- -- Runtime Function: unsigned accum __fractutausa2 (unsigned long long
- accum A)
- -- Runtime Function: unsigned long accum __fractutauda2 (unsigned long
- long accum A)
- -- Runtime Function: signed char __fractutaqi (unsigned long long
- accum A)
- -- Runtime Function: short __fractutahi (unsigned long long accum A)
- -- Runtime Function: int __fractutasi (unsigned long long accum A)
- -- Runtime Function: long __fractutadi (unsigned long long accum A)
- -- Runtime Function: long long __fractutati (unsigned long long accum
- A)
- -- Runtime Function: float __fractutasf (unsigned long long accum A)
- -- Runtime Function: double __fractutadf (unsigned long long accum A)
- -- Runtime Function: short fract __fractqiqq (signed char A)
- -- Runtime Function: fract __fractqihq (signed char A)
- -- Runtime Function: long fract __fractqisq (signed char A)
- -- Runtime Function: long long fract __fractqidq (signed char A)
- -- Runtime Function: short accum __fractqiha (signed char A)
- -- Runtime Function: accum __fractqisa (signed char A)
- -- Runtime Function: long accum __fractqida (signed char A)
- -- Runtime Function: long long accum __fractqita (signed char A)
- -- Runtime Function: unsigned short fract __fractqiuqq (signed char A)
- -- Runtime Function: unsigned fract __fractqiuhq (signed char A)
- -- Runtime Function: unsigned long fract __fractqiusq (signed char A)
- -- Runtime Function: unsigned long long fract __fractqiudq (signed
- char A)
- -- Runtime Function: unsigned short accum __fractqiuha (signed char A)
- -- Runtime Function: unsigned accum __fractqiusa (signed char A)
- -- Runtime Function: unsigned long accum __fractqiuda (signed char A)
- -- Runtime Function: unsigned long long accum __fractqiuta (signed
- char A)
- -- Runtime Function: short fract __fracthiqq (short A)
- -- Runtime Function: fract __fracthihq (short A)
- -- Runtime Function: long fract __fracthisq (short A)
- -- Runtime Function: long long fract __fracthidq (short A)
- -- Runtime Function: short accum __fracthiha (short A)
- -- Runtime Function: accum __fracthisa (short A)
- -- Runtime Function: long accum __fracthida (short A)
- -- Runtime Function: long long accum __fracthita (short A)
- -- Runtime Function: unsigned short fract __fracthiuqq (short A)
- -- Runtime Function: unsigned fract __fracthiuhq (short A)
- -- Runtime Function: unsigned long fract __fracthiusq (short A)
- -- Runtime Function: unsigned long long fract __fracthiudq (short A)
- -- Runtime Function: unsigned short accum __fracthiuha (short A)
- -- Runtime Function: unsigned accum __fracthiusa (short A)
- -- Runtime Function: unsigned long accum __fracthiuda (short A)
- -- Runtime Function: unsigned long long accum __fracthiuta (short A)
- -- Runtime Function: short fract __fractsiqq (int A)
- -- Runtime Function: fract __fractsihq (int A)
- -- Runtime Function: long fract __fractsisq (int A)
- -- Runtime Function: long long fract __fractsidq (int A)
- -- Runtime Function: short accum __fractsiha (int A)
- -- Runtime Function: accum __fractsisa (int A)
- -- Runtime Function: long accum __fractsida (int A)
- -- Runtime Function: long long accum __fractsita (int A)
- -- Runtime Function: unsigned short fract __fractsiuqq (int A)
- -- Runtime Function: unsigned fract __fractsiuhq (int A)
- -- Runtime Function: unsigned long fract __fractsiusq (int A)
- -- Runtime Function: unsigned long long fract __fractsiudq (int A)
- -- Runtime Function: unsigned short accum __fractsiuha (int A)
- -- Runtime Function: unsigned accum __fractsiusa (int A)
- -- Runtime Function: unsigned long accum __fractsiuda (int A)
- -- Runtime Function: unsigned long long accum __fractsiuta (int A)
- -- Runtime Function: short fract __fractdiqq (long A)
- -- Runtime Function: fract __fractdihq (long A)
- -- Runtime Function: long fract __fractdisq (long A)
- -- Runtime Function: long long fract __fractdidq (long A)
- -- Runtime Function: short accum __fractdiha (long A)
- -- Runtime Function: accum __fractdisa (long A)
- -- Runtime Function: long accum __fractdida (long A)
- -- Runtime Function: long long accum __fractdita (long A)
- -- Runtime Function: unsigned short fract __fractdiuqq (long A)
- -- Runtime Function: unsigned fract __fractdiuhq (long A)
- -- Runtime Function: unsigned long fract __fractdiusq (long A)
- -- Runtime Function: unsigned long long fract __fractdiudq (long A)
- -- Runtime Function: unsigned short accum __fractdiuha (long A)
- -- Runtime Function: unsigned accum __fractdiusa (long A)
- -- Runtime Function: unsigned long accum __fractdiuda (long A)
- -- Runtime Function: unsigned long long accum __fractdiuta (long A)
- -- Runtime Function: short fract __fracttiqq (long long A)
- -- Runtime Function: fract __fracttihq (long long A)
- -- Runtime Function: long fract __fracttisq (long long A)
- -- Runtime Function: long long fract __fracttidq (long long A)
- -- Runtime Function: short accum __fracttiha (long long A)
- -- Runtime Function: accum __fracttisa (long long A)
- -- Runtime Function: long accum __fracttida (long long A)
- -- Runtime Function: long long accum __fracttita (long long A)
- -- Runtime Function: unsigned short fract __fracttiuqq (long long A)
- -- Runtime Function: unsigned fract __fracttiuhq (long long A)
- -- Runtime Function: unsigned long fract __fracttiusq (long long A)
- -- Runtime Function: unsigned long long fract __fracttiudq (long long
- A)
- -- Runtime Function: unsigned short accum __fracttiuha (long long A)
- -- Runtime Function: unsigned accum __fracttiusa (long long A)
- -- Runtime Function: unsigned long accum __fracttiuda (long long A)
- -- Runtime Function: unsigned long long accum __fracttiuta (long long
- A)
- -- Runtime Function: short fract __fractsfqq (float A)
- -- Runtime Function: fract __fractsfhq (float A)
- -- Runtime Function: long fract __fractsfsq (float A)
- -- Runtime Function: long long fract __fractsfdq (float A)
- -- Runtime Function: short accum __fractsfha (float A)
- -- Runtime Function: accum __fractsfsa (float A)
- -- Runtime Function: long accum __fractsfda (float A)
- -- Runtime Function: long long accum __fractsfta (float A)
- -- Runtime Function: unsigned short fract __fractsfuqq (float A)
- -- Runtime Function: unsigned fract __fractsfuhq (float A)
- -- Runtime Function: unsigned long fract __fractsfusq (float A)
- -- Runtime Function: unsigned long long fract __fractsfudq (float A)
- -- Runtime Function: unsigned short accum __fractsfuha (float A)
- -- Runtime Function: unsigned accum __fractsfusa (float A)
- -- Runtime Function: unsigned long accum __fractsfuda (float A)
- -- Runtime Function: unsigned long long accum __fractsfuta (float A)
- -- Runtime Function: short fract __fractdfqq (double A)
- -- Runtime Function: fract __fractdfhq (double A)
- -- Runtime Function: long fract __fractdfsq (double A)
- -- Runtime Function: long long fract __fractdfdq (double A)
- -- Runtime Function: short accum __fractdfha (double A)
- -- Runtime Function: accum __fractdfsa (double A)
- -- Runtime Function: long accum __fractdfda (double A)
- -- Runtime Function: long long accum __fractdfta (double A)
- -- Runtime Function: unsigned short fract __fractdfuqq (double A)
- -- Runtime Function: unsigned fract __fractdfuhq (double A)
- -- Runtime Function: unsigned long fract __fractdfusq (double A)
- -- Runtime Function: unsigned long long fract __fractdfudq (double A)
- -- Runtime Function: unsigned short accum __fractdfuha (double A)
- -- Runtime Function: unsigned accum __fractdfusa (double A)
- -- Runtime Function: unsigned long accum __fractdfuda (double A)
- -- Runtime Function: unsigned long long accum __fractdfuta (double A)
- These functions convert from fractional and signed non-fractionals
- to fractionals and signed non-fractionals, without saturation.
-
- -- Runtime Function: fract __satfractqqhq2 (short fract A)
- -- Runtime Function: long fract __satfractqqsq2 (short fract A)
- -- Runtime Function: long long fract __satfractqqdq2 (short fract A)
- -- Runtime Function: short accum __satfractqqha (short fract A)
- -- Runtime Function: accum __satfractqqsa (short fract A)
- -- Runtime Function: long accum __satfractqqda (short fract A)
- -- Runtime Function: long long accum __satfractqqta (short fract A)
- -- Runtime Function: unsigned short fract __satfractqquqq (short fract
- A)
- -- Runtime Function: unsigned fract __satfractqquhq (short fract A)
- -- Runtime Function: unsigned long fract __satfractqqusq (short fract
- A)
- -- Runtime Function: unsigned long long fract __satfractqqudq (short
- fract A)
- -- Runtime Function: unsigned short accum __satfractqquha (short fract
- A)
- -- Runtime Function: unsigned accum __satfractqqusa (short fract A)
- -- Runtime Function: unsigned long accum __satfractqquda (short fract
- A)
- -- Runtime Function: unsigned long long accum __satfractqquta (short
- fract A)
- -- Runtime Function: short fract __satfracthqqq2 (fract A)
- -- Runtime Function: long fract __satfracthqsq2 (fract A)
- -- Runtime Function: long long fract __satfracthqdq2 (fract A)
- -- Runtime Function: short accum __satfracthqha (fract A)
- -- Runtime Function: accum __satfracthqsa (fract A)
- -- Runtime Function: long accum __satfracthqda (fract A)
- -- Runtime Function: long long accum __satfracthqta (fract A)
- -- Runtime Function: unsigned short fract __satfracthquqq (fract A)
- -- Runtime Function: unsigned fract __satfracthquhq (fract A)
- -- Runtime Function: unsigned long fract __satfracthqusq (fract A)
- -- Runtime Function: unsigned long long fract __satfracthqudq (fract A)
- -- Runtime Function: unsigned short accum __satfracthquha (fract A)
- -- Runtime Function: unsigned accum __satfracthqusa (fract A)
- -- Runtime Function: unsigned long accum __satfracthquda (fract A)
- -- Runtime Function: unsigned long long accum __satfracthquta (fract A)
- -- Runtime Function: short fract __satfractsqqq2 (long fract A)
- -- Runtime Function: fract __satfractsqhq2 (long fract A)
- -- Runtime Function: long long fract __satfractsqdq2 (long fract A)
- -- Runtime Function: short accum __satfractsqha (long fract A)
- -- Runtime Function: accum __satfractsqsa (long fract A)
- -- Runtime Function: long accum __satfractsqda (long fract A)
- -- Runtime Function: long long accum __satfractsqta (long fract A)
- -- Runtime Function: unsigned short fract __satfractsquqq (long fract
- A)
- -- Runtime Function: unsigned fract __satfractsquhq (long fract A)
- -- Runtime Function: unsigned long fract __satfractsqusq (long fract A)
- -- Runtime Function: unsigned long long fract __satfractsqudq (long
- fract A)
- -- Runtime Function: unsigned short accum __satfractsquha (long fract
- A)
- -- Runtime Function: unsigned accum __satfractsqusa (long fract A)
- -- Runtime Function: unsigned long accum __satfractsquda (long fract A)
- -- Runtime Function: unsigned long long accum __satfractsquta (long
- fract A)
- -- Runtime Function: short fract __satfractdqqq2 (long long fract A)
- -- Runtime Function: fract __satfractdqhq2 (long long fract A)
- -- Runtime Function: long fract __satfractdqsq2 (long long fract A)
- -- Runtime Function: short accum __satfractdqha (long long fract A)
- -- Runtime Function: accum __satfractdqsa (long long fract A)
- -- Runtime Function: long accum __satfractdqda (long long fract A)
- -- Runtime Function: long long accum __satfractdqta (long long fract A)
- -- Runtime Function: unsigned short fract __satfractdquqq (long long
- fract A)
- -- Runtime Function: unsigned fract __satfractdquhq (long long fract A)
- -- Runtime Function: unsigned long fract __satfractdqusq (long long
- fract A)
- -- Runtime Function: unsigned long long fract __satfractdqudq (long
- long fract A)
- -- Runtime Function: unsigned short accum __satfractdquha (long long
- fract A)
- -- Runtime Function: unsigned accum __satfractdqusa (long long fract A)
- -- Runtime Function: unsigned long accum __satfractdquda (long long
- fract A)
- -- Runtime Function: unsigned long long accum __satfractdquta (long
- long fract A)
- -- Runtime Function: short fract __satfracthaqq (short accum A)
- -- Runtime Function: fract __satfracthahq (short accum A)
- -- Runtime Function: long fract __satfracthasq (short accum A)
- -- Runtime Function: long long fract __satfracthadq (short accum A)
- -- Runtime Function: accum __satfracthasa2 (short accum A)
- -- Runtime Function: long accum __satfracthada2 (short accum A)
- -- Runtime Function: long long accum __satfracthata2 (short accum A)
- -- Runtime Function: unsigned short fract __satfracthauqq (short accum
- A)
- -- Runtime Function: unsigned fract __satfracthauhq (short accum A)
- -- Runtime Function: unsigned long fract __satfracthausq (short accum
- A)
- -- Runtime Function: unsigned long long fract __satfracthaudq (short
- accum A)
- -- Runtime Function: unsigned short accum __satfracthauha (short accum
- A)
- -- Runtime Function: unsigned accum __satfracthausa (short accum A)
- -- Runtime Function: unsigned long accum __satfracthauda (short accum
- A)
- -- Runtime Function: unsigned long long accum __satfracthauta (short
- accum A)
- -- Runtime Function: short fract __satfractsaqq (accum A)
- -- Runtime Function: fract __satfractsahq (accum A)
- -- Runtime Function: long fract __satfractsasq (accum A)
- -- Runtime Function: long long fract __satfractsadq (accum A)
- -- Runtime Function: short accum __satfractsaha2 (accum A)
- -- Runtime Function: long accum __satfractsada2 (accum A)
- -- Runtime Function: long long accum __satfractsata2 (accum A)
- -- Runtime Function: unsigned short fract __satfractsauqq (accum A)
- -- Runtime Function: unsigned fract __satfractsauhq (accum A)
- -- Runtime Function: unsigned long fract __satfractsausq (accum A)
- -- Runtime Function: unsigned long long fract __satfractsaudq (accum A)
- -- Runtime Function: unsigned short accum __satfractsauha (accum A)
- -- Runtime Function: unsigned accum __satfractsausa (accum A)
- -- Runtime Function: unsigned long accum __satfractsauda (accum A)
- -- Runtime Function: unsigned long long accum __satfractsauta (accum A)
- -- Runtime Function: short fract __satfractdaqq (long accum A)
- -- Runtime Function: fract __satfractdahq (long accum A)
- -- Runtime Function: long fract __satfractdasq (long accum A)
- -- Runtime Function: long long fract __satfractdadq (long accum A)
- -- Runtime Function: short accum __satfractdaha2 (long accum A)
- -- Runtime Function: accum __satfractdasa2 (long accum A)
- -- Runtime Function: long long accum __satfractdata2 (long accum A)
- -- Runtime Function: unsigned short fract __satfractdauqq (long accum
- A)
- -- Runtime Function: unsigned fract __satfractdauhq (long accum A)
- -- Runtime Function: unsigned long fract __satfractdausq (long accum A)
- -- Runtime Function: unsigned long long fract __satfractdaudq (long
- accum A)
- -- Runtime Function: unsigned short accum __satfractdauha (long accum
- A)
- -- Runtime Function: unsigned accum __satfractdausa (long accum A)
- -- Runtime Function: unsigned long accum __satfractdauda (long accum A)
- -- Runtime Function: unsigned long long accum __satfractdauta (long
- accum A)
- -- Runtime Function: short fract __satfracttaqq (long long accum A)
- -- Runtime Function: fract __satfracttahq (long long accum A)
- -- Runtime Function: long fract __satfracttasq (long long accum A)
- -- Runtime Function: long long fract __satfracttadq (long long accum A)
- -- Runtime Function: short accum __satfracttaha2 (long long accum A)
- -- Runtime Function: accum __satfracttasa2 (long long accum A)
- -- Runtime Function: long accum __satfracttada2 (long long accum A)
- -- Runtime Function: unsigned short fract __satfracttauqq (long long
- accum A)
- -- Runtime Function: unsigned fract __satfracttauhq (long long accum A)
- -- Runtime Function: unsigned long fract __satfracttausq (long long
- accum A)
- -- Runtime Function: unsigned long long fract __satfracttaudq (long
- long accum A)
- -- Runtime Function: unsigned short accum __satfracttauha (long long
- accum A)
- -- Runtime Function: unsigned accum __satfracttausa (long long accum A)
- -- Runtime Function: unsigned long accum __satfracttauda (long long
- accum A)
- -- Runtime Function: unsigned long long accum __satfracttauta (long
- long accum A)
- -- Runtime Function: short fract __satfractuqqqq (unsigned short fract
- A)
- -- Runtime Function: fract __satfractuqqhq (unsigned short fract A)
- -- Runtime Function: long fract __satfractuqqsq (unsigned short fract
- A)
- -- Runtime Function: long long fract __satfractuqqdq (unsigned short
- fract A)
- -- Runtime Function: short accum __satfractuqqha (unsigned short fract
- A)
- -- Runtime Function: accum __satfractuqqsa (unsigned short fract A)
- -- Runtime Function: long accum __satfractuqqda (unsigned short fract
- A)
- -- Runtime Function: long long accum __satfractuqqta (unsigned short
- fract A)
- -- Runtime Function: unsigned fract __satfractuqquhq2 (unsigned short
- fract A)
- -- Runtime Function: unsigned long fract __satfractuqqusq2 (unsigned
- short fract A)
- -- Runtime Function: unsigned long long fract __satfractuqqudq2
- (unsigned short fract A)
- -- Runtime Function: unsigned short accum __satfractuqquha (unsigned
- short fract A)
- -- Runtime Function: unsigned accum __satfractuqqusa (unsigned short
- fract A)
- -- Runtime Function: unsigned long accum __satfractuqquda (unsigned
- short fract A)
- -- Runtime Function: unsigned long long accum __satfractuqquta
- (unsigned short fract A)
- -- Runtime Function: short fract __satfractuhqqq (unsigned fract A)
- -- Runtime Function: fract __satfractuhqhq (unsigned fract A)
- -- Runtime Function: long fract __satfractuhqsq (unsigned fract A)
- -- Runtime Function: long long fract __satfractuhqdq (unsigned fract A)
- -- Runtime Function: short accum __satfractuhqha (unsigned fract A)
- -- Runtime Function: accum __satfractuhqsa (unsigned fract A)
- -- Runtime Function: long accum __satfractuhqda (unsigned fract A)
- -- Runtime Function: long long accum __satfractuhqta (unsigned fract A)
- -- Runtime Function: unsigned short fract __satfractuhquqq2 (unsigned
- fract A)
- -- Runtime Function: unsigned long fract __satfractuhqusq2 (unsigned
- fract A)
- -- Runtime Function: unsigned long long fract __satfractuhqudq2
- (unsigned fract A)
- -- Runtime Function: unsigned short accum __satfractuhquha (unsigned
- fract A)
- -- Runtime Function: unsigned accum __satfractuhqusa (unsigned fract A)
- -- Runtime Function: unsigned long accum __satfractuhquda (unsigned
- fract A)
- -- Runtime Function: unsigned long long accum __satfractuhquta
- (unsigned fract A)
- -- Runtime Function: short fract __satfractusqqq (unsigned long fract
- A)
- -- Runtime Function: fract __satfractusqhq (unsigned long fract A)
- -- Runtime Function: long fract __satfractusqsq (unsigned long fract A)
- -- Runtime Function: long long fract __satfractusqdq (unsigned long
- fract A)
- -- Runtime Function: short accum __satfractusqha (unsigned long fract
- A)
- -- Runtime Function: accum __satfractusqsa (unsigned long fract A)
- -- Runtime Function: long accum __satfractusqda (unsigned long fract A)
- -- Runtime Function: long long accum __satfractusqta (unsigned long
- fract A)
- -- Runtime Function: unsigned short fract __satfractusquqq2 (unsigned
- long fract A)
- -- Runtime Function: unsigned fract __satfractusquhq2 (unsigned long
- fract A)
- -- Runtime Function: unsigned long long fract __satfractusqudq2
- (unsigned long fract A)
- -- Runtime Function: unsigned short accum __satfractusquha (unsigned
- long fract A)
- -- Runtime Function: unsigned accum __satfractusqusa (unsigned long
- fract A)
- -- Runtime Function: unsigned long accum __satfractusquda (unsigned
- long fract A)
- -- Runtime Function: unsigned long long accum __satfractusquta
- (unsigned long fract A)
- -- Runtime Function: short fract __satfractudqqq (unsigned long long
- fract A)
- -- Runtime Function: fract __satfractudqhq (unsigned long long fract A)
- -- Runtime Function: long fract __satfractudqsq (unsigned long long
- fract A)
- -- Runtime Function: long long fract __satfractudqdq (unsigned long
- long fract A)
- -- Runtime Function: short accum __satfractudqha (unsigned long long
- fract A)
- -- Runtime Function: accum __satfractudqsa (unsigned long long fract A)
- -- Runtime Function: long accum __satfractudqda (unsigned long long
- fract A)
- -- Runtime Function: long long accum __satfractudqta (unsigned long
- long fract A)
- -- Runtime Function: unsigned short fract __satfractudquqq2 (unsigned
- long long fract A)
- -- Runtime Function: unsigned fract __satfractudquhq2 (unsigned long
- long fract A)
- -- Runtime Function: unsigned long fract __satfractudqusq2 (unsigned
- long long fract A)
- -- Runtime Function: unsigned short accum __satfractudquha (unsigned
- long long fract A)
- -- Runtime Function: unsigned accum __satfractudqusa (unsigned long
- long fract A)
- -- Runtime Function: unsigned long accum __satfractudquda (unsigned
- long long fract A)
- -- Runtime Function: unsigned long long accum __satfractudquta
- (unsigned long long fract A)
- -- Runtime Function: short fract __satfractuhaqq (unsigned short accum
- A)
- -- Runtime Function: fract __satfractuhahq (unsigned short accum A)
- -- Runtime Function: long fract __satfractuhasq (unsigned short accum
- A)
- -- Runtime Function: long long fract __satfractuhadq (unsigned short
- accum A)
- -- Runtime Function: short accum __satfractuhaha (unsigned short accum
- A)
- -- Runtime Function: accum __satfractuhasa (unsigned short accum A)
- -- Runtime Function: long accum __satfractuhada (unsigned short accum
- A)
- -- Runtime Function: long long accum __satfractuhata (unsigned short
- accum A)
- -- Runtime Function: unsigned short fract __satfractuhauqq (unsigned
- short accum A)
- -- Runtime Function: unsigned fract __satfractuhauhq (unsigned short
- accum A)
- -- Runtime Function: unsigned long fract __satfractuhausq (unsigned
- short accum A)
- -- Runtime Function: unsigned long long fract __satfractuhaudq
- (unsigned short accum A)
- -- Runtime Function: unsigned accum __satfractuhausa2 (unsigned short
- accum A)
- -- Runtime Function: unsigned long accum __satfractuhauda2 (unsigned
- short accum A)
- -- Runtime Function: unsigned long long accum __satfractuhauta2
- (unsigned short accum A)
- -- Runtime Function: short fract __satfractusaqq (unsigned accum A)
- -- Runtime Function: fract __satfractusahq (unsigned accum A)
- -- Runtime Function: long fract __satfractusasq (unsigned accum A)
- -- Runtime Function: long long fract __satfractusadq (unsigned accum A)
- -- Runtime Function: short accum __satfractusaha (unsigned accum A)
- -- Runtime Function: accum __satfractusasa (unsigned accum A)
- -- Runtime Function: long accum __satfractusada (unsigned accum A)
- -- Runtime Function: long long accum __satfractusata (unsigned accum A)
- -- Runtime Function: unsigned short fract __satfractusauqq (unsigned
- accum A)
- -- Runtime Function: unsigned fract __satfractusauhq (unsigned accum A)
- -- Runtime Function: unsigned long fract __satfractusausq (unsigned
- accum A)
- -- Runtime Function: unsigned long long fract __satfractusaudq
- (unsigned accum A)
- -- Runtime Function: unsigned short accum __satfractusauha2 (unsigned
- accum A)
- -- Runtime Function: unsigned long accum __satfractusauda2 (unsigned
- accum A)
- -- Runtime Function: unsigned long long accum __satfractusauta2
- (unsigned accum A)
- -- Runtime Function: short fract __satfractudaqq (unsigned long accum
- A)
- -- Runtime Function: fract __satfractudahq (unsigned long accum A)
- -- Runtime Function: long fract __satfractudasq (unsigned long accum A)
- -- Runtime Function: long long fract __satfractudadq (unsigned long
- accum A)
- -- Runtime Function: short accum __satfractudaha (unsigned long accum
- A)
- -- Runtime Function: accum __satfractudasa (unsigned long accum A)
- -- Runtime Function: long accum __satfractudada (unsigned long accum A)
- -- Runtime Function: long long accum __satfractudata (unsigned long
- accum A)
- -- Runtime Function: unsigned short fract __satfractudauqq (unsigned
- long accum A)
- -- Runtime Function: unsigned fract __satfractudauhq (unsigned long
- accum A)
- -- Runtime Function: unsigned long fract __satfractudausq (unsigned
- long accum A)
- -- Runtime Function: unsigned long long fract __satfractudaudq
- (unsigned long accum A)
- -- Runtime Function: unsigned short accum __satfractudauha2 (unsigned
- long accum A)
- -- Runtime Function: unsigned accum __satfractudausa2 (unsigned long
- accum A)
- -- Runtime Function: unsigned long long accum __satfractudauta2
- (unsigned long accum A)
- -- Runtime Function: short fract __satfractutaqq (unsigned long long
- accum A)
- -- Runtime Function: fract __satfractutahq (unsigned long long accum A)
- -- Runtime Function: long fract __satfractutasq (unsigned long long
- accum A)
- -- Runtime Function: long long fract __satfractutadq (unsigned long
- long accum A)
- -- Runtime Function: short accum __satfractutaha (unsigned long long
- accum A)
- -- Runtime Function: accum __satfractutasa (unsigned long long accum A)
- -- Runtime Function: long accum __satfractutada (unsigned long long
- accum A)
- -- Runtime Function: long long accum __satfractutata (unsigned long
- long accum A)
- -- Runtime Function: unsigned short fract __satfractutauqq (unsigned
- long long accum A)
- -- Runtime Function: unsigned fract __satfractutauhq (unsigned long
- long accum A)
- -- Runtime Function: unsigned long fract __satfractutausq (unsigned
- long long accum A)
- -- Runtime Function: unsigned long long fract __satfractutaudq
- (unsigned long long accum A)
- -- Runtime Function: unsigned short accum __satfractutauha2 (unsigned
- long long accum A)
- -- Runtime Function: unsigned accum __satfractutausa2 (unsigned long
- long accum A)
- -- Runtime Function: unsigned long accum __satfractutauda2 (unsigned
- long long accum A)
- -- Runtime Function: short fract __satfractqiqq (signed char A)
- -- Runtime Function: fract __satfractqihq (signed char A)
- -- Runtime Function: long fract __satfractqisq (signed char A)
- -- Runtime Function: long long fract __satfractqidq (signed char A)
- -- Runtime Function: short accum __satfractqiha (signed char A)
- -- Runtime Function: accum __satfractqisa (signed char A)
- -- Runtime Function: long accum __satfractqida (signed char A)
- -- Runtime Function: long long accum __satfractqita (signed char A)
- -- Runtime Function: unsigned short fract __satfractqiuqq (signed char
- A)
- -- Runtime Function: unsigned fract __satfractqiuhq (signed char A)
- -- Runtime Function: unsigned long fract __satfractqiusq (signed char
- A)
- -- Runtime Function: unsigned long long fract __satfractqiudq (signed
- char A)
- -- Runtime Function: unsigned short accum __satfractqiuha (signed char
- A)
- -- Runtime Function: unsigned accum __satfractqiusa (signed char A)
- -- Runtime Function: unsigned long accum __satfractqiuda (signed char
- A)
- -- Runtime Function: unsigned long long accum __satfractqiuta (signed
- char A)
- -- Runtime Function: short fract __satfracthiqq (short A)
- -- Runtime Function: fract __satfracthihq (short A)
- -- Runtime Function: long fract __satfracthisq (short A)
- -- Runtime Function: long long fract __satfracthidq (short A)
- -- Runtime Function: short accum __satfracthiha (short A)
- -- Runtime Function: accum __satfracthisa (short A)
- -- Runtime Function: long accum __satfracthida (short A)
- -- Runtime Function: long long accum __satfracthita (short A)
- -- Runtime Function: unsigned short fract __satfracthiuqq (short A)
- -- Runtime Function: unsigned fract __satfracthiuhq (short A)
- -- Runtime Function: unsigned long fract __satfracthiusq (short A)
- -- Runtime Function: unsigned long long fract __satfracthiudq (short A)
- -- Runtime Function: unsigned short accum __satfracthiuha (short A)
- -- Runtime Function: unsigned accum __satfracthiusa (short A)
- -- Runtime Function: unsigned long accum __satfracthiuda (short A)
- -- Runtime Function: unsigned long long accum __satfracthiuta (short A)
- -- Runtime Function: short fract __satfractsiqq (int A)
- -- Runtime Function: fract __satfractsihq (int A)
- -- Runtime Function: long fract __satfractsisq (int A)
- -- Runtime Function: long long fract __satfractsidq (int A)
- -- Runtime Function: short accum __satfractsiha (int A)
- -- Runtime Function: accum __satfractsisa (int A)
- -- Runtime Function: long accum __satfractsida (int A)
- -- Runtime Function: long long accum __satfractsita (int A)
- -- Runtime Function: unsigned short fract __satfractsiuqq (int A)
- -- Runtime Function: unsigned fract __satfractsiuhq (int A)
- -- Runtime Function: unsigned long fract __satfractsiusq (int A)
- -- Runtime Function: unsigned long long fract __satfractsiudq (int A)
- -- Runtime Function: unsigned short accum __satfractsiuha (int A)
- -- Runtime Function: unsigned accum __satfractsiusa (int A)
- -- Runtime Function: unsigned long accum __satfractsiuda (int A)
- -- Runtime Function: unsigned long long accum __satfractsiuta (int A)
- -- Runtime Function: short fract __satfractdiqq (long A)
- -- Runtime Function: fract __satfractdihq (long A)
- -- Runtime Function: long fract __satfractdisq (long A)
- -- Runtime Function: long long fract __satfractdidq (long A)
- -- Runtime Function: short accum __satfractdiha (long A)
- -- Runtime Function: accum __satfractdisa (long A)
- -- Runtime Function: long accum __satfractdida (long A)
- -- Runtime Function: long long accum __satfractdita (long A)
- -- Runtime Function: unsigned short fract __satfractdiuqq (long A)
- -- Runtime Function: unsigned fract __satfractdiuhq (long A)
- -- Runtime Function: unsigned long fract __satfractdiusq (long A)
- -- Runtime Function: unsigned long long fract __satfractdiudq (long A)
- -- Runtime Function: unsigned short accum __satfractdiuha (long A)
- -- Runtime Function: unsigned accum __satfractdiusa (long A)
- -- Runtime Function: unsigned long accum __satfractdiuda (long A)
- -- Runtime Function: unsigned long long accum __satfractdiuta (long A)
- -- Runtime Function: short fract __satfracttiqq (long long A)
- -- Runtime Function: fract __satfracttihq (long long A)
- -- Runtime Function: long fract __satfracttisq (long long A)
- -- Runtime Function: long long fract __satfracttidq (long long A)
- -- Runtime Function: short accum __satfracttiha (long long A)
- -- Runtime Function: accum __satfracttisa (long long A)
- -- Runtime Function: long accum __satfracttida (long long A)
- -- Runtime Function: long long accum __satfracttita (long long A)
- -- Runtime Function: unsigned short fract __satfracttiuqq (long long A)
- -- Runtime Function: unsigned fract __satfracttiuhq (long long A)
- -- Runtime Function: unsigned long fract __satfracttiusq (long long A)
- -- Runtime Function: unsigned long long fract __satfracttiudq (long
- long A)
- -- Runtime Function: unsigned short accum __satfracttiuha (long long A)
- -- Runtime Function: unsigned accum __satfracttiusa (long long A)
- -- Runtime Function: unsigned long accum __satfracttiuda (long long A)
- -- Runtime Function: unsigned long long accum __satfracttiuta (long
- long A)
- -- Runtime Function: short fract __satfractsfqq (float A)
- -- Runtime Function: fract __satfractsfhq (float A)
- -- Runtime Function: long fract __satfractsfsq (float A)
- -- Runtime Function: long long fract __satfractsfdq (float A)
- -- Runtime Function: short accum __satfractsfha (float A)
- -- Runtime Function: accum __satfractsfsa (float A)
- -- Runtime Function: long accum __satfractsfda (float A)
- -- Runtime Function: long long accum __satfractsfta (float A)
- -- Runtime Function: unsigned short fract __satfractsfuqq (float A)
- -- Runtime Function: unsigned fract __satfractsfuhq (float A)
- -- Runtime Function: unsigned long fract __satfractsfusq (float A)
- -- Runtime Function: unsigned long long fract __satfractsfudq (float A)
- -- Runtime Function: unsigned short accum __satfractsfuha (float A)
- -- Runtime Function: unsigned accum __satfractsfusa (float A)
- -- Runtime Function: unsigned long accum __satfractsfuda (float A)
- -- Runtime Function: unsigned long long accum __satfractsfuta (float A)
- -- Runtime Function: short fract __satfractdfqq (double A)
- -- Runtime Function: fract __satfractdfhq (double A)
- -- Runtime Function: long fract __satfractdfsq (double A)
- -- Runtime Function: long long fract __satfractdfdq (double A)
- -- Runtime Function: short accum __satfractdfha (double A)
- -- Runtime Function: accum __satfractdfsa (double A)
- -- Runtime Function: long accum __satfractdfda (double A)
- -- Runtime Function: long long accum __satfractdfta (double A)
- -- Runtime Function: unsigned short fract __satfractdfuqq (double A)
- -- Runtime Function: unsigned fract __satfractdfuhq (double A)
- -- Runtime Function: unsigned long fract __satfractdfusq (double A)
- -- Runtime Function: unsigned long long fract __satfractdfudq (double
- A)
- -- Runtime Function: unsigned short accum __satfractdfuha (double A)
- -- Runtime Function: unsigned accum __satfractdfusa (double A)
- -- Runtime Function: unsigned long accum __satfractdfuda (double A)
- -- Runtime Function: unsigned long long accum __satfractdfuta (double
- A)
- The functions convert from fractional and signed non-fractionals to
- fractionals, with saturation.
-
- -- Runtime Function: unsigned char __fractunsqqqi (short fract A)
- -- Runtime Function: unsigned short __fractunsqqhi (short fract A)
- -- Runtime Function: unsigned int __fractunsqqsi (short fract A)
- -- Runtime Function: unsigned long __fractunsqqdi (short fract A)
- -- Runtime Function: unsigned long long __fractunsqqti (short fract A)
- -- Runtime Function: unsigned char __fractunshqqi (fract A)
- -- Runtime Function: unsigned short __fractunshqhi (fract A)
- -- Runtime Function: unsigned int __fractunshqsi (fract A)
- -- Runtime Function: unsigned long __fractunshqdi (fract A)
- -- Runtime Function: unsigned long long __fractunshqti (fract A)
- -- Runtime Function: unsigned char __fractunssqqi (long fract A)
- -- Runtime Function: unsigned short __fractunssqhi (long fract A)
- -- Runtime Function: unsigned int __fractunssqsi (long fract A)
- -- Runtime Function: unsigned long __fractunssqdi (long fract A)
- -- Runtime Function: unsigned long long __fractunssqti (long fract A)
- -- Runtime Function: unsigned char __fractunsdqqi (long long fract A)
- -- Runtime Function: unsigned short __fractunsdqhi (long long fract A)
- -- Runtime Function: unsigned int __fractunsdqsi (long long fract A)
- -- Runtime Function: unsigned long __fractunsdqdi (long long fract A)
- -- Runtime Function: unsigned long long __fractunsdqti (long long
- fract A)
- -- Runtime Function: unsigned char __fractunshaqi (short accum A)
- -- Runtime Function: unsigned short __fractunshahi (short accum A)
- -- Runtime Function: unsigned int __fractunshasi (short accum A)
- -- Runtime Function: unsigned long __fractunshadi (short accum A)
- -- Runtime Function: unsigned long long __fractunshati (short accum A)
- -- Runtime Function: unsigned char __fractunssaqi (accum A)
- -- Runtime Function: unsigned short __fractunssahi (accum A)
- -- Runtime Function: unsigned int __fractunssasi (accum A)
- -- Runtime Function: unsigned long __fractunssadi (accum A)
- -- Runtime Function: unsigned long long __fractunssati (accum A)
- -- Runtime Function: unsigned char __fractunsdaqi (long accum A)
- -- Runtime Function: unsigned short __fractunsdahi (long accum A)
- -- Runtime Function: unsigned int __fractunsdasi (long accum A)
- -- Runtime Function: unsigned long __fractunsdadi (long accum A)
- -- Runtime Function: unsigned long long __fractunsdati (long accum A)
- -- Runtime Function: unsigned char __fractunstaqi (long long accum A)
- -- Runtime Function: unsigned short __fractunstahi (long long accum A)
- -- Runtime Function: unsigned int __fractunstasi (long long accum A)
- -- Runtime Function: unsigned long __fractunstadi (long long accum A)
- -- Runtime Function: unsigned long long __fractunstati (long long
- accum A)
- -- Runtime Function: unsigned char __fractunsuqqqi (unsigned short
- fract A)
- -- Runtime Function: unsigned short __fractunsuqqhi (unsigned short
- fract A)
- -- Runtime Function: unsigned int __fractunsuqqsi (unsigned short
- fract A)
- -- Runtime Function: unsigned long __fractunsuqqdi (unsigned short
- fract A)
- -- Runtime Function: unsigned long long __fractunsuqqti (unsigned
- short fract A)
- -- Runtime Function: unsigned char __fractunsuhqqi (unsigned fract A)
- -- Runtime Function: unsigned short __fractunsuhqhi (unsigned fract A)
- -- Runtime Function: unsigned int __fractunsuhqsi (unsigned fract A)
- -- Runtime Function: unsigned long __fractunsuhqdi (unsigned fract A)
- -- Runtime Function: unsigned long long __fractunsuhqti (unsigned
- fract A)
- -- Runtime Function: unsigned char __fractunsusqqi (unsigned long
- fract A)
- -- Runtime Function: unsigned short __fractunsusqhi (unsigned long
- fract A)
- -- Runtime Function: unsigned int __fractunsusqsi (unsigned long fract
- A)
- -- Runtime Function: unsigned long __fractunsusqdi (unsigned long
- fract A)
- -- Runtime Function: unsigned long long __fractunsusqti (unsigned long
- fract A)
- -- Runtime Function: unsigned char __fractunsudqqi (unsigned long long
- fract A)
- -- Runtime Function: unsigned short __fractunsudqhi (unsigned long
- long fract A)
- -- Runtime Function: unsigned int __fractunsudqsi (unsigned long long
- fract A)
- -- Runtime Function: unsigned long __fractunsudqdi (unsigned long long
- fract A)
- -- Runtime Function: unsigned long long __fractunsudqti (unsigned long
- long fract A)
- -- Runtime Function: unsigned char __fractunsuhaqi (unsigned short
- accum A)
- -- Runtime Function: unsigned short __fractunsuhahi (unsigned short
- accum A)
- -- Runtime Function: unsigned int __fractunsuhasi (unsigned short
- accum A)
- -- Runtime Function: unsigned long __fractunsuhadi (unsigned short
- accum A)
- -- Runtime Function: unsigned long long __fractunsuhati (unsigned
- short accum A)
- -- Runtime Function: unsigned char __fractunsusaqi (unsigned accum A)
- -- Runtime Function: unsigned short __fractunsusahi (unsigned accum A)
- -- Runtime Function: unsigned int __fractunsusasi (unsigned accum A)
- -- Runtime Function: unsigned long __fractunsusadi (unsigned accum A)
- -- Runtime Function: unsigned long long __fractunsusati (unsigned
- accum A)
- -- Runtime Function: unsigned char __fractunsudaqi (unsigned long
- accum A)
- -- Runtime Function: unsigned short __fractunsudahi (unsigned long
- accum A)
- -- Runtime Function: unsigned int __fractunsudasi (unsigned long accum
- A)
- -- Runtime Function: unsigned long __fractunsudadi (unsigned long
- accum A)
- -- Runtime Function: unsigned long long __fractunsudati (unsigned long
- accum A)
- -- Runtime Function: unsigned char __fractunsutaqi (unsigned long long
- accum A)
- -- Runtime Function: unsigned short __fractunsutahi (unsigned long
- long accum A)
- -- Runtime Function: unsigned int __fractunsutasi (unsigned long long
- accum A)
- -- Runtime Function: unsigned long __fractunsutadi (unsigned long long
- accum A)
- -- Runtime Function: unsigned long long __fractunsutati (unsigned long
- long accum A)
- -- Runtime Function: short fract __fractunsqiqq (unsigned char A)
- -- Runtime Function: fract __fractunsqihq (unsigned char A)
- -- Runtime Function: long fract __fractunsqisq (unsigned char A)
- -- Runtime Function: long long fract __fractunsqidq (unsigned char A)
- -- Runtime Function: short accum __fractunsqiha (unsigned char A)
- -- Runtime Function: accum __fractunsqisa (unsigned char A)
- -- Runtime Function: long accum __fractunsqida (unsigned char A)
- -- Runtime Function: long long accum __fractunsqita (unsigned char A)
- -- Runtime Function: unsigned short fract __fractunsqiuqq (unsigned
- char A)
- -- Runtime Function: unsigned fract __fractunsqiuhq (unsigned char A)
- -- Runtime Function: unsigned long fract __fractunsqiusq (unsigned
- char A)
- -- Runtime Function: unsigned long long fract __fractunsqiudq
- (unsigned char A)
- -- Runtime Function: unsigned short accum __fractunsqiuha (unsigned
- char A)
- -- Runtime Function: unsigned accum __fractunsqiusa (unsigned char A)
- -- Runtime Function: unsigned long accum __fractunsqiuda (unsigned
- char A)
- -- Runtime Function: unsigned long long accum __fractunsqiuta
- (unsigned char A)
- -- Runtime Function: short fract __fractunshiqq (unsigned short A)
- -- Runtime Function: fract __fractunshihq (unsigned short A)
- -- Runtime Function: long fract __fractunshisq (unsigned short A)
- -- Runtime Function: long long fract __fractunshidq (unsigned short A)
- -- Runtime Function: short accum __fractunshiha (unsigned short A)
- -- Runtime Function: accum __fractunshisa (unsigned short A)
- -- Runtime Function: long accum __fractunshida (unsigned short A)
- -- Runtime Function: long long accum __fractunshita (unsigned short A)
- -- Runtime Function: unsigned short fract __fractunshiuqq (unsigned
- short A)
- -- Runtime Function: unsigned fract __fractunshiuhq (unsigned short A)
- -- Runtime Function: unsigned long fract __fractunshiusq (unsigned
- short A)
- -- Runtime Function: unsigned long long fract __fractunshiudq
- (unsigned short A)
- -- Runtime Function: unsigned short accum __fractunshiuha (unsigned
- short A)
- -- Runtime Function: unsigned accum __fractunshiusa (unsigned short A)
- -- Runtime Function: unsigned long accum __fractunshiuda (unsigned
- short A)
- -- Runtime Function: unsigned long long accum __fractunshiuta
- (unsigned short A)
- -- Runtime Function: short fract __fractunssiqq (unsigned int A)
- -- Runtime Function: fract __fractunssihq (unsigned int A)
- -- Runtime Function: long fract __fractunssisq (unsigned int A)
- -- Runtime Function: long long fract __fractunssidq (unsigned int A)
- -- Runtime Function: short accum __fractunssiha (unsigned int A)
- -- Runtime Function: accum __fractunssisa (unsigned int A)
- -- Runtime Function: long accum __fractunssida (unsigned int A)
- -- Runtime Function: long long accum __fractunssita (unsigned int A)
- -- Runtime Function: unsigned short fract __fractunssiuqq (unsigned
- int A)
- -- Runtime Function: unsigned fract __fractunssiuhq (unsigned int A)
- -- Runtime Function: unsigned long fract __fractunssiusq (unsigned int
- A)
- -- Runtime Function: unsigned long long fract __fractunssiudq
- (unsigned int A)
- -- Runtime Function: unsigned short accum __fractunssiuha (unsigned
- int A)
- -- Runtime Function: unsigned accum __fractunssiusa (unsigned int A)
- -- Runtime Function: unsigned long accum __fractunssiuda (unsigned int
- A)
- -- Runtime Function: unsigned long long accum __fractunssiuta
- (unsigned int A)
- -- Runtime Function: short fract __fractunsdiqq (unsigned long A)
- -- Runtime Function: fract __fractunsdihq (unsigned long A)
- -- Runtime Function: long fract __fractunsdisq (unsigned long A)
- -- Runtime Function: long long fract __fractunsdidq (unsigned long A)
- -- Runtime Function: short accum __fractunsdiha (unsigned long A)
- -- Runtime Function: accum __fractunsdisa (unsigned long A)
- -- Runtime Function: long accum __fractunsdida (unsigned long A)
- -- Runtime Function: long long accum __fractunsdita (unsigned long A)
- -- Runtime Function: unsigned short fract __fractunsdiuqq (unsigned
- long A)
- -- Runtime Function: unsigned fract __fractunsdiuhq (unsigned long A)
- -- Runtime Function: unsigned long fract __fractunsdiusq (unsigned
- long A)
- -- Runtime Function: unsigned long long fract __fractunsdiudq
- (unsigned long A)
- -- Runtime Function: unsigned short accum __fractunsdiuha (unsigned
- long A)
- -- Runtime Function: unsigned accum __fractunsdiusa (unsigned long A)
- -- Runtime Function: unsigned long accum __fractunsdiuda (unsigned
- long A)
- -- Runtime Function: unsigned long long accum __fractunsdiuta
- (unsigned long A)
- -- Runtime Function: short fract __fractunstiqq (unsigned long long A)
- -- Runtime Function: fract __fractunstihq (unsigned long long A)
- -- Runtime Function: long fract __fractunstisq (unsigned long long A)
- -- Runtime Function: long long fract __fractunstidq (unsigned long
- long A)
- -- Runtime Function: short accum __fractunstiha (unsigned long long A)
- -- Runtime Function: accum __fractunstisa (unsigned long long A)
- -- Runtime Function: long accum __fractunstida (unsigned long long A)
- -- Runtime Function: long long accum __fractunstita (unsigned long
- long A)
- -- Runtime Function: unsigned short fract __fractunstiuqq (unsigned
- long long A)
- -- Runtime Function: unsigned fract __fractunstiuhq (unsigned long
- long A)
- -- Runtime Function: unsigned long fract __fractunstiusq (unsigned
- long long A)
- -- Runtime Function: unsigned long long fract __fractunstiudq
- (unsigned long long A)
- -- Runtime Function: unsigned short accum __fractunstiuha (unsigned
- long long A)
- -- Runtime Function: unsigned accum __fractunstiusa (unsigned long
- long A)
- -- Runtime Function: unsigned long accum __fractunstiuda (unsigned
- long long A)
- -- Runtime Function: unsigned long long accum __fractunstiuta
- (unsigned long long A)
- These functions convert from fractionals to unsigned
- non-fractionals; and from unsigned non-fractionals to fractionals,
- without saturation.
-
- -- Runtime Function: short fract __satfractunsqiqq (unsigned char A)
- -- Runtime Function: fract __satfractunsqihq (unsigned char A)
- -- Runtime Function: long fract __satfractunsqisq (unsigned char A)
- -- Runtime Function: long long fract __satfractunsqidq (unsigned char
- A)
- -- Runtime Function: short accum __satfractunsqiha (unsigned char A)
- -- Runtime Function: accum __satfractunsqisa (unsigned char A)
- -- Runtime Function: long accum __satfractunsqida (unsigned char A)
- -- Runtime Function: long long accum __satfractunsqita (unsigned char
- A)
- -- Runtime Function: unsigned short fract __satfractunsqiuqq (unsigned
- char A)
- -- Runtime Function: unsigned fract __satfractunsqiuhq (unsigned char
- A)
- -- Runtime Function: unsigned long fract __satfractunsqiusq (unsigned
- char A)
- -- Runtime Function: unsigned long long fract __satfractunsqiudq
- (unsigned char A)
- -- Runtime Function: unsigned short accum __satfractunsqiuha (unsigned
- char A)
- -- Runtime Function: unsigned accum __satfractunsqiusa (unsigned char
- A)
- -- Runtime Function: unsigned long accum __satfractunsqiuda (unsigned
- char A)
- -- Runtime Function: unsigned long long accum __satfractunsqiuta
- (unsigned char A)
- -- Runtime Function: short fract __satfractunshiqq (unsigned short A)
- -- Runtime Function: fract __satfractunshihq (unsigned short A)
- -- Runtime Function: long fract __satfractunshisq (unsigned short A)
- -- Runtime Function: long long fract __satfractunshidq (unsigned short
- A)
- -- Runtime Function: short accum __satfractunshiha (unsigned short A)
- -- Runtime Function: accum __satfractunshisa (unsigned short A)
- -- Runtime Function: long accum __satfractunshida (unsigned short A)
- -- Runtime Function: long long accum __satfractunshita (unsigned short
- A)
- -- Runtime Function: unsigned short fract __satfractunshiuqq (unsigned
- short A)
- -- Runtime Function: unsigned fract __satfractunshiuhq (unsigned short
- A)
- -- Runtime Function: unsigned long fract __satfractunshiusq (unsigned
- short A)
- -- Runtime Function: unsigned long long fract __satfractunshiudq
- (unsigned short A)
- -- Runtime Function: unsigned short accum __satfractunshiuha (unsigned
- short A)
- -- Runtime Function: unsigned accum __satfractunshiusa (unsigned short
- A)
- -- Runtime Function: unsigned long accum __satfractunshiuda (unsigned
- short A)
- -- Runtime Function: unsigned long long accum __satfractunshiuta
- (unsigned short A)
- -- Runtime Function: short fract __satfractunssiqq (unsigned int A)
- -- Runtime Function: fract __satfractunssihq (unsigned int A)
- -- Runtime Function: long fract __satfractunssisq (unsigned int A)
- -- Runtime Function: long long fract __satfractunssidq (unsigned int A)
- -- Runtime Function: short accum __satfractunssiha (unsigned int A)
- -- Runtime Function: accum __satfractunssisa (unsigned int A)
- -- Runtime Function: long accum __satfractunssida (unsigned int A)
- -- Runtime Function: long long accum __satfractunssita (unsigned int A)
- -- Runtime Function: unsigned short fract __satfractunssiuqq (unsigned
- int A)
- -- Runtime Function: unsigned fract __satfractunssiuhq (unsigned int A)
- -- Runtime Function: unsigned long fract __satfractunssiusq (unsigned
- int A)
- -- Runtime Function: unsigned long long fract __satfractunssiudq
- (unsigned int A)
- -- Runtime Function: unsigned short accum __satfractunssiuha (unsigned
- int A)
- -- Runtime Function: unsigned accum __satfractunssiusa (unsigned int A)
- -- Runtime Function: unsigned long accum __satfractunssiuda (unsigned
- int A)
- -- Runtime Function: unsigned long long accum __satfractunssiuta
- (unsigned int A)
- -- Runtime Function: short fract __satfractunsdiqq (unsigned long A)
- -- Runtime Function: fract __satfractunsdihq (unsigned long A)
- -- Runtime Function: long fract __satfractunsdisq (unsigned long A)
- -- Runtime Function: long long fract __satfractunsdidq (unsigned long
- A)
- -- Runtime Function: short accum __satfractunsdiha (unsigned long A)
- -- Runtime Function: accum __satfractunsdisa (unsigned long A)
- -- Runtime Function: long accum __satfractunsdida (unsigned long A)
- -- Runtime Function: long long accum __satfractunsdita (unsigned long
- A)
- -- Runtime Function: unsigned short fract __satfractunsdiuqq (unsigned
- long A)
- -- Runtime Function: unsigned fract __satfractunsdiuhq (unsigned long
- A)
- -- Runtime Function: unsigned long fract __satfractunsdiusq (unsigned
- long A)
- -- Runtime Function: unsigned long long fract __satfractunsdiudq
- (unsigned long A)
- -- Runtime Function: unsigned short accum __satfractunsdiuha (unsigned
- long A)
- -- Runtime Function: unsigned accum __satfractunsdiusa (unsigned long
- A)
- -- Runtime Function: unsigned long accum __satfractunsdiuda (unsigned
- long A)
- -- Runtime Function: unsigned long long accum __satfractunsdiuta
- (unsigned long A)
- -- Runtime Function: short fract __satfractunstiqq (unsigned long long
- A)
- -- Runtime Function: fract __satfractunstihq (unsigned long long A)
- -- Runtime Function: long fract __satfractunstisq (unsigned long long
- A)
- -- Runtime Function: long long fract __satfractunstidq (unsigned long
- long A)
- -- Runtime Function: short accum __satfractunstiha (unsigned long long
- A)
- -- Runtime Function: accum __satfractunstisa (unsigned long long A)
- -- Runtime Function: long accum __satfractunstida (unsigned long long
- A)
- -- Runtime Function: long long accum __satfractunstita (unsigned long
- long A)
- -- Runtime Function: unsigned short fract __satfractunstiuqq (unsigned
- long long A)
- -- Runtime Function: unsigned fract __satfractunstiuhq (unsigned long
- long A)
- -- Runtime Function: unsigned long fract __satfractunstiusq (unsigned
- long long A)
- -- Runtime Function: unsigned long long fract __satfractunstiudq
- (unsigned long long A)
- -- Runtime Function: unsigned short accum __satfractunstiuha (unsigned
- long long A)
- -- Runtime Function: unsigned accum __satfractunstiusa (unsigned long
- long A)
- -- Runtime Function: unsigned long accum __satfractunstiuda (unsigned
- long long A)
- -- Runtime Function: unsigned long long accum __satfractunstiuta
- (unsigned long long A)
- These functions convert from unsigned non-fractionals to
- fractionals, with saturation.
-
-\1f
-File: gccint.info, Node: Exception handling routines, Next: Miscellaneous routines, Prev: Fixed-point fractional library routines, Up: Libgcc
-
-4.5 Language-independent routines for exception handling
-========================================================
-
-document me!
-
- _Unwind_DeleteException
- _Unwind_Find_FDE
- _Unwind_ForcedUnwind
- _Unwind_GetGR
- _Unwind_GetIP
- _Unwind_GetLanguageSpecificData
- _Unwind_GetRegionStart
- _Unwind_GetTextRelBase
- _Unwind_GetDataRelBase
- _Unwind_RaiseException
- _Unwind_Resume
- _Unwind_SetGR
- _Unwind_SetIP
- _Unwind_FindEnclosingFunction
- _Unwind_SjLj_Register
- _Unwind_SjLj_Unregister
- _Unwind_SjLj_RaiseException
- _Unwind_SjLj_ForcedUnwind
- _Unwind_SjLj_Resume
- __deregister_frame
- __deregister_frame_info
- __deregister_frame_info_bases
- __register_frame
- __register_frame_info
- __register_frame_info_bases
- __register_frame_info_table
- __register_frame_info_table_bases
- __register_frame_table
-
-\1f
-File: gccint.info, Node: Miscellaneous routines, Prev: Exception handling routines, Up: Libgcc
-
-4.6 Miscellaneous runtime library routines
-==========================================
-
-4.6.1 Cache control functions
------------------------------
-
- -- Runtime Function: void __clear_cache (char *BEG, char *END)
- This function clears the instruction cache between BEG and END.
-
-\1f
-File: gccint.info, Node: Languages, Next: Source Tree, Prev: Libgcc, Up: Top
-
-5 Language Front Ends in GCC
-****************************
-
-The interface to front ends for languages in GCC, and in particular the
-`tree' structure (*note Trees::), was initially designed for C, and
-many aspects of it are still somewhat biased towards C and C-like
-languages. It is, however, reasonably well suited to other procedural
-languages, and front ends for many such languages have been written for
-GCC.
-
- Writing a compiler as a front end for GCC, rather than compiling
-directly to assembler or generating C code which is then compiled by
-GCC, has several advantages:
-
- * GCC front ends benefit from the support for many different target
- machines already present in GCC.
-
- * GCC front ends benefit from all the optimizations in GCC. Some of
- these, such as alias analysis, may work better when GCC is
- compiling directly from source code then when it is compiling from
- generated C code.
-
- * Better debugging information is generated when compiling directly
- from source code than when going via intermediate generated C code.
-
- Because of the advantages of writing a compiler as a GCC front end,
-GCC front ends have also been created for languages very different from
-those for which GCC was designed, such as the declarative
-logic/functional language Mercury. For these reasons, it may also be
-useful to implement compilers created for specialized purposes (for
-example, as part of a research project) as GCC front ends.
-
-\1f
-File: gccint.info, Node: Source Tree, Next: Options, Prev: Languages, Up: Top
-
-6 Source Tree Structure and Build System
-****************************************
-
-This chapter describes the structure of the GCC source tree, and how
-GCC is built. The user documentation for building and installing GCC
-is in a separate manual (`http://gcc.gnu.org/install/'), with which it
-is presumed that you are familiar.
-
-* Menu:
-
-* Configure Terms:: Configuration terminology and history.
-* Top Level:: The top level source directory.
-* gcc Directory:: The `gcc' subdirectory.
-* Testsuites:: The GCC testsuites.
-
-\1f
-File: gccint.info, Node: Configure Terms, Next: Top Level, Up: Source Tree
-
-6.1 Configure Terms and History
-===============================
-
-The configure and build process has a long and colorful history, and can
-be confusing to anyone who doesn't know why things are the way they are.
-While there are other documents which describe the configuration process
-in detail, here are a few things that everyone working on GCC should
-know.
-
- There are three system names that the build knows about: the machine
-you are building on ("build"), the machine that you are building for
-("host"), and the machine that GCC will produce code for ("target").
-When you configure GCC, you specify these with `--build=', `--host=',
-and `--target='.
-
- Specifying the host without specifying the build should be avoided, as
-`configure' may (and once did) assume that the host you specify is also
-the build, which may not be true.
-
- If build, host, and target are all the same, this is called a
-"native". If build and host are the same but target is different, this
-is called a "cross". If build, host, and target are all different this
-is called a "canadian" (for obscure reasons dealing with Canada's
-political party and the background of the person working on the build
-at that time). If host and target are the same, but build is
-different, you are using a cross-compiler to build a native for a
-different system. Some people call this a "host-x-host", "crossed
-native", or "cross-built native". If build and target are the same,
-but host is different, you are using a cross compiler to build a cross
-compiler that produces code for the machine you're building on. This
-is rare, so there is no common way of describing it. There is a
-proposal to call this a "crossback".
-
- If build and host are the same, the GCC you are building will also be
-used to build the target libraries (like `libstdc++'). If build and
-host are different, you must have already built and installed a cross
-compiler that will be used to build the target libraries (if you
-configured with `--target=foo-bar', this compiler will be called
-`foo-bar-gcc').
-
- In the case of target libraries, the machine you're building for is the
-machine you specified with `--target'. So, build is the machine you're
-building on (no change there), host is the machine you're building for
-(the target libraries are built for the target, so host is the target
-you specified), and target doesn't apply (because you're not building a
-compiler, you're building libraries). The configure/make process will
-adjust these variables as needed. It also sets `$with_cross_host' to
-the original `--host' value in case you need it.
-
- The `libiberty' support library is built up to three times: once for
-the host, once for the target (even if they are the same), and once for
-the build if build and host are different. This allows it to be used
-by all programs which are generated in the course of the build process.
-
-\1f
-File: gccint.info, Node: Top Level, Next: gcc Directory, Prev: Configure Terms, Up: Source Tree
-
-6.2 Top Level Source Directory
-==============================
-
-The top level source directory in a GCC distribution contains several
-files and directories that are shared with other software distributions
-such as that of GNU Binutils. It also contains several subdirectories
-that contain parts of GCC and its runtime libraries:
-
-`boehm-gc'
- The Boehm conservative garbage collector, used as part of the Java
- runtime library.
-
-`contrib'
- Contributed scripts that may be found useful in conjunction with
- GCC. One of these, `contrib/texi2pod.pl', is used to generate man
- pages from Texinfo manuals as part of the GCC build process.
-
-`fastjar'
- An implementation of the `jar' command, used with the Java front
- end.
-
-`fixincludes'
- The support for fixing system headers to work with GCC. See
- `fixincludes/README' for more information. The headers fixed by
- this mechanism are installed in `LIBSUBDIR/include-fixed'. Along
- with those headers, `README-fixinc' is also installed, as
- `LIBSUBDIR/include-fixed/README'.
-
-`gcc'
- The main sources of GCC itself (except for runtime libraries),
- including optimizers, support for different target architectures,
- language front ends, and testsuites. *Note The `gcc'
- Subdirectory: gcc Directory, for details.
-
-`include'
- Headers for the `libiberty' library.
-
-`intl'
- GNU `libintl', from GNU `gettext', for systems which do not
- include it in libc.
-
-`libada'
- The Ada runtime library.
-
-`libcpp'
- The C preprocessor library.
-
-`libgfortran'
- The Fortran runtime library.
-
-`libffi'
- The `libffi' library, used as part of the Java runtime library.
-
-`libiberty'
- The `libiberty' library, used for portability and for some
- generally useful data structures and algorithms. *Note
- Introduction: (libiberty)Top, for more information about this
- library.
-
-`libjava'
- The Java runtime library.
-
-`libmudflap'
- The `libmudflap' library, used for instrumenting pointer and array
- dereferencing operations.
-
-`libobjc'
- The Objective-C and Objective-C++ runtime library.
-
-`libstdc++-v3'
- The C++ runtime library.
-
-`maintainer-scripts'
- Scripts used by the `gccadmin' account on `gcc.gnu.org'.
-
-`zlib'
- The `zlib' compression library, used by the Java front end and as
- part of the Java runtime library.
-
- The build system in the top level directory, including how recursion
-into subdirectories works and how building runtime libraries for
-multilibs is handled, is documented in a separate manual, included with
-GNU Binutils. *Note GNU configure and build system: (configure)Top,
-for details.
-
-\1f
-File: gccint.info, Node: gcc Directory, Next: Testsuites, Prev: Top Level, Up: Source Tree
-
-6.3 The `gcc' Subdirectory
-==========================
-
-The `gcc' directory contains many files that are part of the C sources
-of GCC, other files used as part of the configuration and build
-process, and subdirectories including documentation and a testsuite.
-The files that are sources of GCC are documented in a separate chapter.
-*Note Passes and Files of the Compiler: Passes.
-
-* Menu:
-
-* Subdirectories:: Subdirectories of `gcc'.
-* Configuration:: The configuration process, and the files it uses.
-* Build:: The build system in the `gcc' directory.
-* Makefile:: Targets in `gcc/Makefile'.
-* Library Files:: Library source files and headers under `gcc/'.
-* Headers:: Headers installed by GCC.
-* Documentation:: Building documentation in GCC.
-* Front End:: Anatomy of a language front end.
-* Back End:: Anatomy of a target back end.
-
-\1f
-File: gccint.info, Node: Subdirectories, Next: Configuration, Up: gcc Directory
-
-6.3.1 Subdirectories of `gcc'
------------------------------
-
-The `gcc' directory contains the following subdirectories:
-
-`LANGUAGE'
- Subdirectories for various languages. Directories containing a
- file `config-lang.in' are language subdirectories. The contents of
- the subdirectories `cp' (for C++), `objc' (for Objective-C) and
- `objcp' (for Objective-C++) are documented in this manual (*note
- Passes and Files of the Compiler: Passes.); those for other
- languages are not. *Note Anatomy of a Language Front End: Front
- End, for details of the files in these directories.
-
-`config'
- Configuration files for supported architectures and operating
- systems. *Note Anatomy of a Target Back End: Back End, for
- details of the files in this directory.
-
-`doc'
- Texinfo documentation for GCC, together with automatically
- generated man pages and support for converting the installation
- manual to HTML. *Note Documentation::.
-
-`ginclude'
- System headers installed by GCC, mainly those required by the C
- standard of freestanding implementations. *Note Headers Installed
- by GCC: Headers, for details of when these and other headers are
- installed.
-
-`po'
- Message catalogs with translations of messages produced by GCC into
- various languages, `LANGUAGE.po'. This directory also contains
- `gcc.pot', the template for these message catalogues, `exgettext',
- a wrapper around `gettext' to extract the messages from the GCC
- sources and create `gcc.pot', which is run by `make gcc.pot', and
- `EXCLUDES', a list of files from which messages should not be
- extracted.
-
-`testsuite'
- The GCC testsuites (except for those for runtime libraries).
- *Note Testsuites::.
-
-\1f
-File: gccint.info, Node: Configuration, Next: Build, Prev: Subdirectories, Up: gcc Directory
-
-6.3.2 Configuration in the `gcc' Directory
-------------------------------------------
-
-The `gcc' directory is configured with an Autoconf-generated script
-`configure'. The `configure' script is generated from `configure.ac'
-and `aclocal.m4'. From the files `configure.ac' and `acconfig.h',
-Autoheader generates the file `config.in'. The file `cstamp-h.in' is
-used as a timestamp.
-
-* Menu:
-
-* Config Fragments:: Scripts used by `configure'.
-* System Config:: The `config.build', `config.host', and
- `config.gcc' files.
-* Configuration Files:: Files created by running `configure'.
-
-\1f
-File: gccint.info, Node: Config Fragments, Next: System Config, Up: Configuration
-
-6.3.2.1 Scripts Used by `configure'
-...................................
-
-`configure' uses some other scripts to help in its work:
-
- * The standard GNU `config.sub' and `config.guess' files, kept in
- the top level directory, are used.
-
- * The file `config.gcc' is used to handle configuration specific to
- the particular target machine. The file `config.build' is used to
- handle configuration specific to the particular build machine.
- The file `config.host' is used to handle configuration specific to
- the particular host machine. (In general, these should only be
- used for features that cannot reasonably be tested in Autoconf
- feature tests.) *Note The `config.build'; `config.host'; and
- `config.gcc' Files: System Config, for details of the contents of
- these files.
-
- * Each language subdirectory has a file `LANGUAGE/config-lang.in'
- that is used for front-end-specific configuration. *Note The
- Front End `config-lang.in' File: Front End Config, for details of
- this file.
-
- * A helper script `configure.frag' is used as part of creating the
- output of `configure'.
-
-\1f
-File: gccint.info, Node: System Config, Next: Configuration Files, Prev: Config Fragments, Up: Configuration
-
-6.3.2.2 The `config.build'; `config.host'; and `config.gcc' Files
-.................................................................
-
-The `config.build' file contains specific rules for particular systems
-which GCC is built on. This should be used as rarely as possible, as
-the behavior of the build system can always be detected by autoconf.
-
- The `config.host' file contains specific rules for particular systems
-which GCC will run on. This is rarely needed.
-
- The `config.gcc' file contains specific rules for particular systems
-which GCC will generate code for. This is usually needed.
-
- Each file has a list of the shell variables it sets, with
-descriptions, at the top of the file.
-
- FIXME: document the contents of these files, and what variables should
-be set to control build, host and target configuration.
-
-\1f
-File: gccint.info, Node: Configuration Files, Prev: System Config, Up: Configuration
-
-6.3.2.3 Files Created by `configure'
-....................................
-
-Here we spell out what files will be set up by `configure' in the `gcc'
-directory. Some other files are created as temporary files in the
-configuration process, and are not used in the subsequent build; these
-are not documented.
-
- * `Makefile' is constructed from `Makefile.in', together with the
- host and target fragments (*note Makefile Fragments: Fragments.)
- `t-TARGET' and `x-HOST' from `config', if any, and language
- Makefile fragments `LANGUAGE/Make-lang.in'.
-
- * `auto-host.h' contains information about the host machine
- determined by `configure'. If the host machine is different from
- the build machine, then `auto-build.h' is also created, containing
- such information about the build machine.
-
- * `config.status' is a script that may be run to recreate the
- current configuration.
-
- * `configargs.h' is a header containing details of the arguments
- passed to `configure' to configure GCC, and of the thread model
- used.
-
- * `cstamp-h' is used as a timestamp.
-
- * `fixinc/Makefile' is constructed from `fixinc/Makefile.in'.
-
- * `gccbug', a script for reporting bugs in GCC, is constructed from
- `gccbug.in'.
-
- * `intl/Makefile' is constructed from `intl/Makefile.in'.
-
- * If a language `config-lang.in' file (*note The Front End
- `config-lang.in' File: Front End Config.) sets `outputs', then the
- files listed in `outputs' there are also generated.
-
- The following configuration headers are created from the Makefile,
-using `mkconfig.sh', rather than directly by `configure'. `config.h',
-`bconfig.h' and `tconfig.h' all contain the `xm-MACHINE.h' header, if
-any, appropriate to the host, build and target machines respectively,
-the configuration headers for the target, and some definitions; for the
-host and build machines, these include the autoconfigured headers
-generated by `configure'. The other configuration headers are
-determined by `config.gcc'. They also contain the typedefs for `rtx',
-`rtvec' and `tree'.
-
- * `config.h', for use in programs that run on the host machine.
-
- * `bconfig.h', for use in programs that run on the build machine.
-
- * `tconfig.h', for use in programs and libraries for the target
- machine.
-
- * `tm_p.h', which includes the header `MACHINE-protos.h' that
- contains prototypes for functions in the target `.c' file. FIXME:
- why is such a separate header necessary?
-
-\1f
-File: gccint.info, Node: Build, Next: Makefile, Prev: Configuration, Up: gcc Directory
-
-6.3.3 Build System in the `gcc' Directory
------------------------------------------
-
-FIXME: describe the build system, including what is built in what
-stages. Also list the various source files that are used in the build
-process but aren't source files of GCC itself and so aren't documented
-below (*note Passes::).
-
-\1f
-File: gccint.info, Node: Makefile, Next: Library Files, Prev: Build, Up: gcc Directory
-
-6.3.4 Makefile Targets
-----------------------
-
-These targets are available from the `gcc' directory:
-
-`all'
- This is the default target. Depending on what your
- build/host/target configuration is, it coordinates all the things
- that need to be built.
-
-`doc'
- Produce info-formatted documentation and man pages. Essentially it
- calls `make man' and `make info'.
-
-`dvi'
- Produce DVI-formatted documentation.
-
-`pdf'
- Produce PDF-formatted documentation.
-
-`html'
- Produce HTML-formatted documentation.
-
-`man'
- Generate man pages.
-
-`info'
- Generate info-formatted pages.
-
-`mostlyclean'
- Delete the files made while building the compiler.
-
-`clean'
- That, and all the other files built by `make all'.
-
-`distclean'
- That, and all the files created by `configure'.
-
-`maintainer-clean'
- Distclean plus any file that can be generated from other files.
- Note that additional tools may be required beyond what is normally
- needed to build gcc.
-
-`srcextra'
- Generates files in the source directory that do not exist in CVS
- but should go into a release tarball. One example is
- `gcc/java/parse.c' which is generated from the CVS source file
- `gcc/java/parse.y'.
-
-`srcinfo'
-`srcman'
- Copies the info-formatted and manpage documentation into the source
- directory usually for the purpose of generating a release tarball.
-
-`install'
- Installs gcc.
-
-`uninstall'
- Deletes installed files.
-
-`check'
- Run the testsuite. This creates a `testsuite' subdirectory that
- has various `.sum' and `.log' files containing the results of the
- testing. You can run subsets with, for example, `make check-gcc'.
- You can specify specific tests by setting RUNTESTFLAGS to be the
- name of the `.exp' file, optionally followed by (for some tests)
- an equals and a file wildcard, like:
-
- make check-gcc RUNTESTFLAGS="execute.exp=19980413-*"
-
- Note that running the testsuite may require additional tools be
- installed, such as TCL or dejagnu.
-
- The toplevel tree from which you start GCC compilation is not the GCC
-directory, but rather a complex Makefile that coordinates the various
-steps of the build, including bootstrapping the compiler and using the
-new compiler to build target libraries.
-
- When GCC is configured for a native configuration, the default action
-for `make' is to do a full three-stage bootstrap. This means that GCC
-is built three times--once with the native compiler, once with the
-native-built compiler it just built, and once with the compiler it
-built the second time. In theory, the last two should produce the same
-results, which `make compare' can check. Each stage is configured
-separately and compiled into a separate directory, to minimize problems
-due to ABI incompatibilities between the native compiler and GCC.
-
- If you do a change, rebuilding will also start from the first stage
-and "bubble" up the change through the three stages. Each stage is
-taken from its build directory (if it had been built previously),
-rebuilt, and copied to its subdirectory. This will allow you to, for
-example, continue a bootstrap after fixing a bug which causes the
-stage2 build to crash. It does not provide as good coverage of the
-compiler as bootstrapping from scratch, but it ensures that the new
-code is syntactically correct (e.g., that you did not use GCC extensions
-by mistake), and avoids spurious bootstrap comparison failures(1).
-
- Other targets available from the top level include:
-
-`bootstrap-lean'
- Like `bootstrap', except that the various stages are removed once
- they're no longer needed. This saves disk space.
-
-`bootstrap2'
-`bootstrap2-lean'
- Performs only the first two stages of bootstrap. Unlike a
- three-stage bootstrap, this does not perform a comparison to test
- that the compiler is running properly. Note that the disk space
- required by a "lean" bootstrap is approximately independent of the
- number of stages.
-
-`stageN-bubble (N = 1...4)'
- Rebuild all the stages up to N, with the appropriate flags,
- "bubbling" the changes as described above.
-
-`all-stageN (N = 1...4)'
- Assuming that stage N has already been built, rebuild it with the
- appropriate flags. This is rarely needed.
-
-`cleanstrap'
- Remove everything (`make clean') and rebuilds (`make bootstrap').
-
-`compare'
- Compares the results of stages 2 and 3. This ensures that the
- compiler is running properly, since it should produce the same
- object files regardless of how it itself was compiled.
-
-`profiledbootstrap'
- Builds a compiler with profiling feedback information. For more
- information, see *note Building with profile feedback:
- (gccinstall)Building.
-
-`restrap'
- Restart a bootstrap, so that everything that was not built with
- the system compiler is rebuilt.
-
-`stageN-start (N = 1...4)'
- For each package that is bootstrapped, rename directories so that,
- for example, `gcc' points to the stageN GCC, compiled with the
- stageN-1 GCC(2).
-
- You will invoke this target if you need to test or debug the
- stageN GCC. If you only need to execute GCC (but you need not run
- `make' either to rebuild it or to run test suites), you should be
- able to work directly in the `stageN-gcc' directory. This makes
- it easier to debug multiple stages in parallel.
-
-`stage'
- For each package that is bootstrapped, relocate its build directory
- to indicate its stage. For example, if the `gcc' directory points
- to the stage2 GCC, after invoking this target it will be renamed
- to `stage2-gcc'.
-
-
- If you wish to use non-default GCC flags when compiling the stage2 and
-stage3 compilers, set `BOOT_CFLAGS' on the command line when doing
-`make'.
-
- Usually, the first stage only builds the languages that the compiler
-is written in: typically, C and maybe Ada. If you are debugging a
-miscompilation of a different stage2 front-end (for example, of the
-Fortran front-end), you may want to have front-ends for other languages
-in the first stage as well. To do so, set `STAGE1_LANGUAGES' on the
-command line when doing `make'.
-
- For example, in the aforementioned scenario of debugging a Fortran
-front-end miscompilation caused by the stage1 compiler, you may need a
-command like
-
- make stage2-bubble STAGE1_LANGUAGES=c,fortran
-
- Alternatively, you can use per-language targets to build and test
-languages that are not enabled by default in stage1. For example,
-`make f951' will build a Fortran compiler even in the stage1 build
-directory.
-
- ---------- Footnotes ----------
-
- (1) Except if the compiler was buggy and miscompiled some of the files
-that were not modified. In this case, it's best to use `make restrap'.
-
- (2) Customarily, the system compiler is also termed the `stage0' GCC.
-
-\1f
-File: gccint.info, Node: Library Files, Next: Headers, Prev: Makefile, Up: gcc Directory
-
-6.3.5 Library Source Files and Headers under the `gcc' Directory
-----------------------------------------------------------------
-
-FIXME: list here, with explanation, all the C source files and headers
-under the `gcc' directory that aren't built into the GCC executable but
-rather are part of runtime libraries and object files, such as
-`crtstuff.c' and `unwind-dw2.c'. *Note Headers Installed by GCC:
-Headers, for more information about the `ginclude' directory.
-
-\1f
-File: gccint.info, Node: Headers, Next: Documentation, Prev: Library Files, Up: gcc Directory
-
-6.3.6 Headers Installed by GCC
-------------------------------
-
-In general, GCC expects the system C library to provide most of the
-headers to be used with it. However, GCC will fix those headers if
-necessary to make them work with GCC, and will install some headers
-required of freestanding implementations. These headers are installed
-in `LIBSUBDIR/include'. Headers for non-C runtime libraries are also
-installed by GCC; these are not documented here. (FIXME: document them
-somewhere.)
-
- Several of the headers GCC installs are in the `ginclude' directory.
-These headers, `iso646.h', `stdarg.h', `stdbool.h', and `stddef.h', are
-installed in `LIBSUBDIR/include', unless the target Makefile fragment
-(*note Target Fragment::) overrides this by setting `USER_H'.
-
- In addition to these headers and those generated by fixing system
-headers to work with GCC, some other headers may also be installed in
-`LIBSUBDIR/include'. `config.gcc' may set `extra_headers'; this
-specifies additional headers under `config' to be installed on some
-systems.
-
- GCC installs its own version of `<float.h>', from `ginclude/float.h'.
-This is done to cope with command-line options that change the
-representation of floating point numbers.
-
- GCC also installs its own version of `<limits.h>'; this is generated
-from `glimits.h', together with `limitx.h' and `limity.h' if the system
-also has its own version of `<limits.h>'. (GCC provides its own header
-because it is required of ISO C freestanding implementations, but needs
-to include the system header from its own header as well because other
-standards such as POSIX specify additional values to be defined in
-`<limits.h>'.) The system's `<limits.h>' header is used via
-`LIBSUBDIR/include/syslimits.h', which is copied from `gsyslimits.h' if
-it does not need fixing to work with GCC; if it needs fixing,
-`syslimits.h' is the fixed copy.
-
- GCC can also install `<tgmath.h>'. It will do this when `config.gcc'
-sets `use_gcc_tgmath' to `yes'.
-
-\1f
-File: gccint.info, Node: Documentation, Next: Front End, Prev: Headers, Up: gcc Directory
-
-6.3.7 Building Documentation
-----------------------------
-
-The main GCC documentation is in the form of manuals in Texinfo format.
-These are installed in Info format; DVI versions may be generated by
-`make dvi', PDF versions by `make pdf', and HTML versions by `make
-html'. In addition, some man pages are generated from the Texinfo
-manuals, there are some other text files with miscellaneous
-documentation, and runtime libraries have their own documentation
-outside the `gcc' directory. FIXME: document the documentation for
-runtime libraries somewhere.
-
-* Menu:
-
-* Texinfo Manuals:: GCC manuals in Texinfo format.
-* Man Page Generation:: Generating man pages from Texinfo manuals.
-* Miscellaneous Docs:: Miscellaneous text files with documentation.
-
-\1f
-File: gccint.info, Node: Texinfo Manuals, Next: Man Page Generation, Up: Documentation
-
-6.3.7.1 Texinfo Manuals
-.......................
-
-The manuals for GCC as a whole, and the C and C++ front ends, are in
-files `doc/*.texi'. Other front ends have their own manuals in files
-`LANGUAGE/*.texi'. Common files `doc/include/*.texi' are provided
-which may be included in multiple manuals; the following files are in
-`doc/include':
-
-`fdl.texi'
- The GNU Free Documentation License.
-
-`funding.texi'
- The section "Funding Free Software".
-
-`gcc-common.texi'
- Common definitions for manuals.
-
-`gpl.texi'
-`gpl_v3.texi'
- The GNU General Public License.
-
-`texinfo.tex'
- A copy of `texinfo.tex' known to work with the GCC manuals.
-
- DVI-formatted manuals are generated by `make dvi', which uses
-`texi2dvi' (via the Makefile macro `$(TEXI2DVI)'). PDF-formatted
-manuals are generated by `make pdf', which uses `texi2pdf' (via the
-Makefile macro `$(TEXI2PDF)'). HTML formatted manuals are generated by
-`make html'. Info manuals are generated by `make info' (which is run
-as part of a bootstrap); this generates the manuals in the source
-directory, using `makeinfo' via the Makefile macro `$(MAKEINFO)', and
-they are included in release distributions.
-
- Manuals are also provided on the GCC web site, in both HTML and
-PostScript forms. This is done via the script
-`maintainer-scripts/update_web_docs'. Each manual to be provided
-online must be listed in the definition of `MANUALS' in that file; a
-file `NAME.texi' must only appear once in the source tree, and the
-output manual must have the same name as the source file. (However,
-other Texinfo files, included in manuals but not themselves the root
-files of manuals, may have names that appear more than once in the
-source tree.) The manual file `NAME.texi' should only include other
-files in its own directory or in `doc/include'. HTML manuals will be
-generated by `makeinfo --html', PostScript manuals by `texi2dvi' and
-`dvips', and PDF manuals by `texi2pdf'. All Texinfo files that are
-parts of manuals must be checked into SVN, even if they are generated
-files, for the generation of online manuals to work.
-
- The installation manual, `doc/install.texi', is also provided on the
-GCC web site. The HTML version is generated by the script
-`doc/install.texi2html'.
-
-\1f
-File: gccint.info, Node: Man Page Generation, Next: Miscellaneous Docs, Prev: Texinfo Manuals, Up: Documentation
-
-6.3.7.2 Man Page Generation
-...........................
-
-Because of user demand, in addition to full Texinfo manuals, man pages
-are provided which contain extracts from those manuals. These man
-pages are generated from the Texinfo manuals using
-`contrib/texi2pod.pl' and `pod2man'. (The man page for `g++',
-`cp/g++.1', just contains a `.so' reference to `gcc.1', but all the
-other man pages are generated from Texinfo manuals.)
-
- Because many systems may not have the necessary tools installed to
-generate the man pages, they are only generated if the `configure'
-script detects that recent enough tools are installed, and the
-Makefiles allow generating man pages to fail without aborting the
-build. Man pages are also included in release distributions. They are
-generated in the source directory.
-
- Magic comments in Texinfo files starting `@c man' control what parts
-of a Texinfo file go into a man page. Only a subset of Texinfo is
-supported by `texi2pod.pl', and it may be necessary to add support for
-more Texinfo features to this script when generating new man pages. To
-improve the man page output, some special Texinfo macros are provided
-in `doc/include/gcc-common.texi' which `texi2pod.pl' understands:
-
-`@gcctabopt'
- Use in the form `@table @gcctabopt' for tables of options, where
- for printed output the effect of `@code' is better than that of
- `@option' but for man page output a different effect is wanted.
-
-`@gccoptlist'
- Use for summary lists of options in manuals.
-
-`@gol'
- Use at the end of each line inside `@gccoptlist'. This is
- necessary to avoid problems with differences in how the
- `@gccoptlist' macro is handled by different Texinfo formatters.
-
- FIXME: describe the `texi2pod.pl' input language and magic comments in
-more detail.
-
-\1f
-File: gccint.info, Node: Miscellaneous Docs, Prev: Man Page Generation, Up: Documentation
-
-6.3.7.3 Miscellaneous Documentation
-...................................
-
-In addition to the formal documentation that is installed by GCC, there
-are several other text files with miscellaneous documentation:
-
-`ABOUT-GCC-NLS'
- Notes on GCC's Native Language Support. FIXME: this should be
- part of this manual rather than a separate file.
-
-`ABOUT-NLS'
- Notes on the Free Translation Project.
-
-`COPYING'
- The GNU General Public License.
-
-`COPYING.LIB'
- The GNU Lesser General Public License.
-
-`*ChangeLog*'
-`*/ChangeLog*'
- Change log files for various parts of GCC.
-
-`LANGUAGES'
- Details of a few changes to the GCC front-end interface. FIXME:
- the information in this file should be part of general
- documentation of the front-end interface in this manual.
-
-`ONEWS'
- Information about new features in old versions of GCC. (For recent
- versions, the information is on the GCC web site.)
-
-`README.Portability'
- Information about portability issues when writing code in GCC.
- FIXME: why isn't this part of this manual or of the GCC Coding
- Conventions?
-
- FIXME: document such files in subdirectories, at least `config', `cp',
-`objc', `testsuite'.
-
-\1f
-File: gccint.info, Node: Front End, Next: Back End, Prev: Documentation, Up: gcc Directory
-
-6.3.8 Anatomy of a Language Front End
--------------------------------------
-
-A front end for a language in GCC has the following parts:
-
- * A directory `LANGUAGE' under `gcc' containing source files for
- that front end. *Note The Front End `LANGUAGE' Directory: Front
- End Directory, for details.
-
- * A mention of the language in the list of supported languages in
- `gcc/doc/install.texi'.
-
- * A mention of the name under which the language's runtime library is
- recognized by `--enable-shared=PACKAGE' in the documentation of
- that option in `gcc/doc/install.texi'.
-
- * A mention of any special prerequisites for building the front end
- in the documentation of prerequisites in `gcc/doc/install.texi'.
-
- * Details of contributors to that front end in
- `gcc/doc/contrib.texi'. If the details are in that front end's
- own manual then there should be a link to that manual's list in
- `contrib.texi'.
-
- * Information about support for that language in
- `gcc/doc/frontends.texi'.
-
- * Information about standards for that language, and the front end's
- support for them, in `gcc/doc/standards.texi'. This may be a link
- to such information in the front end's own manual.
-
- * Details of source file suffixes for that language and `-x LANG'
- options supported, in `gcc/doc/invoke.texi'.
-
- * Entries in `default_compilers' in `gcc.c' for source file suffixes
- for that language.
-
- * Preferably testsuites, which may be under `gcc/testsuite' or
- runtime library directories. FIXME: document somewhere how to
- write testsuite harnesses.
-
- * Probably a runtime library for the language, outside the `gcc'
- directory. FIXME: document this further.
-
- * Details of the directories of any runtime libraries in
- `gcc/doc/sourcebuild.texi'.
-
- If the front end is added to the official GCC source repository, the
-following are also necessary:
-
- * At least one Bugzilla component for bugs in that front end and
- runtime libraries. This category needs to be mentioned in
- `gcc/gccbug.in', as well as being added to the Bugzilla database.
-
- * Normally, one or more maintainers of that front end listed in
- `MAINTAINERS'.
-
- * Mentions on the GCC web site in `index.html' and `frontends.html',
- with any relevant links on `readings.html'. (Front ends that are
- not an official part of GCC may also be listed on
- `frontends.html', with relevant links.)
-
- * A news item on `index.html', and possibly an announcement on the
- <gcc-announce@gcc.gnu.org> mailing list.
-
- * The front end's manuals should be mentioned in
- `maintainer-scripts/update_web_docs' (*note Texinfo Manuals::) and
- the online manuals should be linked to from
- `onlinedocs/index.html'.
-
- * Any old releases or CVS repositories of the front end, before its
- inclusion in GCC, should be made available on the GCC FTP site
- `ftp://gcc.gnu.org/pub/gcc/old-releases/'.
-
- * The release and snapshot script `maintainer-scripts/gcc_release'
- should be updated to generate appropriate tarballs for this front
- end. The associated `maintainer-scripts/snapshot-README' and
- `maintainer-scripts/snapshot-index.html' files should be updated
- to list the tarballs and diffs for this front end.
-
- * If this front end includes its own version files that include the
- current date, `maintainer-scripts/update_version' should be
- updated accordingly.
-
-* Menu:
-
-* Front End Directory:: The front end `LANGUAGE' directory.
-* Front End Config:: The front end `config-lang.in' file.
-
-\1f
-File: gccint.info, Node: Front End Directory, Next: Front End Config, Up: Front End
-
-6.3.8.1 The Front End `LANGUAGE' Directory
-..........................................
-
-A front end `LANGUAGE' directory contains the source files of that
-front end (but not of any runtime libraries, which should be outside
-the `gcc' directory). This includes documentation, and possibly some
-subsidiary programs build alongside the front end. Certain files are
-special and other parts of the compiler depend on their names:
-
-`config-lang.in'
- This file is required in all language subdirectories. *Note The
- Front End `config-lang.in' File: Front End Config, for details of
- its contents
-
-`Make-lang.in'
- This file is required in all language subdirectories. It contains
- targets `LANG.HOOK' (where `LANG' is the setting of `language' in
- `config-lang.in') for the following values of `HOOK', and any
- other Makefile rules required to build those targets (which may if
- necessary use other Makefiles specified in `outputs' in
- `config-lang.in', although this is deprecated). It also adds any
- testsuite targets that can use the standard rule in
- `gcc/Makefile.in' to the variable `lang_checks'.
-
- `all.cross'
- `start.encap'
- `rest.encap'
- FIXME: exactly what goes in each of these targets?
-
- `tags'
- Build an `etags' `TAGS' file in the language subdirectory in
- the source tree.
-
- `info'
- Build info documentation for the front end, in the build
- directory. This target is only called by `make bootstrap' if
- a suitable version of `makeinfo' is available, so does not
- need to check for this, and should fail if an error occurs.
-
- `dvi'
- Build DVI documentation for the front end, in the build
- directory. This should be done using `$(TEXI2DVI)', with
- appropriate `-I' arguments pointing to directories of
- included files.
-
- `pdf'
- Build PDF documentation for the front end, in the build
- directory. This should be done using `$(TEXI2PDF)', with
- appropriate `-I' arguments pointing to directories of
- included files.
-
- `html'
- Build HTML documentation for the front end, in the build
- directory.
-
- `man'
- Build generated man pages for the front end from Texinfo
- manuals (*note Man Page Generation::), in the build
- directory. This target is only called if the necessary tools
- are available, but should ignore errors so as not to stop the
- build if errors occur; man pages are optional and the tools
- involved may be installed in a broken way.
-
- `install-common'
- Install everything that is part of the front end, apart from
- the compiler executables listed in `compilers' in
- `config-lang.in'.
-
- `install-info'
- Install info documentation for the front end, if it is
- present in the source directory. This target should have
- dependencies on info files that should be installed.
-
- `install-man'
- Install man pages for the front end. This target should
- ignore errors.
-
- `install-plugin'
- Install headers needed for plugins.
-
- `srcextra'
- Copies its dependencies into the source directory. This
- generally should be used for generated files such as Bison
- output files which are not present in CVS, but should be
- included in any release tarballs. This target will be
- executed during a bootstrap if
- `--enable-generated-files-in-srcdir' was specified as a
- `configure' option.
-
- `srcinfo'
- `srcman'
- Copies its dependencies into the source directory. These
- targets will be executed during a bootstrap if
- `--enable-generated-files-in-srcdir' was specified as a
- `configure' option.
-
- `uninstall'
- Uninstall files installed by installing the compiler. This is
- currently documented not to be supported, so the hook need
- not do anything.
-
- `mostlyclean'
- `clean'
- `distclean'
- `maintainer-clean'
- The language parts of the standard GNU `*clean' targets.
- *Note Standard Targets for Users: (standards)Standard
- Targets, for details of the standard targets. For GCC,
- `maintainer-clean' should delete all generated files in the
- source directory that are not checked into CVS, but should
- not delete anything checked into CVS.
-
- `Make-lang.in' must also define a variable `LANG_OBJS' to a list
- of host object files that are used by that language.
-
-`lang.opt'
- This file registers the set of switches that the front end accepts
- on the command line, and their `--help' text. *Note Options::.
-
-`lang-specs.h'
- This file provides entries for `default_compilers' in `gcc.c'
- which override the default of giving an error that a compiler for
- that language is not installed.
-
-`LANGUAGE-tree.def'
- This file, which need not exist, defines any language-specific tree
- codes.
-
-\1f
-File: gccint.info, Node: Front End Config, Prev: Front End Directory, Up: Front End
-
-6.3.8.2 The Front End `config-lang.in' File
-...........................................
-
-Each language subdirectory contains a `config-lang.in' file. In
-addition the main directory contains `c-config-lang.in', which contains
-limited information for the C language. This file is a shell script
-that may define some variables describing the language:
-
-`language'
- This definition must be present, and gives the name of the language
- for some purposes such as arguments to `--enable-languages'.
-
-`lang_requires'
- If defined, this variable lists (space-separated) language front
- ends other than C that this front end requires to be enabled (with
- the names given being their `language' settings). For example, the
- Java front end depends on the C++ front end, so sets
- `lang_requires=c++'.
-
-`subdir_requires'
- If defined, this variable lists (space-separated) front end
- directories other than C that this front end requires to be
- present. For example, the Objective-C++ front end uses source
- files from the C++ and Objective-C front ends, so sets
- `subdir_requires="cp objc"'.
-
-`target_libs'
- If defined, this variable lists (space-separated) targets in the
- top level `Makefile' to build the runtime libraries for this
- language, such as `target-libobjc'.
-
-`lang_dirs'
- If defined, this variable lists (space-separated) top level
- directories (parallel to `gcc'), apart from the runtime libraries,
- that should not be configured if this front end is not built.
-
-`build_by_default'
- If defined to `no', this language front end is not built unless
- enabled in a `--enable-languages' argument. Otherwise, front ends
- are built by default, subject to any special logic in
- `configure.ac' (as is present to disable the Ada front end if the
- Ada compiler is not already installed).
-
-`boot_language'
- If defined to `yes', this front end is built in stage 1 of the
- bootstrap. This is only relevant to front ends written in their
- own languages.
-
-`compilers'
- If defined, a space-separated list of compiler executables that
- will be run by the driver. The names here will each end with
- `\$(exeext)'.
-
-`outputs'
- If defined, a space-separated list of files that should be
- generated by `configure' substituting values in them. This
- mechanism can be used to create a file `LANGUAGE/Makefile' from
- `LANGUAGE/Makefile.in', but this is deprecated, building
- everything from the single `gcc/Makefile' is preferred.
-
-`gtfiles'
- If defined, a space-separated list of files that should be scanned
- by gengtype.c to generate the garbage collection tables and
- routines for this language. This excludes the files that are
- common to all front ends. *Note Type Information::.
-
-
-\1f
-File: gccint.info, Node: Back End, Prev: Front End, Up: gcc Directory
-
-6.3.9 Anatomy of a Target Back End
-----------------------------------
-
-A back end for a target architecture in GCC has the following parts:
-
- * A directory `MACHINE' under `gcc/config', containing a machine
- description `MACHINE.md' file (*note Machine Descriptions: Machine
- Desc.), header files `MACHINE.h' and `MACHINE-protos.h' and a
- source file `MACHINE.c' (*note Target Description Macros and
- Functions: Target Macros.), possibly a target Makefile fragment
- `t-MACHINE' (*note The Target Makefile Fragment: Target
- Fragment.), and maybe some other files. The names of these files
- may be changed from the defaults given by explicit specifications
- in `config.gcc'.
-
- * If necessary, a file `MACHINE-modes.def' in the `MACHINE'
- directory, containing additional machine modes to represent
- condition codes. *Note Condition Code::, for further details.
-
- * An optional `MACHINE.opt' file in the `MACHINE' directory,
- containing a list of target-specific options. You can also add
- other option files using the `extra_options' variable in
- `config.gcc'. *Note Options::.
-
- * Entries in `config.gcc' (*note The `config.gcc' File: System
- Config.) for the systems with this target architecture.
-
- * Documentation in `gcc/doc/invoke.texi' for any command-line
- options supported by this target (*note Run-time Target
- Specification: Run-time Target.). This means both entries in the
- summary table of options and details of the individual options.
-
- * Documentation in `gcc/doc/extend.texi' for any target-specific
- attributes supported (*note Defining target-specific uses of
- `__attribute__': Target Attributes.), including where the same
- attribute is already supported on some targets, which are
- enumerated in the manual.
-
- * Documentation in `gcc/doc/extend.texi' for any target-specific
- pragmas supported.
-
- * Documentation in `gcc/doc/extend.texi' of any target-specific
- built-in functions supported.
-
- * Documentation in `gcc/doc/extend.texi' of any target-specific
- format checking styles supported.
-
- * Documentation in `gcc/doc/md.texi' of any target-specific
- constraint letters (*note Constraints for Particular Machines:
- Machine Constraints.).
-
- * A note in `gcc/doc/contrib.texi' under the person or people who
- contributed the target support.
-
- * Entries in `gcc/doc/install.texi' for all target triplets
- supported with this target architecture, giving details of any
- special notes about installation for this target, or saying that
- there are no special notes if there are none.
-
- * Possibly other support outside the `gcc' directory for runtime
- libraries. FIXME: reference docs for this. The libstdc++ porting
- manual needs to be installed as info for this to work, or to be a
- chapter of this manual.
-
- If the back end is added to the official GCC source repository, the
-following are also necessary:
-
- * An entry for the target architecture in `readings.html' on the GCC
- web site, with any relevant links.
-
- * Details of the properties of the back end and target architecture
- in `backends.html' on the GCC web site.
-
- * A news item about the contribution of support for that target
- architecture, in `index.html' on the GCC web site.
-
- * Normally, one or more maintainers of that target listed in
- `MAINTAINERS'. Some existing architectures may be unmaintained,
- but it would be unusual to add support for a target that does not
- have a maintainer when support is added.
-
-\1f
-File: gccint.info, Node: Testsuites, Prev: gcc Directory, Up: Source Tree
-
-6.4 Testsuites
-==============
-
-GCC contains several testsuites to help maintain compiler quality.
-Most of the runtime libraries and language front ends in GCC have
-testsuites. Currently only the C language testsuites are documented
-here; FIXME: document the others.
-
-* Menu:
-
-* Test Idioms:: Idioms used in testsuite code.
-* Test Directives:: Directives used within DejaGnu tests.
-* Ada Tests:: The Ada language testsuites.
-* C Tests:: The C language testsuites.
-* libgcj Tests:: The Java library testsuites.
-* gcov Testing:: Support for testing gcov.
-* profopt Testing:: Support for testing profile-directed optimizations.
-* compat Testing:: Support for testing binary compatibility.
-* Torture Tests:: Support for torture testing using multiple options.
-
-\1f
-File: gccint.info, Node: Test Idioms, Next: Test Directives, Up: Testsuites
-
-6.4.1 Idioms Used in Testsuite Code
------------------------------------
-
-In general, C testcases have a trailing `-N.c', starting with `-1.c',
-in case other testcases with similar names are added later. If the
-test is a test of some well-defined feature, it should have a name
-referring to that feature such as `FEATURE-1.c'. If it does not test a
-well-defined feature but just happens to exercise a bug somewhere in
-the compiler, and a bug report has been filed for this bug in the GCC
-bug database, `prBUG-NUMBER-1.c' is the appropriate form of name.
-Otherwise (for miscellaneous bugs not filed in the GCC bug database),
-and previously more generally, test cases are named after the date on
-which they were added. This allows people to tell at a glance whether
-a test failure is because of a recently found bug that has not yet been
-fixed, or whether it may be a regression, but does not give any other
-information about the bug or where discussion of it may be found. Some
-other language testsuites follow similar conventions.
-
- In the `gcc.dg' testsuite, it is often necessary to test that an error
-is indeed a hard error and not just a warning--for example, where it is
-a constraint violation in the C standard, which must become an error
-with `-pedantic-errors'. The following idiom, where the first line
-shown is line LINE of the file and the line that generates the error,
-is used for this:
-
- /* { dg-bogus "warning" "warning in place of error" } */
- /* { dg-error "REGEXP" "MESSAGE" { target *-*-* } LINE } */
-
- It may be necessary to check that an expression is an integer constant
-expression and has a certain value. To check that `E' has value `V',
-an idiom similar to the following is used:
-
- char x[((E) == (V) ? 1 : -1)];
-
- In `gcc.dg' tests, `__typeof__' is sometimes used to make assertions
-about the types of expressions. See, for example,
-`gcc.dg/c99-condexpr-1.c'. The more subtle uses depend on the exact
-rules for the types of conditional expressions in the C standard; see,
-for example, `gcc.dg/c99-intconst-1.c'.
-
- It is useful to be able to test that optimizations are being made
-properly. This cannot be done in all cases, but it can be done where
-the optimization will lead to code being optimized away (for example,
-where flow analysis or alias analysis should show that certain code
-cannot be called) or to functions not being called because they have
-been expanded as built-in functions. Such tests go in
-`gcc.c-torture/execute'. Where code should be optimized away, a call
-to a nonexistent function such as `link_failure ()' may be inserted; a
-definition
-
- #ifndef __OPTIMIZE__
- void
- link_failure (void)
- {
- abort ();
- }
- #endif
-
-will also be needed so that linking still succeeds when the test is run
-without optimization. When all calls to a built-in function should
-have been optimized and no calls to the non-built-in version of the
-function should remain, that function may be defined as `static' to
-call `abort ()' (although redeclaring a function as static may not work
-on all targets).
-
- All testcases must be portable. Target-specific testcases must have
-appropriate code to avoid causing failures on unsupported systems;
-unfortunately, the mechanisms for this differ by directory.
-
- FIXME: discuss non-C testsuites here.
-
-\1f
-File: gccint.info, Node: Test Directives, Next: Ada Tests, Prev: Test Idioms, Up: Testsuites
-
-6.4.2 Directives used within DejaGnu tests
-------------------------------------------
-
-Test directives appear within comments in a test source file and begin
-with `dg-'. Some of these are defined within DejaGnu and others are
-local to the GCC testsuite.
-
- The order in which test directives appear in a test can be important:
-directives local to GCC sometimes override information used by the
-DejaGnu directives, which know nothing about the GCC directives, so the
-DejaGnu directives must precede GCC directives.
-
- Several test directives include selectors which are usually preceded by
-the keyword `target' or `xfail'. A selector is: one or more target
-triplets, possibly including wildcard characters; a single
-effective-target keyword; or a logical expression. Depending on the
-context, the selector specifies whether a test is skipped and reported
-as unsupported or is expected to fail. Use `*-*-*' to match any target.
-Effective-target keywords are defined in `target-supports.exp' in the
-GCC testsuite.
-
- A selector expression appears within curly braces and uses a single
-logical operator: one of `!', `&&', or `||'. An operand is another
-selector expression, an effective-target keyword, a single target
-triplet, or a list of target triplets within quotes or curly braces.
-For example:
-
- { target { ! "hppa*-*-* ia64*-*-*" } }
- { target { powerpc*-*-* && lp64 } }
- { xfail { lp64 || vect_no_align } }
-
-`{ dg-do DO-WHAT-KEYWORD [{ target/xfail SELECTOR }] }'
- DO-WHAT-KEYWORD specifies how the test is compiled and whether it
- is executed. It is one of:
-
- `preprocess'
- Compile with `-E' to run only the preprocessor.
-
- `compile'
- Compile with `-S' to produce an assembly code file.
-
- `assemble'
- Compile with `-c' to produce a relocatable object file.
-
- `link'
- Compile, assemble, and link to produce an executable file.
-
- `run'
- Produce and run an executable file, which is expected to
- return an exit code of 0.
-
- The default is `compile'. That can be overridden for a set of
- tests by redefining `dg-do-what-default' within the `.exp' file
- for those tests.
-
- If the directive includes the optional `{ target SELECTOR }' then
- the test is skipped unless the target system is included in the
- list of target triplets or matches the effective-target keyword.
-
- If `do-what-keyword' is `run' and the directive includes the
- optional `{ xfail SELECTOR }' and the selector is met then the
- test is expected to fail. The `xfail' clause is ignored for other
- values of `do-what-keyword'; those tests can use directive
- `dg-xfail-if'.
-
-`{ dg-options OPTIONS [{ target SELECTOR }] }'
- This DejaGnu directive provides a list of compiler options, to be
- used if the target system matches SELECTOR, that replace the
- default options used for this set of tests.
-
-`{ dg-add-options FEATURE ... }'
- Add any compiler options that are needed to access certain
- features. This directive does nothing on targets that enable the
- features by default, or that don't provide them at all. It must
- come after all `dg-options' directives.
-
- The supported values of FEATURE are:
- `c99_runtime'
- The target's C99 runtime (both headers and libraries).
-
- `mips16_attribute'
- `mips16' function attributes. Only MIPS targets support this
- feature, and only then in certain modes.
-
-`{ dg-timeout N [{target SELECTOR }] }'
- Set the time limit for the compilation and for the execution of
- the test to the specified number of seconds.
-
-`{ dg-timeout-factor X [{ target SELECTOR }] }'
- Multiply the normal time limit for compilation and execution of
- the test by the specified floating-point factor. The normal
- timeout limit, in seconds, is found by searching the following in
- order:
-
- * the value defined by an earlier `dg-timeout' directive in the
- test
-
- * variable TOOL_TIMEOUT defined by the set of tests
-
- * GCC,TIMEOUT set in the target board
-
- * 300
-
-`{ dg-skip-if COMMENT { SELECTOR } { INCLUDE-OPTS } { EXCLUDE-OPTS } }'
- Skip the test if the test system is included in SELECTOR and if
- each of the options in INCLUDE-OPTS is in the set of options with
- which the test would be compiled and if none of the options in
- EXCLUDE-OPTS is in the set of options with which the test would be
- compiled.
-
- Use `"*"' for an empty INCLUDE-OPTS list and `""' for an empty
- EXCLUDE-OPTS list.
-
-`{ dg-xfail-if COMMENT { SELECTOR } { INCLUDE-OPTS } { EXCLUDE-OPTS } }'
- Expect the test to fail if the conditions (which are the same as
- for `dg-skip-if') are met. This does not affect the execute step.
-
-`{ dg-xfail-run-if COMMENT { SELECTOR } { INCLUDE-OPTS } { EXCLUDE-OPTS } }'
- Expect the execute step of a test to fail if the conditions (which
- are the same as for `dg-skip-if') and `dg-xfail-if') are met.
-
-`{ dg-require-SUPPORT args }'
- Skip the test if the target does not provide the required support;
- see `gcc-dg.exp' in the GCC testsuite for the actual directives.
- These directives must appear after any `dg-do' directive in the
- test and before any `dg-additional-sources' directive. They
- require at least one argument, which can be an empty string if the
- specific procedure does not examine the argument.
-
-`{ dg-require-effective-target KEYWORD }'
- Skip the test if the test target, including current multilib flags,
- is not covered by the effective-target keyword. This directive
- must appear after any `dg-do' directive in the test and before any
- `dg-additional-sources' directive.
-
-`{ dg-shouldfail COMMENT { SELECTOR } { INCLUDE-OPTS } { EXCLUDE-OPTS } }'
- Expect the test executable to return a nonzero exit status if the
- conditions (which are the same as for `dg-skip-if') are met.
-
-`{ dg-error REGEXP [COMMENT [{ target/xfail SELECTOR } [LINE] }]] }'
- This DejaGnu directive appears on a source line that is expected
- to get an error message, or else specifies the source line
- associated with the message. If there is no message for that line
- or if the text of that message is not matched by REGEXP then the
- check fails and COMMENT is included in the `FAIL' message. The
- check does not look for the string `"error"' unless it is part of
- REGEXP.
-
-`{ dg-warning REGEXP [COMMENT [{ target/xfail SELECTOR } [LINE] }]] }'
- This DejaGnu directive appears on a source line that is expected
- to get a warning message, or else specifies the source line
- associated with the message. If there is no message for that line
- or if the text of that message is not matched by REGEXP then the
- check fails and COMMENT is included in the `FAIL' message. The
- check does not look for the string `"warning"' unless it is part
- of REGEXP.
-
-`{ dg-message REGEXP [COMMENT [{ target/xfail SELECTOR } [LINE] }]] }'
- The line is expected to get a message other than an error or
- warning. If there is no message for that line or if the text of
- that message is not matched by REGEXP then the check fails and
- COMMENT is included in the `FAIL' message.
-
-`{ dg-bogus REGEXP [COMMENT [{ target/xfail SELECTOR } [LINE] }]] }'
- This DejaGnu directive appears on a source line that should not
- get a message matching REGEXP, or else specifies the source line
- associated with the bogus message. It is usually used with `xfail'
- to indicate that the message is a known problem for a particular
- set of targets.
-
-`{ dg-excess-errors COMMENT [{ target/xfail SELECTOR }] }'
- This DejaGnu directive indicates that the test is expected to fail
- due to compiler messages that are not handled by `dg-error',
- `dg-warning' or `dg-bogus'. For this directive `xfail' has the
- same effect as `target'.
-
-`{ dg-output REGEXP [{ target/xfail SELECTOR }] }'
- This DejaGnu directive compares REGEXP to the combined output that
- the test executable writes to `stdout' and `stderr'.
-
-`{ dg-prune-output REGEXP }'
- Prune messages matching REGEXP from test output.
-
-`{ dg-additional-files "FILELIST" }'
- Specify additional files, other than source files, that must be
- copied to the system where the compiler runs.
-
-`{ dg-additional-sources "FILELIST" }'
- Specify additional source files to appear in the compile line
- following the main test file.
-
-`{ dg-final { LOCAL-DIRECTIVE } }'
- This DejaGnu directive is placed within a comment anywhere in the
- source file and is processed after the test has been compiled and
- run. Multiple `dg-final' commands are processed in the order in
- which they appear in the source file.
-
- The GCC testsuite defines the following directives to be used
- within `dg-final'.
-
- `cleanup-coverage-files'
- Removes coverage data files generated for this test.
-
- `cleanup-repo-files'
- Removes files generated for this test for `-frepo'.
-
- `cleanup-rtl-dump SUFFIX'
- Removes RTL dump files generated for this test.
-
- `cleanup-tree-dump SUFFIX'
- Removes tree dump files matching SUFFIX which were generated
- for this test.
-
- `cleanup-saved-temps'
- Removes files for the current test which were kept for
- `--save-temps'.
-
- `scan-file FILENAME REGEXP [{ target/xfail SELECTOR }]'
- Passes if REGEXP matches text in FILENAME.
-
- `scan-file-not FILENAME REGEXP [{ target/xfail SELECTOR }]'
- Passes if REGEXP does not match text in FILENAME.
-
- `scan-hidden SYMBOL [{ target/xfail SELECTOR }]'
- Passes if SYMBOL is defined as a hidden symbol in the test's
- assembly output.
-
- `scan-not-hidden SYMBOL [{ target/xfail SELECTOR }]'
- Passes if SYMBOL is not defined as a hidden symbol in the
- test's assembly output.
-
- `scan-assembler-times REGEX NUM [{ target/xfail SELECTOR }]'
- Passes if REGEX is matched exactly NUM times in the test's
- assembler output.
-
- `scan-assembler REGEX [{ target/xfail SELECTOR }]'
- Passes if REGEX matches text in the test's assembler output.
-
- `scan-assembler-not REGEX [{ target/xfail SELECTOR }]'
- Passes if REGEX does not match text in the test's assembler
- output.
-
- `scan-assembler-dem REGEX [{ target/xfail SELECTOR }]'
- Passes if REGEX matches text in the test's demangled
- assembler output.
-
- `scan-assembler-dem-not REGEX [{ target/xfail SELECTOR }]'
- Passes if REGEX does not match text in the test's demangled
- assembler output.
-
- `scan-tree-dump-times REGEX NUM SUFFIX [{ target/xfail SELECTOR }]'
- Passes if REGEX is found exactly NUM times in the dump file
- with suffix SUFFIX.
-
- `scan-tree-dump REGEX SUFFIX [{ target/xfail SELECTOR }]'
- Passes if REGEX matches text in the dump file with suffix
- SUFFIX.
-
- `scan-tree-dump-not REGEX SUFFIX [{ target/xfail SELECTOR }]'
- Passes if REGEX does not match text in the dump file with
- suffix SUFFIX.
-
- `scan-tree-dump-dem REGEX SUFFIX [{ target/xfail SELECTOR }]'
- Passes if REGEX matches demangled text in the dump file with
- suffix SUFFIX.
-
- `scan-tree-dump-dem-not REGEX SUFFIX [{ target/xfail SELECTOR }]'
- Passes if REGEX does not match demangled text in the dump
- file with suffix SUFFIX.
-
- `output-exists [{ target/xfail SELECTOR }]'
- Passes if compiler output file exists.
-
- `output-exists-not [{ target/xfail SELECTOR }]'
- Passes if compiler output file does not exist.
-
- `run-gcov SOURCEFILE'
- Check line counts in `gcov' tests.
-
- `run-gcov [branches] [calls] { OPTS SOURCEFILE }'
- Check branch and/or call counts, in addition to line counts,
- in `gcov' tests.
-
-\1f
-File: gccint.info, Node: Ada Tests, Next: C Tests, Prev: Test Directives, Up: Testsuites
-
-6.4.3 Ada Language Testsuites
------------------------------
-
-The Ada testsuite includes executable tests from the ACATS 2.5
-testsuite, publicly available at
-`http://www.adaic.org/compilers/acats/2.5'
-
- These tests are integrated in the GCC testsuite in the
-`gcc/testsuite/ada/acats' directory, and enabled automatically when
-running `make check', assuming the Ada language has been enabled when
-configuring GCC.
-
- You can also run the Ada testsuite independently, using `make
-check-ada', or run a subset of the tests by specifying which chapter to
-run, e.g.:
-
- $ make check-ada CHAPTERS="c3 c9"
-
- The tests are organized by directory, each directory corresponding to
-a chapter of the Ada Reference Manual. So for example, c9 corresponds
-to chapter 9, which deals with tasking features of the language.
-
- There is also an extra chapter called `gcc' containing a template for
-creating new executable tests.
-
- The tests are run using two `sh' scripts: `run_acats' and
-`run_all.sh'. To run the tests using a simulator or a cross target,
-see the small customization section at the top of `run_all.sh'.
-
- These tests are run using the build tree: they can be run without doing
-a `make install'.
-
-\1f
-File: gccint.info, Node: C Tests, Next: libgcj Tests, Prev: Ada Tests, Up: Testsuites
-
-6.4.4 C Language Testsuites
----------------------------
-
-GCC contains the following C language testsuites, in the
-`gcc/testsuite' directory:
-
-`gcc.dg'
- This contains tests of particular features of the C compiler,
- using the more modern `dg' harness. Correctness tests for various
- compiler features should go here if possible.
-
- Magic comments determine whether the file is preprocessed,
- compiled, linked or run. In these tests, error and warning
- message texts are compared against expected texts or regular
- expressions given in comments. These tests are run with the
- options `-ansi -pedantic' unless other options are given in the
- test. Except as noted below they are not run with multiple
- optimization options.
-
-`gcc.dg/compat'
- This subdirectory contains tests for binary compatibility using
- `compat.exp', which in turn uses the language-independent support
- (*note Support for testing binary compatibility: compat Testing.).
-
-`gcc.dg/cpp'
- This subdirectory contains tests of the preprocessor.
-
-`gcc.dg/debug'
- This subdirectory contains tests for debug formats. Tests in this
- subdirectory are run for each debug format that the compiler
- supports.
-
-`gcc.dg/format'
- This subdirectory contains tests of the `-Wformat' format
- checking. Tests in this directory are run with and without
- `-DWIDE'.
-
-`gcc.dg/noncompile'
- This subdirectory contains tests of code that should not compile
- and does not need any special compilation options. They are run
- with multiple optimization options, since sometimes invalid code
- crashes the compiler with optimization.
-
-`gcc.dg/special'
- FIXME: describe this.
-
-`gcc.c-torture'
- This contains particular code fragments which have historically
- broken easily. These tests are run with multiple optimization
- options, so tests for features which only break at some
- optimization levels belong here. This also contains tests to
- check that certain optimizations occur. It might be worthwhile to
- separate the correctness tests cleanly from the code quality
- tests, but it hasn't been done yet.
-
-`gcc.c-torture/compat'
- FIXME: describe this.
-
- This directory should probably not be used for new tests.
-
-`gcc.c-torture/compile'
- This testsuite contains test cases that should compile, but do not
- need to link or run. These test cases are compiled with several
- different combinations of optimization options. All warnings are
- disabled for these test cases, so this directory is not suitable if
- you wish to test for the presence or absence of compiler warnings.
- While special options can be set, and tests disabled on specific
- platforms, by the use of `.x' files, mostly these test cases
- should not contain platform dependencies. FIXME: discuss how
- defines such as `NO_LABEL_VALUES' and `STACK_SIZE' are used.
-
-`gcc.c-torture/execute'
- This testsuite contains test cases that should compile, link and
- run; otherwise the same comments as for `gcc.c-torture/compile'
- apply.
-
-`gcc.c-torture/execute/ieee'
- This contains tests which are specific to IEEE floating point.
-
-`gcc.c-torture/unsorted'
- FIXME: describe this.
-
- This directory should probably not be used for new tests.
-
-`gcc.c-torture/misc-tests'
- This directory contains C tests that require special handling.
- Some of these tests have individual expect files, and others share
- special-purpose expect files:
-
- ``bprob*.c''
- Test `-fbranch-probabilities' using `bprob.exp', which in
- turn uses the generic, language-independent framework (*note
- Support for testing profile-directed optimizations: profopt
- Testing.).
-
- ``dg-*.c''
- Test the testsuite itself using `dg-test.exp'.
-
- ``gcov*.c''
- Test `gcov' output using `gcov.exp', which in turn uses the
- language-independent support (*note Support for testing gcov:
- gcov Testing.).
-
- ``i386-pf-*.c''
- Test i386-specific support for data prefetch using
- `i386-prefetch.exp'.
-
-
- FIXME: merge in `testsuite/README.gcc' and discuss the format of test
-cases and magic comments more.
-
-\1f
-File: gccint.info, Node: libgcj Tests, Next: gcov Testing, Prev: C Tests, Up: Testsuites
-
-6.4.5 The Java library testsuites.
-----------------------------------
-
-Runtime tests are executed via `make check' in the
-`TARGET/libjava/testsuite' directory in the build tree. Additional
-runtime tests can be checked into this testsuite.
-
- Regression testing of the core packages in libgcj is also covered by
-the Mauve testsuite. The Mauve Project develops tests for the Java
-Class Libraries. These tests are run as part of libgcj testing by
-placing the Mauve tree within the libjava testsuite sources at
-`libjava/testsuite/libjava.mauve/mauve', or by specifying the location
-of that tree when invoking `make', as in `make MAUVEDIR=~/mauve check'.
-
- To detect regressions, a mechanism in `mauve.exp' compares the
-failures for a test run against the list of expected failures in
-`libjava/testsuite/libjava.mauve/xfails' from the source hierarchy.
-Update this file when adding new failing tests to Mauve, or when fixing
-bugs in libgcj that had caused Mauve test failures.
-
- We encourage developers to contribute test cases to Mauve.
-
-\1f
-File: gccint.info, Node: gcov Testing, Next: profopt Testing, Prev: libgcj Tests, Up: Testsuites
-
-6.4.6 Support for testing `gcov'
---------------------------------
-
-Language-independent support for testing `gcov', and for checking that
-branch profiling produces expected values, is provided by the expect
-file `gcov.exp'. `gcov' tests also rely on procedures in `gcc.dg.exp'
-to compile and run the test program. A typical `gcov' test contains
-the following DejaGnu commands within comments:
-
- { dg-options "-fprofile-arcs -ftest-coverage" }
- { dg-do run { target native } }
- { dg-final { run-gcov sourcefile } }
-
- Checks of `gcov' output can include line counts, branch percentages,
-and call return percentages. All of these checks are requested via
-commands that appear in comments in the test's source file. Commands
-to check line counts are processed by default. Commands to check
-branch percentages and call return percentages are processed if the
-`run-gcov' command has arguments `branches' or `calls', respectively.
-For example, the following specifies checking both, as well as passing
-`-b' to `gcov':
-
- { dg-final { run-gcov branches calls { -b sourcefile } } }
-
- A line count command appears within a comment on the source line that
-is expected to get the specified count and has the form `count(CNT)'.
-A test should only check line counts for lines that will get the same
-count for any architecture.
-
- Commands to check branch percentages (`branch') and call return
-percentages (`returns') are very similar to each other. A beginning
-command appears on or before the first of a range of lines that will
-report the percentage, and the ending command follows that range of
-lines. The beginning command can include a list of percentages, all of
-which are expected to be found within the range. A range is terminated
-by the next command of the same kind. A command `branch(end)' or
-`returns(end)' marks the end of a range without starting a new one.
-For example:
-
- if (i > 10 && j > i && j < 20) /* branch(27 50 75) */
- /* branch(end) */
- foo (i, j);
-
- For a call return percentage, the value specified is the percentage of
-calls reported to return. For a branch percentage, the value is either
-the expected percentage or 100 minus that value, since the direction of
-a branch can differ depending on the target or the optimization level.
-
- Not all branches and calls need to be checked. A test should not
-check for branches that might be optimized away or replaced with
-predicated instructions. Don't check for calls inserted by the
-compiler or ones that might be inlined or optimized away.
-
- A single test can check for combinations of line counts, branch
-percentages, and call return percentages. The command to check a line
-count must appear on the line that will report that count, but commands
-to check branch percentages and call return percentages can bracket the
-lines that report them.
-
-\1f
-File: gccint.info, Node: profopt Testing, Next: compat Testing, Prev: gcov Testing, Up: Testsuites
-
-6.4.7 Support for testing profile-directed optimizations
---------------------------------------------------------
-
-The file `profopt.exp' provides language-independent support for
-checking correct execution of a test built with profile-directed
-optimization. This testing requires that a test program be built and
-executed twice. The first time it is compiled to generate profile
-data, and the second time it is compiled to use the data that was
-generated during the first execution. The second execution is to
-verify that the test produces the expected results.
-
- To check that the optimization actually generated better code, a test
-can be built and run a third time with normal optimizations to verify
-that the performance is better with the profile-directed optimizations.
-`profopt.exp' has the beginnings of this kind of support.
-
- `profopt.exp' provides generic support for profile-directed
-optimizations. Each set of tests that uses it provides information
-about a specific optimization:
-
-`tool'
- tool being tested, e.g., `gcc'
-
-`profile_option'
- options used to generate profile data
-
-`feedback_option'
- options used to optimize using that profile data
-
-`prof_ext'
- suffix of profile data files
-
-`PROFOPT_OPTIONS'
- list of options with which to run each test, similar to the lists
- for torture tests
-
-\1f
-File: gccint.info, Node: compat Testing, Next: Torture Tests, Prev: profopt Testing, Up: Testsuites
-
-6.4.8 Support for testing binary compatibility
-----------------------------------------------
-
-The file `compat.exp' provides language-independent support for binary
-compatibility testing. It supports testing interoperability of two
-compilers that follow the same ABI, or of multiple sets of compiler
-options that should not affect binary compatibility. It is intended to
-be used for testsuites that complement ABI testsuites.
-
- A test supported by this framework has three parts, each in a separate
-source file: a main program and two pieces that interact with each
-other to split up the functionality being tested.
-
-`TESTNAME_main.SUFFIX'
- Contains the main program, which calls a function in file
- `TESTNAME_x.SUFFIX'.
-
-`TESTNAME_x.SUFFIX'
- Contains at least one call to a function in `TESTNAME_y.SUFFIX'.
-
-`TESTNAME_y.SUFFIX'
- Shares data with, or gets arguments from, `TESTNAME_x.SUFFIX'.
-
- Within each test, the main program and one functional piece are
-compiled by the GCC under test. The other piece can be compiled by an
-alternate compiler. If no alternate compiler is specified, then all
-three source files are all compiled by the GCC under test. You can
-specify pairs of sets of compiler options. The first element of such a
-pair specifies options used with the GCC under test, and the second
-element of the pair specifies options used with the alternate compiler.
-Each test is compiled with each pair of options.
-
- `compat.exp' defines default pairs of compiler options. These can be
-overridden by defining the environment variable `COMPAT_OPTIONS' as:
-
- COMPAT_OPTIONS="[list [list {TST1} {ALT1}]
- ...[list {TSTN} {ALTN}]]"
-
- where TSTI and ALTI are lists of options, with TSTI used by the
-compiler under test and ALTI used by the alternate compiler. For
-example, with `[list [list {-g -O0} {-O3}] [list {-fpic} {-fPIC -O2}]]',
-the test is first built with `-g -O0' by the compiler under test and
-with `-O3' by the alternate compiler. The test is built a second time
-using `-fpic' by the compiler under test and `-fPIC -O2' by the
-alternate compiler.
-
- An alternate compiler is specified by defining an environment variable
-to be the full pathname of an installed compiler; for C define
-`ALT_CC_UNDER_TEST', and for C++ define `ALT_CXX_UNDER_TEST'. These
-will be written to the `site.exp' file used by DejaGnu. The default is
-to build each test with the compiler under test using the first of each
-pair of compiler options from `COMPAT_OPTIONS'. When
-`ALT_CC_UNDER_TEST' or `ALT_CXX_UNDER_TEST' is `same', each test is
-built using the compiler under test but with combinations of the
-options from `COMPAT_OPTIONS'.
-
- To run only the C++ compatibility suite using the compiler under test
-and another version of GCC using specific compiler options, do the
-following from `OBJDIR/gcc':
-
- rm site.exp
- make -k \
- ALT_CXX_UNDER_TEST=${alt_prefix}/bin/g++ \
- COMPAT_OPTIONS="lists as shown above" \
- check-c++ \
- RUNTESTFLAGS="compat.exp"
-
- A test that fails when the source files are compiled with different
-compilers, but passes when the files are compiled with the same
-compiler, demonstrates incompatibility of the generated code or runtime
-support. A test that fails for the alternate compiler but passes for
-the compiler under test probably tests for a bug that was fixed in the
-compiler under test but is present in the alternate compiler.
-
- The binary compatibility tests support a small number of test framework
-commands that appear within comments in a test file.
-
-`dg-require-*'
- These commands can be used in `TESTNAME_main.SUFFIX' to skip the
- test if specific support is not available on the target.
-
-`dg-options'
- The specified options are used for compiling this particular source
- file, appended to the options from `COMPAT_OPTIONS'. When this
- command appears in `TESTNAME_main.SUFFIX' the options are also
- used to link the test program.
-
-`dg-xfail-if'
- This command can be used in a secondary source file to specify that
- compilation is expected to fail for particular options on
- particular targets.
-
-\1f
-File: gccint.info, Node: Torture Tests, Prev: compat Testing, Up: Testsuites
-
-6.4.9 Support for torture testing using multiple options
---------------------------------------------------------
-
-Throughout the compiler testsuite there are several directories whose
-tests are run multiple times, each with a different set of options.
-These are known as torture tests.
-`gcc/testsuite/lib/torture-options.exp' defines procedures to set up
-these lists:
-
-`torture-init'
- Initialize use of torture lists.
-
-`set-torture-options'
- Set lists of torture options to use for tests with and without
- loops. Optionally combine a set of torture options with a set of
- other options, as is done with Objective-C runtime options.
-
-`torture-finish'
- Finalize use of torture lists.
-
- The `.exp' file for a set of tests that use torture options must
-include calls to these three procedures if:
-
- * It calls `gcc-dg-runtest' and overrides DG_TORTURE_OPTIONS.
-
- * It calls ${TOOL}`-torture' or ${TOOL}`-torture-execute', where
- TOOL is `c', `fortran', or `objc'.
-
- * It calls `dg-pch'.
-
- It is not necessary for a `.exp' file that calls `gcc-dg-runtest' to
-call the torture procedures if the tests should use the list in
-DG_TORTURE_OPTIONS defined in `gcc-dg.exp'.
-
- Most uses of torture options can override the default lists by defining
-TORTURE_OPTIONS or add to the default list by defining
-ADDITIONAL_TORTURE_OPTIONS. Define these in a `.dejagnurc' file or add
-them to the `site.exp' file; for example
-
- set ADDITIONAL_TORTURE_OPTIONS [list \
- { -O2 -ftree-loop-linear } \
- { -O2 -fpeel-loops } ]
-
-\1f
-File: gccint.info, Node: Options, Next: Passes, Prev: Source Tree, Up: Top
-
-7 Option specification files
-****************************
-
-Most GCC command-line options are described by special option
-definition files, the names of which conventionally end in `.opt'.
-This chapter describes the format of these files.
-
-* Menu:
-
-* Option file format:: The general layout of the files
-* Option properties:: Supported option properties
-
-\1f
-File: gccint.info, Node: Option file format, Next: Option properties, Up: Options
-
-7.1 Option file format
-======================
-
-Option files are a simple list of records in which each field occupies
-its own line and in which the records themselves are separated by blank
-lines. Comments may appear on their own line anywhere within the file
-and are preceded by semicolons. Whitespace is allowed before the
-semicolon.
-
- The files can contain the following types of record:
-
- * A language definition record. These records have two fields: the
- string `Language' and the name of the language. Once a language
- has been declared in this way, it can be used as an option
- property. *Note Option properties::.
-
- * A target specific save record to save additional information. These
- records have two fields: the string `TargetSave', and a
- declaration type to go in the `cl_target_option' structure.
-
- * An option definition record. These records have the following
- fields:
- 1. the name of the option, with the leading "-" removed
-
- 2. a space-separated list of option properties (*note Option
- properties::)
-
- 3. the help text to use for `--help' (omitted if the second field
- contains the `Undocumented' property).
-
- By default, all options beginning with "f", "W" or "m" are
- implicitly assumed to take a "no-" form. This form should not be
- listed separately. If an option beginning with one of these
- letters does not have a "no-" form, you can use the
- `RejectNegative' property to reject it.
-
- The help text is automatically line-wrapped before being displayed.
- Normally the name of the option is printed on the left-hand side of
- the output and the help text is printed on the right. However, if
- the help text contains a tab character, the text to the left of
- the tab is used instead of the option's name and the text to the
- right of the tab forms the help text. This allows you to
- elaborate on what type of argument the option takes.
-
- * A target mask record. These records have one field of the form
- `Mask(X)'. The options-processing script will automatically
- allocate a bit in `target_flags' (*note Run-time Target::) for
- each mask name X and set the macro `MASK_X' to the appropriate
- bitmask. It will also declare a `TARGET_X' macro that has the
- value 1 when bit `MASK_X' is set and 0 otherwise.
-
- They are primarily intended to declare target masks that are not
- associated with user options, either because these masks represent
- internal switches or because the options are not available on all
- configurations and yet the masks always need to be defined.
-
-\1f
-File: gccint.info, Node: Option properties, Prev: Option file format, Up: Options
-
-7.2 Option properties
-=====================
-
-The second field of an option record can specify the following
-properties:
-
-`Common'
- The option is available for all languages and targets.
-
-`Target'
- The option is available for all languages but is target-specific.
-
-`LANGUAGE'
- The option is available when compiling for the given language.
-
- It is possible to specify several different languages for the same
- option. Each LANGUAGE must have been declared by an earlier
- `Language' record. *Note Option file format::.
-
-`RejectNegative'
- The option does not have a "no-" form. All options beginning with
- "f", "W" or "m" are assumed to have a "no-" form unless this
- property is used.
-
-`Negative(OTHERNAME)'
- The option will turn off another option OTHERNAME, which is the
- the option name with the leading "-" removed. This chain action
- will propagate through the `Negative' property of the option to be
- turned off.
-
-`Joined'
-`Separate'
- The option takes a mandatory argument. `Joined' indicates that
- the option and argument can be included in the same `argv' entry
- (as with `-mflush-func=NAME', for example). `Separate' indicates
- that the option and argument can be separate `argv' entries (as
- with `-o'). An option is allowed to have both of these properties.
-
-`JoinedOrMissing'
- The option takes an optional argument. If the argument is given,
- it will be part of the same `argv' entry as the option itself.
-
- This property cannot be used alongside `Joined' or `Separate'.
-
-`UInteger'
- The option's argument is a non-negative integer. The option parser
- will check and convert the argument before passing it to the
- relevant option handler. `UInteger' should also be used on
- options like `-falign-loops' where both `-falign-loops' and
- `-falign-loops'=N are supported to make sure the saved options are
- given a full integer.
-
-`Var(VAR)'
- The state of this option should be stored in variable VAR. The
- way that the state is stored depends on the type of option:
-
- * If the option uses the `Mask' or `InverseMask' properties,
- VAR is the integer variable that contains the mask.
-
- * If the option is a normal on/off switch, VAR is an integer
- variable that is nonzero when the option is enabled. The
- options parser will set the variable to 1 when the positive
- form of the option is used and 0 when the "no-" form is used.
-
- * If the option takes an argument and has the `UInteger'
- property, VAR is an integer variable that stores the value of
- the argument.
-
- * Otherwise, if the option takes an argument, VAR is a pointer
- to the argument string. The pointer will be null if the
- argument is optional and wasn't given.
-
- The option-processing script will usually declare VAR in
- `options.c' and leave it to be zero-initialized at start-up time.
- You can modify this behavior using `VarExists' and `Init'.
-
-`Var(VAR, SET)'
- The option controls an integer variable VAR and is active when VAR
- equals SET. The option parser will set VAR to SET when the
- positive form of the option is used and `!SET' when the "no-" form
- is used.
-
- VAR is declared in the same way as for the single-argument form
- described above.
-
-`VarExists'
- The variable specified by the `Var' property already exists. No
- definition should be added to `options.c' in response to this
- option record.
-
- You should use this property only if the variable is declared
- outside `options.c'.
-
-`Init(VALUE)'
- The variable specified by the `Var' property should be statically
- initialized to VALUE.
-
-`Mask(NAME)'
- The option is associated with a bit in the `target_flags' variable
- (*note Run-time Target::) and is active when that bit is set. You
- may also specify `Var' to select a variable other than
- `target_flags'.
-
- The options-processing script will automatically allocate a unique
- bit for the option. If the option is attached to `target_flags',
- the script will set the macro `MASK_NAME' to the appropriate
- bitmask. It will also declare a `TARGET_NAME' macro that has the
- value 1 when the option is active and 0 otherwise. If you use
- `Var' to attach the option to a different variable, the associated
- macros are called `OPTION_MASK_NAME' and `OPTION_NAME'
- respectively.
-
- You can disable automatic bit allocation using `MaskExists'.
-
-`InverseMask(OTHERNAME)'
-`InverseMask(OTHERNAME, THISNAME)'
- The option is the inverse of another option that has the
- `Mask(OTHERNAME)' property. If THISNAME is given, the
- options-processing script will declare a `TARGET_THISNAME' macro
- that is 1 when the option is active and 0 otherwise.
-
-`MaskExists'
- The mask specified by the `Mask' property already exists. No
- `MASK' or `TARGET' definitions should be added to `options.h' in
- response to this option record.
-
- The main purpose of this property is to support synonymous options.
- The first option should use `Mask(NAME)' and the others should use
- `Mask(NAME) MaskExists'.
-
-`Report'
- The state of the option should be printed by `-fverbose-asm'.
-
-`Undocumented'
- The option is deliberately missing documentation and should not be
- included in the `--help' output.
-
-`Condition(COND)'
- The option should only be accepted if preprocessor condition COND
- is true. Note that any C declarations associated with the option
- will be present even if COND is false; COND simply controls
- whether the option is accepted and whether it is printed in the
- `--help' output.
-
-`Save'
- Build the `cl_target_option' structure to hold a copy of the
- option, add the functions `cl_target_option_save' and
- `cl_target_option_restore' to save and restore the options.
-
-\1f
-File: gccint.info, Node: Passes, Next: Trees, Prev: Options, Up: Top
-
-8 Passes and Files of the Compiler
-**********************************
-
-This chapter is dedicated to giving an overview of the optimization and
-code generation passes of the compiler. In the process, it describes
-some of the language front end interface, though this description is no
-where near complete.
-
-* Menu:
-
-* Parsing pass:: The language front end turns text into bits.
-* Gimplification pass:: The bits are turned into something we can optimize.
-* Pass manager:: Sequencing the optimization passes.
-* Tree SSA passes:: Optimizations on a high-level representation.
-* RTL passes:: Optimizations on a low-level representation.
-
-\1f
-File: gccint.info, Node: Parsing pass, Next: Gimplification pass, Up: Passes
-
-8.1 Parsing pass
-================
-
-The language front end is invoked only once, via
-`lang_hooks.parse_file', to parse the entire input. The language front
-end may use any intermediate language representation deemed
-appropriate. The C front end uses GENERIC trees (CROSSREF), plus a
-double handful of language specific tree codes defined in
-`c-common.def'. The Fortran front end uses a completely different
-private representation.
-
- At some point the front end must translate the representation used in
-the front end to a representation understood by the language-independent
-portions of the compiler. Current practice takes one of two forms.
-The C front end manually invokes the gimplifier (CROSSREF) on each
-function, and uses the gimplifier callbacks to convert the
-language-specific tree nodes directly to GIMPLE (CROSSREF) before
-passing the function off to be compiled. The Fortran front end
-converts from a private representation to GENERIC, which is later
-lowered to GIMPLE when the function is compiled. Which route to choose
-probably depends on how well GENERIC (plus extensions) can be made to
-match up with the source language and necessary parsing data structures.
-
- BUG: Gimplification must occur before nested function lowering, and
-nested function lowering must be done by the front end before passing
-the data off to cgraph.
-
- TODO: Cgraph should control nested function lowering. It would only
-be invoked when it is certain that the outer-most function is used.
-
- TODO: Cgraph needs a gimplify_function callback. It should be invoked
-when (1) it is certain that the function is used, (2) warning flags
-specified by the user require some amount of compilation in order to
-honor, (3) the language indicates that semantic analysis is not
-complete until gimplification occurs. Hum... this sounds overly
-complicated. Perhaps we should just have the front end gimplify
-always; in most cases it's only one function call.
-
- The front end needs to pass all function definitions and top level
-declarations off to the middle-end so that they can be compiled and
-emitted to the object file. For a simple procedural language, it is
-usually most convenient to do this as each top level declaration or
-definition is seen. There is also a distinction to be made between
-generating functional code and generating complete debug information.
-The only thing that is absolutely required for functional code is that
-function and data _definitions_ be passed to the middle-end. For
-complete debug information, function, data and type declarations should
-all be passed as well.
-
- In any case, the front end needs each complete top-level function or
-data declaration, and each data definition should be passed to
-`rest_of_decl_compilation'. Each complete type definition should be
-passed to `rest_of_type_compilation'. Each function definition should
-be passed to `cgraph_finalize_function'.
-
- TODO: I know rest_of_compilation currently has all sorts of RTL
-generation semantics. I plan to move all code generation bits (both
-Tree and RTL) to compile_function. Should we hide cgraph from the
-front ends and move back to rest_of_compilation as the official
-interface? Possibly we should rename all three interfaces such that
-the names match in some meaningful way and that is more descriptive
-than "rest_of".
-
- The middle-end will, at its option, emit the function and data
-definitions immediately or queue them for later processing.
-
-\1f
-File: gccint.info, Node: Gimplification pass, Next: Pass manager, Prev: Parsing pass, Up: Passes
-
-8.2 Gimplification pass
-=======================
-
-"Gimplification" is a whimsical term for the process of converting the
-intermediate representation of a function into the GIMPLE language
-(CROSSREF). The term stuck, and so words like "gimplification",
-"gimplify", "gimplifier" and the like are sprinkled throughout this
-section of code.
-
- While a front end may certainly choose to generate GIMPLE directly if
-it chooses, this can be a moderately complex process unless the
-intermediate language used by the front end is already fairly simple.
-Usually it is easier to generate GENERIC trees plus extensions and let
-the language-independent gimplifier do most of the work.
-
- The main entry point to this pass is `gimplify_function_tree' located
-in `gimplify.c'. From here we process the entire function gimplifying
-each statement in turn. The main workhorse for this pass is
-`gimplify_expr'. Approximately everything passes through here at least
-once, and it is from here that we invoke the `lang_hooks.gimplify_expr'
-callback.
-
- The callback should examine the expression in question and return
-`GS_UNHANDLED' if the expression is not a language specific construct
-that requires attention. Otherwise it should alter the expression in
-some way to such that forward progress is made toward producing valid
-GIMPLE. If the callback is certain that the transformation is complete
-and the expression is valid GIMPLE, it should return `GS_ALL_DONE'.
-Otherwise it should return `GS_OK', which will cause the expression to
-be processed again. If the callback encounters an error during the
-transformation (because the front end is relying on the gimplification
-process to finish semantic checks), it should return `GS_ERROR'.
-
-\1f
-File: gccint.info, Node: Pass manager, Next: Tree SSA passes, Prev: Gimplification pass, Up: Passes
-
-8.3 Pass manager
-================
-
-The pass manager is located in `passes.c', `tree-optimize.c' and
-`tree-pass.h'. Its job is to run all of the individual passes in the
-correct order, and take care of standard bookkeeping that applies to
-every pass.
-
- The theory of operation is that each pass defines a structure that
-represents everything we need to know about that pass--when it should
-be run, how it should be run, what intermediate language form or
-on-the-side data structures it needs. We register the pass to be run
-in some particular order, and the pass manager arranges for everything
-to happen in the correct order.
-
- The actuality doesn't completely live up to the theory at present.
-Command-line switches and `timevar_id_t' enumerations must still be
-defined elsewhere. The pass manager validates constraints but does not
-attempt to (re-)generate data structures or lower intermediate language
-form based on the requirements of the next pass. Nevertheless, what is
-present is useful, and a far sight better than nothing at all.
-
- Each pass may have its own dump file (for GCC debugging purposes).
-Passes without any names, or with a name starting with a star, do not
-dump anything.
-
- TODO: describe the global variables set up by the pass manager, and a
-brief description of how a new pass should use it. I need to look at
-what info RTL passes use first...
-
-\1f
-File: gccint.info, Node: Tree SSA passes, Next: RTL passes, Prev: Pass manager, Up: Passes
-
-8.4 Tree SSA passes
-===================
-
-The following briefly describes the Tree optimization passes that are
-run after gimplification and what source files they are located in.
-
- * Remove useless statements
-
- This pass is an extremely simple sweep across the gimple code in
- which we identify obviously dead code and remove it. Here we do
- things like simplify `if' statements with constant conditions,
- remove exception handling constructs surrounding code that
- obviously cannot throw, remove lexical bindings that contain no
- variables, and other assorted simplistic cleanups. The idea is to
- get rid of the obvious stuff quickly rather than wait until later
- when it's more work to get rid of it. This pass is located in
- `tree-cfg.c' and described by `pass_remove_useless_stmts'.
-
- * Mudflap declaration registration
-
- If mudflap (*note -fmudflap -fmudflapth -fmudflapir: (gcc)Optimize
- Options.) is enabled, we generate code to register some variable
- declarations with the mudflap runtime. Specifically, the runtime
- tracks the lifetimes of those variable declarations that have
- their addresses taken, or whose bounds are unknown at compile time
- (`extern'). This pass generates new exception handling constructs
- (`try'/`finally'), and so must run before those are lowered. In
- addition, the pass enqueues declarations of static variables whose
- lifetimes extend to the entire program. The pass is located in
- `tree-mudflap.c' and is described by `pass_mudflap_1'.
-
- * OpenMP lowering
-
- If OpenMP generation (`-fopenmp') is enabled, this pass lowers
- OpenMP constructs into GIMPLE.
-
- Lowering of OpenMP constructs involves creating replacement
- expressions for local variables that have been mapped using data
- sharing clauses, exposing the control flow of most synchronization
- directives and adding region markers to facilitate the creation of
- the control flow graph. The pass is located in `omp-low.c' and is
- described by `pass_lower_omp'.
-
- * OpenMP expansion
-
- If OpenMP generation (`-fopenmp') is enabled, this pass expands
- parallel regions into their own functions to be invoked by the
- thread library. The pass is located in `omp-low.c' and is
- described by `pass_expand_omp'.
-
- * Lower control flow
-
- This pass flattens `if' statements (`COND_EXPR') and moves lexical
- bindings (`BIND_EXPR') out of line. After this pass, all `if'
- statements will have exactly two `goto' statements in its `then'
- and `else' arms. Lexical binding information for each statement
- will be found in `TREE_BLOCK' rather than being inferred from its
- position under a `BIND_EXPR'. This pass is found in
- `gimple-low.c' and is described by `pass_lower_cf'.
-
- * Lower exception handling control flow
-
- This pass decomposes high-level exception handling constructs
- (`TRY_FINALLY_EXPR' and `TRY_CATCH_EXPR') into a form that
- explicitly represents the control flow involved. After this pass,
- `lookup_stmt_eh_region' will return a non-negative number for any
- statement that may have EH control flow semantics; examine
- `tree_can_throw_internal' or `tree_can_throw_external' for exact
- semantics. Exact control flow may be extracted from
- `foreach_reachable_handler'. The EH region nesting tree is defined
- in `except.h' and built in `except.c'. The lowering pass itself
- is in `tree-eh.c' and is described by `pass_lower_eh'.
-
- * Build the control flow graph
-
- This pass decomposes a function into basic blocks and creates all
- of the edges that connect them. It is located in `tree-cfg.c' and
- is described by `pass_build_cfg'.
-
- * Find all referenced variables
-
- This pass walks the entire function and collects an array of all
- variables referenced in the function, `referenced_vars'. The
- index at which a variable is found in the array is used as a UID
- for the variable within this function. This data is needed by the
- SSA rewriting routines. The pass is located in `tree-dfa.c' and
- is described by `pass_referenced_vars'.
-
- * Enter static single assignment form
-
- This pass rewrites the function such that it is in SSA form. After
- this pass, all `is_gimple_reg' variables will be referenced by
- `SSA_NAME', and all occurrences of other variables will be
- annotated with `VDEFS' and `VUSES'; PHI nodes will have been
- inserted as necessary for each basic block. This pass is located
- in `tree-ssa.c' and is described by `pass_build_ssa'.
-
- * Warn for uninitialized variables
-
- This pass scans the function for uses of `SSA_NAME's that are fed
- by default definition. For non-parameter variables, such uses are
- uninitialized. The pass is run twice, before and after
- optimization (if turned on). In the first pass we only warn for
- uses that are positively uninitialized; in the second pass we warn
- for uses that are possibly uninitialized. The pass is located in
- `tree-ssa.c' and is defined by `pass_early_warn_uninitialized' and
- `pass_late_warn_uninitialized'.
-
- * Dead code elimination
-
- This pass scans the function for statements without side effects
- whose result is unused. It does not do memory life analysis, so
- any value that is stored in memory is considered used. The pass
- is run multiple times throughout the optimization process. It is
- located in `tree-ssa-dce.c' and is described by `pass_dce'.
-
- * Dominator optimizations
-
- This pass performs trivial dominator-based copy and constant
- propagation, expression simplification, and jump threading. It is
- run multiple times throughout the optimization process. It it
- located in `tree-ssa-dom.c' and is described by `pass_dominator'.
-
- * Forward propagation of single-use variables
-
- This pass attempts to remove redundant computation by substituting
- variables that are used once into the expression that uses them and
- seeing if the result can be simplified. It is located in
- `tree-ssa-forwprop.c' and is described by `pass_forwprop'.
-
- * Copy Renaming
-
- This pass attempts to change the name of compiler temporaries
- involved in copy operations such that SSA->normal can coalesce the
- copy away. When compiler temporaries are copies of user
- variables, it also renames the compiler temporary to the user
- variable resulting in better use of user symbols. It is located
- in `tree-ssa-copyrename.c' and is described by `pass_copyrename'.
-
- * PHI node optimizations
-
- This pass recognizes forms of PHI inputs that can be represented as
- conditional expressions and rewrites them into straight line code.
- It is located in `tree-ssa-phiopt.c' and is described by
- `pass_phiopt'.
-
- * May-alias optimization
-
- This pass performs a flow sensitive SSA-based points-to analysis.
- The resulting may-alias, must-alias, and escape analysis
- information is used to promote variables from in-memory
- addressable objects to non-aliased variables that can be renamed
- into SSA form. We also update the `VDEF'/`VUSE' memory tags for
- non-renameable aggregates so that we get fewer false kills. The
- pass is located in `tree-ssa-alias.c' and is described by
- `pass_may_alias'.
-
- Interprocedural points-to information is located in
- `tree-ssa-structalias.c' and described by `pass_ipa_pta'.
-
- * Profiling
-
- This pass rewrites the function in order to collect runtime block
- and value profiling data. Such data may be fed back into the
- compiler on a subsequent run so as to allow optimization based on
- expected execution frequencies. The pass is located in
- `predict.c' and is described by `pass_profile'.
-
- * Lower complex arithmetic
-
- This pass rewrites complex arithmetic operations into their
- component scalar arithmetic operations. The pass is located in
- `tree-complex.c' and is described by `pass_lower_complex'.
-
- * Scalar replacement of aggregates
-
- This pass rewrites suitable non-aliased local aggregate variables
- into a set of scalar variables. The resulting scalar variables are
- rewritten into SSA form, which allows subsequent optimization
- passes to do a significantly better job with them. The pass is
- located in `tree-sra.c' and is described by `pass_sra'.
-
- * Dead store elimination
-
- This pass eliminates stores to memory that are subsequently
- overwritten by another store, without any intervening loads. The
- pass is located in `tree-ssa-dse.c' and is described by `pass_dse'.
-
- * Tail recursion elimination
-
- This pass transforms tail recursion into a loop. It is located in
- `tree-tailcall.c' and is described by `pass_tail_recursion'.
-
- * Forward store motion
-
- This pass sinks stores and assignments down the flowgraph closer
- to their use point. The pass is located in `tree-ssa-sink.c' and
- is described by `pass_sink_code'.
-
- * Partial redundancy elimination
-
- This pass eliminates partially redundant computations, as well as
- performing load motion. The pass is located in `tree-ssa-pre.c'
- and is described by `pass_pre'.
-
- Just before partial redundancy elimination, if
- `-funsafe-math-optimizations' is on, GCC tries to convert
- divisions to multiplications by the reciprocal. The pass is
- located in `tree-ssa-math-opts.c' and is described by
- `pass_cse_reciprocal'.
-
- * Full redundancy elimination
-
- This is a simpler form of PRE that only eliminates redundancies
- that occur an all paths. It is located in `tree-ssa-pre.c' and
- described by `pass_fre'.
-
- * Loop optimization
-
- The main driver of the pass is placed in `tree-ssa-loop.c' and
- described by `pass_loop'.
-
- The optimizations performed by this pass are:
-
- Loop invariant motion. This pass moves only invariants that would
- be hard to handle on RTL level (function calls, operations that
- expand to nontrivial sequences of insns). With `-funswitch-loops'
- it also moves operands of conditions that are invariant out of the
- loop, so that we can use just trivial invariantness analysis in
- loop unswitching. The pass also includes store motion. The pass
- is implemented in `tree-ssa-loop-im.c'.
-
- Canonical induction variable creation. This pass creates a simple
- counter for number of iterations of the loop and replaces the exit
- condition of the loop using it, in case when a complicated
- analysis is necessary to determine the number of iterations.
- Later optimizations then may determine the number easily. The
- pass is implemented in `tree-ssa-loop-ivcanon.c'.
-
- Induction variable optimizations. This pass performs standard
- induction variable optimizations, including strength reduction,
- induction variable merging and induction variable elimination.
- The pass is implemented in `tree-ssa-loop-ivopts.c'.
-
- Loop unswitching. This pass moves the conditional jumps that are
- invariant out of the loops. To achieve this, a duplicate of the
- loop is created for each possible outcome of conditional jump(s).
- The pass is implemented in `tree-ssa-loop-unswitch.c'. This pass
- should eventually replace the RTL level loop unswitching in
- `loop-unswitch.c', but currently the RTL level pass is not
- completely redundant yet due to deficiencies in tree level alias
- analysis.
-
- The optimizations also use various utility functions contained in
- `tree-ssa-loop-manip.c', `cfgloop.c', `cfgloopanal.c' and
- `cfgloopmanip.c'.
-
- Vectorization. This pass transforms loops to operate on vector
- types instead of scalar types. Data parallelism across loop
- iterations is exploited to group data elements from consecutive
- iterations into a vector and operate on them in parallel.
- Depending on available target support the loop is conceptually
- unrolled by a factor `VF' (vectorization factor), which is the
- number of elements operated upon in parallel in each iteration,
- and the `VF' copies of each scalar operation are fused to form a
- vector operation. Additional loop transformations such as peeling
- and versioning may take place to align the number of iterations,
- and to align the memory accesses in the loop. The pass is
- implemented in `tree-vectorizer.c' (the main driver and general
- utilities), `tree-vect-analyze.c' and `tree-vect-transform.c'.
- Analysis of data references is in `tree-data-ref.c'.
-
- Autoparallelization. This pass splits the loop iteration space to
- run into several threads. The pass is implemented in
- `tree-parloops.c'.
-
- * Tree level if-conversion for vectorizer
-
- This pass applies if-conversion to simple loops to help vectorizer.
- We identify if convertible loops, if-convert statements and merge
- basic blocks in one big block. The idea is to present loop in such
- form so that vectorizer can have one to one mapping between
- statements and available vector operations. This patch
- re-introduces COND_EXPR at GIMPLE level. This pass is located in
- `tree-if-conv.c' and is described by `pass_if_conversion'.
-
- * Conditional constant propagation
-
- This pass relaxes a lattice of values in order to identify those
- that must be constant even in the presence of conditional branches.
- The pass is located in `tree-ssa-ccp.c' and is described by
- `pass_ccp'.
-
- A related pass that works on memory loads and stores, and not just
- register values, is located in `tree-ssa-ccp.c' and described by
- `pass_store_ccp'.
-
- * Conditional copy propagation
-
- This is similar to constant propagation but the lattice of values
- is the "copy-of" relation. It eliminates redundant copies from the
- code. The pass is located in `tree-ssa-copy.c' and described by
- `pass_copy_prop'.
-
- A related pass that works on memory copies, and not just register
- copies, is located in `tree-ssa-copy.c' and described by
- `pass_store_copy_prop'.
-
- * Value range propagation
-
- This transformation is similar to constant propagation but instead
- of propagating single constant values, it propagates known value
- ranges. The implementation is based on Patterson's range
- propagation algorithm (Accurate Static Branch Prediction by Value
- Range Propagation, J. R. C. Patterson, PLDI '95). In contrast to
- Patterson's algorithm, this implementation does not propagate
- branch probabilities nor it uses more than a single range per SSA
- name. This means that the current implementation cannot be used
- for branch prediction (though adapting it would not be difficult).
- The pass is located in `tree-vrp.c' and is described by `pass_vrp'.
-
- * Folding built-in functions
-
- This pass simplifies built-in functions, as applicable, with
- constant arguments or with inferable string lengths. It is
- located in `tree-ssa-ccp.c' and is described by
- `pass_fold_builtins'.
-
- * Split critical edges
-
- This pass identifies critical edges and inserts empty basic blocks
- such that the edge is no longer critical. The pass is located in
- `tree-cfg.c' and is described by `pass_split_crit_edges'.
-
- * Control dependence dead code elimination
-
- This pass is a stronger form of dead code elimination that can
- eliminate unnecessary control flow statements. It is located in
- `tree-ssa-dce.c' and is described by `pass_cd_dce'.
-
- * Tail call elimination
-
- This pass identifies function calls that may be rewritten into
- jumps. No code transformation is actually applied here, but the
- data and control flow problem is solved. The code transformation
- requires target support, and so is delayed until RTL. In the
- meantime `CALL_EXPR_TAILCALL' is set indicating the possibility.
- The pass is located in `tree-tailcall.c' and is described by
- `pass_tail_calls'. The RTL transformation is handled by
- `fixup_tail_calls' in `calls.c'.
-
- * Warn for function return without value
-
- For non-void functions, this pass locates return statements that do
- not specify a value and issues a warning. Such a statement may
- have been injected by falling off the end of the function. This
- pass is run last so that we have as much time as possible to prove
- that the statement is not reachable. It is located in
- `tree-cfg.c' and is described by `pass_warn_function_return'.
-
- * Mudflap statement annotation
-
- If mudflap is enabled, we rewrite some memory accesses with code to
- validate that the memory access is correct. In particular,
- expressions involving pointer dereferences (`INDIRECT_REF',
- `ARRAY_REF', etc.) are replaced by code that checks the selected
- address range against the mudflap runtime's database of valid
- regions. This check includes an inline lookup into a
- direct-mapped cache, based on shift/mask operations of the pointer
- value, with a fallback function call into the runtime. The pass
- is located in `tree-mudflap.c' and is described by
- `pass_mudflap_2'.
-
- * Leave static single assignment form
-
- This pass rewrites the function such that it is in normal form. At
- the same time, we eliminate as many single-use temporaries as
- possible, so the intermediate language is no longer GIMPLE, but
- GENERIC. The pass is located in `tree-outof-ssa.c' and is
- described by `pass_del_ssa'.
-
- * Merge PHI nodes that feed into one another
-
- This is part of the CFG cleanup passes. It attempts to join PHI
- nodes from a forwarder CFG block into another block with PHI
- nodes. The pass is located in `tree-cfgcleanup.c' and is
- described by `pass_merge_phi'.
-
- * Return value optimization
-
- If a function always returns the same local variable, and that
- local variable is an aggregate type, then the variable is replaced
- with the return value for the function (i.e., the function's
- DECL_RESULT). This is equivalent to the C++ named return value
- optimization applied to GIMPLE. The pass is located in
- `tree-nrv.c' and is described by `pass_nrv'.
-
- * Return slot optimization
-
- If a function returns a memory object and is called as `var =
- foo()', this pass tries to change the call so that the address of
- `var' is sent to the caller to avoid an extra memory copy. This
- pass is located in `tree-nrv.c' and is described by
- `pass_return_slot'.
-
- * Optimize calls to `__builtin_object_size'
-
- This is a propagation pass similar to CCP that tries to remove
- calls to `__builtin_object_size' when the size of the object can be
- computed at compile-time. This pass is located in
- `tree-object-size.c' and is described by `pass_object_sizes'.
-
- * Loop invariant motion
-
- This pass removes expensive loop-invariant computations out of
- loops. The pass is located in `tree-ssa-loop.c' and described by
- `pass_lim'.
-
- * Loop nest optimizations
-
- This is a family of loop transformations that works on loop nests.
- It includes loop interchange, scaling, skewing and reversal and
- they are all geared to the optimization of data locality in array
- traversals and the removal of dependencies that hamper
- optimizations such as loop parallelization and vectorization. The
- pass is located in `tree-loop-linear.c' and described by
- `pass_linear_transform'.
-
- * Removal of empty loops
-
- This pass removes loops with no code in them. The pass is located
- in `tree-ssa-loop-ivcanon.c' and described by `pass_empty_loop'.
-
- * Unrolling of small loops
-
- This pass completely unrolls loops with few iterations. The pass
- is located in `tree-ssa-loop-ivcanon.c' and described by
- `pass_complete_unroll'.
-
- * Predictive commoning
-
- This pass makes the code reuse the computations from the previous
- iterations of the loops, especially loads and stores to memory.
- It does so by storing the values of these computations to a bank
- of temporary variables that are rotated at the end of loop. To
- avoid the need for this rotation, the loop is then unrolled and
- the copies of the loop body are rewritten to use the appropriate
- version of the temporary variable. This pass is located in
- `tree-predcom.c' and described by `pass_predcom'.
-
- * Array prefetching
-
- This pass issues prefetch instructions for array references inside
- loops. The pass is located in `tree-ssa-loop-prefetch.c' and
- described by `pass_loop_prefetch'.
-
- * Reassociation
-
- This pass rewrites arithmetic expressions to enable optimizations
- that operate on them, like redundancy elimination and
- vectorization. The pass is located in `tree-ssa-reassoc.c' and
- described by `pass_reassoc'.
-
- * Optimization of `stdarg' functions
-
- This pass tries to avoid the saving of register arguments into the
- stack on entry to `stdarg' functions. If the function doesn't use
- any `va_start' macros, no registers need to be saved. If
- `va_start' macros are used, the `va_list' variables don't escape
- the function, it is only necessary to save registers that will be
- used in `va_arg' macros. For instance, if `va_arg' is only used
- with integral types in the function, floating point registers
- don't need to be saved. This pass is located in `tree-stdarg.c'
- and described by `pass_stdarg'.
-
-
-\1f
-File: gccint.info, Node: RTL passes, Prev: Tree SSA passes, Up: Passes
-
-8.5 RTL passes
-==============
-
-The following briefly describes the RTL generation and optimization
-passes that are run after the Tree optimization passes.
-
- * RTL generation
-
- The source files for RTL generation include `stmt.c', `calls.c',
- `expr.c', `explow.c', `expmed.c', `function.c', `optabs.c' and
- `emit-rtl.c'. Also, the file `insn-emit.c', generated from the
- machine description by the program `genemit', is used in this
- pass. The header file `expr.h' is used for communication within
- this pass.
-
- The header files `insn-flags.h' and `insn-codes.h', generated from
- the machine description by the programs `genflags' and `gencodes',
- tell this pass which standard names are available for use and
- which patterns correspond to them.
-
- * Generation of exception landing pads
-
- This pass generates the glue that handles communication between the
- exception handling library routines and the exception handlers
- within the function. Entry points in the function that are
- invoked by the exception handling library are called "landing
- pads". The code for this pass is located in `except.c'.
-
- * Control flow graph cleanup
-
- This pass removes unreachable code, simplifies jumps to next,
- jumps to jump, jumps across jumps, etc. The pass is run multiple
- times. For historical reasons, it is occasionally referred to as
- the "jump optimization pass". The bulk of the code for this pass
- is in `cfgcleanup.c', and there are support routines in `cfgrtl.c'
- and `jump.c'.
-
- * Forward propagation of single-def values
-
- This pass attempts to remove redundant computation by substituting
- variables that come from a single definition, and seeing if the
- result can be simplified. It performs copy propagation and
- addressing mode selection. The pass is run twice, with values
- being propagated into loops only on the second run. The code is
- located in `fwprop.c'.
-
- * Common subexpression elimination
-
- This pass removes redundant computation within basic blocks, and
- optimizes addressing modes based on cost. The pass is run twice.
- The code for this pass is located in `cse.c'.
-
- * Global common subexpression elimination
-
- This pass performs two different types of GCSE depending on
- whether you are optimizing for size or not (LCM based GCSE tends
- to increase code size for a gain in speed, while Morel-Renvoise
- based GCSE does not). When optimizing for size, GCSE is done
- using Morel-Renvoise Partial Redundancy Elimination, with the
- exception that it does not try to move invariants out of
- loops--that is left to the loop optimization pass. If MR PRE
- GCSE is done, code hoisting (aka unification) is also done, as
- well as load motion. If you are optimizing for speed, LCM (lazy
- code motion) based GCSE is done. LCM is based on the work of
- Knoop, Ruthing, and Steffen. LCM based GCSE also does loop
- invariant code motion. We also perform load and store motion when
- optimizing for speed. Regardless of which type of GCSE is used,
- the GCSE pass also performs global constant and copy propagation.
- The source file for this pass is `gcse.c', and the LCM routines
- are in `lcm.c'.
-
- * Loop optimization
-
- This pass performs several loop related optimizations. The source
- files `cfgloopanal.c' and `cfgloopmanip.c' contain generic loop
- analysis and manipulation code. Initialization and finalization
- of loop structures is handled by `loop-init.c'. A loop invariant
- motion pass is implemented in `loop-invariant.c'. Basic block
- level optimizations--unrolling, peeling and unswitching loops--
- are implemented in `loop-unswitch.c' and `loop-unroll.c'.
- Replacing of the exit condition of loops by special
- machine-dependent instructions is handled by `loop-doloop.c'.
-
- * Jump bypassing
-
- This pass is an aggressive form of GCSE that transforms the control
- flow graph of a function by propagating constants into conditional
- branch instructions. The source file for this pass is `gcse.c'.
-
- * If conversion
-
- This pass attempts to replace conditional branches and surrounding
- assignments with arithmetic, boolean value producing comparison
- instructions, and conditional move instructions. In the very last
- invocation after reload, it will generate predicated instructions
- when supported by the target. The code is located in `ifcvt.c'.
-
- * Web construction
-
- This pass splits independent uses of each pseudo-register. This
- can improve effect of the other transformation, such as CSE or
- register allocation. The code for this pass is located in `web.c'.
-
- * Instruction combination
-
- This pass attempts to combine groups of two or three instructions
- that are related by data flow into single instructions. It
- combines the RTL expressions for the instructions by substitution,
- simplifies the result using algebra, and then attempts to match
- the result against the machine description. The code is located
- in `combine.c'.
-
- * Register movement
-
- This pass looks for cases where matching constraints would force an
- instruction to need a reload, and this reload would be a
- register-to-register move. It then attempts to change the
- registers used by the instruction to avoid the move instruction.
- The code is located in `regmove.c'.
-
- * Mode switching optimization
-
- This pass looks for instructions that require the processor to be
- in a specific "mode" and minimizes the number of mode changes
- required to satisfy all users. What these modes are, and what
- they apply to are completely target-specific. The code for this
- pass is located in `mode-switching.c'.
-
- * Modulo scheduling
-
- This pass looks at innermost loops and reorders their instructions
- by overlapping different iterations. Modulo scheduling is
- performed immediately before instruction scheduling. The code for
- this pass is located in `modulo-sched.c'.
-
- * Instruction scheduling
-
- This pass looks for instructions whose output will not be
- available by the time that it is used in subsequent instructions.
- Memory loads and floating point instructions often have this
- behavior on RISC machines. It re-orders instructions within a
- basic block to try to separate the definition and use of items
- that otherwise would cause pipeline stalls. This pass is
- performed twice, before and after register allocation. The code
- for this pass is located in `haifa-sched.c', `sched-deps.c',
- `sched-ebb.c', `sched-rgn.c' and `sched-vis.c'.
-
- * Register allocation
-
- These passes make sure that all occurrences of pseudo registers are
- eliminated, either by allocating them to a hard register, replacing
- them by an equivalent expression (e.g. a constant) or by placing
- them on the stack. This is done in several subpasses:
-
- * Register move optimizations. This pass makes some simple RTL
- code transformations which improve the subsequent register
- allocation. The source file is `regmove.c'.
-
- * The integrated register allocator (IRA). It is called
- integrated because coalescing, register live range splitting,
- and hard register preferencing are done on-the-fly during
- coloring. It also has better integration with the reload
- pass. Pseudo-registers spilled by the allocator or the
- reload have still a chance to get hard-registers if the
- reload evicts some pseudo-registers from hard-registers. The
- allocator helps to choose better pseudos for spilling based
- on their live ranges and to coalesce stack slots allocated
- for the spilled pseudo-registers. IRA is a regional register
- allocator which is transformed into Chaitin-Briggs allocator
- if there is one region. By default, IRA chooses regions using
- register pressure but the user can force it to use one region
- or regions corresponding to all loops.
-
- Source files of the allocator are `ira.c', `ira-build.c',
- `ira-costs.c', `ira-conflicts.c', `ira-color.c',
- `ira-emit.c', `ira-lives', plus header files `ira.h' and
- `ira-int.h' used for the communication between the allocator
- and the rest of the compiler and between the IRA files.
-
- * Reloading. This pass renumbers pseudo registers with the
- hardware registers numbers they were allocated. Pseudo
- registers that did not get hard registers are replaced with
- stack slots. Then it finds instructions that are invalid
- because a value has failed to end up in a register, or has
- ended up in a register of the wrong kind. It fixes up these
- instructions by reloading the problematical values
- temporarily into registers. Additional instructions are
- generated to do the copying.
-
- The reload pass also optionally eliminates the frame pointer
- and inserts instructions to save and restore call-clobbered
- registers around calls.
-
- Source files are `reload.c' and `reload1.c', plus the header
- `reload.h' used for communication between them.
-
- * Basic block reordering
-
- This pass implements profile guided code positioning. If profile
- information is not available, various types of static analysis are
- performed to make the predictions normally coming from the profile
- feedback (IE execution frequency, branch probability, etc). It is
- implemented in the file `bb-reorder.c', and the various prediction
- routines are in `predict.c'.
-
- * Variable tracking
-
- This pass computes where the variables are stored at each position
- in code and generates notes describing the variable locations to
- RTL code. The location lists are then generated according to these
- notes to debug information if the debugging information format
- supports location lists. The code is located in `var-tracking.c'.
-
- * Delayed branch scheduling
-
- This optional pass attempts to find instructions that can go into
- the delay slots of other instructions, usually jumps and calls.
- The code for this pass is located in `reorg.c'.
-
- * Branch shortening
-
- On many RISC machines, branch instructions have a limited range.
- Thus, longer sequences of instructions must be used for long
- branches. In this pass, the compiler figures out what how far
- each instruction will be from each other instruction, and
- therefore whether the usual instructions, or the longer sequences,
- must be used for each branch. The code for this pass is located
- in `final.c'.
-
- * Register-to-stack conversion
-
- Conversion from usage of some hard registers to usage of a register
- stack may be done at this point. Currently, this is supported only
- for the floating-point registers of the Intel 80387 coprocessor.
- The code for this pass is located in `reg-stack.c'.
-
- * Final
-
- This pass outputs the assembler code for the function. The source
- files are `final.c' plus `insn-output.c'; the latter is generated
- automatically from the machine description by the tool `genoutput'.
- The header file `conditions.h' is used for communication between
- these files. If mudflap is enabled, the queue of deferred
- declarations and any addressed constants (e.g., string literals)
- is processed by `mudflap_finish_file' into a synthetic constructor
- function containing calls into the mudflap runtime.
-
- * Debugging information output
-
- This is run after final because it must output the stack slot
- offsets for pseudo registers that did not get hard registers.
- Source files are `dbxout.c' for DBX symbol table format,
- `sdbout.c' for SDB symbol table format, `dwarfout.c' for DWARF
- symbol table format, files `dwarf2out.c' and `dwarf2asm.c' for
- DWARF2 symbol table format, and `vmsdbgout.c' for VMS debug symbol
- table format.
-
-
-\1f
-File: gccint.info, Node: Trees, Next: GENERIC, Prev: Passes, Up: Top
-
-9 Trees: The intermediate representation used by the C and C++ front ends
-*************************************************************************
-
-This chapter documents the internal representation used by GCC to
-represent C and C++ source programs. When presented with a C or C++
-source program, GCC parses the program, performs semantic analysis
-(including the generation of error messages), and then produces the
-internal representation described here. This representation contains a
-complete representation for the entire translation unit provided as
-input to the front end. This representation is then typically processed
-by a code-generator in order to produce machine code, but could also be
-used in the creation of source browsers, intelligent editors, automatic
-documentation generators, interpreters, and any other programs needing
-the ability to process C or C++ code.
-
- This chapter explains the internal representation. In particular, it
-documents the internal representation for C and C++ source constructs,
-and the macros, functions, and variables that can be used to access
-these constructs. The C++ representation is largely a superset of the
-representation used in the C front end. There is only one construct
-used in C that does not appear in the C++ front end and that is the GNU
-"nested function" extension. Many of the macros documented here do not
-apply in C because the corresponding language constructs do not appear
-in C.
-
- If you are developing a "back end", be it is a code-generator or some
-other tool, that uses this representation, you may occasionally find
-that you need to ask questions not easily answered by the functions and
-macros available here. If that situation occurs, it is quite likely
-that GCC already supports the functionality you desire, but that the
-interface is simply not documented here. In that case, you should ask
-the GCC maintainers (via mail to <gcc@gcc.gnu.org>) about documenting
-the functionality you require. Similarly, if you find yourself writing
-functions that do not deal directly with your back end, but instead
-might be useful to other people using the GCC front end, you should
-submit your patches for inclusion in GCC.
-
-* Menu:
-
-* Deficiencies:: Topics net yet covered in this document.
-* Tree overview:: All about `tree's.
-* Types:: Fundamental and aggregate types.
-* Scopes:: Namespaces and classes.
-* Functions:: Overloading, function bodies, and linkage.
-* Declarations:: Type declarations and variables.
-* Attributes:: Declaration and type attributes.
-* Expression trees:: From `typeid' to `throw'.
-
-\1f
-File: gccint.info, Node: Deficiencies, Next: Tree overview, Up: Trees
-
-9.1 Deficiencies
-================
-
-There are many places in which this document is incomplet and incorrekt.
-It is, as of yet, only _preliminary_ documentation.
-
-\1f
-File: gccint.info, Node: Tree overview, Next: Types, Prev: Deficiencies, Up: Trees
-
-9.2 Overview
-============
-
-The central data structure used by the internal representation is the
-`tree'. These nodes, while all of the C type `tree', are of many
-varieties. A `tree' is a pointer type, but the object to which it
-points may be of a variety of types. From this point forward, we will
-refer to trees in ordinary type, rather than in `this font', except
-when talking about the actual C type `tree'.
-
- You can tell what kind of node a particular tree is by using the
-`TREE_CODE' macro. Many, many macros take trees as input and return
-trees as output. However, most macros require a certain kind of tree
-node as input. In other words, there is a type-system for trees, but
-it is not reflected in the C type-system.
-
- For safety, it is useful to configure GCC with `--enable-checking'.
-Although this results in a significant performance penalty (since all
-tree types are checked at run-time), and is therefore inappropriate in a
-release version, it is extremely helpful during the development process.
-
- Many macros behave as predicates. Many, although not all, of these
-predicates end in `_P'. Do not rely on the result type of these macros
-being of any particular type. You may, however, rely on the fact that
-the type can be compared to `0', so that statements like
- if (TEST_P (t) && !TEST_P (y))
- x = 1;
- and
- int i = (TEST_P (t) != 0);
- are legal. Macros that return `int' values now may be changed to
-return `tree' values, or other pointers in the future. Even those that
-continue to return `int' may return multiple nonzero codes where
-previously they returned only zero and one. Therefore, you should not
-write code like
- if (TEST_P (t) == 1)
- as this code is not guaranteed to work correctly in the future.
-
- You should not take the address of values returned by the macros or
-functions described here. In particular, no guarantee is given that the
-values are lvalues.
-
- In general, the names of macros are all in uppercase, while the names
-of functions are entirely in lowercase. There are rare exceptions to
-this rule. You should assume that any macro or function whose name is
-made up entirely of uppercase letters may evaluate its arguments more
-than once. You may assume that a macro or function whose name is made
-up entirely of lowercase letters will evaluate its arguments only once.
-
- The `error_mark_node' is a special tree. Its tree code is
-`ERROR_MARK', but since there is only ever one node with that code, the
-usual practice is to compare the tree against `error_mark_node'. (This
-test is just a test for pointer equality.) If an error has occurred
-during front-end processing the flag `errorcount' will be set. If the
-front end has encountered code it cannot handle, it will issue a
-message to the user and set `sorrycount'. When these flags are set,
-any macro or function which normally returns a tree of a particular
-kind may instead return the `error_mark_node'. Thus, if you intend to
-do any processing of erroneous code, you must be prepared to deal with
-the `error_mark_node'.
-
- Occasionally, a particular tree slot (like an operand to an expression,
-or a particular field in a declaration) will be referred to as
-"reserved for the back end". These slots are used to store RTL when
-the tree is converted to RTL for use by the GCC back end. However, if
-that process is not taking place (e.g., if the front end is being hooked
-up to an intelligent editor), then those slots may be used by the back
-end presently in use.
-
- If you encounter situations that do not match this documentation, such
-as tree nodes of types not mentioned here, or macros documented to
-return entities of a particular kind that instead return entities of
-some different kind, you have found a bug, either in the front end or in
-the documentation. Please report these bugs as you would any other bug.
-
-* Menu:
-
-* Macros and Functions::Macros and functions that can be used with all trees.
-* Identifiers:: The names of things.
-* Containers:: Lists and vectors.
-
-\1f
-File: gccint.info, Node: Macros and Functions, Next: Identifiers, Up: Tree overview
-
-9.2.1 Trees
------------
-
-This section is not here yet.
-
-\1f
-File: gccint.info, Node: Identifiers, Next: Containers, Prev: Macros and Functions, Up: Tree overview
-
-9.2.2 Identifiers
------------------
-
-An `IDENTIFIER_NODE' represents a slightly more general concept that
-the standard C or C++ concept of identifier. In particular, an
-`IDENTIFIER_NODE' may contain a `$', or other extraordinary characters.
-
- There are never two distinct `IDENTIFIER_NODE's representing the same
-identifier. Therefore, you may use pointer equality to compare
-`IDENTIFIER_NODE's, rather than using a routine like `strcmp'.
-
- You can use the following macros to access identifiers:
-`IDENTIFIER_POINTER'
- The string represented by the identifier, represented as a
- `char*'. This string is always `NUL'-terminated, and contains no
- embedded `NUL' characters.
-
-`IDENTIFIER_LENGTH'
- The length of the string returned by `IDENTIFIER_POINTER', not
- including the trailing `NUL'. This value of `IDENTIFIER_LENGTH
- (x)' is always the same as `strlen (IDENTIFIER_POINTER (x))'.
-
-`IDENTIFIER_OPNAME_P'
- This predicate holds if the identifier represents the name of an
- overloaded operator. In this case, you should not depend on the
- contents of either the `IDENTIFIER_POINTER' or the
- `IDENTIFIER_LENGTH'.
-
-`IDENTIFIER_TYPENAME_P'
- This predicate holds if the identifier represents the name of a
- user-defined conversion operator. In this case, the `TREE_TYPE' of
- the `IDENTIFIER_NODE' holds the type to which the conversion
- operator converts.
-
-
-\1f
-File: gccint.info, Node: Containers, Prev: Identifiers, Up: Tree overview
-
-9.2.3 Containers
-----------------
-
-Two common container data structures can be represented directly with
-tree nodes. A `TREE_LIST' is a singly linked list containing two trees
-per node. These are the `TREE_PURPOSE' and `TREE_VALUE' of each node.
-(Often, the `TREE_PURPOSE' contains some kind of tag, or additional
-information, while the `TREE_VALUE' contains the majority of the
-payload. In other cases, the `TREE_PURPOSE' is simply `NULL_TREE',
-while in still others both the `TREE_PURPOSE' and `TREE_VALUE' are of
-equal stature.) Given one `TREE_LIST' node, the next node is found by
-following the `TREE_CHAIN'. If the `TREE_CHAIN' is `NULL_TREE', then
-you have reached the end of the list.
-
- A `TREE_VEC' is a simple vector. The `TREE_VEC_LENGTH' is an integer
-(not a tree) giving the number of nodes in the vector. The nodes
-themselves are accessed using the `TREE_VEC_ELT' macro, which takes two
-arguments. The first is the `TREE_VEC' in question; the second is an
-integer indicating which element in the vector is desired. The
-elements are indexed from zero.
-
-\1f
-File: gccint.info, Node: Types, Next: Scopes, Prev: Tree overview, Up: Trees
-
-9.3 Types
-=========
-
-All types have corresponding tree nodes. However, you should not assume
-that there is exactly one tree node corresponding to each type. There
-are often multiple nodes corresponding to the same type.
-
- For the most part, different kinds of types have different tree codes.
-(For example, pointer types use a `POINTER_TYPE' code while arrays use
-an `ARRAY_TYPE' code.) However, pointers to member functions use the
-`RECORD_TYPE' code. Therefore, when writing a `switch' statement that
-depends on the code associated with a particular type, you should take
-care to handle pointers to member functions under the `RECORD_TYPE'
-case label.
-
- In C++, an array type is not qualified; rather the type of the array
-elements is qualified. This situation is reflected in the intermediate
-representation. The macros described here will always examine the
-qualification of the underlying element type when applied to an array
-type. (If the element type is itself an array, then the recursion
-continues until a non-array type is found, and the qualification of this
-type is examined.) So, for example, `CP_TYPE_CONST_P' will hold of the
-type `const int ()[7]', denoting an array of seven `int's.
-
- The following functions and macros deal with cv-qualification of types:
-`CP_TYPE_QUALS'
- This macro returns the set of type qualifiers applied to this type.
- This value is `TYPE_UNQUALIFIED' if no qualifiers have been
- applied. The `TYPE_QUAL_CONST' bit is set if the type is
- `const'-qualified. The `TYPE_QUAL_VOLATILE' bit is set if the
- type is `volatile'-qualified. The `TYPE_QUAL_RESTRICT' bit is set
- if the type is `restrict'-qualified.
-
-`CP_TYPE_CONST_P'
- This macro holds if the type is `const'-qualified.
-
-`CP_TYPE_VOLATILE_P'
- This macro holds if the type is `volatile'-qualified.
-
-`CP_TYPE_RESTRICT_P'
- This macro holds if the type is `restrict'-qualified.
-
-`CP_TYPE_CONST_NON_VOLATILE_P'
- This predicate holds for a type that is `const'-qualified, but
- _not_ `volatile'-qualified; other cv-qualifiers are ignored as
- well: only the `const'-ness is tested.
-
-`TYPE_MAIN_VARIANT'
- This macro returns the unqualified version of a type. It may be
- applied to an unqualified type, but it is not always the identity
- function in that case.
-
- A few other macros and functions are usable with all types:
-`TYPE_SIZE'
- The number of bits required to represent the type, represented as
- an `INTEGER_CST'. For an incomplete type, `TYPE_SIZE' will be
- `NULL_TREE'.
-
-`TYPE_ALIGN'
- The alignment of the type, in bits, represented as an `int'.
-
-`TYPE_NAME'
- This macro returns a declaration (in the form of a `TYPE_DECL') for
- the type. (Note this macro does _not_ return a `IDENTIFIER_NODE',
- as you might expect, given its name!) You can look at the
- `DECL_NAME' of the `TYPE_DECL' to obtain the actual name of the
- type. The `TYPE_NAME' will be `NULL_TREE' for a type that is not
- a built-in type, the result of a typedef, or a named class type.
-
-`CP_INTEGRAL_TYPE'
- This predicate holds if the type is an integral type. Notice that
- in C++, enumerations are _not_ integral types.
-
-`ARITHMETIC_TYPE_P'
- This predicate holds if the type is an integral type (in the C++
- sense) or a floating point type.
-
-`CLASS_TYPE_P'
- This predicate holds for a class-type.
-
-`TYPE_BUILT_IN'
- This predicate holds for a built-in type.
-
-`TYPE_PTRMEM_P'
- This predicate holds if the type is a pointer to data member.
-
-`TYPE_PTR_P'
- This predicate holds if the type is a pointer type, and the
- pointee is not a data member.
-
-`TYPE_PTRFN_P'
- This predicate holds for a pointer to function type.
-
-`TYPE_PTROB_P'
- This predicate holds for a pointer to object type. Note however
- that it does not hold for the generic pointer to object type `void
- *'. You may use `TYPE_PTROBV_P' to test for a pointer to object
- type as well as `void *'.
-
-`TYPE_CANONICAL'
- This macro returns the "canonical" type for the given type node.
- Canonical types are used to improve performance in the C++ and
- Objective-C++ front ends by allowing efficient comparison between
- two type nodes in `same_type_p': if the `TYPE_CANONICAL' values of
- the types are equal, the types are equivalent; otherwise, the types
- are not equivalent. The notion of equivalence for canonical types
- is the same as the notion of type equivalence in the language
- itself. For instance,
-
- When `TYPE_CANONICAL' is `NULL_TREE', there is no canonical type
- for the given type node. In this case, comparison between this
- type and any other type requires the compiler to perform a deep,
- "structural" comparison to see if the two type nodes have the same
- form and properties.
-
- The canonical type for a node is always the most fundamental type
- in the equivalence class of types. For instance, `int' is its own
- canonical type. A typedef `I' of `int' will have `int' as its
- canonical type. Similarly, `I*' and a typedef `IP' (defined to
- `I*') will has `int*' as their canonical type. When building a new
- type node, be sure to set `TYPE_CANONICAL' to the appropriate
- canonical type. If the new type is a compound type (built from
- other types), and any of those other types require structural
- equality, use `SET_TYPE_STRUCTURAL_EQUALITY' to ensure that the
- new type also requires structural equality. Finally, if for some
- reason you cannot guarantee that `TYPE_CANONICAL' will point to
- the canonical type, use `SET_TYPE_STRUCTURAL_EQUALITY' to make
- sure that the new type-and any type constructed based on
- it-requires structural equality. If you suspect that the canonical
- type system is miscomparing types, pass `--param
- verify-canonical-types=1' to the compiler or configure with
- `--enable-checking' to force the compiler to verify its
- canonical-type comparisons against the structural comparisons; the
- compiler will then print any warnings if the canonical types
- miscompare.
-
-`TYPE_STRUCTURAL_EQUALITY_P'
- This predicate holds when the node requires structural equality
- checks, e.g., when `TYPE_CANONICAL' is `NULL_TREE'.
-
-`SET_TYPE_STRUCTURAL_EQUALITY'
- This macro states that the type node it is given requires
- structural equality checks, e.g., it sets `TYPE_CANONICAL' to
- `NULL_TREE'.
-
-`same_type_p'
- This predicate takes two types as input, and holds if they are the
- same type. For example, if one type is a `typedef' for the other,
- or both are `typedef's for the same type. This predicate also
- holds if the two trees given as input are simply copies of one
- another; i.e., there is no difference between them at the source
- level, but, for whatever reason, a duplicate has been made in the
- representation. You should never use `==' (pointer equality) to
- compare types; always use `same_type_p' instead.
-
- Detailed below are the various kinds of types, and the macros that can
-be used to access them. Although other kinds of types are used
-elsewhere in G++, the types described here are the only ones that you
-will encounter while examining the intermediate representation.
-
-`VOID_TYPE'
- Used to represent the `void' type.
-
-`INTEGER_TYPE'
- Used to represent the various integral types, including `char',
- `short', `int', `long', and `long long'. This code is not used
- for enumeration types, nor for the `bool' type. The
- `TYPE_PRECISION' is the number of bits used in the representation,
- represented as an `unsigned int'. (Note that in the general case
- this is not the same value as `TYPE_SIZE'; suppose that there were
- a 24-bit integer type, but that alignment requirements for the ABI
- required 32-bit alignment. Then, `TYPE_SIZE' would be an
- `INTEGER_CST' for 32, while `TYPE_PRECISION' would be 24.) The
- integer type is unsigned if `TYPE_UNSIGNED' holds; otherwise, it
- is signed.
-
- The `TYPE_MIN_VALUE' is an `INTEGER_CST' for the smallest integer
- that may be represented by this type. Similarly, the
- `TYPE_MAX_VALUE' is an `INTEGER_CST' for the largest integer that
- may be represented by this type.
-
-`REAL_TYPE'
- Used to represent the `float', `double', and `long double' types.
- The number of bits in the floating-point representation is given
- by `TYPE_PRECISION', as in the `INTEGER_TYPE' case.
-
-`FIXED_POINT_TYPE'
- Used to represent the `short _Fract', `_Fract', `long _Fract',
- `long long _Fract', `short _Accum', `_Accum', `long _Accum', and
- `long long _Accum' types. The number of bits in the fixed-point
- representation is given by `TYPE_PRECISION', as in the
- `INTEGER_TYPE' case. There may be padding bits, fractional bits
- and integral bits. The number of fractional bits is given by
- `TYPE_FBIT', and the number of integral bits is given by
- `TYPE_IBIT'. The fixed-point type is unsigned if `TYPE_UNSIGNED'
- holds; otherwise, it is signed. The fixed-point type is
- saturating if `TYPE_SATURATING' holds; otherwise, it is not
- saturating.
-
-`COMPLEX_TYPE'
- Used to represent GCC built-in `__complex__' data types. The
- `TREE_TYPE' is the type of the real and imaginary parts.
-
-`ENUMERAL_TYPE'
- Used to represent an enumeration type. The `TYPE_PRECISION' gives
- (as an `int'), the number of bits used to represent the type. If
- there are no negative enumeration constants, `TYPE_UNSIGNED' will
- hold. The minimum and maximum enumeration constants may be
- obtained with `TYPE_MIN_VALUE' and `TYPE_MAX_VALUE', respectively;
- each of these macros returns an `INTEGER_CST'.
-
- The actual enumeration constants themselves may be obtained by
- looking at the `TYPE_VALUES'. This macro will return a
- `TREE_LIST', containing the constants. The `TREE_PURPOSE' of each
- node will be an `IDENTIFIER_NODE' giving the name of the constant;
- the `TREE_VALUE' will be an `INTEGER_CST' giving the value
- assigned to that constant. These constants will appear in the
- order in which they were declared. The `TREE_TYPE' of each of
- these constants will be the type of enumeration type itself.
-
-`BOOLEAN_TYPE'
- Used to represent the `bool' type.
-
-`POINTER_TYPE'
- Used to represent pointer types, and pointer to data member types.
- The `TREE_TYPE' gives the type to which this type points. If the
- type is a pointer to data member type, then `TYPE_PTRMEM_P' will
- hold. For a pointer to data member type of the form `T X::*',
- `TYPE_PTRMEM_CLASS_TYPE' will be the type `X', while
- `TYPE_PTRMEM_POINTED_TO_TYPE' will be the type `T'.
-
-`REFERENCE_TYPE'
- Used to represent reference types. The `TREE_TYPE' gives the type
- to which this type refers.
-
-`FUNCTION_TYPE'
- Used to represent the type of non-member functions and of static
- member functions. The `TREE_TYPE' gives the return type of the
- function. The `TYPE_ARG_TYPES' are a `TREE_LIST' of the argument
- types. The `TREE_VALUE' of each node in this list is the type of
- the corresponding argument; the `TREE_PURPOSE' is an expression
- for the default argument value, if any. If the last node in the
- list is `void_list_node' (a `TREE_LIST' node whose `TREE_VALUE' is
- the `void_type_node'), then functions of this type do not take
- variable arguments. Otherwise, they do take a variable number of
- arguments.
-
- Note that in C (but not in C++) a function declared like `void f()'
- is an unprototyped function taking a variable number of arguments;
- the `TYPE_ARG_TYPES' of such a function will be `NULL'.
-
-`METHOD_TYPE'
- Used to represent the type of a non-static member function. Like a
- `FUNCTION_TYPE', the return type is given by the `TREE_TYPE'. The
- type of `*this', i.e., the class of which functions of this type
- are a member, is given by the `TYPE_METHOD_BASETYPE'. The
- `TYPE_ARG_TYPES' is the parameter list, as for a `FUNCTION_TYPE',
- and includes the `this' argument.
-
-`ARRAY_TYPE'
- Used to represent array types. The `TREE_TYPE' gives the type of
- the elements in the array. If the array-bound is present in the
- type, the `TYPE_DOMAIN' is an `INTEGER_TYPE' whose
- `TYPE_MIN_VALUE' and `TYPE_MAX_VALUE' will be the lower and upper
- bounds of the array, respectively. The `TYPE_MIN_VALUE' will
- always be an `INTEGER_CST' for zero, while the `TYPE_MAX_VALUE'
- will be one less than the number of elements in the array, i.e.,
- the highest value which may be used to index an element in the
- array.
-
-`RECORD_TYPE'
- Used to represent `struct' and `class' types, as well as pointers
- to member functions and similar constructs in other languages.
- `TYPE_FIELDS' contains the items contained in this type, each of
- which can be a `FIELD_DECL', `VAR_DECL', `CONST_DECL', or
- `TYPE_DECL'. You may not make any assumptions about the ordering
- of the fields in the type or whether one or more of them overlap.
- If `TYPE_PTRMEMFUNC_P' holds, then this type is a pointer-to-member
- type. In that case, the `TYPE_PTRMEMFUNC_FN_TYPE' is a
- `POINTER_TYPE' pointing to a `METHOD_TYPE'. The `METHOD_TYPE' is
- the type of a function pointed to by the pointer-to-member
- function. If `TYPE_PTRMEMFUNC_P' does not hold, this type is a
- class type. For more information, see *note Classes::.
-
-`UNION_TYPE'
- Used to represent `union' types. Similar to `RECORD_TYPE' except
- that all `FIELD_DECL' nodes in `TYPE_FIELD' start at bit position
- zero.
-
-`QUAL_UNION_TYPE'
- Used to represent part of a variant record in Ada. Similar to
- `UNION_TYPE' except that each `FIELD_DECL' has a `DECL_QUALIFIER'
- field, which contains a boolean expression that indicates whether
- the field is present in the object. The type will only have one
- field, so each field's `DECL_QUALIFIER' is only evaluated if none
- of the expressions in the previous fields in `TYPE_FIELDS' are
- nonzero. Normally these expressions will reference a field in the
- outer object using a `PLACEHOLDER_EXPR'.
-
-`UNKNOWN_TYPE'
- This node is used to represent a type the knowledge of which is
- insufficient for a sound processing.
-
-`OFFSET_TYPE'
- This node is used to represent a pointer-to-data member. For a
- data member `X::m' the `TYPE_OFFSET_BASETYPE' is `X' and the
- `TREE_TYPE' is the type of `m'.
-
-`TYPENAME_TYPE'
- Used to represent a construct of the form `typename T::A'. The
- `TYPE_CONTEXT' is `T'; the `TYPE_NAME' is an `IDENTIFIER_NODE' for
- `A'. If the type is specified via a template-id, then
- `TYPENAME_TYPE_FULLNAME' yields a `TEMPLATE_ID_EXPR'. The
- `TREE_TYPE' is non-`NULL' if the node is implicitly generated in
- support for the implicit typename extension; in which case the
- `TREE_TYPE' is a type node for the base-class.
-
-`TYPEOF_TYPE'
- Used to represent the `__typeof__' extension. The `TYPE_FIELDS'
- is the expression the type of which is being represented.
-
- There are variables whose values represent some of the basic types.
-These include:
-`void_type_node'
- A node for `void'.
-
-`integer_type_node'
- A node for `int'.
-
-`unsigned_type_node.'
- A node for `unsigned int'.
-
-`char_type_node.'
- A node for `char'.
- It may sometimes be useful to compare one of these variables with a
-type in hand, using `same_type_p'.
-
-\1f
-File: gccint.info, Node: Scopes, Next: Functions, Prev: Types, Up: Trees
-
-9.4 Scopes
-==========
-
-The root of the entire intermediate representation is the variable
-`global_namespace'. This is the namespace specified with `::' in C++
-source code. All other namespaces, types, variables, functions, and so
-forth can be found starting with this namespace.
-
- Besides namespaces, the other high-level scoping construct in C++ is
-the class. (Throughout this manual the term "class" is used to mean the
-types referred to in the ANSI/ISO C++ Standard as classes; these include
-types defined with the `class', `struct', and `union' keywords.)
-
-* Menu:
-
-* Namespaces:: Member functions, types, etc.
-* Classes:: Members, bases, friends, etc.
-
-\1f
-File: gccint.info, Node: Namespaces, Next: Classes, Up: Scopes
-
-9.4.1 Namespaces
-----------------
-
-A namespace is represented by a `NAMESPACE_DECL' node.
-
- However, except for the fact that it is distinguished as the root of
-the representation, the global namespace is no different from any other
-namespace. Thus, in what follows, we describe namespaces generally,
-rather than the global namespace in particular.
-
- The following macros and functions can be used on a `NAMESPACE_DECL':
-
-`DECL_NAME'
- This macro is used to obtain the `IDENTIFIER_NODE' corresponding to
- the unqualified name of the name of the namespace (*note
- Identifiers::). The name of the global namespace is `::', even
- though in C++ the global namespace is unnamed. However, you
- should use comparison with `global_namespace', rather than
- `DECL_NAME' to determine whether or not a namespace is the global
- one. An unnamed namespace will have a `DECL_NAME' equal to
- `anonymous_namespace_name'. Within a single translation unit, all
- unnamed namespaces will have the same name.
-
-`DECL_CONTEXT'
- This macro returns the enclosing namespace. The `DECL_CONTEXT' for
- the `global_namespace' is `NULL_TREE'.
-
-`DECL_NAMESPACE_ALIAS'
- If this declaration is for a namespace alias, then
- `DECL_NAMESPACE_ALIAS' is the namespace for which this one is an
- alias.
-
- Do not attempt to use `cp_namespace_decls' for a namespace which is
- an alias. Instead, follow `DECL_NAMESPACE_ALIAS' links until you
- reach an ordinary, non-alias, namespace, and call
- `cp_namespace_decls' there.
-
-`DECL_NAMESPACE_STD_P'
- This predicate holds if the namespace is the special `::std'
- namespace.
-
-`cp_namespace_decls'
- This function will return the declarations contained in the
- namespace, including types, overloaded functions, other
- namespaces, and so forth. If there are no declarations, this
- function will return `NULL_TREE'. The declarations are connected
- through their `TREE_CHAIN' fields.
-
- Although most entries on this list will be declarations,
- `TREE_LIST' nodes may also appear. In this case, the `TREE_VALUE'
- will be an `OVERLOAD'. The value of the `TREE_PURPOSE' is
- unspecified; back ends should ignore this value. As with the
- other kinds of declarations returned by `cp_namespace_decls', the
- `TREE_CHAIN' will point to the next declaration in this list.
-
- For more information on the kinds of declarations that can occur
- on this list, *Note Declarations::. Some declarations will not
- appear on this list. In particular, no `FIELD_DECL',
- `LABEL_DECL', or `PARM_DECL' nodes will appear here.
-
- This function cannot be used with namespaces that have
- `DECL_NAMESPACE_ALIAS' set.
-
-
-\1f
-File: gccint.info, Node: Classes, Prev: Namespaces, Up: Scopes
-
-9.4.2 Classes
--------------
-
-A class type is represented by either a `RECORD_TYPE' or a
-`UNION_TYPE'. A class declared with the `union' tag is represented by
-a `UNION_TYPE', while classes declared with either the `struct' or the
-`class' tag are represented by `RECORD_TYPE's. You can use the
-`CLASSTYPE_DECLARED_CLASS' macro to discern whether or not a particular
-type is a `class' as opposed to a `struct'. This macro will be true
-only for classes declared with the `class' tag.
-
- Almost all non-function members are available on the `TYPE_FIELDS'
-list. Given one member, the next can be found by following the
-`TREE_CHAIN'. You should not depend in any way on the order in which
-fields appear on this list. All nodes on this list will be `DECL'
-nodes. A `FIELD_DECL' is used to represent a non-static data member, a
-`VAR_DECL' is used to represent a static data member, and a `TYPE_DECL'
-is used to represent a type. Note that the `CONST_DECL' for an
-enumeration constant will appear on this list, if the enumeration type
-was declared in the class. (Of course, the `TYPE_DECL' for the
-enumeration type will appear here as well.) There are no entries for
-base classes on this list. In particular, there is no `FIELD_DECL' for
-the "base-class portion" of an object.
-
- The `TYPE_VFIELD' is a compiler-generated field used to point to
-virtual function tables. It may or may not appear on the `TYPE_FIELDS'
-list. However, back ends should handle the `TYPE_VFIELD' just like all
-the entries on the `TYPE_FIELDS' list.
-
- The function members are available on the `TYPE_METHODS' list. Again,
-subsequent members are found by following the `TREE_CHAIN' field. If a
-function is overloaded, each of the overloaded functions appears; no
-`OVERLOAD' nodes appear on the `TYPE_METHODS' list. Implicitly
-declared functions (including default constructors, copy constructors,
-assignment operators, and destructors) will appear on this list as well.
-
- Every class has an associated "binfo", which can be obtained with
-`TYPE_BINFO'. Binfos are used to represent base-classes. The binfo
-given by `TYPE_BINFO' is the degenerate case, whereby every class is
-considered to be its own base-class. The base binfos for a particular
-binfo are held in a vector, whose length is obtained with
-`BINFO_N_BASE_BINFOS'. The base binfos themselves are obtained with
-`BINFO_BASE_BINFO' and `BINFO_BASE_ITERATE'. To add a new binfo, use
-`BINFO_BASE_APPEND'. The vector of base binfos can be obtained with
-`BINFO_BASE_BINFOS', but normally you do not need to use that. The
-class type associated with a binfo is given by `BINFO_TYPE'. It is not
-always the case that `BINFO_TYPE (TYPE_BINFO (x))', because of typedefs
-and qualified types. Neither is it the case that `TYPE_BINFO
-(BINFO_TYPE (y))' is the same binfo as `y'. The reason is that if `y'
-is a binfo representing a base-class `B' of a derived class `D', then
-`BINFO_TYPE (y)' will be `B', and `TYPE_BINFO (BINFO_TYPE (y))' will be
-`B' as its own base-class, rather than as a base-class of `D'.
-
- The access to a base type can be found with `BINFO_BASE_ACCESS'. This
-will produce `access_public_node', `access_private_node' or
-`access_protected_node'. If bases are always public,
-`BINFO_BASE_ACCESSES' may be `NULL'.
-
- `BINFO_VIRTUAL_P' is used to specify whether the binfo is inherited
-virtually or not. The other flags, `BINFO_MARKED_P' and `BINFO_FLAG_1'
-to `BINFO_FLAG_6' can be used for language specific use.
-
- The following macros can be used on a tree node representing a
-class-type.
-
-`LOCAL_CLASS_P'
- This predicate holds if the class is local class _i.e._ declared
- inside a function body.
-
-`TYPE_POLYMORPHIC_P'
- This predicate holds if the class has at least one virtual function
- (declared or inherited).
-
-`TYPE_HAS_DEFAULT_CONSTRUCTOR'
- This predicate holds whenever its argument represents a class-type
- with default constructor.
-
-`CLASSTYPE_HAS_MUTABLE'
-`TYPE_HAS_MUTABLE_P'
- These predicates hold for a class-type having a mutable data
- member.
-
-`CLASSTYPE_NON_POD_P'
- This predicate holds only for class-types that are not PODs.
-
-`TYPE_HAS_NEW_OPERATOR'
- This predicate holds for a class-type that defines `operator new'.
-
-`TYPE_HAS_ARRAY_NEW_OPERATOR'
- This predicate holds for a class-type for which `operator new[]'
- is defined.
-
-`TYPE_OVERLOADS_CALL_EXPR'
- This predicate holds for class-type for which the function call
- `operator()' is overloaded.
-
-`TYPE_OVERLOADS_ARRAY_REF'
- This predicate holds for a class-type that overloads `operator[]'
-
-`TYPE_OVERLOADS_ARROW'
- This predicate holds for a class-type for which `operator->' is
- overloaded.
-
-
-\1f
-File: gccint.info, Node: Declarations, Next: Attributes, Prev: Functions, Up: Trees
-
-9.5 Declarations
-================
-
-This section covers the various kinds of declarations that appear in the
-internal representation, except for declarations of functions
-(represented by `FUNCTION_DECL' nodes), which are described in *note
-Functions::.
-
-* Menu:
-
-* Working with declarations:: Macros and functions that work on
-declarations.
-* Internal structure:: How declaration nodes are represented.
-
-\1f
-File: gccint.info, Node: Working with declarations, Next: Internal structure, Up: Declarations
-
-9.5.1 Working with declarations
--------------------------------
-
-Some macros can be used with any kind of declaration. These include:
-`DECL_NAME'
- This macro returns an `IDENTIFIER_NODE' giving the name of the
- entity.
-
-`TREE_TYPE'
- This macro returns the type of the entity declared.
-
-`TREE_FILENAME'
- This macro returns the name of the file in which the entity was
- declared, as a `char*'. For an entity declared implicitly by the
- compiler (like `__builtin_memcpy'), this will be the string
- `"<internal>"'.
-
-`TREE_LINENO'
- This macro returns the line number at which the entity was
- declared, as an `int'.
-
-`DECL_ARTIFICIAL'
- This predicate holds if the declaration was implicitly generated
- by the compiler. For example, this predicate will hold of an
- implicitly declared member function, or of the `TYPE_DECL'
- implicitly generated for a class type. Recall that in C++ code
- like:
- struct S {};
- is roughly equivalent to C code like:
- struct S {};
- typedef struct S S;
- The implicitly generated `typedef' declaration is represented by a
- `TYPE_DECL' for which `DECL_ARTIFICIAL' holds.
-
-`DECL_NAMESPACE_SCOPE_P'
- This predicate holds if the entity was declared at a namespace
- scope.
-
-`DECL_CLASS_SCOPE_P'
- This predicate holds if the entity was declared at a class scope.
-
-`DECL_FUNCTION_SCOPE_P'
- This predicate holds if the entity was declared inside a function
- body.
-
-
- The various kinds of declarations include:
-`LABEL_DECL'
- These nodes are used to represent labels in function bodies. For
- more information, see *note Functions::. These nodes only appear
- in block scopes.
-
-`CONST_DECL'
- These nodes are used to represent enumeration constants. The
- value of the constant is given by `DECL_INITIAL' which will be an
- `INTEGER_CST' with the same type as the `TREE_TYPE' of the
- `CONST_DECL', i.e., an `ENUMERAL_TYPE'.
-
-`RESULT_DECL'
- These nodes represent the value returned by a function. When a
- value is assigned to a `RESULT_DECL', that indicates that the
- value should be returned, via bitwise copy, by the function. You
- can use `DECL_SIZE' and `DECL_ALIGN' on a `RESULT_DECL', just as
- with a `VAR_DECL'.
-
-`TYPE_DECL'
- These nodes represent `typedef' declarations. The `TREE_TYPE' is
- the type declared to have the name given by `DECL_NAME'. In some
- cases, there is no associated name.
-
-`VAR_DECL'
- These nodes represent variables with namespace or block scope, as
- well as static data members. The `DECL_SIZE' and `DECL_ALIGN' are
- analogous to `TYPE_SIZE' and `TYPE_ALIGN'. For a declaration, you
- should always use the `DECL_SIZE' and `DECL_ALIGN' rather than the
- `TYPE_SIZE' and `TYPE_ALIGN' given by the `TREE_TYPE', since
- special attributes may have been applied to the variable to give
- it a particular size and alignment. You may use the predicates
- `DECL_THIS_STATIC' or `DECL_THIS_EXTERN' to test whether the
- storage class specifiers `static' or `extern' were used to declare
- a variable.
-
- If this variable is initialized (but does not require a
- constructor), the `DECL_INITIAL' will be an expression for the
- initializer. The initializer should be evaluated, and a bitwise
- copy into the variable performed. If the `DECL_INITIAL' is the
- `error_mark_node', there is an initializer, but it is given by an
- explicit statement later in the code; no bitwise copy is required.
-
- GCC provides an extension that allows either automatic variables,
- or global variables, to be placed in particular registers. This
- extension is being used for a particular `VAR_DECL' if
- `DECL_REGISTER' holds for the `VAR_DECL', and if
- `DECL_ASSEMBLER_NAME' is not equal to `DECL_NAME'. In that case,
- `DECL_ASSEMBLER_NAME' is the name of the register into which the
- variable will be placed.
-
-`PARM_DECL'
- Used to represent a parameter to a function. Treat these nodes
- similarly to `VAR_DECL' nodes. These nodes only appear in the
- `DECL_ARGUMENTS' for a `FUNCTION_DECL'.
-
- The `DECL_ARG_TYPE' for a `PARM_DECL' is the type that will
- actually be used when a value is passed to this function. It may
- be a wider type than the `TREE_TYPE' of the parameter; for
- example, the ordinary type might be `short' while the
- `DECL_ARG_TYPE' is `int'.
-
-`FIELD_DECL'
- These nodes represent non-static data members. The `DECL_SIZE' and
- `DECL_ALIGN' behave as for `VAR_DECL' nodes. The position of the
- field within the parent record is specified by a combination of
- three attributes. `DECL_FIELD_OFFSET' is the position, counting
- in bytes, of the `DECL_OFFSET_ALIGN'-bit sized word containing the
- bit of the field closest to the beginning of the structure.
- `DECL_FIELD_BIT_OFFSET' is the bit offset of the first bit of the
- field within this word; this may be nonzero even for fields that
- are not bit-fields, since `DECL_OFFSET_ALIGN' may be greater than
- the natural alignment of the field's type.
-
- If `DECL_C_BIT_FIELD' holds, this field is a bit-field. In a
- bit-field, `DECL_BIT_FIELD_TYPE' also contains the type that was
- originally specified for it, while DECL_TYPE may be a modified
- type with lesser precision, according to the size of the bit field.
-
-`NAMESPACE_DECL'
- *Note Namespaces::.
-
-`TEMPLATE_DECL'
- These nodes are used to represent class, function, and variable
- (static data member) templates. The
- `DECL_TEMPLATE_SPECIALIZATIONS' are a `TREE_LIST'. The
- `TREE_VALUE' of each node in the list is a `TEMPLATE_DECL's or
- `FUNCTION_DECL's representing specializations (including
- instantiations) of this template. Back ends can safely ignore
- `TEMPLATE_DECL's, but should examine `FUNCTION_DECL' nodes on the
- specializations list just as they would ordinary `FUNCTION_DECL'
- nodes.
-
- For a class template, the `DECL_TEMPLATE_INSTANTIATIONS' list
- contains the instantiations. The `TREE_VALUE' of each node is an
- instantiation of the class. The `DECL_TEMPLATE_SPECIALIZATIONS'
- contains partial specializations of the class.
-
-`USING_DECL'
- Back ends can safely ignore these nodes.
-
-
-\1f
-File: gccint.info, Node: Internal structure, Prev: Working with declarations, Up: Declarations
-
-9.5.2 Internal structure
-------------------------
-
-`DECL' nodes are represented internally as a hierarchy of structures.
-
-* Menu:
-
-* Current structure hierarchy:: The current DECL node structure
-hierarchy.
-* Adding new DECL node types:: How to add a new DECL node to a
-frontend.
-
-\1f
-File: gccint.info, Node: Current structure hierarchy, Next: Adding new DECL node types, Up: Internal structure
-
-9.5.2.1 Current structure hierarchy
-...................................
-
-`struct tree_decl_minimal'
- This is the minimal structure to inherit from in order for common
- `DECL' macros to work. The fields it contains are a unique ID,
- source location, context, and name.
-
-`struct tree_decl_common'
- This structure inherits from `struct tree_decl_minimal'. It
- contains fields that most `DECL' nodes need, such as a field to
- store alignment, machine mode, size, and attributes.
-
-`struct tree_field_decl'
- This structure inherits from `struct tree_decl_common'. It is
- used to represent `FIELD_DECL'.
-
-`struct tree_label_decl'
- This structure inherits from `struct tree_decl_common'. It is
- used to represent `LABEL_DECL'.
-
-`struct tree_translation_unit_decl'
- This structure inherits from `struct tree_decl_common'. It is
- used to represent `TRANSLATION_UNIT_DECL'.
-
-`struct tree_decl_with_rtl'
- This structure inherits from `struct tree_decl_common'. It
- contains a field to store the low-level RTL associated with a
- `DECL' node.
-
-`struct tree_result_decl'
- This structure inherits from `struct tree_decl_with_rtl'. It is
- used to represent `RESULT_DECL'.
-
-`struct tree_const_decl'
- This structure inherits from `struct tree_decl_with_rtl'. It is
- used to represent `CONST_DECL'.
-
-`struct tree_parm_decl'
- This structure inherits from `struct tree_decl_with_rtl'. It is
- used to represent `PARM_DECL'.
-
-`struct tree_decl_with_vis'
- This structure inherits from `struct tree_decl_with_rtl'. It
- contains fields necessary to store visibility information, as well
- as a section name and assembler name.
-
-`struct tree_var_decl'
- This structure inherits from `struct tree_decl_with_vis'. It is
- used to represent `VAR_DECL'.
-
-`struct tree_function_decl'
- This structure inherits from `struct tree_decl_with_vis'. It is
- used to represent `FUNCTION_DECL'.
-
-
-\1f
-File: gccint.info, Node: Adding new DECL node types, Prev: Current structure hierarchy, Up: Internal structure
-
-9.5.2.2 Adding new DECL node types
-..................................
-
-Adding a new `DECL' tree consists of the following steps
-
-Add a new tree code for the `DECL' node
- For language specific `DECL' nodes, there is a `.def' file in each
- frontend directory where the tree code should be added. For
- `DECL' nodes that are part of the middle-end, the code should be
- added to `tree.def'.
-
-Create a new structure type for the `DECL' node
- These structures should inherit from one of the existing
- structures in the language hierarchy by using that structure as
- the first member.
-
- struct tree_foo_decl
- {
- struct tree_decl_with_vis common;
- }
-
- Would create a structure name `tree_foo_decl' that inherits from
- `struct tree_decl_with_vis'.
-
- For language specific `DECL' nodes, this new structure type should
- go in the appropriate `.h' file. For `DECL' nodes that are part
- of the middle-end, the structure type should go in `tree.h'.
-
-Add a member to the tree structure enumerator for the node
- For garbage collection and dynamic checking purposes, each `DECL'
- node structure type is required to have a unique enumerator value
- specified with it. For language specific `DECL' nodes, this new
- enumerator value should go in the appropriate `.def' file. For
- `DECL' nodes that are part of the middle-end, the enumerator
- values are specified in `treestruct.def'.
-
-Update `union tree_node'
- In order to make your new structure type usable, it must be added
- to `union tree_node'. For language specific `DECL' nodes, a new
- entry should be added to the appropriate `.h' file of the form
- struct tree_foo_decl GTY ((tag ("TS_VAR_DECL"))) foo_decl;
- For `DECL' nodes that are part of the middle-end, the additional
- member goes directly into `union tree_node' in `tree.h'.
-
-Update dynamic checking info
- In order to be able to check whether accessing a named portion of
- `union tree_node' is legal, and whether a certain `DECL' node
- contains one of the enumerated `DECL' node structures in the
- hierarchy, a simple lookup table is used. This lookup table needs
- to be kept up to date with the tree structure hierarchy, or else
- checking and containment macros will fail inappropriately.
-
- For language specific `DECL' nodes, their is an `init_ts' function
- in an appropriate `.c' file, which initializes the lookup table.
- Code setting up the table for new `DECL' nodes should be added
- there. For each `DECL' tree code and enumerator value
- representing a member of the inheritance hierarchy, the table
- should contain 1 if that tree code inherits (directly or
- indirectly) from that member. Thus, a `FOO_DECL' node derived
- from `struct decl_with_rtl', and enumerator value `TS_FOO_DECL',
- would be set up as follows
- tree_contains_struct[FOO_DECL][TS_FOO_DECL] = 1;
- tree_contains_struct[FOO_DECL][TS_DECL_WRTL] = 1;
- tree_contains_struct[FOO_DECL][TS_DECL_COMMON] = 1;
- tree_contains_struct[FOO_DECL][TS_DECL_MINIMAL] = 1;
-
- For `DECL' nodes that are part of the middle-end, the setup code
- goes into `tree.c'.
-
-Add macros to access any new fields and flags
- Each added field or flag should have a macro that is used to access
- it, that performs appropriate checking to ensure only the right
- type of `DECL' nodes access the field.
-
- These macros generally take the following form
- #define FOO_DECL_FIELDNAME(NODE) FOO_DECL_CHECK(NODE)->foo_decl.fieldname
- However, if the structure is simply a base class for further
- structures, something like the following should be used
- #define BASE_STRUCT_CHECK(T) CONTAINS_STRUCT_CHECK(T, TS_BASE_STRUCT)
- #define BASE_STRUCT_FIELDNAME(NODE) \
- (BASE_STRUCT_CHECK(NODE)->base_struct.fieldname
-
-
-\1f
-File: gccint.info, Node: Functions, Next: Declarations, Prev: Scopes, Up: Trees
-
-9.6 Functions
-=============
-
-A function is represented by a `FUNCTION_DECL' node. A set of
-overloaded functions is sometimes represented by a `OVERLOAD' node.
-
- An `OVERLOAD' node is not a declaration, so none of the `DECL_' macros
-should be used on an `OVERLOAD'. An `OVERLOAD' node is similar to a
-`TREE_LIST'. Use `OVL_CURRENT' to get the function associated with an
-`OVERLOAD' node; use `OVL_NEXT' to get the next `OVERLOAD' node in the
-list of overloaded functions. The macros `OVL_CURRENT' and `OVL_NEXT'
-are actually polymorphic; you can use them to work with `FUNCTION_DECL'
-nodes as well as with overloads. In the case of a `FUNCTION_DECL',
-`OVL_CURRENT' will always return the function itself, and `OVL_NEXT'
-will always be `NULL_TREE'.
-
- To determine the scope of a function, you can use the `DECL_CONTEXT'
-macro. This macro will return the class (either a `RECORD_TYPE' or a
-`UNION_TYPE') or namespace (a `NAMESPACE_DECL') of which the function
-is a member. For a virtual function, this macro returns the class in
-which the function was actually defined, not the base class in which
-the virtual declaration occurred.
-
- If a friend function is defined in a class scope, the
-`DECL_FRIEND_CONTEXT' macro can be used to determine the class in which
-it was defined. For example, in
- class C { friend void f() {} };
- the `DECL_CONTEXT' for `f' will be the `global_namespace', but the
-`DECL_FRIEND_CONTEXT' will be the `RECORD_TYPE' for `C'.
-
- In C, the `DECL_CONTEXT' for a function maybe another function. This
-representation indicates that the GNU nested function extension is in
-use. For details on the semantics of nested functions, see the GCC
-Manual. The nested function can refer to local variables in its
-containing function. Such references are not explicitly marked in the
-tree structure; back ends must look at the `DECL_CONTEXT' for the
-referenced `VAR_DECL'. If the `DECL_CONTEXT' for the referenced
-`VAR_DECL' is not the same as the function currently being processed,
-and neither `DECL_EXTERNAL' nor `TREE_STATIC' hold, then the reference
-is to a local variable in a containing function, and the back end must
-take appropriate action.
-
-* Menu:
-
-* Function Basics:: Function names, linkage, and so forth.
-* Function Bodies:: The statements that make up a function body.
-
-\1f
-File: gccint.info, Node: Function Basics, Next: Function Bodies, Up: Functions
-
-9.6.1 Function Basics
----------------------
-
-The following macros and functions can be used on a `FUNCTION_DECL':
-`DECL_MAIN_P'
- This predicate holds for a function that is the program entry point
- `::code'.
-
-`DECL_NAME'
- This macro returns the unqualified name of the function, as an
- `IDENTIFIER_NODE'. For an instantiation of a function template,
- the `DECL_NAME' is the unqualified name of the template, not
- something like `f<int>'. The value of `DECL_NAME' is undefined
- when used on a constructor, destructor, overloaded operator, or
- type-conversion operator, or any function that is implicitly
- generated by the compiler. See below for macros that can be used
- to distinguish these cases.
-
-`DECL_ASSEMBLER_NAME'
- This macro returns the mangled name of the function, also an
- `IDENTIFIER_NODE'. This name does not contain leading underscores
- on systems that prefix all identifiers with underscores. The
- mangled name is computed in the same way on all platforms; if
- special processing is required to deal with the object file format
- used on a particular platform, it is the responsibility of the
- back end to perform those modifications. (Of course, the back end
- should not modify `DECL_ASSEMBLER_NAME' itself.)
-
- Using `DECL_ASSEMBLER_NAME' will cause additional memory to be
- allocated (for the mangled name of the entity) so it should be used
- only when emitting assembly code. It should not be used within the
- optimizers to determine whether or not two declarations are the
- same, even though some of the existing optimizers do use it in
- that way. These uses will be removed over time.
-
-`DECL_EXTERNAL'
- This predicate holds if the function is undefined.
-
-`TREE_PUBLIC'
- This predicate holds if the function has external linkage.
-
-`DECL_LOCAL_FUNCTION_P'
- This predicate holds if the function was declared at block scope,
- even though it has a global scope.
-
-`DECL_ANTICIPATED'
- This predicate holds if the function is a built-in function but its
- prototype is not yet explicitly declared.
-
-`DECL_EXTERN_C_FUNCTION_P'
- This predicate holds if the function is declared as an ``extern
- "C"'' function.
-
-`DECL_LINKONCE_P'
- This macro holds if multiple copies of this function may be
- emitted in various translation units. It is the responsibility of
- the linker to merge the various copies. Template instantiations
- are the most common example of functions for which
- `DECL_LINKONCE_P' holds; G++ instantiates needed templates in all
- translation units which require them, and then relies on the
- linker to remove duplicate instantiations.
-
- FIXME: This macro is not yet implemented.
-
-`DECL_FUNCTION_MEMBER_P'
- This macro holds if the function is a member of a class, rather
- than a member of a namespace.
-
-`DECL_STATIC_FUNCTION_P'
- This predicate holds if the function a static member function.
-
-`DECL_NONSTATIC_MEMBER_FUNCTION_P'
- This macro holds for a non-static member function.
-
-`DECL_CONST_MEMFUNC_P'
- This predicate holds for a `const'-member function.
-
-`DECL_VOLATILE_MEMFUNC_P'
- This predicate holds for a `volatile'-member function.
-
-`DECL_CONSTRUCTOR_P'
- This macro holds if the function is a constructor.
-
-`DECL_NONCONVERTING_P'
- This predicate holds if the constructor is a non-converting
- constructor.
-
-`DECL_COMPLETE_CONSTRUCTOR_P'
- This predicate holds for a function which is a constructor for an
- object of a complete type.
-
-`DECL_BASE_CONSTRUCTOR_P'
- This predicate holds for a function which is a constructor for a
- base class sub-object.
-
-`DECL_COPY_CONSTRUCTOR_P'
- This predicate holds for a function which is a copy-constructor.
-
-`DECL_DESTRUCTOR_P'
- This macro holds if the function is a destructor.
-
-`DECL_COMPLETE_DESTRUCTOR_P'
- This predicate holds if the function is the destructor for an
- object a complete type.
-
-`DECL_OVERLOADED_OPERATOR_P'
- This macro holds if the function is an overloaded operator.
-
-`DECL_CONV_FN_P'
- This macro holds if the function is a type-conversion operator.
-
-`DECL_GLOBAL_CTOR_P'
- This predicate holds if the function is a file-scope initialization
- function.
-
-`DECL_GLOBAL_DTOR_P'
- This predicate holds if the function is a file-scope finalization
- function.
-
-`DECL_THUNK_P'
- This predicate holds if the function is a thunk.
-
- These functions represent stub code that adjusts the `this' pointer
- and then jumps to another function. When the jumped-to function
- returns, control is transferred directly to the caller, without
- returning to the thunk. The first parameter to the thunk is
- always the `this' pointer; the thunk should add `THUNK_DELTA' to
- this value. (The `THUNK_DELTA' is an `int', not an `INTEGER_CST'.)
-
- Then, if `THUNK_VCALL_OFFSET' (an `INTEGER_CST') is nonzero the
- adjusted `this' pointer must be adjusted again. The complete
- calculation is given by the following pseudo-code:
-
- this += THUNK_DELTA
- if (THUNK_VCALL_OFFSET)
- this += (*((ptrdiff_t **) this))[THUNK_VCALL_OFFSET]
-
- Finally, the thunk should jump to the location given by
- `DECL_INITIAL'; this will always be an expression for the address
- of a function.
-
-`DECL_NON_THUNK_FUNCTION_P'
- This predicate holds if the function is _not_ a thunk function.
-
-`GLOBAL_INIT_PRIORITY'
- If either `DECL_GLOBAL_CTOR_P' or `DECL_GLOBAL_DTOR_P' holds, then
- this gives the initialization priority for the function. The
- linker will arrange that all functions for which
- `DECL_GLOBAL_CTOR_P' holds are run in increasing order of priority
- before `main' is called. When the program exits, all functions for
- which `DECL_GLOBAL_DTOR_P' holds are run in the reverse order.
-
-`DECL_ARTIFICIAL'
- This macro holds if the function was implicitly generated by the
- compiler, rather than explicitly declared. In addition to
- implicitly generated class member functions, this macro holds for
- the special functions created to implement static initialization
- and destruction, to compute run-time type information, and so
- forth.
-
-`DECL_ARGUMENTS'
- This macro returns the `PARM_DECL' for the first argument to the
- function. Subsequent `PARM_DECL' nodes can be obtained by
- following the `TREE_CHAIN' links.
-
-`DECL_RESULT'
- This macro returns the `RESULT_DECL' for the function.
-
-`TREE_TYPE'
- This macro returns the `FUNCTION_TYPE' or `METHOD_TYPE' for the
- function.
-
-`TYPE_RAISES_EXCEPTIONS'
- This macro returns the list of exceptions that a (member-)function
- can raise. The returned list, if non `NULL', is comprised of nodes
- whose `TREE_VALUE' represents a type.
-
-`TYPE_NOTHROW_P'
- This predicate holds when the exception-specification of its
- arguments is of the form ``()''.
-
-`DECL_ARRAY_DELETE_OPERATOR_P'
- This predicate holds if the function an overloaded `operator
- delete[]'.
-
-`DECL_FUNCTION_SPECIFIC_TARGET'
- This macro returns a tree node that holds the target options that
- are to be used to compile this particular function or `NULL_TREE'
- if the function is to be compiled with the target options
- specified on the command line.
-
-`DECL_FUNCTION_SPECIFIC_OPTIMIZATION'
- This macro returns a tree node that holds the optimization options
- that are to be used to compile this particular function or
- `NULL_TREE' if the function is to be compiled with the
- optimization options specified on the command line.
-
-\1f
-File: gccint.info, Node: Function Bodies, Prev: Function Basics, Up: Functions
-
-9.6.2 Function Bodies
----------------------
-
-A function that has a definition in the current translation unit will
-have a non-`NULL' `DECL_INITIAL'. However, back ends should not make
-use of the particular value given by `DECL_INITIAL'.
-
- The `DECL_SAVED_TREE' macro will give the complete body of the
-function.
-
-9.6.2.1 Statements
-..................
-
-There are tree nodes corresponding to all of the source-level statement
-constructs, used within the C and C++ frontends. These are enumerated
-here, together with a list of the various macros that can be used to
-obtain information about them. There are a few macros that can be used
-with all statements:
-
-`STMT_IS_FULL_EXPR_P'
- In C++, statements normally constitute "full expressions";
- temporaries created during a statement are destroyed when the
- statement is complete. However, G++ sometimes represents
- expressions by statements; these statements will not have
- `STMT_IS_FULL_EXPR_P' set. Temporaries created during such
- statements should be destroyed when the innermost enclosing
- statement with `STMT_IS_FULL_EXPR_P' set is exited.
-
-
- Here is the list of the various statement nodes, and the macros used to
-access them. This documentation describes the use of these nodes in
-non-template functions (including instantiations of template functions).
-In template functions, the same nodes are used, but sometimes in
-slightly different ways.
-
- Many of the statements have substatements. For example, a `while'
-loop will have a body, which is itself a statement. If the substatement
-is `NULL_TREE', it is considered equivalent to a statement consisting
-of a single `;', i.e., an expression statement in which the expression
-has been omitted. A substatement may in fact be a list of statements,
-connected via their `TREE_CHAIN's. So, you should always process the
-statement tree by looping over substatements, like this:
- void process_stmt (stmt)
- tree stmt;
- {
- while (stmt)
- {
- switch (TREE_CODE (stmt))
- {
- case IF_STMT:
- process_stmt (THEN_CLAUSE (stmt));
- /* More processing here. */
- break;
-
- ...
- }
-
- stmt = TREE_CHAIN (stmt);
- }
- }
- In other words, while the `then' clause of an `if' statement in C++
-can be only one statement (although that one statement may be a
-compound statement), the intermediate representation will sometimes use
-several statements chained together.
-
-`ASM_EXPR'
- Used to represent an inline assembly statement. For an inline
- assembly statement like:
- asm ("mov x, y");
- The `ASM_STRING' macro will return a `STRING_CST' node for `"mov
- x, y"'. If the original statement made use of the
- extended-assembly syntax, then `ASM_OUTPUTS', `ASM_INPUTS', and
- `ASM_CLOBBERS' will be the outputs, inputs, and clobbers for the
- statement, represented as `STRING_CST' nodes. The
- extended-assembly syntax looks like:
- asm ("fsinx %1,%0" : "=f" (result) : "f" (angle));
- The first string is the `ASM_STRING', containing the instruction
- template. The next two strings are the output and inputs,
- respectively; this statement has no clobbers. As this example
- indicates, "plain" assembly statements are merely a special case
- of extended assembly statements; they have no cv-qualifiers,
- outputs, inputs, or clobbers. All of the strings will be
- `NUL'-terminated, and will contain no embedded `NUL'-characters.
-
- If the assembly statement is declared `volatile', or if the
- statement was not an extended assembly statement, and is therefore
- implicitly volatile, then the predicate `ASM_VOLATILE_P' will hold
- of the `ASM_EXPR'.
-
-`BREAK_STMT'
- Used to represent a `break' statement. There are no additional
- fields.
-
-`CASE_LABEL_EXPR'
- Use to represent a `case' label, range of `case' labels, or a
- `default' label. If `CASE_LOW' is `NULL_TREE', then this is a
- `default' label. Otherwise, if `CASE_HIGH' is `NULL_TREE', then
- this is an ordinary `case' label. In this case, `CASE_LOW' is an
- expression giving the value of the label. Both `CASE_LOW' and
- `CASE_HIGH' are `INTEGER_CST' nodes. These values will have the
- same type as the condition expression in the switch statement.
-
- Otherwise, if both `CASE_LOW' and `CASE_HIGH' are defined, the
- statement is a range of case labels. Such statements originate
- with the extension that allows users to write things of the form:
- case 2 ... 5:
- The first value will be `CASE_LOW', while the second will be
- `CASE_HIGH'.
-
-`CLEANUP_STMT'
- Used to represent an action that should take place upon exit from
- the enclosing scope. Typically, these actions are calls to
- destructors for local objects, but back ends cannot rely on this
- fact. If these nodes are in fact representing such destructors,
- `CLEANUP_DECL' will be the `VAR_DECL' destroyed. Otherwise,
- `CLEANUP_DECL' will be `NULL_TREE'. In any case, the
- `CLEANUP_EXPR' is the expression to execute. The cleanups
- executed on exit from a scope should be run in the reverse order
- of the order in which the associated `CLEANUP_STMT's were
- encountered.
-
-`CONTINUE_STMT'
- Used to represent a `continue' statement. There are no additional
- fields.
-
-`CTOR_STMT'
- Used to mark the beginning (if `CTOR_BEGIN_P' holds) or end (if
- `CTOR_END_P' holds of the main body of a constructor. See also
- `SUBOBJECT' for more information on how to use these nodes.
-
-`DECL_STMT'
- Used to represent a local declaration. The `DECL_STMT_DECL' macro
- can be used to obtain the entity declared. This declaration may
- be a `LABEL_DECL', indicating that the label declared is a local
- label. (As an extension, GCC allows the declaration of labels
- with scope.) In C, this declaration may be a `FUNCTION_DECL',
- indicating the use of the GCC nested function extension. For more
- information, *note Functions::.
-
-`DO_STMT'
- Used to represent a `do' loop. The body of the loop is given by
- `DO_BODY' while the termination condition for the loop is given by
- `DO_COND'. The condition for a `do'-statement is always an
- expression.
-
-`EMPTY_CLASS_EXPR'
- Used to represent a temporary object of a class with no data whose
- address is never taken. (All such objects are interchangeable.)
- The `TREE_TYPE' represents the type of the object.
-
-`EXPR_STMT'
- Used to represent an expression statement. Use `EXPR_STMT_EXPR' to
- obtain the expression.
-
-`FOR_STMT'
- Used to represent a `for' statement. The `FOR_INIT_STMT' is the
- initialization statement for the loop. The `FOR_COND' is the
- termination condition. The `FOR_EXPR' is the expression executed
- right before the `FOR_COND' on each loop iteration; often, this
- expression increments a counter. The body of the loop is given by
- `FOR_BODY'. Note that `FOR_INIT_STMT' and `FOR_BODY' return
- statements, while `FOR_COND' and `FOR_EXPR' return expressions.
-
-`GOTO_EXPR'
- Used to represent a `goto' statement. The `GOTO_DESTINATION' will
- usually be a `LABEL_DECL'. However, if the "computed goto"
- extension has been used, the `GOTO_DESTINATION' will be an
- arbitrary expression indicating the destination. This expression
- will always have pointer type.
-
-`HANDLER'
- Used to represent a C++ `catch' block. The `HANDLER_TYPE' is the
- type of exception that will be caught by this handler; it is equal
- (by pointer equality) to `NULL' if this handler is for all types.
- `HANDLER_PARMS' is the `DECL_STMT' for the catch parameter, and
- `HANDLER_BODY' is the code for the block itself.
-
-`IF_STMT'
- Used to represent an `if' statement. The `IF_COND' is the
- expression.
-
- If the condition is a `TREE_LIST', then the `TREE_PURPOSE' is a
- statement (usually a `DECL_STMT'). Each time the condition is
- evaluated, the statement should be executed. Then, the
- `TREE_VALUE' should be used as the conditional expression itself.
- This representation is used to handle C++ code like this:
-
- if (int i = 7) ...
-
- where there is a new local variable (or variables) declared within
- the condition.
-
- The `THEN_CLAUSE' represents the statement given by the `then'
- condition, while the `ELSE_CLAUSE' represents the statement given
- by the `else' condition.
-
-`LABEL_EXPR'
- Used to represent a label. The `LABEL_DECL' declared by this
- statement can be obtained with the `LABEL_EXPR_LABEL' macro. The
- `IDENTIFIER_NODE' giving the name of the label can be obtained from
- the `LABEL_DECL' with `DECL_NAME'.
-
-`RETURN_STMT'
- Used to represent a `return' statement. The `RETURN_EXPR' is the
- expression returned; it will be `NULL_TREE' if the statement was
- just
- return;
-
-`SUBOBJECT'
- In a constructor, these nodes are used to mark the point at which a
- subobject of `this' is fully constructed. If, after this point, an
- exception is thrown before a `CTOR_STMT' with `CTOR_END_P' set is
- encountered, the `SUBOBJECT_CLEANUP' must be executed. The
- cleanups must be executed in the reverse order in which they
- appear.
-
-`SWITCH_STMT'
- Used to represent a `switch' statement. The `SWITCH_STMT_COND' is
- the expression on which the switch is occurring. See the
- documentation for an `IF_STMT' for more information on the
- representation used for the condition. The `SWITCH_STMT_BODY' is
- the body of the switch statement. The `SWITCH_STMT_TYPE' is the
- original type of switch expression as given in the source, before
- any compiler conversions.
-
-`TRY_BLOCK'
- Used to represent a `try' block. The body of the try block is
- given by `TRY_STMTS'. Each of the catch blocks is a `HANDLER'
- node. The first handler is given by `TRY_HANDLERS'. Subsequent
- handlers are obtained by following the `TREE_CHAIN' link from one
- handler to the next. The body of the handler is given by
- `HANDLER_BODY'.
-
- If `CLEANUP_P' holds of the `TRY_BLOCK', then the `TRY_HANDLERS'
- will not be a `HANDLER' node. Instead, it will be an expression
- that should be executed if an exception is thrown in the try
- block. It must rethrow the exception after executing that code.
- And, if an exception is thrown while the expression is executing,
- `terminate' must be called.
-
-`USING_STMT'
- Used to represent a `using' directive. The namespace is given by
- `USING_STMT_NAMESPACE', which will be a NAMESPACE_DECL. This node
- is needed inside template functions, to implement using directives
- during instantiation.
-
-`WHILE_STMT'
- Used to represent a `while' loop. The `WHILE_COND' is the
- termination condition for the loop. See the documentation for an
- `IF_STMT' for more information on the representation used for the
- condition.
-
- The `WHILE_BODY' is the body of the loop.
-
-
-\1f
-File: gccint.info, Node: Attributes, Next: Expression trees, Prev: Declarations, Up: Trees
-
-9.7 Attributes in trees
-=======================
-
-Attributes, as specified using the `__attribute__' keyword, are
-represented internally as a `TREE_LIST'. The `TREE_PURPOSE' is the
-name of the attribute, as an `IDENTIFIER_NODE'. The `TREE_VALUE' is a
-`TREE_LIST' of the arguments of the attribute, if any, or `NULL_TREE'
-if there are no arguments; the arguments are stored as the `TREE_VALUE'
-of successive entries in the list, and may be identifiers or
-expressions. The `TREE_CHAIN' of the attribute is the next attribute
-in a list of attributes applying to the same declaration or type, or
-`NULL_TREE' if there are no further attributes in the list.
-
- Attributes may be attached to declarations and to types; these
-attributes may be accessed with the following macros. All attributes
-are stored in this way, and many also cause other changes to the
-declaration or type or to other internal compiler data structures.
-
- -- Tree Macro: tree DECL_ATTRIBUTES (tree DECL)
- This macro returns the attributes on the declaration DECL.
-
- -- Tree Macro: tree TYPE_ATTRIBUTES (tree TYPE)
- This macro returns the attributes on the type TYPE.
-
-\1f
-File: gccint.info, Node: Expression trees, Prev: Attributes, Up: Trees
-
-9.8 Expressions
-===============
-
-The internal representation for expressions is for the most part quite
-straightforward. However, there are a few facts that one must bear in
-mind. In particular, the expression "tree" is actually a directed
-acyclic graph. (For example there may be many references to the integer
-constant zero throughout the source program; many of these will be
-represented by the same expression node.) You should not rely on
-certain kinds of node being shared, nor should you rely on certain
-kinds of nodes being unshared.
-
- The following macros can be used with all expression nodes:
-
-`TREE_TYPE'
- Returns the type of the expression. This value may not be
- precisely the same type that would be given the expression in the
- original program.
-
- In what follows, some nodes that one might expect to always have type
-`bool' are documented to have either integral or boolean type. At some
-point in the future, the C front end may also make use of this same
-intermediate representation, and at this point these nodes will
-certainly have integral type. The previous sentence is not meant to
-imply that the C++ front end does not or will not give these nodes
-integral type.
-
- Below, we list the various kinds of expression nodes. Except where
-noted otherwise, the operands to an expression are accessed using the
-`TREE_OPERAND' macro. For example, to access the first operand to a
-binary plus expression `expr', use:
-
- TREE_OPERAND (expr, 0)
- As this example indicates, the operands are zero-indexed.
-
- All the expressions starting with `OMP_' represent directives and
-clauses used by the OpenMP API `http://www.openmp.org/'.
-
- The table below begins with constants, moves on to unary expressions,
-then proceeds to binary expressions, and concludes with various other
-kinds of expressions:
-
-`INTEGER_CST'
- These nodes represent integer constants. Note that the type of
- these constants is obtained with `TREE_TYPE'; they are not always
- of type `int'. In particular, `char' constants are represented
- with `INTEGER_CST' nodes. The value of the integer constant `e' is
- given by
- ((TREE_INT_CST_HIGH (e) << HOST_BITS_PER_WIDE_INT)
- + TREE_INST_CST_LOW (e))
- HOST_BITS_PER_WIDE_INT is at least thirty-two on all platforms.
- Both `TREE_INT_CST_HIGH' and `TREE_INT_CST_LOW' return a
- `HOST_WIDE_INT'. The value of an `INTEGER_CST' is interpreted as
- a signed or unsigned quantity depending on the type of the
- constant. In general, the expression given above will overflow,
- so it should not be used to calculate the value of the constant.
-
- The variable `integer_zero_node' is an integer constant with value
- zero. Similarly, `integer_one_node' is an integer constant with
- value one. The `size_zero_node' and `size_one_node' variables are
- analogous, but have type `size_t' rather than `int'.
-
- The function `tree_int_cst_lt' is a predicate which holds if its
- first argument is less than its second. Both constants are
- assumed to have the same signedness (i.e., either both should be
- signed or both should be unsigned.) The full width of the
- constant is used when doing the comparison; the usual rules about
- promotions and conversions are ignored. Similarly,
- `tree_int_cst_equal' holds if the two constants are equal. The
- `tree_int_cst_sgn' function returns the sign of a constant. The
- value is `1', `0', or `-1' according on whether the constant is
- greater than, equal to, or less than zero. Again, the signedness
- of the constant's type is taken into account; an unsigned constant
- is never less than zero, no matter what its bit-pattern.
-
-`REAL_CST'
- FIXME: Talk about how to obtain representations of this constant,
- do comparisons, and so forth.
-
-`FIXED_CST'
- These nodes represent fixed-point constants. The type of these
- constants is obtained with `TREE_TYPE'. `TREE_FIXED_CST_PTR'
- points to to struct fixed_value; `TREE_FIXED_CST' returns the
- structure itself. Struct fixed_value contains `data' with the
- size of two HOST_BITS_PER_WIDE_INT and `mode' as the associated
- fixed-point machine mode for `data'.
-
-`COMPLEX_CST'
- These nodes are used to represent complex number constants, that
- is a `__complex__' whose parts are constant nodes. The
- `TREE_REALPART' and `TREE_IMAGPART' return the real and the
- imaginary parts respectively.
-
-`VECTOR_CST'
- These nodes are used to represent vector constants, whose parts are
- constant nodes. Each individual constant node is either an
- integer or a double constant node. The first operand is a
- `TREE_LIST' of the constant nodes and is accessed through
- `TREE_VECTOR_CST_ELTS'.
-
-`STRING_CST'
- These nodes represent string-constants. The `TREE_STRING_LENGTH'
- returns the length of the string, as an `int'. The
- `TREE_STRING_POINTER' is a `char*' containing the string itself.
- The string may not be `NUL'-terminated, and it may contain
- embedded `NUL' characters. Therefore, the `TREE_STRING_LENGTH'
- includes the trailing `NUL' if it is present.
-
- For wide string constants, the `TREE_STRING_LENGTH' is the number
- of bytes in the string, and the `TREE_STRING_POINTER' points to an
- array of the bytes of the string, as represented on the target
- system (that is, as integers in the target endianness). Wide and
- non-wide string constants are distinguished only by the `TREE_TYPE'
- of the `STRING_CST'.
-
- FIXME: The formats of string constants are not well-defined when
- the target system bytes are not the same width as host system
- bytes.
-
-`PTRMEM_CST'
- These nodes are used to represent pointer-to-member constants. The
- `PTRMEM_CST_CLASS' is the class type (either a `RECORD_TYPE' or
- `UNION_TYPE' within which the pointer points), and the
- `PTRMEM_CST_MEMBER' is the declaration for the pointed to object.
- Note that the `DECL_CONTEXT' for the `PTRMEM_CST_MEMBER' is in
- general different from the `PTRMEM_CST_CLASS'. For example, given:
- struct B { int i; };
- struct D : public B {};
- int D::*dp = &D::i;
- The `PTRMEM_CST_CLASS' for `&D::i' is `D', even though the
- `DECL_CONTEXT' for the `PTRMEM_CST_MEMBER' is `B', since `B::i' is
- a member of `B', not `D'.
-
-`VAR_DECL'
- These nodes represent variables, including static data members.
- For more information, *note Declarations::.
-
-`NEGATE_EXPR'
- These nodes represent unary negation of the single operand, for
- both integer and floating-point types. The type of negation can be
- determined by looking at the type of the expression.
-
- The behavior of this operation on signed arithmetic overflow is
- controlled by the `flag_wrapv' and `flag_trapv' variables.
-
-`ABS_EXPR'
- These nodes represent the absolute value of the single operand, for
- both integer and floating-point types. This is typically used to
- implement the `abs', `labs' and `llabs' builtins for integer
- types, and the `fabs', `fabsf' and `fabsl' builtins for floating
- point types. The type of abs operation can be determined by
- looking at the type of the expression.
-
- This node is not used for complex types. To represent the modulus
- or complex abs of a complex value, use the `BUILT_IN_CABS',
- `BUILT_IN_CABSF' or `BUILT_IN_CABSL' builtins, as used to
- implement the C99 `cabs', `cabsf' and `cabsl' built-in functions.
-
-`BIT_NOT_EXPR'
- These nodes represent bitwise complement, and will always have
- integral type. The only operand is the value to be complemented.
-
-`TRUTH_NOT_EXPR'
- These nodes represent logical negation, and will always have
- integral (or boolean) type. The operand is the value being
- negated. The type of the operand and that of the result are
- always of `BOOLEAN_TYPE' or `INTEGER_TYPE'.
-
-`PREDECREMENT_EXPR'
-`PREINCREMENT_EXPR'
-`POSTDECREMENT_EXPR'
-`POSTINCREMENT_EXPR'
- These nodes represent increment and decrement expressions. The
- value of the single operand is computed, and the operand
- incremented or decremented. In the case of `PREDECREMENT_EXPR' and
- `PREINCREMENT_EXPR', the value of the expression is the value
- resulting after the increment or decrement; in the case of
- `POSTDECREMENT_EXPR' and `POSTINCREMENT_EXPR' is the value before
- the increment or decrement occurs. The type of the operand, like
- that of the result, will be either integral, boolean, or
- floating-point.
-
-`ADDR_EXPR'
- These nodes are used to represent the address of an object. (These
- expressions will always have pointer or reference type.) The
- operand may be another expression, or it may be a declaration.
-
- As an extension, GCC allows users to take the address of a label.
- In this case, the operand of the `ADDR_EXPR' will be a
- `LABEL_DECL'. The type of such an expression is `void*'.
-
- If the object addressed is not an lvalue, a temporary is created,
- and the address of the temporary is used.
-
-`INDIRECT_REF'
- These nodes are used to represent the object pointed to by a
- pointer. The operand is the pointer being dereferenced; it will
- always have pointer or reference type.
-
-`FIX_TRUNC_EXPR'
- These nodes represent conversion of a floating-point value to an
- integer. The single operand will have a floating-point type, while
- the complete expression will have an integral (or boolean) type.
- The operand is rounded towards zero.
-
-`FLOAT_EXPR'
- These nodes represent conversion of an integral (or boolean) value
- to a floating-point value. The single operand will have integral
- type, while the complete expression will have a floating-point
- type.
-
- FIXME: How is the operand supposed to be rounded? Is this
- dependent on `-mieee'?
-
-`COMPLEX_EXPR'
- These nodes are used to represent complex numbers constructed from
- two expressions of the same (integer or real) type. The first
- operand is the real part and the second operand is the imaginary
- part.
-
-`CONJ_EXPR'
- These nodes represent the conjugate of their operand.
-
-`REALPART_EXPR'
-`IMAGPART_EXPR'
- These nodes represent respectively the real and the imaginary parts
- of complex numbers (their sole argument).
-
-`NON_LVALUE_EXPR'
- These nodes indicate that their one and only operand is not an
- lvalue. A back end can treat these identically to the single
- operand.
-
-`NOP_EXPR'
- These nodes are used to represent conversions that do not require
- any code-generation. For example, conversion of a `char*' to an
- `int*' does not require any code be generated; such a conversion is
- represented by a `NOP_EXPR'. The single operand is the expression
- to be converted. The conversion from a pointer to a reference is
- also represented with a `NOP_EXPR'.
-
-`CONVERT_EXPR'
- These nodes are similar to `NOP_EXPR's, but are used in those
- situations where code may need to be generated. For example, if an
- `int*' is converted to an `int' code may need to be generated on
- some platforms. These nodes are never used for C++-specific
- conversions, like conversions between pointers to different
- classes in an inheritance hierarchy. Any adjustments that need to
- be made in such cases are always indicated explicitly. Similarly,
- a user-defined conversion is never represented by a
- `CONVERT_EXPR'; instead, the function calls are made explicit.
-
-`FIXED_CONVERT_EXPR'
- These nodes are used to represent conversions that involve
- fixed-point values. For example, from a fixed-point value to
- another fixed-point value, from an integer to a fixed-point value,
- from a fixed-point value to an integer, from a floating-point
- value to a fixed-point value, or from a fixed-point value to a
- floating-point value.
-
-`THROW_EXPR'
- These nodes represent `throw' expressions. The single operand is
- an expression for the code that should be executed to throw the
- exception. However, there is one implicit action not represented
- in that expression; namely the call to `__throw'. This function
- takes no arguments. If `setjmp'/`longjmp' exceptions are used, the
- function `__sjthrow' is called instead. The normal GCC back end
- uses the function `emit_throw' to generate this code; you can
- examine this function to see what needs to be done.
-
-`LSHIFT_EXPR'
-`RSHIFT_EXPR'
- These nodes represent left and right shifts, respectively. The
- first operand is the value to shift; it will always be of integral
- type. The second operand is an expression for the number of bits
- by which to shift. Right shift should be treated as arithmetic,
- i.e., the high-order bits should be zero-filled when the
- expression has unsigned type and filled with the sign bit when the
- expression has signed type. Note that the result is undefined if
- the second operand is larger than or equal to the first operand's
- type size.
-
-`BIT_IOR_EXPR'
-`BIT_XOR_EXPR'
-`BIT_AND_EXPR'
- These nodes represent bitwise inclusive or, bitwise exclusive or,
- and bitwise and, respectively. Both operands will always have
- integral type.
-
-`TRUTH_ANDIF_EXPR'
-`TRUTH_ORIF_EXPR'
- These nodes represent logical "and" and logical "or", respectively.
- These operators are not strict; i.e., the second operand is
- evaluated only if the value of the expression is not determined by
- evaluation of the first operand. The type of the operands and
- that of the result are always of `BOOLEAN_TYPE' or `INTEGER_TYPE'.
-
-`TRUTH_AND_EXPR'
-`TRUTH_OR_EXPR'
-`TRUTH_XOR_EXPR'
- These nodes represent logical and, logical or, and logical
- exclusive or. They are strict; both arguments are always
- evaluated. There are no corresponding operators in C or C++, but
- the front end will sometimes generate these expressions anyhow, if
- it can tell that strictness does not matter. The type of the
- operands and that of the result are always of `BOOLEAN_TYPE' or
- `INTEGER_TYPE'.
-
-`POINTER_PLUS_EXPR'
- This node represents pointer arithmetic. The first operand is
- always a pointer/reference type. The second operand is always an
- unsigned integer type compatible with sizetype. This is the only
- binary arithmetic operand that can operate on pointer types.
-
-`PLUS_EXPR'
-`MINUS_EXPR'
-`MULT_EXPR'
- These nodes represent various binary arithmetic operations.
- Respectively, these operations are addition, subtraction (of the
- second operand from the first) and multiplication. Their operands
- may have either integral or floating type, but there will never be
- case in which one operand is of floating type and the other is of
- integral type.
-
- The behavior of these operations on signed arithmetic overflow is
- controlled by the `flag_wrapv' and `flag_trapv' variables.
-
-`RDIV_EXPR'
- This node represents a floating point division operation.
-
-`TRUNC_DIV_EXPR'
-`FLOOR_DIV_EXPR'
-`CEIL_DIV_EXPR'
-`ROUND_DIV_EXPR'
- These nodes represent integer division operations that return an
- integer result. `TRUNC_DIV_EXPR' rounds towards zero,
- `FLOOR_DIV_EXPR' rounds towards negative infinity, `CEIL_DIV_EXPR'
- rounds towards positive infinity and `ROUND_DIV_EXPR' rounds to
- the closest integer. Integer division in C and C++ is truncating,
- i.e. `TRUNC_DIV_EXPR'.
-
- The behavior of these operations on signed arithmetic overflow,
- when dividing the minimum signed integer by minus one, is
- controlled by the `flag_wrapv' and `flag_trapv' variables.
-
-`TRUNC_MOD_EXPR'
-`FLOOR_MOD_EXPR'
-`CEIL_MOD_EXPR'
-`ROUND_MOD_EXPR'
- These nodes represent the integer remainder or modulus operation.
- The integer modulus of two operands `a' and `b' is defined as `a -
- (a/b)*b' where the division calculated using the corresponding
- division operator. Hence for `TRUNC_MOD_EXPR' this definition
- assumes division using truncation towards zero, i.e.
- `TRUNC_DIV_EXPR'. Integer remainder in C and C++ uses truncating
- division, i.e. `TRUNC_MOD_EXPR'.
-
-`EXACT_DIV_EXPR'
- The `EXACT_DIV_EXPR' code is used to represent integer divisions
- where the numerator is known to be an exact multiple of the
- denominator. This allows the backend to choose between the faster
- of `TRUNC_DIV_EXPR', `CEIL_DIV_EXPR' and `FLOOR_DIV_EXPR' for the
- current target.
-
-`ARRAY_REF'
- These nodes represent array accesses. The first operand is the
- array; the second is the index. To calculate the address of the
- memory accessed, you must scale the index by the size of the type
- of the array elements. The type of these expressions must be the
- type of a component of the array. The third and fourth operands
- are used after gimplification to represent the lower bound and
- component size but should not be used directly; call
- `array_ref_low_bound' and `array_ref_element_size' instead.
-
-`ARRAY_RANGE_REF'
- These nodes represent access to a range (or "slice") of an array.
- The operands are the same as that for `ARRAY_REF' and have the same
- meanings. The type of these expressions must be an array whose
- component type is the same as that of the first operand. The
- range of that array type determines the amount of data these
- expressions access.
-
-`TARGET_MEM_REF'
- These nodes represent memory accesses whose address directly map to
- an addressing mode of the target architecture. The first argument
- is `TMR_SYMBOL' and must be a `VAR_DECL' of an object with a fixed
- address. The second argument is `TMR_BASE' and the third one is
- `TMR_INDEX'. The fourth argument is `TMR_STEP' and must be an
- `INTEGER_CST'. The fifth argument is `TMR_OFFSET' and must be an
- `INTEGER_CST'. Any of the arguments may be NULL if the
- appropriate component does not appear in the address. Address of
- the `TARGET_MEM_REF' is determined in the following way.
-
- &TMR_SYMBOL + TMR_BASE + TMR_INDEX * TMR_STEP + TMR_OFFSET
-
- The sixth argument is the reference to the original memory access,
- which is preserved for the purposes of the RTL alias analysis.
- The seventh argument is a tag representing the results of tree
- level alias analysis.
-
-`LT_EXPR'
-`LE_EXPR'
-`GT_EXPR'
-`GE_EXPR'
-`EQ_EXPR'
-`NE_EXPR'
- These nodes represent the less than, less than or equal to, greater
- than, greater than or equal to, equal, and not equal comparison
- operators. The first and second operand with either be both of
- integral type or both of floating type. The result type of these
- expressions will always be of integral or boolean type. These
- operations return the result type's zero value for false, and the
- result type's one value for true.
-
- For floating point comparisons, if we honor IEEE NaNs and either
- operand is NaN, then `NE_EXPR' always returns true and the
- remaining operators always return false. On some targets,
- comparisons against an IEEE NaN, other than equality and
- inequality, may generate a floating point exception.
-
-`ORDERED_EXPR'
-`UNORDERED_EXPR'
- These nodes represent non-trapping ordered and unordered comparison
- operators. These operations take two floating point operands and
- determine whether they are ordered or unordered relative to each
- other. If either operand is an IEEE NaN, their comparison is
- defined to be unordered, otherwise the comparison is defined to be
- ordered. The result type of these expressions will always be of
- integral or boolean type. These operations return the result
- type's zero value for false, and the result type's one value for
- true.
-
-`UNLT_EXPR'
-`UNLE_EXPR'
-`UNGT_EXPR'
-`UNGE_EXPR'
-`UNEQ_EXPR'
-`LTGT_EXPR'
- These nodes represent the unordered comparison operators. These
- operations take two floating point operands and determine whether
- the operands are unordered or are less than, less than or equal to,
- greater than, greater than or equal to, or equal respectively. For
- example, `UNLT_EXPR' returns true if either operand is an IEEE NaN
- or the first operand is less than the second. With the possible
- exception of `LTGT_EXPR', all of these operations are guaranteed
- not to generate a floating point exception. The result type of
- these expressions will always be of integral or boolean type.
- These operations return the result type's zero value for false,
- and the result type's one value for true.
-
-`MODIFY_EXPR'
- These nodes represent assignment. The left-hand side is the first
- operand; the right-hand side is the second operand. The left-hand
- side will be a `VAR_DECL', `INDIRECT_REF', `COMPONENT_REF', or
- other lvalue.
-
- These nodes are used to represent not only assignment with `=' but
- also compound assignments (like `+='), by reduction to `='
- assignment. In other words, the representation for `i += 3' looks
- just like that for `i = i + 3'.
-
-`INIT_EXPR'
- These nodes are just like `MODIFY_EXPR', but are used only when a
- variable is initialized, rather than assigned to subsequently.
- This means that we can assume that the target of the
- initialization is not used in computing its own value; any
- reference to the lhs in computing the rhs is undefined.
-
-`COMPONENT_REF'
- These nodes represent non-static data member accesses. The first
- operand is the object (rather than a pointer to it); the second
- operand is the `FIELD_DECL' for the data member. The third
- operand represents the byte offset of the field, but should not be
- used directly; call `component_ref_field_offset' instead.
-
-`COMPOUND_EXPR'
- These nodes represent comma-expressions. The first operand is an
- expression whose value is computed and thrown away prior to the
- evaluation of the second operand. The value of the entire
- expression is the value of the second operand.
-
-`COND_EXPR'
- These nodes represent `?:' expressions. The first operand is of
- boolean or integral type. If it evaluates to a nonzero value, the
- second operand should be evaluated, and returned as the value of
- the expression. Otherwise, the third operand is evaluated, and
- returned as the value of the expression.
-
- The second operand must have the same type as the entire
- expression, unless it unconditionally throws an exception or calls
- a noreturn function, in which case it should have void type. The
- same constraints apply to the third operand. This allows array
- bounds checks to be represented conveniently as `(i >= 0 && i <
- 10) ? i : abort()'.
-
- As a GNU extension, the C language front-ends allow the second
- operand of the `?:' operator may be omitted in the source. For
- example, `x ? : 3' is equivalent to `x ? x : 3', assuming that `x'
- is an expression without side-effects. In the tree
- representation, however, the second operand is always present,
- possibly protected by `SAVE_EXPR' if the first argument does cause
- side-effects.
-
-`CALL_EXPR'
- These nodes are used to represent calls to functions, including
- non-static member functions. `CALL_EXPR's are implemented as
- expression nodes with a variable number of operands. Rather than
- using `TREE_OPERAND' to extract them, it is preferable to use the
- specialized accessor macros and functions that operate
- specifically on `CALL_EXPR' nodes.
-
- `CALL_EXPR_FN' returns a pointer to the function to call; it is
- always an expression whose type is a `POINTER_TYPE'.
-
- The number of arguments to the call is returned by
- `call_expr_nargs', while the arguments themselves can be accessed
- with the `CALL_EXPR_ARG' macro. The arguments are zero-indexed
- and numbered left-to-right. You can iterate over the arguments
- using `FOR_EACH_CALL_EXPR_ARG', as in:
-
- tree call, arg;
- call_expr_arg_iterator iter;
- FOR_EACH_CALL_EXPR_ARG (arg, iter, call)
- /* arg is bound to successive arguments of call. */
- ...;
-
- For non-static member functions, there will be an operand
- corresponding to the `this' pointer. There will always be
- expressions corresponding to all of the arguments, even if the
- function is declared with default arguments and some arguments are
- not explicitly provided at the call sites.
-
- `CALL_EXPR's also have a `CALL_EXPR_STATIC_CHAIN' operand that is
- used to implement nested functions. This operand is otherwise
- null.
-
-`STMT_EXPR'
- These nodes are used to represent GCC's statement-expression
- extension. The statement-expression extension allows code like
- this:
- int f() { return ({ int j; j = 3; j + 7; }); }
- In other words, an sequence of statements may occur where a single
- expression would normally appear. The `STMT_EXPR' node represents
- such an expression. The `STMT_EXPR_STMT' gives the statement
- contained in the expression. The value of the expression is the
- value of the last sub-statement in the body. More precisely, the
- value is the value computed by the last statement nested inside
- `BIND_EXPR', `TRY_FINALLY_EXPR', or `TRY_CATCH_EXPR'. For
- example, in:
- ({ 3; })
- the value is `3' while in:
- ({ if (x) { 3; } })
- there is no value. If the `STMT_EXPR' does not yield a value,
- it's type will be `void'.
-
-`BIND_EXPR'
- These nodes represent local blocks. The first operand is a list of
- variables, connected via their `TREE_CHAIN' field. These will
- never require cleanups. The scope of these variables is just the
- body of the `BIND_EXPR'. The body of the `BIND_EXPR' is the
- second operand.
-
-`LOOP_EXPR'
- These nodes represent "infinite" loops. The `LOOP_EXPR_BODY'
- represents the body of the loop. It should be executed forever,
- unless an `EXIT_EXPR' is encountered.
-
-`EXIT_EXPR'
- These nodes represent conditional exits from the nearest enclosing
- `LOOP_EXPR'. The single operand is the condition; if it is
- nonzero, then the loop should be exited. An `EXIT_EXPR' will only
- appear within a `LOOP_EXPR'.
-
-`CLEANUP_POINT_EXPR'
- These nodes represent full-expressions. The single operand is an
- expression to evaluate. Any destructor calls engendered by the
- creation of temporaries during the evaluation of that expression
- should be performed immediately after the expression is evaluated.
-
-`CONSTRUCTOR'
- These nodes represent the brace-enclosed initializers for a
- structure or array. The first operand is reserved for use by the
- back end. The second operand is a `TREE_LIST'. If the
- `TREE_TYPE' of the `CONSTRUCTOR' is a `RECORD_TYPE' or
- `UNION_TYPE', then the `TREE_PURPOSE' of each node in the
- `TREE_LIST' will be a `FIELD_DECL' and the `TREE_VALUE' of each
- node will be the expression used to initialize that field.
-
- If the `TREE_TYPE' of the `CONSTRUCTOR' is an `ARRAY_TYPE', then
- the `TREE_PURPOSE' of each element in the `TREE_LIST' will be an
- `INTEGER_CST' or a `RANGE_EXPR' of two `INTEGER_CST's. A single
- `INTEGER_CST' indicates which element of the array (indexed from
- zero) is being assigned to. A `RANGE_EXPR' indicates an inclusive
- range of elements to initialize. In both cases the `TREE_VALUE'
- is the corresponding initializer. It is re-evaluated for each
- element of a `RANGE_EXPR'. If the `TREE_PURPOSE' is `NULL_TREE',
- then the initializer is for the next available array element.
-
- In the front end, you should not depend on the fields appearing in
- any particular order. However, in the middle end, fields must
- appear in declaration order. You should not assume that all
- fields will be represented. Unrepresented fields will be set to
- zero.
-
-`COMPOUND_LITERAL_EXPR'
- These nodes represent ISO C99 compound literals. The
- `COMPOUND_LITERAL_EXPR_DECL_STMT' is a `DECL_STMT' containing an
- anonymous `VAR_DECL' for the unnamed object represented by the
- compound literal; the `DECL_INITIAL' of that `VAR_DECL' is a
- `CONSTRUCTOR' representing the brace-enclosed list of initializers
- in the compound literal. That anonymous `VAR_DECL' can also be
- accessed directly by the `COMPOUND_LITERAL_EXPR_DECL' macro.
-
-`SAVE_EXPR'
- A `SAVE_EXPR' represents an expression (possibly involving
- side-effects) that is used more than once. The side-effects should
- occur only the first time the expression is evaluated. Subsequent
- uses should just reuse the computed value. The first operand to
- the `SAVE_EXPR' is the expression to evaluate. The side-effects
- should be executed where the `SAVE_EXPR' is first encountered in a
- depth-first preorder traversal of the expression tree.
-
-`TARGET_EXPR'
- A `TARGET_EXPR' represents a temporary object. The first operand
- is a `VAR_DECL' for the temporary variable. The second operand is
- the initializer for the temporary. The initializer is evaluated
- and, if non-void, copied (bitwise) into the temporary. If the
- initializer is void, that means that it will perform the
- initialization itself.
-
- Often, a `TARGET_EXPR' occurs on the right-hand side of an
- assignment, or as the second operand to a comma-expression which is
- itself the right-hand side of an assignment, etc. In this case,
- we say that the `TARGET_EXPR' is "normal"; otherwise, we say it is
- "orphaned". For a normal `TARGET_EXPR' the temporary variable
- should be treated as an alias for the left-hand side of the
- assignment, rather than as a new temporary variable.
-
- The third operand to the `TARGET_EXPR', if present, is a
- cleanup-expression (i.e., destructor call) for the temporary. If
- this expression is orphaned, then this expression must be executed
- when the statement containing this expression is complete. These
- cleanups must always be executed in the order opposite to that in
- which they were encountered. Note that if a temporary is created
- on one branch of a conditional operator (i.e., in the second or
- third operand to a `COND_EXPR'), the cleanup must be run only if
- that branch is actually executed.
-
- See `STMT_IS_FULL_EXPR_P' for more information about running these
- cleanups.
-
-`AGGR_INIT_EXPR'
- An `AGGR_INIT_EXPR' represents the initialization as the return
- value of a function call, or as the result of a constructor. An
- `AGGR_INIT_EXPR' will only appear as a full-expression, or as the
- second operand of a `TARGET_EXPR'. `AGGR_INIT_EXPR's have a
- representation similar to that of `CALL_EXPR's. You can use the
- `AGGR_INIT_EXPR_FN' and `AGGR_INIT_EXPR_ARG' macros to access the
- function to call and the arguments to pass.
-
- If `AGGR_INIT_VIA_CTOR_P' holds of the `AGGR_INIT_EXPR', then the
- initialization is via a constructor call. The address of the
- `AGGR_INIT_EXPR_SLOT' operand, which is always a `VAR_DECL', is
- taken, and this value replaces the first argument in the argument
- list.
-
- In either case, the expression is void.
-
-`VA_ARG_EXPR'
- This node is used to implement support for the C/C++ variable
- argument-list mechanism. It represents expressions like `va_arg
- (ap, type)'. Its `TREE_TYPE' yields the tree representation for
- `type' and its sole argument yields the representation for `ap'.
-
-`CHANGE_DYNAMIC_TYPE_EXPR'
- Indicates the special aliasing required by C++ placement new. It
- has two operands: a type and a location. It means that the
- dynamic type of the location is changing to be the specified type.
- The alias analysis code takes this into account when doing type
- based alias analysis.
-
-`OMP_PARALLEL'
- Represents `#pragma omp parallel [clause1 ... clauseN]'. It has
- four operands:
-
- Operand `OMP_PARALLEL_BODY' is valid while in GENERIC and High
- GIMPLE forms. It contains the body of code to be executed by all
- the threads. During GIMPLE lowering, this operand becomes `NULL'
- and the body is emitted linearly after `OMP_PARALLEL'.
-
- Operand `OMP_PARALLEL_CLAUSES' is the list of clauses associated
- with the directive.
-
- Operand `OMP_PARALLEL_FN' is created by `pass_lower_omp', it
- contains the `FUNCTION_DECL' for the function that will contain
- the body of the parallel region.
-
- Operand `OMP_PARALLEL_DATA_ARG' is also created by
- `pass_lower_omp'. If there are shared variables to be communicated
- to the children threads, this operand will contain the `VAR_DECL'
- that contains all the shared values and variables.
-
-`OMP_FOR'
- Represents `#pragma omp for [clause1 ... clauseN]'. It has 5
- operands:
-
- Operand `OMP_FOR_BODY' contains the loop body.
-
- Operand `OMP_FOR_CLAUSES' is the list of clauses associated with
- the directive.
-
- Operand `OMP_FOR_INIT' is the loop initialization code of the form
- `VAR = N1'.
-
- Operand `OMP_FOR_COND' is the loop conditional expression of the
- form `VAR {<,>,<=,>=} N2'.
-
- Operand `OMP_FOR_INCR' is the loop index increment of the form
- `VAR {+=,-=} INCR'.
-
- Operand `OMP_FOR_PRE_BODY' contains side-effect code from operands
- `OMP_FOR_INIT', `OMP_FOR_COND' and `OMP_FOR_INC'. These
- side-effects are part of the `OMP_FOR' block but must be evaluated
- before the start of loop body.
-
- The loop index variable `VAR' must be a signed integer variable,
- which is implicitly private to each thread. Bounds `N1' and `N2'
- and the increment expression `INCR' are required to be loop
- invariant integer expressions that are evaluated without any
- synchronization. The evaluation order, frequency of evaluation and
- side-effects are unspecified by the standard.
-
-`OMP_SECTIONS'
- Represents `#pragma omp sections [clause1 ... clauseN]'.
-
- Operand `OMP_SECTIONS_BODY' contains the sections body, which in
- turn contains a set of `OMP_SECTION' nodes for each of the
- concurrent sections delimited by `#pragma omp section'.
-
- Operand `OMP_SECTIONS_CLAUSES' is the list of clauses associated
- with the directive.
-
-`OMP_SECTION'
- Section delimiter for `OMP_SECTIONS'.
-
-`OMP_SINGLE'
- Represents `#pragma omp single'.
-
- Operand `OMP_SINGLE_BODY' contains the body of code to be executed
- by a single thread.
-
- Operand `OMP_SINGLE_CLAUSES' is the list of clauses associated
- with the directive.
-
-`OMP_MASTER'
- Represents `#pragma omp master'.
-
- Operand `OMP_MASTER_BODY' contains the body of code to be executed
- by the master thread.
-
-`OMP_ORDERED'
- Represents `#pragma omp ordered'.
-
- Operand `OMP_ORDERED_BODY' contains the body of code to be
- executed in the sequential order dictated by the loop index
- variable.
-
-`OMP_CRITICAL'
- Represents `#pragma omp critical [name]'.
-
- Operand `OMP_CRITICAL_BODY' is the critical section.
-
- Operand `OMP_CRITICAL_NAME' is an optional identifier to label the
- critical section.
-
-`OMP_RETURN'
- This does not represent any OpenMP directive, it is an artificial
- marker to indicate the end of the body of an OpenMP. It is used by
- the flow graph (`tree-cfg.c') and OpenMP region building code
- (`omp-low.c').
-
-`OMP_CONTINUE'
- Similarly, this instruction does not represent an OpenMP
- directive, it is used by `OMP_FOR' and `OMP_SECTIONS' to mark the
- place where the code needs to loop to the next iteration (in the
- case of `OMP_FOR') or the next section (in the case of
- `OMP_SECTIONS').
-
- In some cases, `OMP_CONTINUE' is placed right before `OMP_RETURN'.
- But if there are cleanups that need to occur right after the
- looping body, it will be emitted between `OMP_CONTINUE' and
- `OMP_RETURN'.
-
-`OMP_ATOMIC'
- Represents `#pragma omp atomic'.
-
- Operand 0 is the address at which the atomic operation is to be
- performed.
-
- Operand 1 is the expression to evaluate. The gimplifier tries
- three alternative code generation strategies. Whenever possible,
- an atomic update built-in is used. If that fails, a
- compare-and-swap loop is attempted. If that also fails, a regular
- critical section around the expression is used.
-
-`OMP_CLAUSE'
- Represents clauses associated with one of the `OMP_' directives.
- Clauses are represented by separate sub-codes defined in `tree.h'.
- Clauses codes can be one of: `OMP_CLAUSE_PRIVATE',
- `OMP_CLAUSE_SHARED', `OMP_CLAUSE_FIRSTPRIVATE',
- `OMP_CLAUSE_LASTPRIVATE', `OMP_CLAUSE_COPYIN',
- `OMP_CLAUSE_COPYPRIVATE', `OMP_CLAUSE_IF',
- `OMP_CLAUSE_NUM_THREADS', `OMP_CLAUSE_SCHEDULE',
- `OMP_CLAUSE_NOWAIT', `OMP_CLAUSE_ORDERED', `OMP_CLAUSE_DEFAULT',
- and `OMP_CLAUSE_REDUCTION'. Each code represents the
- corresponding OpenMP clause.
-
- Clauses associated with the same directive are chained together
- via `OMP_CLAUSE_CHAIN'. Those clauses that accept a list of
- variables are restricted to exactly one, accessed with
- `OMP_CLAUSE_VAR'. Therefore, multiple variables under the same
- clause `C' need to be represented as multiple `C' clauses chained
- together. This facilitates adding new clauses during compilation.
-
-`VEC_LSHIFT_EXPR'
-
-`VEC_RSHIFT_EXPR'
- These nodes represent whole vector left and right shifts,
- respectively. The first operand is the vector to shift; it will
- always be of vector type. The second operand is an expression for
- the number of bits by which to shift. Note that the result is
- undefined if the second operand is larger than or equal to the
- first operand's type size.
-
-`VEC_WIDEN_MULT_HI_EXPR'
-
-`VEC_WIDEN_MULT_LO_EXPR'
- These nodes represent widening vector multiplication of the high
- and low parts of the two input vectors, respectively. Their
- operands are vectors that contain the same number of elements
- (`N') of the same integral type. The result is a vector that
- contains half as many elements, of an integral type whose size is
- twice as wide. In the case of `VEC_WIDEN_MULT_HI_EXPR' the high
- `N/2' elements of the two vector are multiplied to produce the
- vector of `N/2' products. In the case of `VEC_WIDEN_MULT_LO_EXPR'
- the low `N/2' elements of the two vector are multiplied to produce
- the vector of `N/2' products.
-
-`VEC_UNPACK_HI_EXPR'
-
-`VEC_UNPACK_LO_EXPR'
- These nodes represent unpacking of the high and low parts of the
- input vector, respectively. The single operand is a vector that
- contains `N' elements of the same integral or floating point type.
- The result is a vector that contains half as many elements, of an
- integral or floating point type whose size is twice as wide. In
- the case of `VEC_UNPACK_HI_EXPR' the high `N/2' elements of the
- vector are extracted and widened (promoted). In the case of
- `VEC_UNPACK_LO_EXPR' the low `N/2' elements of the vector are
- extracted and widened (promoted).
-
-`VEC_UNPACK_FLOAT_HI_EXPR'
-
-`VEC_UNPACK_FLOAT_LO_EXPR'
- These nodes represent unpacking of the high and low parts of the
- input vector, where the values are converted from fixed point to
- floating point. The single operand is a vector that contains `N'
- elements of the same integral type. The result is a vector that
- contains half as many elements of a floating point type whose size
- is twice as wide. In the case of `VEC_UNPACK_HI_EXPR' the high
- `N/2' elements of the vector are extracted, converted and widened.
- In the case of `VEC_UNPACK_LO_EXPR' the low `N/2' elements of the
- vector are extracted, converted and widened.
-
-`VEC_PACK_TRUNC_EXPR'
- This node represents packing of truncated elements of the two
- input vectors into the output vector. Input operands are vectors
- that contain the same number of elements of the same integral or
- floating point type. The result is a vector that contains twice
- as many elements of an integral or floating point type whose size
- is half as wide. The elements of the two vectors are demoted and
- merged (concatenated) to form the output vector.
-
-`VEC_PACK_SAT_EXPR'
- This node represents packing of elements of the two input vectors
- into the output vector using saturation. Input operands are
- vectors that contain the same number of elements of the same
- integral type. The result is a vector that contains twice as many
- elements of an integral type whose size is half as wide. The
- elements of the two vectors are demoted and merged (concatenated)
- to form the output vector.
-
-`VEC_PACK_FIX_TRUNC_EXPR'
- This node represents packing of elements of the two input vectors
- into the output vector, where the values are converted from
- floating point to fixed point. Input operands are vectors that
- contain the same number of elements of a floating point type. The
- result is a vector that contains twice as many elements of an
- integral type whose size is half as wide. The elements of the two
- vectors are merged (concatenated) to form the output vector.
-
-`VEC_EXTRACT_EVEN_EXPR'
-
-`VEC_EXTRACT_ODD_EXPR'
- These nodes represent extracting of the even/odd elements of the
- two input vectors, respectively. Their operands and result are
- vectors that contain the same number of elements of the same type.
-
-`VEC_INTERLEAVE_HIGH_EXPR'
-
-`VEC_INTERLEAVE_LOW_EXPR'
- These nodes represent merging and interleaving of the high/low
- elements of the two input vectors, respectively. The operands and
- the result are vectors that contain the same number of elements
- (`N') of the same type. In the case of
- `VEC_INTERLEAVE_HIGH_EXPR', the high `N/2' elements of the first
- input vector are interleaved with the high `N/2' elements of the
- second input vector. In the case of `VEC_INTERLEAVE_LOW_EXPR', the
- low `N/2' elements of the first input vector are interleaved with
- the low `N/2' elements of the second input vector.
-
-
-\1f
-File: gccint.info, Node: RTL, Next: Control Flow, Prev: Tree SSA, Up: Top
-
-10 RTL Representation
-*********************
-
-The last part of the compiler work is done on a low-level intermediate
-representation called Register Transfer Language. In this language, the
-instructions to be output are described, pretty much one by one, in an
-algebraic form that describes what the instruction does.
-
- RTL is inspired by Lisp lists. It has both an internal form, made up
-of structures that point at other structures, and a textual form that
-is used in the machine description and in printed debugging dumps. The
-textual form uses nested parentheses to indicate the pointers in the
-internal form.
-
-* Menu:
-
-* RTL Objects:: Expressions vs vectors vs strings vs integers.
-* RTL Classes:: Categories of RTL expression objects, and their structure.
-* Accessors:: Macros to access expression operands or vector elts.
-* Special Accessors:: Macros to access specific annotations on RTL.
-* Flags:: Other flags in an RTL expression.
-* Machine Modes:: Describing the size and format of a datum.
-* Constants:: Expressions with constant values.
-* Regs and Memory:: Expressions representing register contents or memory.
-* Arithmetic:: Expressions representing arithmetic on other expressions.
-* Comparisons:: Expressions representing comparison of expressions.
-* Bit-Fields:: Expressions representing bit-fields in memory or reg.
-* Vector Operations:: Expressions involving vector datatypes.
-* Conversions:: Extending, truncating, floating or fixing.
-* RTL Declarations:: Declaring volatility, constancy, etc.
-* Side Effects:: Expressions for storing in registers, etc.
-* Incdec:: Embedded side-effects for autoincrement addressing.
-* Assembler:: Representing `asm' with operands.
-* Insns:: Expression types for entire insns.
-* Calls:: RTL representation of function call insns.
-* Sharing:: Some expressions are unique; others *must* be copied.
-* Reading RTL:: Reading textual RTL from a file.
-
-\1f
-File: gccint.info, Node: RTL Objects, Next: RTL Classes, Up: RTL
-
-10.1 RTL Object Types
-=====================
-
-RTL uses five kinds of objects: expressions, integers, wide integers,
-strings and vectors. Expressions are the most important ones. An RTL
-expression ("RTX", for short) is a C structure, but it is usually
-referred to with a pointer; a type that is given the typedef name `rtx'.
-
- An integer is simply an `int'; their written form uses decimal digits.
-A wide integer is an integral object whose type is `HOST_WIDE_INT';
-their written form uses decimal digits.
-
- A string is a sequence of characters. In core it is represented as a
-`char *' in usual C fashion, and it is written in C syntax as well.
-However, strings in RTL may never be null. If you write an empty
-string in a machine description, it is represented in core as a null
-pointer rather than as a pointer to a null character. In certain
-contexts, these null pointers instead of strings are valid. Within RTL
-code, strings are most commonly found inside `symbol_ref' expressions,
-but they appear in other contexts in the RTL expressions that make up
-machine descriptions.
-
- In a machine description, strings are normally written with double
-quotes, as you would in C. However, strings in machine descriptions may
-extend over many lines, which is invalid C, and adjacent string
-constants are not concatenated as they are in C. Any string constant
-may be surrounded with a single set of parentheses. Sometimes this
-makes the machine description easier to read.
-
- There is also a special syntax for strings, which can be useful when C
-code is embedded in a machine description. Wherever a string can
-appear, it is also valid to write a C-style brace block. The entire
-brace block, including the outermost pair of braces, is considered to be
-the string constant. Double quote characters inside the braces are not
-special. Therefore, if you write string constants in the C code, you
-need not escape each quote character with a backslash.
-
- A vector contains an arbitrary number of pointers to expressions. The
-number of elements in the vector is explicitly present in the vector.
-The written form of a vector consists of square brackets (`[...]')
-surrounding the elements, in sequence and with whitespace separating
-them. Vectors of length zero are not created; null pointers are used
-instead.
-
- Expressions are classified by "expression codes" (also called RTX
-codes). The expression code is a name defined in `rtl.def', which is
-also (in uppercase) a C enumeration constant. The possible expression
-codes and their meanings are machine-independent. The code of an RTX
-can be extracted with the macro `GET_CODE (X)' and altered with
-`PUT_CODE (X, NEWCODE)'.
-
- The expression code determines how many operands the expression
-contains, and what kinds of objects they are. In RTL, unlike Lisp, you
-cannot tell by looking at an operand what kind of object it is.
-Instead, you must know from its context--from the expression code of
-the containing expression. For example, in an expression of code
-`subreg', the first operand is to be regarded as an expression and the
-second operand as an integer. In an expression of code `plus', there
-are two operands, both of which are to be regarded as expressions. In
-a `symbol_ref' expression, there is one operand, which is to be
-regarded as a string.
-
- Expressions are written as parentheses containing the name of the
-expression type, its flags and machine mode if any, and then the
-operands of the expression (separated by spaces).
-
- Expression code names in the `md' file are written in lowercase, but
-when they appear in C code they are written in uppercase. In this
-manual, they are shown as follows: `const_int'.
-
- In a few contexts a null pointer is valid where an expression is
-normally wanted. The written form of this is `(nil)'.
-
-\1f
-File: gccint.info, Node: RTL Classes, Next: Accessors, Prev: RTL Objects, Up: RTL
-
-10.2 RTL Classes and Formats
-============================
-
-The various expression codes are divided into several "classes", which
-are represented by single characters. You can determine the class of
-an RTX code with the macro `GET_RTX_CLASS (CODE)'. Currently,
-`rtl.def' defines these classes:
-
-`RTX_OBJ'
- An RTX code that represents an actual object, such as a register
- (`REG') or a memory location (`MEM', `SYMBOL_REF'). `LO_SUM') is
- also included; instead, `SUBREG' and `STRICT_LOW_PART' are not in
- this class, but in class `x'.
-
-`RTX_CONST_OBJ'
- An RTX code that represents a constant object. `HIGH' is also
- included in this class.
-
-`RTX_COMPARE'
- An RTX code for a non-symmetric comparison, such as `GEU' or `LT'.
-
-`RTX_COMM_COMPARE'
- An RTX code for a symmetric (commutative) comparison, such as `EQ'
- or `ORDERED'.
-
-`RTX_UNARY'
- An RTX code for a unary arithmetic operation, such as `NEG',
- `NOT', or `ABS'. This category also includes value extension
- (sign or zero) and conversions between integer and floating point.
-
-`RTX_COMM_ARITH'
- An RTX code for a commutative binary operation, such as `PLUS' or
- `AND'. `NE' and `EQ' are comparisons, so they have class `<'.
-
-`RTX_BIN_ARITH'
- An RTX code for a non-commutative binary operation, such as
- `MINUS', `DIV', or `ASHIFTRT'.
-
-`RTX_BITFIELD_OPS'
- An RTX code for a bit-field operation. Currently only
- `ZERO_EXTRACT' and `SIGN_EXTRACT'. These have three inputs and
- are lvalues (so they can be used for insertion as well). *Note
- Bit-Fields::.
-
-`RTX_TERNARY'
- An RTX code for other three input operations. Currently only
- `IF_THEN_ELSE' and `VEC_MERGE'.
-
-`RTX_INSN'
- An RTX code for an entire instruction: `INSN', `JUMP_INSN', and
- `CALL_INSN'. *Note Insns::.
-
-`RTX_MATCH'
- An RTX code for something that matches in insns, such as
- `MATCH_DUP'. These only occur in machine descriptions.
-
-`RTX_AUTOINC'
- An RTX code for an auto-increment addressing mode, such as
- `POST_INC'.
-
-`RTX_EXTRA'
- All other RTX codes. This category includes the remaining codes
- used only in machine descriptions (`DEFINE_*', etc.). It also
- includes all the codes describing side effects (`SET', `USE',
- `CLOBBER', etc.) and the non-insns that may appear on an insn
- chain, such as `NOTE', `BARRIER', and `CODE_LABEL'. `SUBREG' is
- also part of this class.
-
- For each expression code, `rtl.def' specifies the number of contained
-objects and their kinds using a sequence of characters called the
-"format" of the expression code. For example, the format of `subreg'
-is `ei'.
-
- These are the most commonly used format characters:
-
-`e'
- An expression (actually a pointer to an expression).
-
-`i'
- An integer.
-
-`w'
- A wide integer.
-
-`s'
- A string.
-
-`E'
- A vector of expressions.
-
- A few other format characters are used occasionally:
-
-`u'
- `u' is equivalent to `e' except that it is printed differently in
- debugging dumps. It is used for pointers to insns.
-
-`n'
- `n' is equivalent to `i' except that it is printed differently in
- debugging dumps. It is used for the line number or code number of
- a `note' insn.
-
-`S'
- `S' indicates a string which is optional. In the RTL objects in
- core, `S' is equivalent to `s', but when the object is read, from
- an `md' file, the string value of this operand may be omitted. An
- omitted string is taken to be the null string.
-
-`V'
- `V' indicates a vector which is optional. In the RTL objects in
- core, `V' is equivalent to `E', but when the object is read from
- an `md' file, the vector value of this operand may be omitted. An
- omitted vector is effectively the same as a vector of no elements.
-
-`B'
- `B' indicates a pointer to basic block structure.
-
-`0'
- `0' means a slot whose contents do not fit any normal category.
- `0' slots are not printed at all in dumps, and are often used in
- special ways by small parts of the compiler.
-
- There are macros to get the number of operands and the format of an
-expression code:
-
-`GET_RTX_LENGTH (CODE)'
- Number of operands of an RTX of code CODE.
-
-`GET_RTX_FORMAT (CODE)'
- The format of an RTX of code CODE, as a C string.
-
- Some classes of RTX codes always have the same format. For example, it
-is safe to assume that all comparison operations have format `ee'.
-
-`1'
- All codes of this class have format `e'.
-
-`<'
-`c'
-`2'
- All codes of these classes have format `ee'.
-
-`b'
-`3'
- All codes of these classes have format `eee'.
-
-`i'
- All codes of this class have formats that begin with `iuueiee'.
- *Note Insns::. Note that not all RTL objects linked onto an insn
- chain are of class `i'.
-
-`o'
-`m'
-`x'
- You can make no assumptions about the format of these codes.
-
-\1f
-File: gccint.info, Node: Accessors, Next: Special Accessors, Prev: RTL Classes, Up: RTL
-
-10.3 Access to Operands
-=======================
-
-Operands of expressions are accessed using the macros `XEXP', `XINT',
-`XWINT' and `XSTR'. Each of these macros takes two arguments: an
-expression-pointer (RTX) and an operand number (counting from zero).
-Thus,
-
- XEXP (X, 2)
-
-accesses operand 2 of expression X, as an expression.
-
- XINT (X, 2)
-
-accesses the same operand as an integer. `XSTR', used in the same
-fashion, would access it as a string.
-
- Any operand can be accessed as an integer, as an expression or as a
-string. You must choose the correct method of access for the kind of
-value actually stored in the operand. You would do this based on the
-expression code of the containing expression. That is also how you
-would know how many operands there are.
-
- For example, if X is a `subreg' expression, you know that it has two
-operands which can be correctly accessed as `XEXP (X, 0)' and `XINT (X,
-1)'. If you did `XINT (X, 0)', you would get the address of the
-expression operand but cast as an integer; that might occasionally be
-useful, but it would be cleaner to write `(int) XEXP (X, 0)'. `XEXP
-(X, 1)' would also compile without error, and would return the second,
-integer operand cast as an expression pointer, which would probably
-result in a crash when accessed. Nothing stops you from writing `XEXP
-(X, 28)' either, but this will access memory past the end of the
-expression with unpredictable results.
-
- Access to operands which are vectors is more complicated. You can use
-the macro `XVEC' to get the vector-pointer itself, or the macros
-`XVECEXP' and `XVECLEN' to access the elements and length of a vector.
-
-`XVEC (EXP, IDX)'
- Access the vector-pointer which is operand number IDX in EXP.
-
-`XVECLEN (EXP, IDX)'
- Access the length (number of elements) in the vector which is in
- operand number IDX in EXP. This value is an `int'.
-
-`XVECEXP (EXP, IDX, ELTNUM)'
- Access element number ELTNUM in the vector which is in operand
- number IDX in EXP. This value is an RTX.
-
- It is up to you to make sure that ELTNUM is not negative and is
- less than `XVECLEN (EXP, IDX)'.
-
- All the macros defined in this section expand into lvalues and
-therefore can be used to assign the operands, lengths and vector
-elements as well as to access them.
-
-\1f
-File: gccint.info, Node: Special Accessors, Next: Flags, Prev: Accessors, Up: RTL
-
-10.4 Access to Special Operands
-===============================
-
-Some RTL nodes have special annotations associated with them.
-
-`MEM'
-
- `MEM_ALIAS_SET (X)'
- If 0, X is not in any alias set, and may alias anything.
- Otherwise, X can only alias `MEM's in a conflicting alias
- set. This value is set in a language-dependent manner in the
- front-end, and should not be altered in the back-end. In
- some front-ends, these numbers may correspond in some way to
- types, or other language-level entities, but they need not,
- and the back-end makes no such assumptions. These set
- numbers are tested with `alias_sets_conflict_p'.
-
- `MEM_EXPR (X)'
- If this register is known to hold the value of some user-level
- declaration, this is that tree node. It may also be a
- `COMPONENT_REF', in which case this is some field reference,
- and `TREE_OPERAND (X, 0)' contains the declaration, or
- another `COMPONENT_REF', or null if there is no compile-time
- object associated with the reference.
-
- `MEM_OFFSET (X)'
- The offset from the start of `MEM_EXPR' as a `CONST_INT' rtx.
-
- `MEM_SIZE (X)'
- The size in bytes of the memory reference as a `CONST_INT'
- rtx. This is mostly relevant for `BLKmode' references as
- otherwise the size is implied by the mode.
-
- `MEM_ALIGN (X)'
- The known alignment in bits of the memory reference.
-
-`REG'
-
- `ORIGINAL_REGNO (X)'
- This field holds the number the register "originally" had;
- for a pseudo register turned into a hard reg this will hold
- the old pseudo register number.
-
- `REG_EXPR (X)'
- If this register is known to hold the value of some user-level
- declaration, this is that tree node.
-
- `REG_OFFSET (X)'
- If this register is known to hold the value of some user-level
- declaration, this is the offset into that logical storage.
-
-`SYMBOL_REF'
-
- `SYMBOL_REF_DECL (X)'
- If the `symbol_ref' X was created for a `VAR_DECL' or a
- `FUNCTION_DECL', that tree is recorded here. If this value is
- null, then X was created by back end code generation routines,
- and there is no associated front end symbol table entry.
-
- `SYMBOL_REF_DECL' may also point to a tree of class `'c'',
- that is, some sort of constant. In this case, the
- `symbol_ref' is an entry in the per-file constant pool;
- again, there is no associated front end symbol table entry.
-
- `SYMBOL_REF_CONSTANT (X)'
- If `CONSTANT_POOL_ADDRESS_P (X)' is true, this is the constant
- pool entry for X. It is null otherwise.
-
- `SYMBOL_REF_DATA (X)'
- A field of opaque type used to store `SYMBOL_REF_DECL' or
- `SYMBOL_REF_CONSTANT'.
-
- `SYMBOL_REF_FLAGS (X)'
- In a `symbol_ref', this is used to communicate various
- predicates about the symbol. Some of these are common enough
- to be computed by common code, some are specific to the
- target. The common bits are:
-
- `SYMBOL_FLAG_FUNCTION'
- Set if the symbol refers to a function.
-
- `SYMBOL_FLAG_LOCAL'
- Set if the symbol is local to this "module". See
- `TARGET_BINDS_LOCAL_P'.
-
- `SYMBOL_FLAG_EXTERNAL'
- Set if this symbol is not defined in this translation
- unit. Note that this is not the inverse of
- `SYMBOL_FLAG_LOCAL'.
-
- `SYMBOL_FLAG_SMALL'
- Set if the symbol is located in the small data section.
- See `TARGET_IN_SMALL_DATA_P'.
-
- `SYMBOL_REF_TLS_MODEL (X)'
- This is a multi-bit field accessor that returns the
- `tls_model' to be used for a thread-local storage
- symbol. It returns zero for non-thread-local symbols.
-
- `SYMBOL_FLAG_HAS_BLOCK_INFO'
- Set if the symbol has `SYMBOL_REF_BLOCK' and
- `SYMBOL_REF_BLOCK_OFFSET' fields.
-
- `SYMBOL_FLAG_ANCHOR'
- Set if the symbol is used as a section anchor. "Section
- anchors" are symbols that have a known position within
- an `object_block' and that can be used to access nearby
- members of that block. They are used to implement
- `-fsection-anchors'.
-
- If this flag is set, then `SYMBOL_FLAG_HAS_BLOCK_INFO'
- will be too.
-
- Bits beginning with `SYMBOL_FLAG_MACH_DEP' are available for
- the target's use.
-
-`SYMBOL_REF_BLOCK (X)'
- If `SYMBOL_REF_HAS_BLOCK_INFO_P (X)', this is the `object_block'
- structure to which the symbol belongs, or `NULL' if it has not
- been assigned a block.
-
-`SYMBOL_REF_BLOCK_OFFSET (X)'
- If `SYMBOL_REF_HAS_BLOCK_INFO_P (X)', this is the offset of X from
- the first object in `SYMBOL_REF_BLOCK (X)'. The value is negative
- if X has not yet been assigned to a block, or it has not been
- given an offset within that block.
-
-\1f
-File: gccint.info, Node: Flags, Next: Machine Modes, Prev: Special Accessors, Up: RTL
-
-10.5 Flags in an RTL Expression
-===============================
-
-RTL expressions contain several flags (one-bit bit-fields) that are
-used in certain types of expression. Most often they are accessed with
-the following macros, which expand into lvalues.
-
-`CONSTANT_POOL_ADDRESS_P (X)'
- Nonzero in a `symbol_ref' if it refers to part of the current
- function's constant pool. For most targets these addresses are in
- a `.rodata' section entirely separate from the function, but for
- some targets the addresses are close to the beginning of the
- function. In either case GCC assumes these addresses can be
- addressed directly, perhaps with the help of base registers.
- Stored in the `unchanging' field and printed as `/u'.
-
-`RTL_CONST_CALL_P (X)'
- In a `call_insn' indicates that the insn represents a call to a
- const function. Stored in the `unchanging' field and printed as
- `/u'.
-
-`RTL_PURE_CALL_P (X)'
- In a `call_insn' indicates that the insn represents a call to a
- pure function. Stored in the `return_val' field and printed as
- `/i'.
-
-`RTL_CONST_OR_PURE_CALL_P (X)'
- In a `call_insn', true if `RTL_CONST_CALL_P' or `RTL_PURE_CALL_P'
- is true.
-
-`RTL_LOOPING_CONST_OR_PURE_CALL_P (X)'
- In a `call_insn' indicates that the insn represents a possibly
- infinite looping call to a const or pure function. Stored in the
- `call' field and printed as `/c'. Only true if one of
- `RTL_CONST_CALL_P' or `RTL_PURE_CALL_P' is true.
-
-`INSN_ANNULLED_BRANCH_P (X)'
- In a `jump_insn', `call_insn', or `insn' indicates that the branch
- is an annulling one. See the discussion under `sequence' below.
- Stored in the `unchanging' field and printed as `/u'.
-
-`INSN_DELETED_P (X)'
- In an `insn', `call_insn', `jump_insn', `code_label', `barrier',
- or `note', nonzero if the insn has been deleted. Stored in the
- `volatil' field and printed as `/v'.
-
-`INSN_FROM_TARGET_P (X)'
- In an `insn' or `jump_insn' or `call_insn' in a delay slot of a
- branch, indicates that the insn is from the target of the branch.
- If the branch insn has `INSN_ANNULLED_BRANCH_P' set, this insn
- will only be executed if the branch is taken. For annulled
- branches with `INSN_FROM_TARGET_P' clear, the insn will be
- executed only if the branch is not taken. When
- `INSN_ANNULLED_BRANCH_P' is not set, this insn will always be
- executed. Stored in the `in_struct' field and printed as `/s'.
-
-`LABEL_PRESERVE_P (X)'
- In a `code_label' or `note', indicates that the label is
- referenced by code or data not visible to the RTL of a given
- function. Labels referenced by a non-local goto will have this
- bit set. Stored in the `in_struct' field and printed as `/s'.
-
-`LABEL_REF_NONLOCAL_P (X)'
- In `label_ref' and `reg_label' expressions, nonzero if this is a
- reference to a non-local label. Stored in the `volatil' field and
- printed as `/v'.
-
-`MEM_IN_STRUCT_P (X)'
- In `mem' expressions, nonzero for reference to an entire structure,
- union or array, or to a component of one. Zero for references to a
- scalar variable or through a pointer to a scalar. If both this
- flag and `MEM_SCALAR_P' are clear, then we don't know whether this
- `mem' is in a structure or not. Both flags should never be
- simultaneously set. Stored in the `in_struct' field and printed
- as `/s'.
-
-`MEM_KEEP_ALIAS_SET_P (X)'
- In `mem' expressions, 1 if we should keep the alias set for this
- mem unchanged when we access a component. Set to 1, for example,
- when we are already in a non-addressable component of an aggregate.
- Stored in the `jump' field and printed as `/j'.
-
-`MEM_SCALAR_P (X)'
- In `mem' expressions, nonzero for reference to a scalar known not
- to be a member of a structure, union, or array. Zero for such
- references and for indirections through pointers, even pointers
- pointing to scalar types. If both this flag and `MEM_IN_STRUCT_P'
- are clear, then we don't know whether this `mem' is in a structure
- or not. Both flags should never be simultaneously set. Stored in
- the `return_val' field and printed as `/i'.
-
-`MEM_VOLATILE_P (X)'
- In `mem', `asm_operands', and `asm_input' expressions, nonzero for
- volatile memory references. Stored in the `volatil' field and
- printed as `/v'.
-
-`MEM_NOTRAP_P (X)'
- In `mem', nonzero for memory references that will not trap.
- Stored in the `call' field and printed as `/c'.
-
-`MEM_POINTER (X)'
- Nonzero in a `mem' if the memory reference holds a pointer.
- Stored in the `frame_related' field and printed as `/f'.
-
-`REG_FUNCTION_VALUE_P (X)'
- Nonzero in a `reg' if it is the place in which this function's
- value is going to be returned. (This happens only in a hard
- register.) Stored in the `return_val' field and printed as `/i'.
-
-`REG_POINTER (X)'
- Nonzero in a `reg' if the register holds a pointer. Stored in the
- `frame_related' field and printed as `/f'.
-
-`REG_USERVAR_P (X)'
- In a `reg', nonzero if it corresponds to a variable present in the
- user's source code. Zero for temporaries generated internally by
- the compiler. Stored in the `volatil' field and printed as `/v'.
-
- The same hard register may be used also for collecting the values
- of functions called by this one, but `REG_FUNCTION_VALUE_P' is zero
- in this kind of use.
-
-`RTX_FRAME_RELATED_P (X)'
- Nonzero in an `insn', `call_insn', `jump_insn', `barrier', or
- `set' which is part of a function prologue and sets the stack
- pointer, sets the frame pointer, or saves a register. This flag
- should also be set on an instruction that sets up a temporary
- register to use in place of the frame pointer. Stored in the
- `frame_related' field and printed as `/f'.
-
- In particular, on RISC targets where there are limits on the sizes
- of immediate constants, it is sometimes impossible to reach the
- register save area directly from the stack pointer. In that case,
- a temporary register is used that is near enough to the register
- save area, and the Canonical Frame Address, i.e., DWARF2's logical
- frame pointer, register must (temporarily) be changed to be this
- temporary register. So, the instruction that sets this temporary
- register must be marked as `RTX_FRAME_RELATED_P'.
-
- If the marked instruction is overly complex (defined in terms of
- what `dwarf2out_frame_debug_expr' can handle), you will also have
- to create a `REG_FRAME_RELATED_EXPR' note and attach it to the
- instruction. This note should contain a simple expression of the
- computation performed by this instruction, i.e., one that
- `dwarf2out_frame_debug_expr' can handle.
-
- This flag is required for exception handling support on targets
- with RTL prologues.
-
-`MEM_READONLY_P (X)'
- Nonzero in a `mem', if the memory is statically allocated and
- read-only.
-
- Read-only in this context means never modified during the lifetime
- of the program, not necessarily in ROM or in write-disabled pages.
- A common example of the later is a shared library's global offset
- table. This table is initialized by the runtime loader, so the
- memory is technically writable, but after control is transfered
- from the runtime loader to the application, this memory will never
- be subsequently modified.
-
- Stored in the `unchanging' field and printed as `/u'.
-
-`SCHED_GROUP_P (X)'
- During instruction scheduling, in an `insn', `call_insn' or
- `jump_insn', indicates that the previous insn must be scheduled
- together with this insn. This is used to ensure that certain
- groups of instructions will not be split up by the instruction
- scheduling pass, for example, `use' insns before a `call_insn' may
- not be separated from the `call_insn'. Stored in the `in_struct'
- field and printed as `/s'.
-
-`SET_IS_RETURN_P (X)'
- For a `set', nonzero if it is for a return. Stored in the `jump'
- field and printed as `/j'.
-
-`SIBLING_CALL_P (X)'
- For a `call_insn', nonzero if the insn is a sibling call. Stored
- in the `jump' field and printed as `/j'.
-
-`STRING_POOL_ADDRESS_P (X)'
- For a `symbol_ref' expression, nonzero if it addresses this
- function's string constant pool. Stored in the `frame_related'
- field and printed as `/f'.
-
-`SUBREG_PROMOTED_UNSIGNED_P (X)'
- Returns a value greater then zero for a `subreg' that has
- `SUBREG_PROMOTED_VAR_P' nonzero if the object being referenced is
- kept zero-extended, zero if it is kept sign-extended, and less
- then zero if it is extended some other way via the `ptr_extend'
- instruction. Stored in the `unchanging' field and `volatil'
- field, printed as `/u' and `/v'. This macro may only be used to
- get the value it may not be used to change the value. Use
- `SUBREG_PROMOTED_UNSIGNED_SET' to change the value.
-
-`SUBREG_PROMOTED_UNSIGNED_SET (X)'
- Set the `unchanging' and `volatil' fields in a `subreg' to reflect
- zero, sign, or other extension. If `volatil' is zero, then
- `unchanging' as nonzero means zero extension and as zero means
- sign extension. If `volatil' is nonzero then some other type of
- extension was done via the `ptr_extend' instruction.
-
-`SUBREG_PROMOTED_VAR_P (X)'
- Nonzero in a `subreg' if it was made when accessing an object that
- was promoted to a wider mode in accord with the `PROMOTED_MODE'
- machine description macro (*note Storage Layout::). In this case,
- the mode of the `subreg' is the declared mode of the object and
- the mode of `SUBREG_REG' is the mode of the register that holds
- the object. Promoted variables are always either sign- or
- zero-extended to the wider mode on every assignment. Stored in
- the `in_struct' field and printed as `/s'.
-
-`SYMBOL_REF_USED (X)'
- In a `symbol_ref', indicates that X has been used. This is
- normally only used to ensure that X is only declared external
- once. Stored in the `used' field.
-
-`SYMBOL_REF_WEAK (X)'
- In a `symbol_ref', indicates that X has been declared weak.
- Stored in the `return_val' field and printed as `/i'.
-
-`SYMBOL_REF_FLAG (X)'
- In a `symbol_ref', this is used as a flag for machine-specific
- purposes. Stored in the `volatil' field and printed as `/v'.
-
- Most uses of `SYMBOL_REF_FLAG' are historic and may be subsumed by
- `SYMBOL_REF_FLAGS'. Certainly use of `SYMBOL_REF_FLAGS' is
- mandatory if the target requires more than one bit of storage.
-
- These are the fields to which the above macros refer:
-
-`call'
- In a `mem', 1 means that the memory reference will not trap.
-
- In a `call', 1 means that this pure or const call may possibly
- infinite loop.
-
- In an RTL dump, this flag is represented as `/c'.
-
-`frame_related'
- In an `insn' or `set' expression, 1 means that it is part of a
- function prologue and sets the stack pointer, sets the frame
- pointer, saves a register, or sets up a temporary register to use
- in place of the frame pointer.
-
- In `reg' expressions, 1 means that the register holds a pointer.
-
- In `mem' expressions, 1 means that the memory reference holds a
- pointer.
-
- In `symbol_ref' expressions, 1 means that the reference addresses
- this function's string constant pool.
-
- In an RTL dump, this flag is represented as `/f'.
-
-`in_struct'
- In `mem' expressions, it is 1 if the memory datum referred to is
- all or part of a structure or array; 0 if it is (or might be) a
- scalar variable. A reference through a C pointer has 0 because
- the pointer might point to a scalar variable. This information
- allows the compiler to determine something about possible cases of
- aliasing.
-
- In `reg' expressions, it is 1 if the register has its entire life
- contained within the test expression of some loop.
-
- In `subreg' expressions, 1 means that the `subreg' is accessing an
- object that has had its mode promoted from a wider mode.
-
- In `label_ref' expressions, 1 means that the referenced label is
- outside the innermost loop containing the insn in which the
- `label_ref' was found.
-
- In `code_label' expressions, it is 1 if the label may never be
- deleted. This is used for labels which are the target of
- non-local gotos. Such a label that would have been deleted is
- replaced with a `note' of type `NOTE_INSN_DELETED_LABEL'.
-
- In an `insn' during dead-code elimination, 1 means that the insn is
- dead code.
-
- In an `insn' or `jump_insn' during reorg for an insn in the delay
- slot of a branch, 1 means that this insn is from the target of the
- branch.
-
- In an `insn' during instruction scheduling, 1 means that this insn
- must be scheduled as part of a group together with the previous
- insn.
-
- In an RTL dump, this flag is represented as `/s'.
-
-`return_val'
- In `reg' expressions, 1 means the register contains the value to
- be returned by the current function. On machines that pass
- parameters in registers, the same register number may be used for
- parameters as well, but this flag is not set on such uses.
-
- In `mem' expressions, 1 means the memory reference is to a scalar
- known not to be a member of a structure, union, or array.
-
- In `symbol_ref' expressions, 1 means the referenced symbol is weak.
-
- In `call' expressions, 1 means the call is pure.
-
- In an RTL dump, this flag is represented as `/i'.
-
-`jump'
- In a `mem' expression, 1 means we should keep the alias set for
- this mem unchanged when we access a component.
-
- In a `set', 1 means it is for a return.
-
- In a `call_insn', 1 means it is a sibling call.
-
- In an RTL dump, this flag is represented as `/j'.
-
-`unchanging'
- In `reg' and `mem' expressions, 1 means that the value of the
- expression never changes.
-
- In `subreg' expressions, it is 1 if the `subreg' references an
- unsigned object whose mode has been promoted to a wider mode.
-
- In an `insn' or `jump_insn' in the delay slot of a branch
- instruction, 1 means an annulling branch should be used.
-
- In a `symbol_ref' expression, 1 means that this symbol addresses
- something in the per-function constant pool.
-
- In a `call_insn' 1 means that this instruction is a call to a const
- function.
-
- In an RTL dump, this flag is represented as `/u'.
-
-`used'
- This flag is used directly (without an access macro) at the end of
- RTL generation for a function, to count the number of times an
- expression appears in insns. Expressions that appear more than
- once are copied, according to the rules for shared structure
- (*note Sharing::).
-
- For a `reg', it is used directly (without an access macro) by the
- leaf register renumbering code to ensure that each register is only
- renumbered once.
-
- In a `symbol_ref', it indicates that an external declaration for
- the symbol has already been written.
-
-`volatil'
- In a `mem', `asm_operands', or `asm_input' expression, it is 1 if
- the memory reference is volatile. Volatile memory references may
- not be deleted, reordered or combined.
-
- In a `symbol_ref' expression, it is used for machine-specific
- purposes.
-
- In a `reg' expression, it is 1 if the value is a user-level
- variable. 0 indicates an internal compiler temporary.
-
- In an `insn', 1 means the insn has been deleted.
-
- In `label_ref' and `reg_label' expressions, 1 means a reference to
- a non-local label.
-
- In an RTL dump, this flag is represented as `/v'.
-
-\1f
-File: gccint.info, Node: Machine Modes, Next: Constants, Prev: Flags, Up: RTL
-
-10.6 Machine Modes
-==================
-
-A machine mode describes a size of data object and the representation
-used for it. In the C code, machine modes are represented by an
-enumeration type, `enum machine_mode', defined in `machmode.def'. Each
-RTL expression has room for a machine mode and so do certain kinds of
-tree expressions (declarations and types, to be precise).
-
- In debugging dumps and machine descriptions, the machine mode of an RTL
-expression is written after the expression code with a colon to separate
-them. The letters `mode' which appear at the end of each machine mode
-name are omitted. For example, `(reg:SI 38)' is a `reg' expression
-with machine mode `SImode'. If the mode is `VOIDmode', it is not
-written at all.
-
- Here is a table of machine modes. The term "byte" below refers to an
-object of `BITS_PER_UNIT' bits (*note Storage Layout::).
-
-`BImode'
- "Bit" mode represents a single bit, for predicate registers.
-
-`QImode'
- "Quarter-Integer" mode represents a single byte treated as an
- integer.
-
-`HImode'
- "Half-Integer" mode represents a two-byte integer.
-
-`PSImode'
- "Partial Single Integer" mode represents an integer which occupies
- four bytes but which doesn't really use all four. On some
- machines, this is the right mode to use for pointers.
-
-`SImode'
- "Single Integer" mode represents a four-byte integer.
-
-`PDImode'
- "Partial Double Integer" mode represents an integer which occupies
- eight bytes but which doesn't really use all eight. On some
- machines, this is the right mode to use for certain pointers.
-
-`DImode'
- "Double Integer" mode represents an eight-byte integer.
-
-`TImode'
- "Tetra Integer" (?) mode represents a sixteen-byte integer.
-
-`OImode'
- "Octa Integer" (?) mode represents a thirty-two-byte integer.
-
-`QFmode'
- "Quarter-Floating" mode represents a quarter-precision (single
- byte) floating point number.
-
-`HFmode'
- "Half-Floating" mode represents a half-precision (two byte)
- floating point number.
-
-`TQFmode'
- "Three-Quarter-Floating" (?) mode represents a
- three-quarter-precision (three byte) floating point number.
-
-`SFmode'
- "Single Floating" mode represents a four byte floating point
- number. In the common case, of a processor with IEEE arithmetic
- and 8-bit bytes, this is a single-precision IEEE floating point
- number; it can also be used for double-precision (on processors
- with 16-bit bytes) and single-precision VAX and IBM types.
-
-`DFmode'
- "Double Floating" mode represents an eight byte floating point
- number. In the common case, of a processor with IEEE arithmetic
- and 8-bit bytes, this is a double-precision IEEE floating point
- number.
-
-`XFmode'
- "Extended Floating" mode represents an IEEE extended floating point
- number. This mode only has 80 meaningful bits (ten bytes). Some
- processors require such numbers to be padded to twelve bytes,
- others to sixteen; this mode is used for either.
-
-`SDmode'
- "Single Decimal Floating" mode represents a four byte decimal
- floating point number (as distinct from conventional binary
- floating point).
-
-`DDmode'
- "Double Decimal Floating" mode represents an eight byte decimal
- floating point number.
-
-`TDmode'
- "Tetra Decimal Floating" mode represents a sixteen byte decimal
- floating point number all 128 of whose bits are meaningful.
-
-`TFmode'
- "Tetra Floating" mode represents a sixteen byte floating point
- number all 128 of whose bits are meaningful. One common use is the
- IEEE quad-precision format.
-
-`QQmode'
- "Quarter-Fractional" mode represents a single byte treated as a
- signed fractional number. The default format is "s.7".
-
-`HQmode'
- "Half-Fractional" mode represents a two-byte signed fractional
- number. The default format is "s.15".
-
-`SQmode'
- "Single Fractional" mode represents a four-byte signed fractional
- number. The default format is "s.31".
-
-`DQmode'
- "Double Fractional" mode represents an eight-byte signed
- fractional number. The default format is "s.63".
-
-`TQmode'
- "Tetra Fractional" mode represents a sixteen-byte signed
- fractional number. The default format is "s.127".
-
-`UQQmode'
- "Unsigned Quarter-Fractional" mode represents a single byte
- treated as an unsigned fractional number. The default format is
- ".8".
-
-`UHQmode'
- "Unsigned Half-Fractional" mode represents a two-byte unsigned
- fractional number. The default format is ".16".
-
-`USQmode'
- "Unsigned Single Fractional" mode represents a four-byte unsigned
- fractional number. The default format is ".32".
-
-`UDQmode'
- "Unsigned Double Fractional" mode represents an eight-byte unsigned
- fractional number. The default format is ".64".
-
-`UTQmode'
- "Unsigned Tetra Fractional" mode represents a sixteen-byte unsigned
- fractional number. The default format is ".128".
-
-`HAmode'
- "Half-Accumulator" mode represents a two-byte signed accumulator.
- The default format is "s8.7".
-
-`SAmode'
- "Single Accumulator" mode represents a four-byte signed
- accumulator. The default format is "s16.15".
-
-`DAmode'
- "Double Accumulator" mode represents an eight-byte signed
- accumulator. The default format is "s32.31".
-
-`TAmode'
- "Tetra Accumulator" mode represents a sixteen-byte signed
- accumulator. The default format is "s64.63".
-
-`UHAmode'
- "Unsigned Half-Accumulator" mode represents a two-byte unsigned
- accumulator. The default format is "8.8".
-
-`USAmode'
- "Unsigned Single Accumulator" mode represents a four-byte unsigned
- accumulator. The default format is "16.16".
-
-`UDAmode'
- "Unsigned Double Accumulator" mode represents an eight-byte
- unsigned accumulator. The default format is "32.32".
-
-`UTAmode'
- "Unsigned Tetra Accumulator" mode represents a sixteen-byte
- unsigned accumulator. The default format is "64.64".
-
-`CCmode'
- "Condition Code" mode represents the value of a condition code,
- which is a machine-specific set of bits used to represent the
- result of a comparison operation. Other machine-specific modes
- may also be used for the condition code. These modes are not used
- on machines that use `cc0' (see *note Condition Code::).
-
-`BLKmode'
- "Block" mode represents values that are aggregates to which none of
- the other modes apply. In RTL, only memory references can have
- this mode, and only if they appear in string-move or vector
- instructions. On machines which have no such instructions,
- `BLKmode' will not appear in RTL.
-
-`VOIDmode'
- Void mode means the absence of a mode or an unspecified mode. For
- example, RTL expressions of code `const_int' have mode `VOIDmode'
- because they can be taken to have whatever mode the context
- requires. In debugging dumps of RTL, `VOIDmode' is expressed by
- the absence of any mode.
-
-`QCmode, HCmode, SCmode, DCmode, XCmode, TCmode'
- These modes stand for a complex number represented as a pair of
- floating point values. The floating point values are in `QFmode',
- `HFmode', `SFmode', `DFmode', `XFmode', and `TFmode', respectively.
-
-`CQImode, CHImode, CSImode, CDImode, CTImode, COImode'
- These modes stand for a complex number represented as a pair of
- integer values. The integer values are in `QImode', `HImode',
- `SImode', `DImode', `TImode', and `OImode', respectively.
-
- The machine description defines `Pmode' as a C macro which expands
-into the machine mode used for addresses. Normally this is the mode
-whose size is `BITS_PER_WORD', `SImode' on 32-bit machines.
-
- The only modes which a machine description must support are `QImode',
-and the modes corresponding to `BITS_PER_WORD', `FLOAT_TYPE_SIZE' and
-`DOUBLE_TYPE_SIZE'. The compiler will attempt to use `DImode' for
-8-byte structures and unions, but this can be prevented by overriding
-the definition of `MAX_FIXED_MODE_SIZE'. Alternatively, you can have
-the compiler use `TImode' for 16-byte structures and unions. Likewise,
-you can arrange for the C type `short int' to avoid using `HImode'.
-
- Very few explicit references to machine modes remain in the compiler
-and these few references will soon be removed. Instead, the machine
-modes are divided into mode classes. These are represented by the
-enumeration type `enum mode_class' defined in `machmode.h'. The
-possible mode classes are:
-
-`MODE_INT'
- Integer modes. By default these are `BImode', `QImode', `HImode',
- `SImode', `DImode', `TImode', and `OImode'.
-
-`MODE_PARTIAL_INT'
- The "partial integer" modes, `PQImode', `PHImode', `PSImode' and
- `PDImode'.
-
-`MODE_FLOAT'
- Floating point modes. By default these are `QFmode', `HFmode',
- `TQFmode', `SFmode', `DFmode', `XFmode' and `TFmode'.
-
-`MODE_DECIMAL_FLOAT'
- Decimal floating point modes. By default these are `SDmode',
- `DDmode' and `TDmode'.
-
-`MODE_FRACT'
- Signed fractional modes. By default these are `QQmode', `HQmode',
- `SQmode', `DQmode' and `TQmode'.
-
-`MODE_UFRACT'
- Unsigned fractional modes. By default these are `UQQmode',
- `UHQmode', `USQmode', `UDQmode' and `UTQmode'.
-
-`MODE_ACCUM'
- Signed accumulator modes. By default these are `HAmode',
- `SAmode', `DAmode' and `TAmode'.
-
-`MODE_UACCUM'
- Unsigned accumulator modes. By default these are `UHAmode',
- `USAmode', `UDAmode' and `UTAmode'.
-
-`MODE_COMPLEX_INT'
- Complex integer modes. (These are not currently implemented).
-
-`MODE_COMPLEX_FLOAT'
- Complex floating point modes. By default these are `QCmode',
- `HCmode', `SCmode', `DCmode', `XCmode', and `TCmode'.
-
-`MODE_FUNCTION'
- Algol or Pascal function variables including a static chain.
- (These are not currently implemented).
-
-`MODE_CC'
- Modes representing condition code values. These are `CCmode' plus
- any `CC_MODE' modes listed in the `MACHINE-modes.def'. *Note Jump
- Patterns::, also see *note Condition Code::.
-
-`MODE_RANDOM'
- This is a catchall mode class for modes which don't fit into the
- above classes. Currently `VOIDmode' and `BLKmode' are in
- `MODE_RANDOM'.
-
- Here are some C macros that relate to machine modes:
-
-`GET_MODE (X)'
- Returns the machine mode of the RTX X.
-
-`PUT_MODE (X, NEWMODE)'
- Alters the machine mode of the RTX X to be NEWMODE.
-
-`NUM_MACHINE_MODES'
- Stands for the number of machine modes available on the target
- machine. This is one greater than the largest numeric value of any
- machine mode.
-
-`GET_MODE_NAME (M)'
- Returns the name of mode M as a string.
-
-`GET_MODE_CLASS (M)'
- Returns the mode class of mode M.
-
-`GET_MODE_WIDER_MODE (M)'
- Returns the next wider natural mode. For example, the expression
- `GET_MODE_WIDER_MODE (QImode)' returns `HImode'.
-
-`GET_MODE_SIZE (M)'
- Returns the size in bytes of a datum of mode M.
-
-`GET_MODE_BITSIZE (M)'
- Returns the size in bits of a datum of mode M.
-
-`GET_MODE_IBIT (M)'
- Returns the number of integral bits of a datum of fixed-point mode
- M.
-
-`GET_MODE_FBIT (M)'
- Returns the number of fractional bits of a datum of fixed-point
- mode M.
-
-`GET_MODE_MASK (M)'
- Returns a bitmask containing 1 for all bits in a word that fit
- within mode M. This macro can only be used for modes whose
- bitsize is less than or equal to `HOST_BITS_PER_INT'.
-
-`GET_MODE_ALIGNMENT (M)'
- Return the required alignment, in bits, for an object of mode M.
-
-`GET_MODE_UNIT_SIZE (M)'
- Returns the size in bytes of the subunits of a datum of mode M.
- This is the same as `GET_MODE_SIZE' except in the case of complex
- modes. For them, the unit size is the size of the real or
- imaginary part.
-
-`GET_MODE_NUNITS (M)'
- Returns the number of units contained in a mode, i.e.,
- `GET_MODE_SIZE' divided by `GET_MODE_UNIT_SIZE'.
-
-`GET_CLASS_NARROWEST_MODE (C)'
- Returns the narrowest mode in mode class C.
-
- The global variables `byte_mode' and `word_mode' contain modes whose
-classes are `MODE_INT' and whose bitsizes are either `BITS_PER_UNIT' or
-`BITS_PER_WORD', respectively. On 32-bit machines, these are `QImode'
-and `SImode', respectively.
-
-\1f
-File: gccint.info, Node: Constants, Next: Regs and Memory, Prev: Machine Modes, Up: RTL
-
-10.7 Constant Expression Types
-==============================
-
-The simplest RTL expressions are those that represent constant values.
-
-`(const_int I)'
- This type of expression represents the integer value I. I is
- customarily accessed with the macro `INTVAL' as in `INTVAL (EXP)',
- which is equivalent to `XWINT (EXP, 0)'.
-
- Constants generated for modes with fewer bits than `HOST_WIDE_INT'
- must be sign extended to full width (e.g., with `gen_int_mode').
-
- There is only one expression object for the integer value zero; it
- is the value of the variable `const0_rtx'. Likewise, the only
- expression for integer value one is found in `const1_rtx', the only
- expression for integer value two is found in `const2_rtx', and the
- only expression for integer value negative one is found in
- `constm1_rtx'. Any attempt to create an expression of code
- `const_int' and value zero, one, two or negative one will return
- `const0_rtx', `const1_rtx', `const2_rtx' or `constm1_rtx' as
- appropriate.
-
- Similarly, there is only one object for the integer whose value is
- `STORE_FLAG_VALUE'. It is found in `const_true_rtx'. If
- `STORE_FLAG_VALUE' is one, `const_true_rtx' and `const1_rtx' will
- point to the same object. If `STORE_FLAG_VALUE' is -1,
- `const_true_rtx' and `constm1_rtx' will point to the same object.
-
-`(const_double:M I0 I1 ...)'
- Represents either a floating-point constant of mode M or an
- integer constant too large to fit into `HOST_BITS_PER_WIDE_INT'
- bits but small enough to fit within twice that number of bits (GCC
- does not provide a mechanism to represent even larger constants).
- In the latter case, M will be `VOIDmode'.
-
- If M is `VOIDmode', the bits of the value are stored in I0 and I1.
- I0 is customarily accessed with the macro `CONST_DOUBLE_LOW' and
- I1 with `CONST_DOUBLE_HIGH'.
-
- If the constant is floating point (regardless of its precision),
- then the number of integers used to store the value depends on the
- size of `REAL_VALUE_TYPE' (*note Floating Point::). The integers
- represent a floating point number, but not precisely in the target
- machine's or host machine's floating point format. To convert
- them to the precise bit pattern used by the target machine, use
- the macro `REAL_VALUE_TO_TARGET_DOUBLE' and friends (*note Data
- Output::).
-
-`(const_fixed:M ...)'
- Represents a fixed-point constant of mode M. The operand is a
- data structure of type `struct fixed_value' and is accessed with
- the macro `CONST_FIXED_VALUE'. The high part of data is accessed
- with `CONST_FIXED_VALUE_HIGH'; the low part is accessed with
- `CONST_FIXED_VALUE_LOW'.
-
-`(const_vector:M [X0 X1 ...])'
- Represents a vector constant. The square brackets stand for the
- vector containing the constant elements. X0, X1 and so on are the
- `const_int', `const_double' or `const_fixed' elements.
-
- The number of units in a `const_vector' is obtained with the macro
- `CONST_VECTOR_NUNITS' as in `CONST_VECTOR_NUNITS (V)'.
-
- Individual elements in a vector constant are accessed with the
- macro `CONST_VECTOR_ELT' as in `CONST_VECTOR_ELT (V, N)' where V
- is the vector constant and N is the element desired.
-
-`(const_string STR)'
- Represents a constant string with value STR. Currently this is
- used only for insn attributes (*note Insn Attributes::) since
- constant strings in C are placed in memory.
-
-`(symbol_ref:MODE SYMBOL)'
- Represents the value of an assembler label for data. SYMBOL is a
- string that describes the name of the assembler label. If it
- starts with a `*', the label is the rest of SYMBOL not including
- the `*'. Otherwise, the label is SYMBOL, usually prefixed with
- `_'.
-
- The `symbol_ref' contains a mode, which is usually `Pmode'.
- Usually that is the only mode for which a symbol is directly valid.
-
-`(label_ref:MODE LABEL)'
- Represents the value of an assembler label for code. It contains
- one operand, an expression, which must be a `code_label' or a
- `note' of type `NOTE_INSN_DELETED_LABEL' that appears in the
- instruction sequence to identify the place where the label should
- go.
-
- The reason for using a distinct expression type for code label
- references is so that jump optimization can distinguish them.
-
- The `label_ref' contains a mode, which is usually `Pmode'.
- Usually that is the only mode for which a label is directly valid.
-
-`(const:M EXP)'
- Represents a constant that is the result of an assembly-time
- arithmetic computation. The operand, EXP, is an expression that
- contains only constants (`const_int', `symbol_ref' and `label_ref'
- expressions) combined with `plus' and `minus'. However, not all
- combinations are valid, since the assembler cannot do arbitrary
- arithmetic on relocatable symbols.
-
- M should be `Pmode'.
-
-`(high:M EXP)'
- Represents the high-order bits of EXP, usually a `symbol_ref'.
- The number of bits is machine-dependent and is normally the number
- of bits specified in an instruction that initializes the high
- order bits of a register. It is used with `lo_sum' to represent
- the typical two-instruction sequence used in RISC machines to
- reference a global memory location.
-
- M should be `Pmode'.
-
- The macro `CONST0_RTX (MODE)' refers to an expression with value 0 in
-mode MODE. If mode MODE is of mode class `MODE_INT', it returns
-`const0_rtx'. If mode MODE is of mode class `MODE_FLOAT', it returns a
-`CONST_DOUBLE' expression in mode MODE. Otherwise, it returns a
-`CONST_VECTOR' expression in mode MODE. Similarly, the macro
-`CONST1_RTX (MODE)' refers to an expression with value 1 in mode MODE
-and similarly for `CONST2_RTX'. The `CONST1_RTX' and `CONST2_RTX'
-macros are undefined for vector modes.
-
-\1f
-File: gccint.info, Node: Regs and Memory, Next: Arithmetic, Prev: Constants, Up: RTL
-
-10.8 Registers and Memory
-=========================
-
-Here are the RTL expression types for describing access to machine
-registers and to main memory.
-
-`(reg:M N)'
- For small values of the integer N (those that are less than
- `FIRST_PSEUDO_REGISTER'), this stands for a reference to machine
- register number N: a "hard register". For larger values of N, it
- stands for a temporary value or "pseudo register". The compiler's
- strategy is to generate code assuming an unlimited number of such
- pseudo registers, and later convert them into hard registers or
- into memory references.
-
- M is the machine mode of the reference. It is necessary because
- machines can generally refer to each register in more than one
- mode. For example, a register may contain a full word but there
- may be instructions to refer to it as a half word or as a single
- byte, as well as instructions to refer to it as a floating point
- number of various precisions.
-
- Even for a register that the machine can access in only one mode,
- the mode must always be specified.
-
- The symbol `FIRST_PSEUDO_REGISTER' is defined by the machine
- description, since the number of hard registers on the machine is
- an invariant characteristic of the machine. Note, however, that
- not all of the machine registers must be general registers. All
- the machine registers that can be used for storage of data are
- given hard register numbers, even those that can be used only in
- certain instructions or can hold only certain types of data.
-
- A hard register may be accessed in various modes throughout one
- function, but each pseudo register is given a natural mode and is
- accessed only in that mode. When it is necessary to describe an
- access to a pseudo register using a nonnatural mode, a `subreg'
- expression is used.
-
- A `reg' expression with a machine mode that specifies more than
- one word of data may actually stand for several consecutive
- registers. If in addition the register number specifies a
- hardware register, then it actually represents several consecutive
- hardware registers starting with the specified one.
-
- Each pseudo register number used in a function's RTL code is
- represented by a unique `reg' expression.
-
- Some pseudo register numbers, those within the range of
- `FIRST_VIRTUAL_REGISTER' to `LAST_VIRTUAL_REGISTER' only appear
- during the RTL generation phase and are eliminated before the
- optimization phases. These represent locations in the stack frame
- that cannot be determined until RTL generation for the function
- has been completed. The following virtual register numbers are
- defined:
-
- `VIRTUAL_INCOMING_ARGS_REGNUM'
- This points to the first word of the incoming arguments
- passed on the stack. Normally these arguments are placed
- there by the caller, but the callee may have pushed some
- arguments that were previously passed in registers.
-
- When RTL generation is complete, this virtual register is
- replaced by the sum of the register given by
- `ARG_POINTER_REGNUM' and the value of `FIRST_PARM_OFFSET'.
-
- `VIRTUAL_STACK_VARS_REGNUM'
- If `FRAME_GROWS_DOWNWARD' is defined to a nonzero value, this
- points to immediately above the first variable on the stack.
- Otherwise, it points to the first variable on the stack.
-
- `VIRTUAL_STACK_VARS_REGNUM' is replaced with the sum of the
- register given by `FRAME_POINTER_REGNUM' and the value
- `STARTING_FRAME_OFFSET'.
-
- `VIRTUAL_STACK_DYNAMIC_REGNUM'
- This points to the location of dynamically allocated memory
- on the stack immediately after the stack pointer has been
- adjusted by the amount of memory desired.
-
- This virtual register is replaced by the sum of the register
- given by `STACK_POINTER_REGNUM' and the value
- `STACK_DYNAMIC_OFFSET'.
-
- `VIRTUAL_OUTGOING_ARGS_REGNUM'
- This points to the location in the stack at which outgoing
- arguments should be written when the stack is pre-pushed
- (arguments pushed using push insns should always use
- `STACK_POINTER_REGNUM').
-
- This virtual register is replaced by the sum of the register
- given by `STACK_POINTER_REGNUM' and the value
- `STACK_POINTER_OFFSET'.
-
-`(subreg:M1 REG:M2 BYTENUM)'
- `subreg' expressions are used to refer to a register in a machine
- mode other than its natural one, or to refer to one register of a
- multi-part `reg' that actually refers to several registers.
-
- Each pseudo register has a natural mode. If it is necessary to
- operate on it in a different mode, the register must be enclosed
- in a `subreg'.
-
- There are currently three supported types for the first operand of
- a `subreg':
- * pseudo registers This is the most common case. Most
- `subreg's have pseudo `reg's as their first operand.
-
- * mem `subreg's of `mem' were common in earlier versions of GCC
- and are still supported. During the reload pass these are
- replaced by plain `mem's. On machines that do not do
- instruction scheduling, use of `subreg's of `mem' are still
- used, but this is no longer recommended. Such `subreg's are
- considered to be `register_operand's rather than
- `memory_operand's before and during reload. Because of this,
- the scheduling passes cannot properly schedule instructions
- with `subreg's of `mem', so for machines that do scheduling,
- `subreg's of `mem' should never be used. To support this,
- the combine and recog passes have explicit code to inhibit
- the creation of `subreg's of `mem' when `INSN_SCHEDULING' is
- defined.
-
- The use of `subreg's of `mem' after the reload pass is an area
- that is not well understood and should be avoided. There is
- still some code in the compiler to support this, but this
- code has possibly rotted. This use of `subreg's is
- discouraged and will most likely not be supported in the
- future.
-
- * hard registers It is seldom necessary to wrap hard registers
- in `subreg's; such registers would normally reduce to a
- single `reg' rtx. This use of `subreg's is discouraged and
- may not be supported in the future.
-
-
- `subreg's of `subreg's are not supported. Using
- `simplify_gen_subreg' is the recommended way to avoid this problem.
-
- `subreg's come in two distinct flavors, each having its own usage
- and rules:
-
- Paradoxical subregs
- When M1 is strictly wider than M2, the `subreg' expression is
- called "paradoxical". The canonical test for this class of
- `subreg' is:
-
- GET_MODE_SIZE (M1) > GET_MODE_SIZE (M2)
-
- Paradoxical `subreg's can be used as both lvalues and rvalues.
- When used as an lvalue, the low-order bits of the source value
- are stored in REG and the high-order bits are discarded.
- When used as an rvalue, the low-order bits of the `subreg' are
- taken from REG while the high-order bits may or may not be
- defined.
-
- The high-order bits of rvalues are in the following
- circumstances:
-
- * `subreg's of `mem' When M2 is smaller than a word, the
- macro `LOAD_EXTEND_OP', can control how the high-order
- bits are defined.
-
- * `subreg' of `reg's The upper bits are defined when
- `SUBREG_PROMOTED_VAR_P' is true.
- `SUBREG_PROMOTED_UNSIGNED_P' describes what the upper
- bits hold. Such subregs usually represent local
- variables, register variables and parameter pseudo
- variables that have been promoted to a wider mode.
-
-
- BYTENUM is always zero for a paradoxical `subreg', even on
- big-endian targets.
-
- For example, the paradoxical `subreg':
-
- (set (subreg:SI (reg:HI X) 0) Y)
-
- stores the lower 2 bytes of Y in X and discards the upper 2
- bytes. A subsequent:
-
- (set Z (subreg:SI (reg:HI X) 0))
-
- would set the lower two bytes of Z to Y and set the upper two
- bytes to an unknown value assuming `SUBREG_PROMOTED_VAR_P' is
- false.
-
- Normal subregs
- When M1 is at least as narrow as M2 the `subreg' expression
- is called "normal".
-
- Normal `subreg's restrict consideration to certain bits of
- REG. There are two cases. If M1 is smaller than a word, the
- `subreg' refers to the least-significant part (or "lowpart")
- of one word of REG. If M1 is word-sized or greater, the
- `subreg' refers to one or more complete words.
-
- When used as an lvalue, `subreg' is a word-based accessor.
- Storing to a `subreg' modifies all the words of REG that
- overlap the `subreg', but it leaves the other words of REG
- alone.
-
- When storing to a normal `subreg' that is smaller than a word,
- the other bits of the referenced word are usually left in an
- undefined state. This laxity makes it easier to generate
- efficient code for such instructions. To represent an
- instruction that preserves all the bits outside of those in
- the `subreg', use `strict_low_part' or `zero_extract' around
- the `subreg'.
-
- BYTENUM must identify the offset of the first byte of the
- `subreg' from the start of REG, assuming that REG is laid out
- in memory order. The memory order of bytes is defined by two
- target macros, `WORDS_BIG_ENDIAN' and `BYTES_BIG_ENDIAN':
-
- * `WORDS_BIG_ENDIAN', if set to 1, says that byte number
- zero is part of the most significant word; otherwise, it
- is part of the least significant word.
-
- * `BYTES_BIG_ENDIAN', if set to 1, says that byte number
- zero is the most significant byte within a word;
- otherwise, it is the least significant byte within a
- word.
-
- On a few targets, `FLOAT_WORDS_BIG_ENDIAN' disagrees with
- `WORDS_BIG_ENDIAN'. However, most parts of the compiler treat
- floating point values as if they had the same endianness as
- integer values. This works because they handle them solely
- as a collection of integer values, with no particular
- numerical value. Only real.c and the runtime libraries care
- about `FLOAT_WORDS_BIG_ENDIAN'.
-
- Thus,
-
- (subreg:HI (reg:SI X) 2)
-
- on a `BYTES_BIG_ENDIAN', `UNITS_PER_WORD == 4' target is the
- same as
-
- (subreg:HI (reg:SI X) 0)
-
- on a little-endian, `UNITS_PER_WORD == 4' target. Both
- `subreg's access the lower two bytes of register X.
-
-
- A `MODE_PARTIAL_INT' mode behaves as if it were as wide as the
- corresponding `MODE_INT' mode, except that it has an unknown
- number of undefined bits. For example:
-
- (subreg:PSI (reg:SI 0) 0)
-
- accesses the whole of `(reg:SI 0)', but the exact relationship
- between the `PSImode' value and the `SImode' value is not defined.
- If we assume `UNITS_PER_WORD <= 4', then the following two
- `subreg's:
-
- (subreg:PSI (reg:DI 0) 0)
- (subreg:PSI (reg:DI 0) 4)
-
- represent independent 4-byte accesses to the two halves of
- `(reg:DI 0)'. Both `subreg's have an unknown number of undefined
- bits.
-
- If `UNITS_PER_WORD <= 2' then these two `subreg's:
-
- (subreg:HI (reg:PSI 0) 0)
- (subreg:HI (reg:PSI 0) 2)
-
- represent independent 2-byte accesses that together span the whole
- of `(reg:PSI 0)'. Storing to the first `subreg' does not affect
- the value of the second, and vice versa. `(reg:PSI 0)' has an
- unknown number of undefined bits, so the assignment:
-
- (set (subreg:HI (reg:PSI 0) 0) (reg:HI 4))
-
- does not guarantee that `(subreg:HI (reg:PSI 0) 0)' has the value
- `(reg:HI 4)'.
-
- The rules above apply to both pseudo REGs and hard REGs. If the
- semantics are not correct for particular combinations of M1, M2
- and hard REG, the target-specific code must ensure that those
- combinations are never used. For example:
-
- CANNOT_CHANGE_MODE_CLASS (M2, M1, CLASS)
-
- must be true for every class CLASS that includes REG.
-
- The first operand of a `subreg' expression is customarily accessed
- with the `SUBREG_REG' macro and the second operand is customarily
- accessed with the `SUBREG_BYTE' macro.
-
- It has been several years since a platform in which
- `BYTES_BIG_ENDIAN' not equal to `WORDS_BIG_ENDIAN' has been
- tested. Anyone wishing to support such a platform in the future
- may be confronted with code rot.
-
-`(scratch:M)'
- This represents a scratch register that will be required for the
- execution of a single instruction and not used subsequently. It is
- converted into a `reg' by either the local register allocator or
- the reload pass.
-
- `scratch' is usually present inside a `clobber' operation (*note
- Side Effects::).
-
-`(cc0)'
- This refers to the machine's condition code register. It has no
- operands and may not have a machine mode. There are two ways to
- use it:
-
- * To stand for a complete set of condition code flags. This is
- best on most machines, where each comparison sets the entire
- series of flags.
-
- With this technique, `(cc0)' may be validly used in only two
- contexts: as the destination of an assignment (in test and
- compare instructions) and in comparison operators comparing
- against zero (`const_int' with value zero; that is to say,
- `const0_rtx').
-
- * To stand for a single flag that is the result of a single
- condition. This is useful on machines that have only a
- single flag bit, and in which comparison instructions must
- specify the condition to test.
-
- With this technique, `(cc0)' may be validly used in only two
- contexts: as the destination of an assignment (in test and
- compare instructions) where the source is a comparison
- operator, and as the first operand of `if_then_else' (in a
- conditional branch).
-
- There is only one expression object of code `cc0'; it is the value
- of the variable `cc0_rtx'. Any attempt to create an expression of
- code `cc0' will return `cc0_rtx'.
-
- Instructions can set the condition code implicitly. On many
- machines, nearly all instructions set the condition code based on
- the value that they compute or store. It is not necessary to
- record these actions explicitly in the RTL because the machine
- description includes a prescription for recognizing the
- instructions that do so (by means of the macro
- `NOTICE_UPDATE_CC'). *Note Condition Code::. Only instructions
- whose sole purpose is to set the condition code, and instructions
- that use the condition code, need mention `(cc0)'.
-
- On some machines, the condition code register is given a register
- number and a `reg' is used instead of `(cc0)'. This is usually the
- preferable approach if only a small subset of instructions modify
- the condition code. Other machines store condition codes in
- general registers; in such cases a pseudo register should be used.
-
- Some machines, such as the SPARC and RS/6000, have two sets of
- arithmetic instructions, one that sets and one that does not set
- the condition code. This is best handled by normally generating
- the instruction that does not set the condition code, and making a
- pattern that both performs the arithmetic and sets the condition
- code register (which would not be `(cc0)' in this case). For
- examples, search for `addcc' and `andcc' in `sparc.md'.
-
-`(pc)'
- This represents the machine's program counter. It has no operands
- and may not have a machine mode. `(pc)' may be validly used only
- in certain specific contexts in jump instructions.
-
- There is only one expression object of code `pc'; it is the value
- of the variable `pc_rtx'. Any attempt to create an expression of
- code `pc' will return `pc_rtx'.
-
- All instructions that do not jump alter the program counter
- implicitly by incrementing it, but there is no need to mention
- this in the RTL.
-
-`(mem:M ADDR ALIAS)'
- This RTX represents a reference to main memory at an address
- represented by the expression ADDR. M specifies how large a unit
- of memory is accessed. ALIAS specifies an alias set for the
- reference. In general two items are in different alias sets if
- they cannot reference the same memory address.
-
- The construct `(mem:BLK (scratch))' is considered to alias all
- other memories. Thus it may be used as a memory barrier in
- epilogue stack deallocation patterns.
-
-`(concatM RTX RTX)'
- This RTX represents the concatenation of two other RTXs. This is
- used for complex values. It should only appear in the RTL
- attached to declarations and during RTL generation. It should not
- appear in the ordinary insn chain.
-
-`(concatnM [RTX ...])'
- This RTX represents the concatenation of all the RTX to make a
- single value. Like `concat', this should only appear in
- declarations, and not in the insn chain.
-
-\1f
-File: gccint.info, Node: Arithmetic, Next: Comparisons, Prev: Regs and Memory, Up: RTL
-
-10.9 RTL Expressions for Arithmetic
-===================================
-
-Unless otherwise specified, all the operands of arithmetic expressions
-must be valid for mode M. An operand is valid for mode M if it has
-mode M, or if it is a `const_int' or `const_double' and M is a mode of
-class `MODE_INT'.
-
- For commutative binary operations, constants should be placed in the
-second operand.
-
-`(plus:M X Y)'
-`(ss_plus:M X Y)'
-`(us_plus:M X Y)'
- These three expressions all represent the sum of the values
- represented by X and Y carried out in machine mode M. They differ
- in their behavior on overflow of integer modes. `plus' wraps
- round modulo the width of M; `ss_plus' saturates at the maximum
- signed value representable in M; `us_plus' saturates at the
- maximum unsigned value.
-
-`(lo_sum:M X Y)'
- This expression represents the sum of X and the low-order bits of
- Y. It is used with `high' (*note Constants::) to represent the
- typical two-instruction sequence used in RISC machines to
- reference a global memory location.
-
- The number of low order bits is machine-dependent but is normally
- the number of bits in a `Pmode' item minus the number of bits set
- by `high'.
-
- M should be `Pmode'.
-
-`(minus:M X Y)'
-`(ss_minus:M X Y)'
-`(us_minus:M X Y)'
- These three expressions represent the result of subtracting Y from
- X, carried out in mode M. Behavior on overflow is the same as for
- the three variants of `plus' (see above).
-
-`(compare:M X Y)'
- Represents the result of subtracting Y from X for purposes of
- comparison. The result is computed without overflow, as if with
- infinite precision.
-
- Of course, machines can't really subtract with infinite precision.
- However, they can pretend to do so when only the sign of the
- result will be used, which is the case when the result is stored
- in the condition code. And that is the _only_ way this kind of
- expression may validly be used: as a value to be stored in the
- condition codes, either `(cc0)' or a register. *Note
- Comparisons::.
-
- The mode M is not related to the modes of X and Y, but instead is
- the mode of the condition code value. If `(cc0)' is used, it is
- `VOIDmode'. Otherwise it is some mode in class `MODE_CC', often
- `CCmode'. *Note Condition Code::. If M is `VOIDmode' or
- `CCmode', the operation returns sufficient information (in an
- unspecified format) so that any comparison operator can be applied
- to the result of the `COMPARE' operation. For other modes in
- class `MODE_CC', the operation only returns a subset of this
- information.
-
- Normally, X and Y must have the same mode. Otherwise, `compare'
- is valid only if the mode of X is in class `MODE_INT' and Y is a
- `const_int' or `const_double' with mode `VOIDmode'. The mode of X
- determines what mode the comparison is to be done in; thus it must
- not be `VOIDmode'.
-
- If one of the operands is a constant, it should be placed in the
- second operand and the comparison code adjusted as appropriate.
-
- A `compare' specifying two `VOIDmode' constants is not valid since
- there is no way to know in what mode the comparison is to be
- performed; the comparison must either be folded during the
- compilation or the first operand must be loaded into a register
- while its mode is still known.
-
-`(neg:M X)'
-`(ss_neg:M X)'
-`(us_neg:M X)'
- These two expressions represent the negation (subtraction from
- zero) of the value represented by X, carried out in mode M. They
- differ in the behavior on overflow of integer modes. In the case
- of `neg', the negation of the operand may be a number not
- representable in mode M, in which case it is truncated to M.
- `ss_neg' and `us_neg' ensure that an out-of-bounds result
- saturates to the maximum or minimum signed or unsigned value.
-
-`(mult:M X Y)'
-`(ss_mult:M X Y)'
-`(us_mult:M X Y)'
- Represents the signed product of the values represented by X and Y
- carried out in machine mode M. `ss_mult' and `us_mult' ensure
- that an out-of-bounds result saturates to the maximum or minimum
- signed or unsigned value.
-
- Some machines support a multiplication that generates a product
- wider than the operands. Write the pattern for this as
-
- (mult:M (sign_extend:M X) (sign_extend:M Y))
-
- where M is wider than the modes of X and Y, which need not be the
- same.
-
- For unsigned widening multiplication, use the same idiom, but with
- `zero_extend' instead of `sign_extend'.
-
-`(div:M X Y)'
-`(ss_div:M X Y)'
- Represents the quotient in signed division of X by Y, carried out
- in machine mode M. If M is a floating point mode, it represents
- the exact quotient; otherwise, the integerized quotient. `ss_div'
- ensures that an out-of-bounds result saturates to the maximum or
- minimum signed value.
-
- Some machines have division instructions in which the operands and
- quotient widths are not all the same; you should represent such
- instructions using `truncate' and `sign_extend' as in,
-
- (truncate:M1 (div:M2 X (sign_extend:M2 Y)))
-
-`(udiv:M X Y)'
-`(us_div:M X Y)'
- Like `div' but represents unsigned division. `us_div' ensures
- that an out-of-bounds result saturates to the maximum or minimum
- unsigned value.
-
-`(mod:M X Y)'
-`(umod:M X Y)'
- Like `div' and `udiv' but represent the remainder instead of the
- quotient.
-
-`(smin:M X Y)'
-`(smax:M X Y)'
- Represents the smaller (for `smin') or larger (for `smax') of X
- and Y, interpreted as signed values in mode M. When used with
- floating point, if both operands are zeros, or if either operand
- is `NaN', then it is unspecified which of the two operands is
- returned as the result.
-
-`(umin:M X Y)'
-`(umax:M X Y)'
- Like `smin' and `smax', but the values are interpreted as unsigned
- integers.
-
-`(not:M X)'
- Represents the bitwise complement of the value represented by X,
- carried out in mode M, which must be a fixed-point machine mode.
-
-`(and:M X Y)'
- Represents the bitwise logical-and of the values represented by X
- and Y, carried out in machine mode M, which must be a fixed-point
- machine mode.
-
-`(ior:M X Y)'
- Represents the bitwise inclusive-or of the values represented by X
- and Y, carried out in machine mode M, which must be a fixed-point
- mode.
-
-`(xor:M X Y)'
- Represents the bitwise exclusive-or of the values represented by X
- and Y, carried out in machine mode M, which must be a fixed-point
- mode.
-
-`(ashift:M X C)'
-`(ss_ashift:M X C)'
-`(us_ashift:M X C)'
- These three expressions represent the result of arithmetically
- shifting X left by C places. They differ in their behavior on
- overflow of integer modes. An `ashift' operation is a plain shift
- with no special behavior in case of a change in the sign bit;
- `ss_ashift' and `us_ashift' saturates to the minimum or maximum
- representable value if any of the bits shifted out differs from
- the final sign bit.
-
- X have mode M, a fixed-point machine mode. C be a fixed-point
- mode or be a constant with mode `VOIDmode'; which mode is
- determined by the mode called for in the machine description entry
- for the left-shift instruction. For example, on the VAX, the mode
- of C is `QImode' regardless of M.
-
-`(lshiftrt:M X C)'
-`(ashiftrt:M X C)'
- Like `ashift' but for right shift. Unlike the case for left shift,
- these two operations are distinct.
-
-`(rotate:M X C)'
-`(rotatert:M X C)'
- Similar but represent left and right rotate. If C is a constant,
- use `rotate'.
-
-`(abs:M X)'
- Represents the absolute value of X, computed in mode M.
-
-`(sqrt:M X)'
- Represents the square root of X, computed in mode M. Most often M
- will be a floating point mode.
-
-`(ffs:M X)'
- Represents one plus the index of the least significant 1-bit in X,
- represented as an integer of mode M. (The value is zero if X is
- zero.) The mode of X need not be M; depending on the target
- machine, various mode combinations may be valid.
-
-`(clz:M X)'
- Represents the number of leading 0-bits in X, represented as an
- integer of mode M, starting at the most significant bit position.
- If X is zero, the value is determined by
- `CLZ_DEFINED_VALUE_AT_ZERO' (*note Misc::). Note that this is one
- of the few expressions that is not invariant under widening. The
- mode of X will usually be an integer mode.
-
-`(ctz:M X)'
- Represents the number of trailing 0-bits in X, represented as an
- integer of mode M, starting at the least significant bit position.
- If X is zero, the value is determined by
- `CTZ_DEFINED_VALUE_AT_ZERO' (*note Misc::). Except for this case,
- `ctz(x)' is equivalent to `ffs(X) - 1'. The mode of X will
- usually be an integer mode.
-
-`(popcount:M X)'
- Represents the number of 1-bits in X, represented as an integer of
- mode M. The mode of X will usually be an integer mode.
-
-`(parity:M X)'
- Represents the number of 1-bits modulo 2 in X, represented as an
- integer of mode M. The mode of X will usually be an integer mode.
-
-`(bswap:M X)'
- Represents the value X with the order of bytes reversed, carried
- out in mode M, which must be a fixed-point machine mode.
-
-\1f
-File: gccint.info, Node: Comparisons, Next: Bit-Fields, Prev: Arithmetic, Up: RTL
-
-10.10 Comparison Operations
-===========================
-
-Comparison operators test a relation on two operands and are considered
-to represent a machine-dependent nonzero value described by, but not
-necessarily equal to, `STORE_FLAG_VALUE' (*note Misc::) if the relation
-holds, or zero if it does not, for comparison operators whose results
-have a `MODE_INT' mode, `FLOAT_STORE_FLAG_VALUE' (*note Misc::) if the
-relation holds, or zero if it does not, for comparison operators that
-return floating-point values, and a vector of either
-`VECTOR_STORE_FLAG_VALUE' (*note Misc::) if the relation holds, or of
-zeros if it does not, for comparison operators that return vector
-results. The mode of the comparison operation is independent of the
-mode of the data being compared. If the comparison operation is being
-tested (e.g., the first operand of an `if_then_else'), the mode must be
-`VOIDmode'.
-
- There are two ways that comparison operations may be used. The
-comparison operators may be used to compare the condition codes `(cc0)'
-against zero, as in `(eq (cc0) (const_int 0))'. Such a construct
-actually refers to the result of the preceding instruction in which the
-condition codes were set. The instruction setting the condition code
-must be adjacent to the instruction using the condition code; only
-`note' insns may separate them.
-
- Alternatively, a comparison operation may directly compare two data
-objects. The mode of the comparison is determined by the operands; they
-must both be valid for a common machine mode. A comparison with both
-operands constant would be invalid as the machine mode could not be
-deduced from it, but such a comparison should never exist in RTL due to
-constant folding.
-
- In the example above, if `(cc0)' were last set to `(compare X Y)', the
-comparison operation is identical to `(eq X Y)'. Usually only one style
-of comparisons is supported on a particular machine, but the combine
-pass will try to merge the operations to produce the `eq' shown in case
-it exists in the context of the particular insn involved.
-
- Inequality comparisons come in two flavors, signed and unsigned. Thus,
-there are distinct expression codes `gt' and `gtu' for signed and
-unsigned greater-than. These can produce different results for the same
-pair of integer values: for example, 1 is signed greater-than -1 but not
-unsigned greater-than, because -1 when regarded as unsigned is actually
-`0xffffffff' which is greater than 1.
-
- The signed comparisons are also used for floating point values.
-Floating point comparisons are distinguished by the machine modes of
-the operands.
-
-`(eq:M X Y)'
- `STORE_FLAG_VALUE' if the values represented by X and Y are equal,
- otherwise 0.
-
-`(ne:M X Y)'
- `STORE_FLAG_VALUE' if the values represented by X and Y are not
- equal, otherwise 0.
-
-`(gt:M X Y)'
- `STORE_FLAG_VALUE' if the X is greater than Y. If they are
- fixed-point, the comparison is done in a signed sense.
-
-`(gtu:M X Y)'
- Like `gt' but does unsigned comparison, on fixed-point numbers
- only.
-
-`(lt:M X Y)'
-`(ltu:M X Y)'
- Like `gt' and `gtu' but test for "less than".
-
-`(ge:M X Y)'
-`(geu:M X Y)'
- Like `gt' and `gtu' but test for "greater than or equal".
-
-`(le:M X Y)'
-`(leu:M X Y)'
- Like `gt' and `gtu' but test for "less than or equal".
-
-`(if_then_else COND THEN ELSE)'
- This is not a comparison operation but is listed here because it is
- always used in conjunction with a comparison operation. To be
- precise, COND is a comparison expression. This expression
- represents a choice, according to COND, between the value
- represented by THEN and the one represented by ELSE.
-
- On most machines, `if_then_else' expressions are valid only to
- express conditional jumps.
-
-`(cond [TEST1 VALUE1 TEST2 VALUE2 ...] DEFAULT)'
- Similar to `if_then_else', but more general. Each of TEST1,
- TEST2, ... is performed in turn. The result of this expression is
- the VALUE corresponding to the first nonzero test, or DEFAULT if
- none of the tests are nonzero expressions.
-
- This is currently not valid for instruction patterns and is
- supported only for insn attributes. *Note Insn Attributes::.
-
-\1f
-File: gccint.info, Node: Bit-Fields, Next: Vector Operations, Prev: Comparisons, Up: RTL
-
-10.11 Bit-Fields
-================
-
-Special expression codes exist to represent bit-field instructions.
-
-`(sign_extract:M LOC SIZE POS)'
- This represents a reference to a sign-extended bit-field contained
- or starting in LOC (a memory or register reference). The bit-field
- is SIZE bits wide and starts at bit POS. The compilation option
- `BITS_BIG_ENDIAN' says which end of the memory unit POS counts
- from.
-
- If LOC is in memory, its mode must be a single-byte integer mode.
- If LOC is in a register, the mode to use is specified by the
- operand of the `insv' or `extv' pattern (*note Standard Names::)
- and is usually a full-word integer mode, which is the default if
- none is specified.
-
- The mode of POS is machine-specific and is also specified in the
- `insv' or `extv' pattern.
-
- The mode M is the same as the mode that would be used for LOC if
- it were a register.
-
- A `sign_extract' can not appear as an lvalue, or part thereof, in
- RTL.
-
-`(zero_extract:M LOC SIZE POS)'
- Like `sign_extract' but refers to an unsigned or zero-extended
- bit-field. The same sequence of bits are extracted, but they are
- filled to an entire word with zeros instead of by sign-extension.
-
- Unlike `sign_extract', this type of expressions can be lvalues in
- RTL; they may appear on the left side of an assignment, indicating
- insertion of a value into the specified bit-field.
-
-\1f
-File: gccint.info, Node: Vector Operations, Next: Conversions, Prev: Bit-Fields, Up: RTL
-
-10.12 Vector Operations
-=======================
-
-All normal RTL expressions can be used with vector modes; they are
-interpreted as operating on each part of the vector independently.
-Additionally, there are a few new expressions to describe specific
-vector operations.
-
-`(vec_merge:M VEC1 VEC2 ITEMS)'
- This describes a merge operation between two vectors. The result
- is a vector of mode M; its elements are selected from either VEC1
- or VEC2. Which elements are selected is described by ITEMS, which
- is a bit mask represented by a `const_int'; a zero bit indicates
- the corresponding element in the result vector is taken from VEC2
- while a set bit indicates it is taken from VEC1.
-
-`(vec_select:M VEC1 SELECTION)'
- This describes an operation that selects parts of a vector. VEC1
- is the source vector, SELECTION is a `parallel' that contains a
- `const_int' for each of the subparts of the result vector, giving
- the number of the source subpart that should be stored into it.
-
-`(vec_concat:M VEC1 VEC2)'
- Describes a vector concat operation. The result is a
- concatenation of the vectors VEC1 and VEC2; its length is the sum
- of the lengths of the two inputs.
-
-`(vec_duplicate:M VEC)'
- This operation converts a small vector into a larger one by
- duplicating the input values. The output vector mode must have
- the same submodes as the input vector mode, and the number of
- output parts must be an integer multiple of the number of input
- parts.
-
-
-\1f
-File: gccint.info, Node: Conversions, Next: RTL Declarations, Prev: Vector Operations, Up: RTL
-
-10.13 Conversions
-=================
-
-All conversions between machine modes must be represented by explicit
-conversion operations. For example, an expression which is the sum of
-a byte and a full word cannot be written as `(plus:SI (reg:QI 34)
-(reg:SI 80))' because the `plus' operation requires two operands of the
-same machine mode. Therefore, the byte-sized operand is enclosed in a
-conversion operation, as in
-
- (plus:SI (sign_extend:SI (reg:QI 34)) (reg:SI 80))
-
- The conversion operation is not a mere placeholder, because there may
-be more than one way of converting from a given starting mode to the
-desired final mode. The conversion operation code says how to do it.
-
- For all conversion operations, X must not be `VOIDmode' because the
-mode in which to do the conversion would not be known. The conversion
-must either be done at compile-time or X must be placed into a register.
-
-`(sign_extend:M X)'
- Represents the result of sign-extending the value X to machine
- mode M. M must be a fixed-point mode and X a fixed-point value of
- a mode narrower than M.
-
-`(zero_extend:M X)'
- Represents the result of zero-extending the value X to machine
- mode M. M must be a fixed-point mode and X a fixed-point value of
- a mode narrower than M.
-
-`(float_extend:M X)'
- Represents the result of extending the value X to machine mode M.
- M must be a floating point mode and X a floating point value of a
- mode narrower than M.
-
-`(truncate:M X)'
- Represents the result of truncating the value X to machine mode M.
- M must be a fixed-point mode and X a fixed-point value of a mode
- wider than M.
-
-`(ss_truncate:M X)'
- Represents the result of truncating the value X to machine mode M,
- using signed saturation in the case of overflow. Both M and the
- mode of X must be fixed-point modes.
-
-`(us_truncate:M X)'
- Represents the result of truncating the value X to machine mode M,
- using unsigned saturation in the case of overflow. Both M and the
- mode of X must be fixed-point modes.
-
-`(float_truncate:M X)'
- Represents the result of truncating the value X to machine mode M.
- M must be a floating point mode and X a floating point value of a
- mode wider than M.
-
-`(float:M X)'
- Represents the result of converting fixed point value X, regarded
- as signed, to floating point mode M.
-
-`(unsigned_float:M X)'
- Represents the result of converting fixed point value X, regarded
- as unsigned, to floating point mode M.
-
-`(fix:M X)'
- When M is a floating-point mode, represents the result of
- converting floating point value X (valid for mode M) to an
- integer, still represented in floating point mode M, by rounding
- towards zero.
-
- When M is a fixed-point mode, represents the result of converting
- floating point value X to mode M, regarded as signed. How
- rounding is done is not specified, so this operation may be used
- validly in compiling C code only for integer-valued operands.
-
-`(unsigned_fix:M X)'
- Represents the result of converting floating point value X to
- fixed point mode M, regarded as unsigned. How rounding is done is
- not specified.
-
-`(fract_convert:M X)'
- Represents the result of converting fixed-point value X to
- fixed-point mode M, signed integer value X to fixed-point mode M,
- floating-point value X to fixed-point mode M, fixed-point value X
- to integer mode M regarded as signed, or fixed-point value X to
- floating-point mode M. When overflows or underflows happen, the
- results are undefined.
-
-`(sat_fract:M X)'
- Represents the result of converting fixed-point value X to
- fixed-point mode M, signed integer value X to fixed-point mode M,
- or floating-point value X to fixed-point mode M. When overflows
- or underflows happen, the results are saturated to the maximum or
- the minimum.
-
-`(unsigned_fract_convert:M X)'
- Represents the result of converting fixed-point value X to integer
- mode M regarded as unsigned, or unsigned integer value X to
- fixed-point mode M. When overflows or underflows happen, the
- results are undefined.
-
-`(unsigned_sat_fract:M X)'
- Represents the result of converting unsigned integer value X to
- fixed-point mode M. When overflows or underflows happen, the
- results are saturated to the maximum or the minimum.
-
-\1f
-File: gccint.info, Node: RTL Declarations, Next: Side Effects, Prev: Conversions, Up: RTL
-
-10.14 Declarations
-==================
-
-Declaration expression codes do not represent arithmetic operations but
-rather state assertions about their operands.
-
-`(strict_low_part (subreg:M (reg:N R) 0))'
- This expression code is used in only one context: as the
- destination operand of a `set' expression. In addition, the
- operand of this expression must be a non-paradoxical `subreg'
- expression.
-
- The presence of `strict_low_part' says that the part of the
- register which is meaningful in mode N, but is not part of mode M,
- is not to be altered. Normally, an assignment to such a subreg is
- allowed to have undefined effects on the rest of the register when
- M is less than a word.
-
-\1f
-File: gccint.info, Node: Side Effects, Next: Incdec, Prev: RTL Declarations, Up: RTL
-
-10.15 Side Effect Expressions
-=============================
-
-The expression codes described so far represent values, not actions.
-But machine instructions never produce values; they are meaningful only
-for their side effects on the state of the machine. Special expression
-codes are used to represent side effects.
-
- The body of an instruction is always one of these side effect codes;
-the codes described above, which represent values, appear only as the
-operands of these.
-
-`(set LVAL X)'
- Represents the action of storing the value of X into the place
- represented by LVAL. LVAL must be an expression representing a
- place that can be stored in: `reg' (or `subreg', `strict_low_part'
- or `zero_extract'), `mem', `pc', `parallel', or `cc0'.
-
- If LVAL is a `reg', `subreg' or `mem', it has a machine mode; then
- X must be valid for that mode.
-
- If LVAL is a `reg' whose machine mode is less than the full width
- of the register, then it means that the part of the register
- specified by the machine mode is given the specified value and the
- rest of the register receives an undefined value. Likewise, if
- LVAL is a `subreg' whose machine mode is narrower than the mode of
- the register, the rest of the register can be changed in an
- undefined way.
-
- If LVAL is a `strict_low_part' of a subreg, then the part of the
- register specified by the machine mode of the `subreg' is given
- the value X and the rest of the register is not changed.
-
- If LVAL is a `zero_extract', then the referenced part of the
- bit-field (a memory or register reference) specified by the
- `zero_extract' is given the value X and the rest of the bit-field
- is not changed. Note that `sign_extract' can not appear in LVAL.
-
- If LVAL is `(cc0)', it has no machine mode, and X may be either a
- `compare' expression or a value that may have any mode. The
- latter case represents a "test" instruction. The expression `(set
- (cc0) (reg:M N))' is equivalent to `(set (cc0) (compare (reg:M N)
- (const_int 0)))'. Use the former expression to save space during
- the compilation.
-
- If LVAL is a `parallel', it is used to represent the case of a
- function returning a structure in multiple registers. Each element
- of the `parallel' is an `expr_list' whose first operand is a `reg'
- and whose second operand is a `const_int' representing the offset
- (in bytes) into the structure at which the data in that register
- corresponds. The first element may be null to indicate that the
- structure is also passed partly in memory.
-
- If LVAL is `(pc)', we have a jump instruction, and the
- possibilities for X are very limited. It may be a `label_ref'
- expression (unconditional jump). It may be an `if_then_else'
- (conditional jump), in which case either the second or the third
- operand must be `(pc)' (for the case which does not jump) and the
- other of the two must be a `label_ref' (for the case which does
- jump). X may also be a `mem' or `(plus:SI (pc) Y)', where Y may
- be a `reg' or a `mem'; these unusual patterns are used to
- represent jumps through branch tables.
-
- If LVAL is neither `(cc0)' nor `(pc)', the mode of LVAL must not
- be `VOIDmode' and the mode of X must be valid for the mode of LVAL.
-
- LVAL is customarily accessed with the `SET_DEST' macro and X with
- the `SET_SRC' macro.
-
-`(return)'
- As the sole expression in a pattern, represents a return from the
- current function, on machines where this can be done with one
- instruction, such as VAXen. On machines where a multi-instruction
- "epilogue" must be executed in order to return from the function,
- returning is done by jumping to a label which precedes the
- epilogue, and the `return' expression code is never used.
-
- Inside an `if_then_else' expression, represents the value to be
- placed in `pc' to return to the caller.
-
- Note that an insn pattern of `(return)' is logically equivalent to
- `(set (pc) (return))', but the latter form is never used.
-
-`(call FUNCTION NARGS)'
- Represents a function call. FUNCTION is a `mem' expression whose
- address is the address of the function to be called. NARGS is an
- expression which can be used for two purposes: on some machines it
- represents the number of bytes of stack argument; on others, it
- represents the number of argument registers.
-
- Each machine has a standard machine mode which FUNCTION must have.
- The machine description defines macro `FUNCTION_MODE' to expand
- into the requisite mode name. The purpose of this mode is to
- specify what kind of addressing is allowed, on machines where the
- allowed kinds of addressing depend on the machine mode being
- addressed.
-
-`(clobber X)'
- Represents the storing or possible storing of an unpredictable,
- undescribed value into X, which must be a `reg', `scratch',
- `parallel' or `mem' expression.
-
- One place this is used is in string instructions that store
- standard values into particular hard registers. It may not be
- worth the trouble to describe the values that are stored, but it
- is essential to inform the compiler that the registers will be
- altered, lest it attempt to keep data in them across the string
- instruction.
-
- If X is `(mem:BLK (const_int 0))' or `(mem:BLK (scratch))', it
- means that all memory locations must be presumed clobbered. If X
- is a `parallel', it has the same meaning as a `parallel' in a
- `set' expression.
-
- Note that the machine description classifies certain hard
- registers as "call-clobbered". All function call instructions are
- assumed by default to clobber these registers, so there is no need
- to use `clobber' expressions to indicate this fact. Also, each
- function call is assumed to have the potential to alter any memory
- location, unless the function is declared `const'.
-
- If the last group of expressions in a `parallel' are each a
- `clobber' expression whose arguments are `reg' or `match_scratch'
- (*note RTL Template::) expressions, the combiner phase can add the
- appropriate `clobber' expressions to an insn it has constructed
- when doing so will cause a pattern to be matched.
-
- This feature can be used, for example, on a machine that whose
- multiply and add instructions don't use an MQ register but which
- has an add-accumulate instruction that does clobber the MQ
- register. Similarly, a combined instruction might require a
- temporary register while the constituent instructions might not.
-
- When a `clobber' expression for a register appears inside a
- `parallel' with other side effects, the register allocator
- guarantees that the register is unoccupied both before and after
- that insn if it is a hard register clobber. For pseudo-register
- clobber, the register allocator and the reload pass do not assign
- the same hard register to the clobber and the input operands if
- there is an insn alternative containing the `&' constraint (*note
- Modifiers::) for the clobber and the hard register is in register
- classes of the clobber in the alternative. You can clobber either
- a specific hard register, a pseudo register, or a `scratch'
- expression; in the latter two cases, GCC will allocate a hard
- register that is available there for use as a temporary.
-
- For instructions that require a temporary register, you should use
- `scratch' instead of a pseudo-register because this will allow the
- combiner phase to add the `clobber' when required. You do this by
- coding (`clobber' (`match_scratch' ...)). If you do clobber a
- pseudo register, use one which appears nowhere else--generate a
- new one each time. Otherwise, you may confuse CSE.
-
- There is one other known use for clobbering a pseudo register in a
- `parallel': when one of the input operands of the insn is also
- clobbered by the insn. In this case, using the same pseudo
- register in the clobber and elsewhere in the insn produces the
- expected results.
-
-`(use X)'
- Represents the use of the value of X. It indicates that the value
- in X at this point in the program is needed, even though it may
- not be apparent why this is so. Therefore, the compiler will not
- attempt to delete previous instructions whose only effect is to
- store a value in X. X must be a `reg' expression.
-
- In some situations, it may be tempting to add a `use' of a
- register in a `parallel' to describe a situation where the value
- of a special register will modify the behavior of the instruction.
- An hypothetical example might be a pattern for an addition that can
- either wrap around or use saturating addition depending on the
- value of a special control register:
-
- (parallel [(set (reg:SI 2) (unspec:SI [(reg:SI 3)
- (reg:SI 4)] 0))
- (use (reg:SI 1))])
-
- This will not work, several of the optimizers only look at
- expressions locally; it is very likely that if you have multiple
- insns with identical inputs to the `unspec', they will be
- optimized away even if register 1 changes in between.
-
- This means that `use' can _only_ be used to describe that the
- register is live. You should think twice before adding `use'
- statements, more often you will want to use `unspec' instead. The
- `use' RTX is most commonly useful to describe that a fixed
- register is implicitly used in an insn. It is also safe to use in
- patterns where the compiler knows for other reasons that the result
- of the whole pattern is variable, such as `movmemM' or `call'
- patterns.
-
- During the reload phase, an insn that has a `use' as pattern can
- carry a reg_equal note. These `use' insns will be deleted before
- the reload phase exits.
-
- During the delayed branch scheduling phase, X may be an insn.
- This indicates that X previously was located at this place in the
- code and its data dependencies need to be taken into account.
- These `use' insns will be deleted before the delayed branch
- scheduling phase exits.
-
-`(parallel [X0 X1 ...])'
- Represents several side effects performed in parallel. The square
- brackets stand for a vector; the operand of `parallel' is a vector
- of expressions. X0, X1 and so on are individual side effect
- expressions--expressions of code `set', `call', `return',
- `clobber' or `use'.
-
- "In parallel" means that first all the values used in the
- individual side-effects are computed, and second all the actual
- side-effects are performed. For example,
-
- (parallel [(set (reg:SI 1) (mem:SI (reg:SI 1)))
- (set (mem:SI (reg:SI 1)) (reg:SI 1))])
-
- says unambiguously that the values of hard register 1 and the
- memory location addressed by it are interchanged. In both places
- where `(reg:SI 1)' appears as a memory address it refers to the
- value in register 1 _before_ the execution of the insn.
-
- It follows that it is _incorrect_ to use `parallel' and expect the
- result of one `set' to be available for the next one. For
- example, people sometimes attempt to represent a jump-if-zero
- instruction this way:
-
- (parallel [(set (cc0) (reg:SI 34))
- (set (pc) (if_then_else
- (eq (cc0) (const_int 0))
- (label_ref ...)
- (pc)))])
-
- But this is incorrect, because it says that the jump condition
- depends on the condition code value _before_ this instruction, not
- on the new value that is set by this instruction.
-
- Peephole optimization, which takes place together with final
- assembly code output, can produce insns whose patterns consist of
- a `parallel' whose elements are the operands needed to output the
- resulting assembler code--often `reg', `mem' or constant
- expressions. This would not be well-formed RTL at any other stage
- in compilation, but it is ok then because no further optimization
- remains to be done. However, the definition of the macro
- `NOTICE_UPDATE_CC', if any, must deal with such insns if you
- define any peephole optimizations.
-
-`(cond_exec [COND EXPR])'
- Represents a conditionally executed expression. The EXPR is
- executed only if the COND is nonzero. The COND expression must
- not have side-effects, but the EXPR may very well have
- side-effects.
-
-`(sequence [INSNS ...])'
- Represents a sequence of insns. Each of the INSNS that appears in
- the vector is suitable for appearing in the chain of insns, so it
- must be an `insn', `jump_insn', `call_insn', `code_label',
- `barrier' or `note'.
-
- A `sequence' RTX is never placed in an actual insn during RTL
- generation. It represents the sequence of insns that result from a
- `define_expand' _before_ those insns are passed to `emit_insn' to
- insert them in the chain of insns. When actually inserted, the
- individual sub-insns are separated out and the `sequence' is
- forgotten.
-
- After delay-slot scheduling is completed, an insn and all the
- insns that reside in its delay slots are grouped together into a
- `sequence'. The insn requiring the delay slot is the first insn
- in the vector; subsequent insns are to be placed in the delay slot.
-
- `INSN_ANNULLED_BRANCH_P' is set on an insn in a delay slot to
- indicate that a branch insn should be used that will conditionally
- annul the effect of the insns in the delay slots. In such a case,
- `INSN_FROM_TARGET_P' indicates that the insn is from the target of
- the branch and should be executed only if the branch is taken;
- otherwise the insn should be executed only if the branch is not
- taken. *Note Delay Slots::.
-
- These expression codes appear in place of a side effect, as the body of
-an insn, though strictly speaking they do not always describe side
-effects as such:
-
-`(asm_input S)'
- Represents literal assembler code as described by the string S.
-
-`(unspec [OPERANDS ...] INDEX)'
-`(unspec_volatile [OPERANDS ...] INDEX)'
- Represents a machine-specific operation on OPERANDS. INDEX
- selects between multiple machine-specific operations.
- `unspec_volatile' is used for volatile operations and operations
- that may trap; `unspec' is used for other operations.
-
- These codes may appear inside a `pattern' of an insn, inside a
- `parallel', or inside an expression.
-
-`(addr_vec:M [LR0 LR1 ...])'
- Represents a table of jump addresses. The vector elements LR0,
- etc., are `label_ref' expressions. The mode M specifies how much
- space is given to each address; normally M would be `Pmode'.
-
-`(addr_diff_vec:M BASE [LR0 LR1 ...] MIN MAX FLAGS)'
- Represents a table of jump addresses expressed as offsets from
- BASE. The vector elements LR0, etc., are `label_ref' expressions
- and so is BASE. The mode M specifies how much space is given to
- each address-difference. MIN and MAX are set up by branch
- shortening and hold a label with a minimum and a maximum address,
- respectively. FLAGS indicates the relative position of BASE, MIN
- and MAX to the containing insn and of MIN and MAX to BASE. See
- rtl.def for details.
-
-`(prefetch:M ADDR RW LOCALITY)'
- Represents prefetch of memory at address ADDR. Operand RW is 1 if
- the prefetch is for data to be written, 0 otherwise; targets that
- do not support write prefetches should treat this as a normal
- prefetch. Operand LOCALITY specifies the amount of temporal
- locality; 0 if there is none or 1, 2, or 3 for increasing levels
- of temporal locality; targets that do not support locality hints
- should ignore this.
-
- This insn is used to minimize cache-miss latency by moving data
- into a cache before it is accessed. It should use only
- non-faulting data prefetch instructions.
-
-\1f
-File: gccint.info, Node: Incdec, Next: Assembler, Prev: Side Effects, Up: RTL
-
-10.16 Embedded Side-Effects on Addresses
-========================================
-
-Six special side-effect expression codes appear as memory addresses.
-
-`(pre_dec:M X)'
- Represents the side effect of decrementing X by a standard amount
- and represents also the value that X has after being decremented.
- X must be a `reg' or `mem', but most machines allow only a `reg'.
- M must be the machine mode for pointers on the machine in use.
- The amount X is decremented by is the length in bytes of the
- machine mode of the containing memory reference of which this
- expression serves as the address. Here is an example of its use:
-
- (mem:DF (pre_dec:SI (reg:SI 39)))
-
- This says to decrement pseudo register 39 by the length of a
- `DFmode' value and use the result to address a `DFmode' value.
-
-`(pre_inc:M X)'
- Similar, but specifies incrementing X instead of decrementing it.
-
-`(post_dec:M X)'
- Represents the same side effect as `pre_dec' but a different
- value. The value represented here is the value X has before being
- decremented.
-
-`(post_inc:M X)'
- Similar, but specifies incrementing X instead of decrementing it.
-
-`(post_modify:M X Y)'
- Represents the side effect of setting X to Y and represents X
- before X is modified. X must be a `reg' or `mem', but most
- machines allow only a `reg'. M must be the machine mode for
- pointers on the machine in use.
-
- The expression Y must be one of three forms: `(plus:M X Z)',
- `(minus:M X Z)', or `(plus:M X I)', where Z is an index register
- and I is a constant.
-
- Here is an example of its use:
-
- (mem:SF (post_modify:SI (reg:SI 42) (plus (reg:SI 42)
- (reg:SI 48))))
-
- This says to modify pseudo register 42 by adding the contents of
- pseudo register 48 to it, after the use of what ever 42 points to.
-
-`(pre_modify:M X EXPR)'
- Similar except side effects happen before the use.
-
- These embedded side effect expressions must be used with care.
-Instruction patterns may not use them. Until the `flow' pass of the
-compiler, they may occur only to represent pushes onto the stack. The
-`flow' pass finds cases where registers are incremented or decremented
-in one instruction and used as an address shortly before or after;
-these cases are then transformed to use pre- or post-increment or
--decrement.
-
- If a register used as the operand of these expressions is used in
-another address in an insn, the original value of the register is used.
-Uses of the register outside of an address are not permitted within the
-same insn as a use in an embedded side effect expression because such
-insns behave differently on different machines and hence must be treated
-as ambiguous and disallowed.
-
- An instruction that can be represented with an embedded side effect
-could also be represented using `parallel' containing an additional
-`set' to describe how the address register is altered. This is not
-done because machines that allow these operations at all typically
-allow them wherever a memory address is called for. Describing them as
-additional parallel stores would require doubling the number of entries
-in the machine description.
-
-\1f
-File: gccint.info, Node: Assembler, Next: Insns, Prev: Incdec, Up: RTL
-
-10.17 Assembler Instructions as Expressions
-===========================================
-
-The RTX code `asm_operands' represents a value produced by a
-user-specified assembler instruction. It is used to represent an `asm'
-statement with arguments. An `asm' statement with a single output
-operand, like this:
-
- asm ("foo %1,%2,%0" : "=a" (outputvar) : "g" (x + y), "di" (*z));
-
-is represented using a single `asm_operands' RTX which represents the
-value that is stored in `outputvar':
-
- (set RTX-FOR-OUTPUTVAR
- (asm_operands "foo %1,%2,%0" "a" 0
- [RTX-FOR-ADDITION-RESULT RTX-FOR-*Z]
- [(asm_input:M1 "g")
- (asm_input:M2 "di")]))
-
-Here the operands of the `asm_operands' RTX are the assembler template
-string, the output-operand's constraint, the index-number of the output
-operand among the output operands specified, a vector of input operand
-RTX's, and a vector of input-operand modes and constraints. The mode
-M1 is the mode of the sum `x+y'; M2 is that of `*z'.
-
- When an `asm' statement has multiple output values, its insn has
-several such `set' RTX's inside of a `parallel'. Each `set' contains a
-`asm_operands'; all of these share the same assembler template and
-vectors, but each contains the constraint for the respective output
-operand. They are also distinguished by the output-operand index
-number, which is 0, 1, ... for successive output operands.
-
-\1f
-File: gccint.info, Node: Insns, Next: Calls, Prev: Assembler, Up: RTL
-
-10.18 Insns
-===========
-
-The RTL representation of the code for a function is a doubly-linked
-chain of objects called "insns". Insns are expressions with special
-codes that are used for no other purpose. Some insns are actual
-instructions; others represent dispatch tables for `switch' statements;
-others represent labels to jump to or various sorts of declarative
-information.
-
- In addition to its own specific data, each insn must have a unique
-id-number that distinguishes it from all other insns in the current
-function (after delayed branch scheduling, copies of an insn with the
-same id-number may be present in multiple places in a function, but
-these copies will always be identical and will only appear inside a
-`sequence'), and chain pointers to the preceding and following insns.
-These three fields occupy the same position in every insn, independent
-of the expression code of the insn. They could be accessed with `XEXP'
-and `XINT', but instead three special macros are always used:
-
-`INSN_UID (I)'
- Accesses the unique id of insn I.
-
-`PREV_INSN (I)'
- Accesses the chain pointer to the insn preceding I. If I is the
- first insn, this is a null pointer.
-
-`NEXT_INSN (I)'
- Accesses the chain pointer to the insn following I. If I is the
- last insn, this is a null pointer.
-
- The first insn in the chain is obtained by calling `get_insns'; the
-last insn is the result of calling `get_last_insn'. Within the chain
-delimited by these insns, the `NEXT_INSN' and `PREV_INSN' pointers must
-always correspond: if INSN is not the first insn,
-
- NEXT_INSN (PREV_INSN (INSN)) == INSN
-
-is always true and if INSN is not the last insn,
-
- PREV_INSN (NEXT_INSN (INSN)) == INSN
-
-is always true.
-
- After delay slot scheduling, some of the insns in the chain might be
-`sequence' expressions, which contain a vector of insns. The value of
-`NEXT_INSN' in all but the last of these insns is the next insn in the
-vector; the value of `NEXT_INSN' of the last insn in the vector is the
-same as the value of `NEXT_INSN' for the `sequence' in which it is
-contained. Similar rules apply for `PREV_INSN'.
-
- This means that the above invariants are not necessarily true for insns
-inside `sequence' expressions. Specifically, if INSN is the first insn
-in a `sequence', `NEXT_INSN (PREV_INSN (INSN))' is the insn containing
-the `sequence' expression, as is the value of `PREV_INSN (NEXT_INSN
-(INSN))' if INSN is the last insn in the `sequence' expression. You
-can use these expressions to find the containing `sequence' expression.
-
- Every insn has one of the following six expression codes:
-
-`insn'
- The expression code `insn' is used for instructions that do not
- jump and do not do function calls. `sequence' expressions are
- always contained in insns with code `insn' even if one of those
- insns should jump or do function calls.
-
- Insns with code `insn' have four additional fields beyond the three
- mandatory ones listed above. These four are described in a table
- below.
-
-`jump_insn'
- The expression code `jump_insn' is used for instructions that may
- jump (or, more generally, may contain `label_ref' expressions to
- which `pc' can be set in that instruction). If there is an
- instruction to return from the current function, it is recorded as
- a `jump_insn'.
-
- `jump_insn' insns have the same extra fields as `insn' insns,
- accessed in the same way and in addition contain a field
- `JUMP_LABEL' which is defined once jump optimization has completed.
-
- For simple conditional and unconditional jumps, this field contains
- the `code_label' to which this insn will (possibly conditionally)
- branch. In a more complex jump, `JUMP_LABEL' records one of the
- labels that the insn refers to; other jump target labels are
- recorded as `REG_LABEL_TARGET' notes. The exception is `addr_vec'
- and `addr_diff_vec', where `JUMP_LABEL' is `NULL_RTX' and the only
- way to find the labels is to scan the entire body of the insn.
-
- Return insns count as jumps, but since they do not refer to any
- labels, their `JUMP_LABEL' is `NULL_RTX'.
-
-`call_insn'
- The expression code `call_insn' is used for instructions that may
- do function calls. It is important to distinguish these
- instructions because they imply that certain registers and memory
- locations may be altered unpredictably.
-
- `call_insn' insns have the same extra fields as `insn' insns,
- accessed in the same way and in addition contain a field
- `CALL_INSN_FUNCTION_USAGE', which contains a list (chain of
- `expr_list' expressions) containing `use' and `clobber'
- expressions that denote hard registers and `MEM's used or
- clobbered by the called function.
-
- A `MEM' generally points to a stack slots in which arguments passed
- to the libcall by reference (*note TARGET_PASS_BY_REFERENCE:
- Register Arguments.) are stored. If the argument is caller-copied
- (*note TARGET_CALLEE_COPIES: Register Arguments.), the stack slot
- will be mentioned in `CLOBBER' and `USE' entries; if it's
- callee-copied, only a `USE' will appear, and the `MEM' may point
- to addresses that are not stack slots.
-
- `CLOBBER'ed registers in this list augment registers specified in
- `CALL_USED_REGISTERS' (*note Register Basics::).
-
-`code_label'
- A `code_label' insn represents a label that a jump insn can jump
- to. It contains two special fields of data in addition to the
- three standard ones. `CODE_LABEL_NUMBER' is used to hold the
- "label number", a number that identifies this label uniquely among
- all the labels in the compilation (not just in the current
- function). Ultimately, the label is represented in the assembler
- output as an assembler label, usually of the form `LN' where N is
- the label number.
-
- When a `code_label' appears in an RTL expression, it normally
- appears within a `label_ref' which represents the address of the
- label, as a number.
-
- Besides as a `code_label', a label can also be represented as a
- `note' of type `NOTE_INSN_DELETED_LABEL'.
-
- The field `LABEL_NUSES' is only defined once the jump optimization
- phase is completed. It contains the number of times this label is
- referenced in the current function.
-
- The field `LABEL_KIND' differentiates four different types of
- labels: `LABEL_NORMAL', `LABEL_STATIC_ENTRY',
- `LABEL_GLOBAL_ENTRY', and `LABEL_WEAK_ENTRY'. The only labels
- that do not have type `LABEL_NORMAL' are "alternate entry points"
- to the current function. These may be static (visible only in the
- containing translation unit), global (exposed to all translation
- units), or weak (global, but can be overridden by another symbol
- with the same name).
-
- Much of the compiler treats all four kinds of label identically.
- Some of it needs to know whether or not a label is an alternate
- entry point; for this purpose, the macro `LABEL_ALT_ENTRY_P' is
- provided. It is equivalent to testing whether `LABEL_KIND (label)
- == LABEL_NORMAL'. The only place that cares about the distinction
- between static, global, and weak alternate entry points, besides
- the front-end code that creates them, is the function
- `output_alternate_entry_point', in `final.c'.
-
- To set the kind of a label, use the `SET_LABEL_KIND' macro.
-
-`barrier'
- Barriers are placed in the instruction stream when control cannot
- flow past them. They are placed after unconditional jump
- instructions to indicate that the jumps are unconditional and
- after calls to `volatile' functions, which do not return (e.g.,
- `exit'). They contain no information beyond the three standard
- fields.
-
-`note'
- `note' insns are used to represent additional debugging and
- declarative information. They contain two nonstandard fields, an
- integer which is accessed with the macro `NOTE_LINE_NUMBER' and a
- string accessed with `NOTE_SOURCE_FILE'.
-
- If `NOTE_LINE_NUMBER' is positive, the note represents the
- position of a source line and `NOTE_SOURCE_FILE' is the source
- file name that the line came from. These notes control generation
- of line number data in the assembler output.
-
- Otherwise, `NOTE_LINE_NUMBER' is not really a line number but a
- code with one of the following values (and `NOTE_SOURCE_FILE' must
- contain a null pointer):
-
- `NOTE_INSN_DELETED'
- Such a note is completely ignorable. Some passes of the
- compiler delete insns by altering them into notes of this
- kind.
-
- `NOTE_INSN_DELETED_LABEL'
- This marks what used to be a `code_label', but was not used
- for other purposes than taking its address and was
- transformed to mark that no code jumps to it.
-
- `NOTE_INSN_BLOCK_BEG'
- `NOTE_INSN_BLOCK_END'
- These types of notes indicate the position of the beginning
- and end of a level of scoping of variable names. They
- control the output of debugging information.
-
- `NOTE_INSN_EH_REGION_BEG'
- `NOTE_INSN_EH_REGION_END'
- These types of notes indicate the position of the beginning
- and end of a level of scoping for exception handling.
- `NOTE_BLOCK_NUMBER' identifies which `CODE_LABEL' or `note'
- of type `NOTE_INSN_DELETED_LABEL' is associated with the
- given region.
-
- `NOTE_INSN_LOOP_BEG'
- `NOTE_INSN_LOOP_END'
- These types of notes indicate the position of the beginning
- and end of a `while' or `for' loop. They enable the loop
- optimizer to find loops quickly.
-
- `NOTE_INSN_LOOP_CONT'
- Appears at the place in a loop that `continue' statements
- jump to.
-
- `NOTE_INSN_LOOP_VTOP'
- This note indicates the place in a loop where the exit test
- begins for those loops in which the exit test has been
- duplicated. This position becomes another virtual start of
- the loop when considering loop invariants.
-
- `NOTE_INSN_FUNCTION_BEG'
- Appears at the start of the function body, after the function
- prologue.
-
-
- These codes are printed symbolically when they appear in debugging
- dumps.
-
- The machine mode of an insn is normally `VOIDmode', but some phases
-use the mode for various purposes.
-
- The common subexpression elimination pass sets the mode of an insn to
-`QImode' when it is the first insn in a block that has already been
-processed.
-
- The second Haifa scheduling pass, for targets that can multiple issue,
-sets the mode of an insn to `TImode' when it is believed that the
-instruction begins an issue group. That is, when the instruction
-cannot issue simultaneously with the previous. This may be relied on
-by later passes, in particular machine-dependent reorg.
-
- Here is a table of the extra fields of `insn', `jump_insn' and
-`call_insn' insns:
-
-`PATTERN (I)'
- An expression for the side effect performed by this insn. This
- must be one of the following codes: `set', `call', `use',
- `clobber', `return', `asm_input', `asm_output', `addr_vec',
- `addr_diff_vec', `trap_if', `unspec', `unspec_volatile',
- `parallel', `cond_exec', or `sequence'. If it is a `parallel',
- each element of the `parallel' must be one these codes, except that
- `parallel' expressions cannot be nested and `addr_vec' and
- `addr_diff_vec' are not permitted inside a `parallel' expression.
-
-`INSN_CODE (I)'
- An integer that says which pattern in the machine description
- matches this insn, or -1 if the matching has not yet been
- attempted.
-
- Such matching is never attempted and this field remains -1 on an
- insn whose pattern consists of a single `use', `clobber',
- `asm_input', `addr_vec' or `addr_diff_vec' expression.
-
- Matching is also never attempted on insns that result from an `asm'
- statement. These contain at least one `asm_operands' expression.
- The function `asm_noperands' returns a non-negative value for such
- insns.
-
- In the debugging output, this field is printed as a number
- followed by a symbolic representation that locates the pattern in
- the `md' file as some small positive or negative offset from a
- named pattern.
-
-`LOG_LINKS (I)'
- A list (chain of `insn_list' expressions) giving information about
- dependencies between instructions within a basic block. Neither a
- jump nor a label may come between the related insns. These are
- only used by the schedulers and by combine. This is a deprecated
- data structure. Def-use and use-def chains are now preferred.
-
-`REG_NOTES (I)'
- A list (chain of `expr_list' and `insn_list' expressions) giving
- miscellaneous information about the insn. It is often information
- pertaining to the registers used in this insn.
-
- The `LOG_LINKS' field of an insn is a chain of `insn_list'
-expressions. Each of these has two operands: the first is an insn, and
-the second is another `insn_list' expression (the next one in the
-chain). The last `insn_list' in the chain has a null pointer as second
-operand. The significant thing about the chain is which insns appear
-in it (as first operands of `insn_list' expressions). Their order is
-not significant.
-
- This list is originally set up by the flow analysis pass; it is a null
-pointer until then. Flow only adds links for those data dependencies
-which can be used for instruction combination. For each insn, the flow
-analysis pass adds a link to insns which store into registers values
-that are used for the first time in this insn.
-
- The `REG_NOTES' field of an insn is a chain similar to the `LOG_LINKS'
-field but it includes `expr_list' expressions in addition to
-`insn_list' expressions. There are several kinds of register notes,
-which are distinguished by the machine mode, which in a register note
-is really understood as being an `enum reg_note'. The first operand OP
-of the note is data whose meaning depends on the kind of note.
-
- The macro `REG_NOTE_KIND (X)' returns the kind of register note. Its
-counterpart, the macro `PUT_REG_NOTE_KIND (X, NEWKIND)' sets the
-register note type of X to be NEWKIND.
-
- Register notes are of three classes: They may say something about an
-input to an insn, they may say something about an output of an insn, or
-they may create a linkage between two insns. There are also a set of
-values that are only used in `LOG_LINKS'.
-
- These register notes annotate inputs to an insn:
-
-`REG_DEAD'
- The value in OP dies in this insn; that is to say, altering the
- value immediately after this insn would not affect the future
- behavior of the program.
-
- It does not follow that the register OP has no useful value after
- this insn since OP is not necessarily modified by this insn.
- Rather, no subsequent instruction uses the contents of OP.
-
-`REG_UNUSED'
- The register OP being set by this insn will not be used in a
- subsequent insn. This differs from a `REG_DEAD' note, which
- indicates that the value in an input will not be used subsequently.
- These two notes are independent; both may be present for the same
- register.
-
-`REG_INC'
- The register OP is incremented (or decremented; at this level
- there is no distinction) by an embedded side effect inside this
- insn. This means it appears in a `post_inc', `pre_inc',
- `post_dec' or `pre_dec' expression.
-
-`REG_NONNEG'
- The register OP is known to have a nonnegative value when this
- insn is reached. This is used so that decrement and branch until
- zero instructions, such as the m68k dbra, can be matched.
-
- The `REG_NONNEG' note is added to insns only if the machine
- description has a `decrement_and_branch_until_zero' pattern.
-
-`REG_LABEL_OPERAND'
- This insn uses OP, a `code_label' or a `note' of type
- `NOTE_INSN_DELETED_LABEL', but is not a `jump_insn', or it is a
- `jump_insn' that refers to the operand as an ordinary operand.
- The label may still eventually be a jump target, but if so in an
- indirect jump in a subsequent insn. The presence of this note
- allows jump optimization to be aware that OP is, in fact, being
- used, and flow optimization to build an accurate flow graph.
-
-`REG_LABEL_TARGET'
- This insn is a `jump_insn' but not a `addr_vec' or
- `addr_diff_vec'. It uses OP, a `code_label' as a direct or
- indirect jump target. Its purpose is similar to that of
- `REG_LABEL_OPERAND'. This note is only present if the insn has
- multiple targets; the last label in the insn (in the highest
- numbered insn-field) goes into the `JUMP_LABEL' field and does not
- have a `REG_LABEL_TARGET' note. *Note JUMP_LABEL: Insns.
-
-`REG_CROSSING_JUMP'
- This insn is an branching instruction (either an unconditional
- jump or an indirect jump) which crosses between hot and cold
- sections, which could potentially be very far apart in the
- executable. The presence of this note indicates to other
- optimizations that this branching instruction should not be
- "collapsed" into a simpler branching construct. It is used when
- the optimization to partition basic blocks into hot and cold
- sections is turned on.
-
-`REG_SETJMP'
- Appears attached to each `CALL_INSN' to `setjmp' or a related
- function.
-
- The following notes describe attributes of outputs of an insn:
-
-`REG_EQUIV'
-`REG_EQUAL'
- This note is only valid on an insn that sets only one register and
- indicates that that register will be equal to OP at run time; the
- scope of this equivalence differs between the two types of notes.
- The value which the insn explicitly copies into the register may
- look different from OP, but they will be equal at run time. If the
- output of the single `set' is a `strict_low_part' expression, the
- note refers to the register that is contained in `SUBREG_REG' of
- the `subreg' expression.
-
- For `REG_EQUIV', the register is equivalent to OP throughout the
- entire function, and could validly be replaced in all its
- occurrences by OP. ("Validly" here refers to the data flow of the
- program; simple replacement may make some insns invalid.) For
- example, when a constant is loaded into a register that is never
- assigned any other value, this kind of note is used.
-
- When a parameter is copied into a pseudo-register at entry to a
- function, a note of this kind records that the register is
- equivalent to the stack slot where the parameter was passed.
- Although in this case the register may be set by other insns, it
- is still valid to replace the register by the stack slot
- throughout the function.
-
- A `REG_EQUIV' note is also used on an instruction which copies a
- register parameter into a pseudo-register at entry to a function,
- if there is a stack slot where that parameter could be stored.
- Although other insns may set the pseudo-register, it is valid for
- the compiler to replace the pseudo-register by stack slot
- throughout the function, provided the compiler ensures that the
- stack slot is properly initialized by making the replacement in
- the initial copy instruction as well. This is used on machines
- for which the calling convention allocates stack space for
- register parameters. See `REG_PARM_STACK_SPACE' in *note Stack
- Arguments::.
-
- In the case of `REG_EQUAL', the register that is set by this insn
- will be equal to OP at run time at the end of this insn but not
- necessarily elsewhere in the function. In this case, OP is
- typically an arithmetic expression. For example, when a sequence
- of insns such as a library call is used to perform an arithmetic
- operation, this kind of note is attached to the insn that produces
- or copies the final value.
-
- These two notes are used in different ways by the compiler passes.
- `REG_EQUAL' is used by passes prior to register allocation (such as
- common subexpression elimination and loop optimization) to tell
- them how to think of that value. `REG_EQUIV' notes are used by
- register allocation to indicate that there is an available
- substitute expression (either a constant or a `mem' expression for
- the location of a parameter on the stack) that may be used in
- place of a register if insufficient registers are available.
-
- Except for stack homes for parameters, which are indicated by a
- `REG_EQUIV' note and are not useful to the early optimization
- passes and pseudo registers that are equivalent to a memory
- location throughout their entire life, which is not detected until
- later in the compilation, all equivalences are initially indicated
- by an attached `REG_EQUAL' note. In the early stages of register
- allocation, a `REG_EQUAL' note is changed into a `REG_EQUIV' note
- if OP is a constant and the insn represents the only set of its
- destination register.
-
- Thus, compiler passes prior to register allocation need only check
- for `REG_EQUAL' notes and passes subsequent to register allocation
- need only check for `REG_EQUIV' notes.
-
- These notes describe linkages between insns. They occur in pairs: one
-insn has one of a pair of notes that points to a second insn, which has
-the inverse note pointing back to the first insn.
-
-`REG_CC_SETTER'
-`REG_CC_USER'
- On machines that use `cc0', the insns which set and use `cc0' set
- and use `cc0' are adjacent. However, when branch delay slot
- filling is done, this may no longer be true. In this case a
- `REG_CC_USER' note will be placed on the insn setting `cc0' to
- point to the insn using `cc0' and a `REG_CC_SETTER' note will be
- placed on the insn using `cc0' to point to the insn setting `cc0'.
-
- These values are only used in the `LOG_LINKS' field, and indicate the
-type of dependency that each link represents. Links which indicate a
-data dependence (a read after write dependence) do not use any code,
-they simply have mode `VOIDmode', and are printed without any
-descriptive text.
-
-`REG_DEP_TRUE'
- This indicates a true dependence (a read after write dependence).
-
-`REG_DEP_OUTPUT'
- This indicates an output dependence (a write after write
- dependence).
-
-`REG_DEP_ANTI'
- This indicates an anti dependence (a write after read dependence).
-
-
- These notes describe information gathered from gcov profile data. They
-are stored in the `REG_NOTES' field of an insn as an `expr_list'.
-
-`REG_BR_PROB'
- This is used to specify the ratio of branches to non-branches of a
- branch insn according to the profile data. The value is stored as
- a value between 0 and REG_BR_PROB_BASE; larger values indicate a
- higher probability that the branch will be taken.
-
-`REG_BR_PRED'
- These notes are found in JUMP insns after delayed branch scheduling
- has taken place. They indicate both the direction and the
- likelihood of the JUMP. The format is a bitmask of ATTR_FLAG_*
- values.
-
-`REG_FRAME_RELATED_EXPR'
- This is used on an RTX_FRAME_RELATED_P insn wherein the attached
- expression is used in place of the actual insn pattern. This is
- done in cases where the pattern is either complex or misleading.
-
- For convenience, the machine mode in an `insn_list' or `expr_list' is
-printed using these symbolic codes in debugging dumps.
-
- The only difference between the expression codes `insn_list' and
-`expr_list' is that the first operand of an `insn_list' is assumed to
-be an insn and is printed in debugging dumps as the insn's unique id;
-the first operand of an `expr_list' is printed in the ordinary way as
-an expression.
-
-\1f
-File: gccint.info, Node: Calls, Next: Sharing, Prev: Insns, Up: RTL
-
-10.19 RTL Representation of Function-Call Insns
-===============================================
-
-Insns that call subroutines have the RTL expression code `call_insn'.
-These insns must satisfy special rules, and their bodies must use a
-special RTL expression code, `call'.
-
- A `call' expression has two operands, as follows:
-
- (call (mem:FM ADDR) NBYTES)
-
-Here NBYTES is an operand that represents the number of bytes of
-argument data being passed to the subroutine, FM is a machine mode
-(which must equal as the definition of the `FUNCTION_MODE' macro in the
-machine description) and ADDR represents the address of the subroutine.
-
- For a subroutine that returns no value, the `call' expression as shown
-above is the entire body of the insn, except that the insn might also
-contain `use' or `clobber' expressions.
-
- For a subroutine that returns a value whose mode is not `BLKmode', the
-value is returned in a hard register. If this register's number is R,
-then the body of the call insn looks like this:
-
- (set (reg:M R)
- (call (mem:FM ADDR) NBYTES))
-
-This RTL expression makes it clear (to the optimizer passes) that the
-appropriate register receives a useful value in this insn.
-
- When a subroutine returns a `BLKmode' value, it is handled by passing
-to the subroutine the address of a place to store the value. So the
-call insn itself does not "return" any value, and it has the same RTL
-form as a call that returns nothing.
-
- On some machines, the call instruction itself clobbers some register,
-for example to contain the return address. `call_insn' insns on these
-machines should have a body which is a `parallel' that contains both
-the `call' expression and `clobber' expressions that indicate which
-registers are destroyed. Similarly, if the call instruction requires
-some register other than the stack pointer that is not explicitly
-mentioned in its RTL, a `use' subexpression should mention that
-register.
-
- Functions that are called are assumed to modify all registers listed in
-the configuration macro `CALL_USED_REGISTERS' (*note Register Basics::)
-and, with the exception of `const' functions and library calls, to
-modify all of memory.
-
- Insns containing just `use' expressions directly precede the
-`call_insn' insn to indicate which registers contain inputs to the
-function. Similarly, if registers other than those in
-`CALL_USED_REGISTERS' are clobbered by the called function, insns
-containing a single `clobber' follow immediately after the call to
-indicate which registers.
-
-\1f
-File: gccint.info, Node: Sharing, Next: Reading RTL, Prev: Calls, Up: RTL
-
-10.20 Structure Sharing Assumptions
-===================================
-
-The compiler assumes that certain kinds of RTL expressions are unique;
-there do not exist two distinct objects representing the same value.
-In other cases, it makes an opposite assumption: that no RTL expression
-object of a certain kind appears in more than one place in the
-containing structure.
-
- These assumptions refer to a single function; except for the RTL
-objects that describe global variables and external functions, and a
-few standard objects such as small integer constants, no RTL objects
-are common to two functions.
-
- * Each pseudo-register has only a single `reg' object to represent
- it, and therefore only a single machine mode.
-
- * For any symbolic label, there is only one `symbol_ref' object
- referring to it.
-
- * All `const_int' expressions with equal values are shared.
-
- * There is only one `pc' expression.
-
- * There is only one `cc0' expression.
-
- * There is only one `const_double' expression with value 0 for each
- floating point mode. Likewise for values 1 and 2.
-
- * There is only one `const_vector' expression with value 0 for each
- vector mode, be it an integer or a double constant vector.
-
- * No `label_ref' or `scratch' appears in more than one place in the
- RTL structure; in other words, it is safe to do a tree-walk of all
- the insns in the function and assume that each time a `label_ref'
- or `scratch' is seen it is distinct from all others that are seen.
-
- * Only one `mem' object is normally created for each static variable
- or stack slot, so these objects are frequently shared in all the
- places they appear. However, separate but equal objects for these
- variables are occasionally made.
-
- * When a single `asm' statement has multiple output operands, a
- distinct `asm_operands' expression is made for each output operand.
- However, these all share the vector which contains the sequence of
- input operands. This sharing is used later on to test whether two
- `asm_operands' expressions come from the same statement, so all
- optimizations must carefully preserve the sharing if they copy the
- vector at all.
-
- * No RTL object appears in more than one place in the RTL structure
- except as described above. Many passes of the compiler rely on
- this by assuming that they can modify RTL objects in place without
- unwanted side-effects on other insns.
-
- * During initial RTL generation, shared structure is freely
- introduced. After all the RTL for a function has been generated,
- all shared structure is copied by `unshare_all_rtl' in
- `emit-rtl.c', after which the above rules are guaranteed to be
- followed.
-
- * During the combiner pass, shared structure within an insn can exist
- temporarily. However, the shared structure is copied before the
- combiner is finished with the insn. This is done by calling
- `copy_rtx_if_shared', which is a subroutine of `unshare_all_rtl'.
-
-\1f
-File: gccint.info, Node: Reading RTL, Prev: Sharing, Up: RTL
-
-10.21 Reading RTL
-=================
-
-To read an RTL object from a file, call `read_rtx'. It takes one
-argument, a stdio stream, and returns a single RTL object. This routine
-is defined in `read-rtl.c'. It is not available in the compiler
-itself, only the various programs that generate the compiler back end
-from the machine description.
-
- People frequently have the idea of using RTL stored as text in a file
-as an interface between a language front end and the bulk of GCC. This
-idea is not feasible.
-
- GCC was designed to use RTL internally only. Correct RTL for a given
-program is very dependent on the particular target machine. And the RTL
-does not contain all the information about the program.
-
- The proper way to interface GCC to a new language front end is with
-the "tree" data structure, described in the files `tree.h' and
-`tree.def'. The documentation for this structure (*note Trees::) is
-incomplete.
-
-\1f
-File: gccint.info, Node: GENERIC, Next: GIMPLE, Prev: Trees, Up: Top
-
-11 GENERIC
-**********
-
-The purpose of GENERIC is simply to provide a language-independent way
-of representing an entire function in trees. To this end, it was
-necessary to add a few new tree codes to the back end, but most
-everything was already there. If you can express it with the codes in
-`gcc/tree.def', it's GENERIC.
-
- Early on, there was a great deal of debate about how to think about
-statements in a tree IL. In GENERIC, a statement is defined as any
-expression whose value, if any, is ignored. A statement will always
-have `TREE_SIDE_EFFECTS' set (or it will be discarded), but a
-non-statement expression may also have side effects. A `CALL_EXPR',
-for instance.
-
- It would be possible for some local optimizations to work on the
-GENERIC form of a function; indeed, the adapted tree inliner works fine
-on GENERIC, but the current compiler performs inlining after lowering
-to GIMPLE (a restricted form described in the next section). Indeed,
-currently the frontends perform this lowering before handing off to
-`tree_rest_of_compilation', but this seems inelegant.
-
- If necessary, a front end can use some language-dependent tree codes
-in its GENERIC representation, so long as it provides a hook for
-converting them to GIMPLE and doesn't expect them to work with any
-(hypothetical) optimizers that run before the conversion to GIMPLE. The
-intermediate representation used while parsing C and C++ looks very
-little like GENERIC, but the C and C++ gimplifier hooks are perfectly
-happy to take it as input and spit out GIMPLE.
-
-* Menu:
-
-* Statements::
-
-\1f
-File: gccint.info, Node: Statements, Up: GENERIC
-
-11.1 Statements
-===============
-
-Most statements in GIMPLE are assignment statements, represented by
-`GIMPLE_ASSIGN'. No other C expressions can appear at statement level;
-a reference to a volatile object is converted into a `GIMPLE_ASSIGN'.
-
- There are also several varieties of complex statements.
-
-* Menu:
-
-* Blocks::
-* Statement Sequences::
-* Empty Statements::
-* Jumps::
-* Cleanups::
-
-\1f
-File: gccint.info, Node: Blocks, Next: Statement Sequences, Up: Statements
-
-11.1.1 Blocks
--------------
-
-Block scopes and the variables they declare in GENERIC are expressed
-using the `BIND_EXPR' code, which in previous versions of GCC was
-primarily used for the C statement-expression extension.
-
- Variables in a block are collected into `BIND_EXPR_VARS' in
-declaration order. Any runtime initialization is moved out of
-`DECL_INITIAL' and into a statement in the controlled block. When
-gimplifying from C or C++, this initialization replaces the `DECL_STMT'.
-
- Variable-length arrays (VLAs) complicate this process, as their size
-often refers to variables initialized earlier in the block. To handle
-this, we currently split the block at that point, and move the VLA into
-a new, inner `BIND_EXPR'. This strategy may change in the future.
-
- A C++ program will usually contain more `BIND_EXPR's than there are
-syntactic blocks in the source code, since several C++ constructs have
-implicit scopes associated with them. On the other hand, although the
-C++ front end uses pseudo-scopes to handle cleanups for objects with
-destructors, these don't translate into the GIMPLE form; multiple
-declarations at the same level use the same `BIND_EXPR'.
-
-\1f
-File: gccint.info, Node: Statement Sequences, Next: Empty Statements, Prev: Blocks, Up: Statements
-
-11.1.2 Statement Sequences
---------------------------
-
-Multiple statements at the same nesting level are collected into a
-`STATEMENT_LIST'. Statement lists are modified and traversed using the
-interface in `tree-iterator.h'.
-
-\1f
-File: gccint.info, Node: Empty Statements, Next: Jumps, Prev: Statement Sequences, Up: Statements
-
-11.1.3 Empty Statements
------------------------
-
-Whenever possible, statements with no effect are discarded. But if
-they are nested within another construct which cannot be discarded for
-some reason, they are instead replaced with an empty statement,
-generated by `build_empty_stmt'. Initially, all empty statements were
-shared, after the pattern of the Java front end, but this caused a lot
-of trouble in practice.
-
- An empty statement is represented as `(void)0'.
-
-\1f
-File: gccint.info, Node: Jumps, Next: Cleanups, Prev: Empty Statements, Up: Statements
-
-11.1.4 Jumps
-------------
-
-Other jumps are expressed by either `GOTO_EXPR' or `RETURN_EXPR'.
-
- The operand of a `GOTO_EXPR' must be either a label or a variable
-containing the address to jump to.
-
- The operand of a `RETURN_EXPR' is either `NULL_TREE', `RESULT_DECL',
-or a `MODIFY_EXPR' which sets the return value. It would be nice to
-move the `MODIFY_EXPR' into a separate statement, but the special
-return semantics in `expand_return' make that difficult. It may still
-happen in the future, perhaps by moving most of that logic into
-`expand_assignment'.
-
-\1f
-File: gccint.info, Node: Cleanups, Prev: Jumps, Up: Statements
-
-11.1.5 Cleanups
----------------
-
-Destructors for local C++ objects and similar dynamic cleanups are
-represented in GIMPLE by a `TRY_FINALLY_EXPR'. `TRY_FINALLY_EXPR' has
-two operands, both of which are a sequence of statements to execute.
-The first sequence is executed. When it completes the second sequence
-is executed.
-
- The first sequence may complete in the following ways:
-
- 1. Execute the last statement in the sequence and fall off the end.
-
- 2. Execute a goto statement (`GOTO_EXPR') to an ordinary label
- outside the sequence.
-
- 3. Execute a return statement (`RETURN_EXPR').
-
- 4. Throw an exception. This is currently not explicitly represented
- in GIMPLE.
-
-
- The second sequence is not executed if the first sequence completes by
-calling `setjmp' or `exit' or any other function that does not return.
-The second sequence is also not executed if the first sequence
-completes via a non-local goto or a computed goto (in general the
-compiler does not know whether such a goto statement exits the first
-sequence or not, so we assume that it doesn't).
-
- After the second sequence is executed, if it completes normally by
-falling off the end, execution continues wherever the first sequence
-would have continued, by falling off the end, or doing a goto, etc.
-
- `TRY_FINALLY_EXPR' complicates the flow graph, since the cleanup needs
-to appear on every edge out of the controlled block; this reduces the
-freedom to move code across these edges. Therefore, the EH lowering
-pass which runs before most of the optimization passes eliminates these
-expressions by explicitly adding the cleanup to each edge. Rethrowing
-the exception is represented using `RESX_EXPR'.
-
-\1f
-File: gccint.info, Node: GIMPLE, Next: Tree SSA, Prev: GENERIC, Up: Top
-
-12 GIMPLE
-*********
-
-GIMPLE is a three-address representation derived from GENERIC by
-breaking down GENERIC expressions into tuples of no more than 3
-operands (with some exceptions like function calls). GIMPLE was
-heavily influenced by the SIMPLE IL used by the McCAT compiler project
-at McGill University, though we have made some different choices. For
-one thing, SIMPLE doesn't support `goto'.
-
- Temporaries are introduced to hold intermediate values needed to
-compute complex expressions. Additionally, all the control structures
-used in GENERIC are lowered into conditional jumps, lexical scopes are
-removed and exception regions are converted into an on the side
-exception region tree.
-
- The compiler pass which converts GENERIC into GIMPLE is referred to as
-the `gimplifier'. The gimplifier works recursively, generating GIMPLE
-tuples out of the original GENERIC expressions.
-
- One of the early implementation strategies used for the GIMPLE
-representation was to use the same internal data structures used by
-front ends to represent parse trees. This simplified implementation
-because we could leverage existing functionality and interfaces.
-However, GIMPLE is a much more restrictive representation than abstract
-syntax trees (AST), therefore it does not require the full structural
-complexity provided by the main tree data structure.
-
- The GENERIC representation of a function is stored in the
-`DECL_SAVED_TREE' field of the associated `FUNCTION_DECL' tree node.
-It is converted to GIMPLE by a call to `gimplify_function_tree'.
-
- If a front end wants to include language-specific tree codes in the
-tree representation which it provides to the back end, it must provide a
-definition of `LANG_HOOKS_GIMPLIFY_EXPR' which knows how to convert the
-front end trees to GIMPLE. Usually such a hook will involve much of
-the same code for expanding front end trees to RTL. This function can
-return fully lowered GIMPLE, or it can return GENERIC trees and let the
-main gimplifier lower them the rest of the way; this is often simpler.
-GIMPLE that is not fully lowered is known as "High GIMPLE" and consists
-of the IL before the pass `pass_lower_cf'. High GIMPLE contains some
-container statements like lexical scopes (represented by `GIMPLE_BIND')
-and nested expressions (e.g., `GIMPLE_TRY'), while "Low GIMPLE" exposes
-all of the implicit jumps for control and exception expressions
-directly in the IL and EH region trees.
-
- The C and C++ front ends currently convert directly from front end
-trees to GIMPLE, and hand that off to the back end rather than first
-converting to GENERIC. Their gimplifier hooks know about all the
-`_STMT' nodes and how to convert them to GENERIC forms. There was some
-work done on a genericization pass which would run first, but the
-existence of `STMT_EXPR' meant that in order to convert all of the C
-statements into GENERIC equivalents would involve walking the entire
-tree anyway, so it was simpler to lower all the way. This might change
-in the future if someone writes an optimization pass which would work
-better with higher-level trees, but currently the optimizers all expect
-GIMPLE.
-
- You can request to dump a C-like representation of the GIMPLE form
-with the flag `-fdump-tree-gimple'.
-
-* Menu:
-
-* Tuple representation::
-* GIMPLE instruction set::
-* GIMPLE Exception Handling::
-* Temporaries::
-* Operands::
-* Manipulating GIMPLE statements::
-* Tuple specific accessors::
-* GIMPLE sequences::
-* Sequence iterators::
-* Adding a new GIMPLE statement code::
-* Statement and operand traversals::
-
-\1f
-File: gccint.info, Node: Tuple representation, Next: GIMPLE instruction set, Up: GIMPLE
-
-12.1 Tuple representation
-=========================
-
-GIMPLE instructions are tuples of variable size divided in two groups:
-a header describing the instruction and its locations, and a variable
-length body with all the operands. Tuples are organized into a
-hierarchy with 3 main classes of tuples.
-
-12.1.1 `gimple_statement_base' (gsbase)
----------------------------------------
-
-This is the root of the hierarchy, it holds basic information needed by
-most GIMPLE statements. There are some fields that may not be relevant
-to every GIMPLE statement, but those were moved into the base structure
-to take advantage of holes left by other fields (thus making the
-structure more compact). The structure takes 4 words (32 bytes) on 64
-bit hosts:
-
-Field Size (bits)
-`code' 8
-`subcode' 16
-`no_warning' 1
-`visited' 1
-`nontemporal_move' 1
-`plf' 2
-`modified' 1
-`has_volatile_ops' 1
-`references_memory_p' 1
-`uid' 32
-`location' 32
-`num_ops' 32
-`bb' 64
-`block' 63
-Total size 32 bytes
-
- * `code' Main identifier for a GIMPLE instruction.
-
- * `subcode' Used to distinguish different variants of the same basic
- instruction or provide flags applicable to a given code. The
- `subcode' flags field has different uses depending on the code of
- the instruction, but mostly it distinguishes instructions of the
- same family. The most prominent use of this field is in
- assignments, where subcode indicates the operation done on the RHS
- of the assignment. For example, a = b + c is encoded as
- `GIMPLE_ASSIGN <PLUS_EXPR, a, b, c>'.
-
- * `no_warning' Bitflag to indicate whether a warning has already
- been issued on this statement.
-
- * `visited' General purpose "visited" marker. Set and cleared by
- each pass when needed.
-
- * `nontemporal_move' Bitflag used in assignments that represent
- non-temporal moves. Although this bitflag is only used in
- assignments, it was moved into the base to take advantage of the
- bit holes left by the previous fields.
-
- * `plf' Pass Local Flags. This 2-bit mask can be used as general
- purpose markers by any pass. Passes are responsible for clearing
- and setting these two flags accordingly.
-
- * `modified' Bitflag to indicate whether the statement has been
- modified. Used mainly by the operand scanner to determine when to
- re-scan a statement for operands.
-
- * `has_volatile_ops' Bitflag to indicate whether this statement
- contains operands that have been marked volatile.
-
- * `references_memory_p' Bitflag to indicate whether this statement
- contains memory references (i.e., its operands are either global
- variables, or pointer dereferences or anything that must reside in
- memory).
-
- * `uid' This is an unsigned integer used by passes that want to
- assign IDs to every statement. These IDs must be assigned and used
- by each pass.
-
- * `location' This is a `location_t' identifier to specify source code
- location for this statement. It is inherited from the front end.
-
- * `num_ops' Number of operands that this statement has. This
- specifies the size of the operand vector embedded in the tuple.
- Only used in some tuples, but it is declared in the base tuple to
- take advantage of the 32-bit hole left by the previous fields.
-
- * `bb' Basic block holding the instruction.
-
- * `block' Lexical block holding this statement. Also used for debug
- information generation.
-
-12.1.2 `gimple_statement_with_ops'
-----------------------------------
-
-This tuple is actually split in two: `gimple_statement_with_ops_base'
-and `gimple_statement_with_ops'. This is needed to accommodate the way
-the operand vector is allocated. The operand vector is defined to be an
-array of 1 element. So, to allocate a dynamic number of operands, the
-memory allocator (`gimple_alloc') simply allocates enough memory to
-hold the structure itself plus `N - 1' operands which run "off the end"
-of the structure. For example, to allocate space for a tuple with 3
-operands, `gimple_alloc' reserves `sizeof (struct
-gimple_statement_with_ops) + 2 * sizeof (tree)' bytes.
-
- On the other hand, several fields in this tuple need to be shared with
-the `gimple_statement_with_memory_ops' tuple. So, these common fields
-are placed in `gimple_statement_with_ops_base' which is then inherited
-from the other two tuples.
-
-`gsbase' 256
-`addresses_taken' 64
-`def_ops' 64
-`use_ops' 64
-`op' `num_ops' * 64
-Total size 56 + 8 * `num_ops' bytes
-
- * `gsbase' Inherited from `struct gimple_statement_base'.
-
- * `addresses_taken' Bitmap holding the UIDs of all the `VAR_DECL's
- whose addresses are taken by this statement. For example, a
- statement of the form `p = &b' will have the UID for symbol `b' in
- this set.
-
- * `def_ops' Array of pointers into the operand array indicating all
- the slots that contain a variable written-to by the statement.
- This array is also used for immediate use chaining. Note that it
- would be possible to not rely on this array, but the changes
- required to implement this are pretty invasive.
-
- * `use_ops' Similar to `def_ops' but for variables read by the
- statement.
-
- * `op' Array of trees with `num_ops' slots.
-
-12.1.3 `gimple_statement_with_memory_ops'
------------------------------------------
-
-This tuple is essentially identical to `gimple_statement_with_ops',
-except that it contains 4 additional fields to hold vectors related
-memory stores and loads. Similar to the previous case, the structure
-is split in two to accommodate for the operand vector
-(`gimple_statement_with_memory_ops_base' and
-`gimple_statement_with_memory_ops').
-
-Field Size (bits)
-`gsbase' 256
-`addresses_taken' 64
-`def_ops' 64
-`use_ops' 64
-`vdef_ops' 64
-`vuse_ops' 64
-`stores' 64
-`loads' 64
-`op' `num_ops' * 64
-Total size 88 + 8 * `num_ops' bytes
-
- * `vdef_ops' Similar to `def_ops' but for `VDEF' operators. There is
- one entry per memory symbol written by this statement. This is
- used to maintain the memory SSA use-def and def-def chains.
-
- * `vuse_ops' Similar to `use_ops' but for `VUSE' operators. There is
- one entry per memory symbol loaded by this statement. This is used
- to maintain the memory SSA use-def chains.
-
- * `stores' Bitset with all the UIDs for the symbols written-to by the
- statement. This is different than `vdef_ops' in that all the
- affected symbols are mentioned in this set. If memory
- partitioning is enabled, the `vdef_ops' vector will refer to memory
- partitions. Furthermore, no SSA information is stored in this set.
-
- * `loads' Similar to `stores', but for memory loads. (Note that there
- is some amount of redundancy here, it should be possible to reduce
- memory utilization further by removing these sets).
-
- All the other tuples are defined in terms of these three basic ones.
-Each tuple will add some fields. The main gimple type is defined to be
-the union of all these structures (`GTY' markers elided for clarity):
-
- union gimple_statement_d
- {
- struct gimple_statement_base gsbase;
- struct gimple_statement_with_ops gsops;
- struct gimple_statement_with_memory_ops gsmem;
- struct gimple_statement_omp omp;
- struct gimple_statement_bind gimple_bind;
- struct gimple_statement_catch gimple_catch;
- struct gimple_statement_eh_filter gimple_eh_filter;
- struct gimple_statement_phi gimple_phi;
- struct gimple_statement_resx gimple_resx;
- struct gimple_statement_try gimple_try;
- struct gimple_statement_wce gimple_wce;
- struct gimple_statement_asm gimple_asm;
- struct gimple_statement_omp_critical gimple_omp_critical;
- struct gimple_statement_omp_for gimple_omp_for;
- struct gimple_statement_omp_parallel gimple_omp_parallel;
- struct gimple_statement_omp_task gimple_omp_task;
- struct gimple_statement_omp_sections gimple_omp_sections;
- struct gimple_statement_omp_single gimple_omp_single;
- struct gimple_statement_omp_continue gimple_omp_continue;
- struct gimple_statement_omp_atomic_load gimple_omp_atomic_load;
- struct gimple_statement_omp_atomic_store gimple_omp_atomic_store;
- };
-
-\1f
-File: gccint.info, Node: GIMPLE instruction set, Next: GIMPLE Exception Handling, Prev: Tuple representation, Up: GIMPLE
-
-12.2 GIMPLE instruction set
-===========================
-
-The following table briefly describes the GIMPLE instruction set.
-
-Instruction High GIMPLE Low GIMPLE
-`GIMPLE_ASM' x x
-`GIMPLE_ASSIGN' x x
-`GIMPLE_BIND' x
-`GIMPLE_CALL' x x
-`GIMPLE_CATCH' x
-`GIMPLE_CHANGE_DYNAMIC_TYPE' x x
-`GIMPLE_COND' x x
-`GIMPLE_EH_FILTER' x
-`GIMPLE_GOTO' x x
-`GIMPLE_LABEL' x x
-`GIMPLE_NOP' x x
-`GIMPLE_OMP_ATOMIC_LOAD' x x
-`GIMPLE_OMP_ATOMIC_STORE' x x
-`GIMPLE_OMP_CONTINUE' x x
-`GIMPLE_OMP_CRITICAL' x x
-`GIMPLE_OMP_FOR' x x
-`GIMPLE_OMP_MASTER' x x
-`GIMPLE_OMP_ORDERED' x x
-`GIMPLE_OMP_PARALLEL' x x
-`GIMPLE_OMP_RETURN' x x
-`GIMPLE_OMP_SECTION' x x
-`GIMPLE_OMP_SECTIONS' x x
-`GIMPLE_OMP_SECTIONS_SWITCH' x x
-`GIMPLE_OMP_SINGLE' x x
-`GIMPLE_PHI' x
-`GIMPLE_RESX' x
-`GIMPLE_RETURN' x x
-`GIMPLE_SWITCH' x x
-`GIMPLE_TRY' x
-
-\1f
-File: gccint.info, Node: GIMPLE Exception Handling, Next: Temporaries, Prev: GIMPLE instruction set, Up: GIMPLE
-
-12.3 Exception Handling
-=======================
-
-Other exception handling constructs are represented using
-`GIMPLE_TRY_CATCH'. `GIMPLE_TRY_CATCH' has two operands. The first
-operand is a sequence of statements to execute. If executing these
-statements does not throw an exception, then the second operand is
-ignored. Otherwise, if an exception is thrown, then the second operand
-of the `GIMPLE_TRY_CATCH' is checked. The second operand may have the
-following forms:
-
- 1. A sequence of statements to execute. When an exception occurs,
- these statements are executed, and then the exception is rethrown.
-
- 2. A sequence of `GIMPLE_CATCH' statements. Each `GIMPLE_CATCH' has
- a list of applicable exception types and handler code. If the
- thrown exception matches one of the caught types, the associated
- handler code is executed. If the handler code falls off the
- bottom, execution continues after the original `GIMPLE_TRY_CATCH'.
-
- 3. An `GIMPLE_EH_FILTER' statement. This has a list of permitted
- exception types, and code to handle a match failure. If the
- thrown exception does not match one of the allowed types, the
- associated match failure code is executed. If the thrown exception
- does match, it continues unwinding the stack looking for the next
- handler.
-
-
- Currently throwing an exception is not directly represented in GIMPLE,
-since it is implemented by calling a function. At some point in the
-future we will want to add some way to express that the call will throw
-an exception of a known type.
-
- Just before running the optimizers, the compiler lowers the high-level
-EH constructs above into a set of `goto's, magic labels, and EH
-regions. Continuing to unwind at the end of a cleanup is represented
-with a `GIMPLE_RESX'.
-
-\1f
-File: gccint.info, Node: Temporaries, Next: Operands, Prev: GIMPLE Exception Handling, Up: GIMPLE
-
-12.4 Temporaries
-================
-
-When gimplification encounters a subexpression that is too complex, it
-creates a new temporary variable to hold the value of the
-subexpression, and adds a new statement to initialize it before the
-current statement. These special temporaries are known as `expression
-temporaries', and are allocated using `get_formal_tmp_var'. The
-compiler tries to always evaluate identical expressions into the same
-temporary, to simplify elimination of redundant calculations.
-
- We can only use expression temporaries when we know that it will not
-be reevaluated before its value is used, and that it will not be
-otherwise modified(1). Other temporaries can be allocated using
-`get_initialized_tmp_var' or `create_tmp_var'.
-
- Currently, an expression like `a = b + 5' is not reduced any further.
-We tried converting it to something like
- T1 = b + 5;
- a = T1;
- but this bloated the representation for minimal benefit. However, a
-variable which must live in memory cannot appear in an expression; its
-value is explicitly loaded into a temporary first. Similarly, storing
-the value of an expression to a memory variable goes through a
-temporary.
-
- ---------- Footnotes ----------
-
- (1) These restrictions are derived from those in Morgan 4.8.
-
-\1f
-File: gccint.info, Node: Operands, Next: Manipulating GIMPLE statements, Prev: Temporaries, Up: GIMPLE
-
-12.5 Operands
-=============
-
-In general, expressions in GIMPLE consist of an operation and the
-appropriate number of simple operands; these operands must either be a
-GIMPLE rvalue (`is_gimple_val'), i.e. a constant or a register
-variable. More complex operands are factored out into temporaries, so
-that
- a = b + c + d
- becomes
- T1 = b + c;
- a = T1 + d;
-
- The same rule holds for arguments to a `GIMPLE_CALL'.
-
- The target of an assignment is usually a variable, but can also be an
-`INDIRECT_REF' or a compound lvalue as described below.
-
-* Menu:
-
-* Compound Expressions::
-* Compound Lvalues::
-* Conditional Expressions::
-* Logical Operators::
-
-\1f
-File: gccint.info, Node: Compound Expressions, Next: Compound Lvalues, Up: Operands
-
-12.5.1 Compound Expressions
----------------------------
-
-The left-hand side of a C comma expression is simply moved into a
-separate statement.
-
-\1f
-File: gccint.info, Node: Compound Lvalues, Next: Conditional Expressions, Prev: Compound Expressions, Up: Operands
-
-12.5.2 Compound Lvalues
------------------------
-
-Currently compound lvalues involving array and structure field
-references are not broken down; an expression like `a.b[2] = 42' is not
-reduced any further (though complex array subscripts are). This
-restriction is a workaround for limitations in later optimizers; if we
-were to convert this to
-
- T1 = &a.b;
- T1[2] = 42;
-
- alias analysis would not remember that the reference to `T1[2]' came
-by way of `a.b', so it would think that the assignment could alias
-another member of `a'; this broke `struct-alias-1.c'. Future optimizer
-improvements may make this limitation unnecessary.
-
-\1f
-File: gccint.info, Node: Conditional Expressions, Next: Logical Operators, Prev: Compound Lvalues, Up: Operands
-
-12.5.3 Conditional Expressions
-------------------------------
-
-A C `?:' expression is converted into an `if' statement with each
-branch assigning to the same temporary. So,
-
- a = b ? c : d;
- becomes
- if (b == 1)
- T1 = c;
- else
- T1 = d;
- a = T1;
-
- The GIMPLE level if-conversion pass re-introduces `?:' expression, if
-appropriate. It is used to vectorize loops with conditions using vector
-conditional operations.
-
- Note that in GIMPLE, `if' statements are represented using
-`GIMPLE_COND', as described below.
-
-\1f
-File: gccint.info, Node: Logical Operators, Prev: Conditional Expressions, Up: Operands
-
-12.5.4 Logical Operators
-------------------------
-
-Except when they appear in the condition operand of a `GIMPLE_COND',
-logical `and' and `or' operators are simplified as follows: `a = b &&
-c' becomes
-
- T1 = (bool)b;
- if (T1 == true)
- T1 = (bool)c;
- a = T1;
-
- Note that `T1' in this example cannot be an expression temporary,
-because it has two different assignments.
-
-12.5.5 Manipulating operands
-----------------------------
-
-All gimple operands are of type `tree'. But only certain types of
-trees are allowed to be used as operand tuples. Basic validation is
-controlled by the function `get_gimple_rhs_class', which given a tree
-code, returns an `enum' with the following values of type `enum
-gimple_rhs_class'
-
- * `GIMPLE_INVALID_RHS' The tree cannot be used as a GIMPLE operand.
-
- * `GIMPLE_BINARY_RHS' The tree is a valid GIMPLE binary operation.
-
- * `GIMPLE_UNARY_RHS' The tree is a valid GIMPLE unary operation.
-
- * `GIMPLE_SINGLE_RHS' The tree is a single object, that cannot be
- split into simpler operands (for instance, `SSA_NAME', `VAR_DECL',
- `COMPONENT_REF', etc).
-
- This operand class also acts as an escape hatch for tree nodes
- that may be flattened out into the operand vector, but would need
- more than two slots on the RHS. For instance, a `COND_EXPR'
- expression of the form `(a op b) ? x : y' could be flattened out
- on the operand vector using 4 slots, but it would also require
- additional processing to distinguish `c = a op b' from `c = a op b
- ? x : y'. Something similar occurs with `ASSERT_EXPR'. In time,
- these special case tree expressions should be flattened into the
- operand vector.
-
- For tree nodes in the categories `GIMPLE_BINARY_RHS' and
-`GIMPLE_UNARY_RHS', they cannot be stored inside tuples directly. They
-first need to be flattened and separated into individual components.
-For instance, given the GENERIC expression
-
- a = b + c
-
- its tree representation is:
-
- MODIFY_EXPR <VAR_DECL <a>, PLUS_EXPR <VAR_DECL <b>, VAR_DECL <c>>>
-
- In this case, the GIMPLE form for this statement is logically
-identical to its GENERIC form but in GIMPLE, the `PLUS_EXPR' on the RHS
-of the assignment is not represented as a tree, instead the two
-operands are taken out of the `PLUS_EXPR' sub-tree and flattened into
-the GIMPLE tuple as follows:
-
- GIMPLE_ASSIGN <PLUS_EXPR, VAR_DECL <a>, VAR_DECL <b>, VAR_DECL <c>>
-
-12.5.6 Operand vector allocation
---------------------------------
-
-The operand vector is stored at the bottom of the three tuple
-structures that accept operands. This means, that depending on the code
-of a given statement, its operand vector will be at different offsets
-from the base of the structure. To access tuple operands use the
-following accessors
-
- -- GIMPLE function: unsigned gimple_num_ops (gimple g)
- Returns the number of operands in statement G.
-
- -- GIMPLE function: tree gimple_op (gimple g, unsigned i)
- Returns operand `I' from statement `G'.
-
- -- GIMPLE function: tree *gimple_ops (gimple g)
- Returns a pointer into the operand vector for statement `G'. This
- is computed using an internal table called `gimple_ops_offset_'[].
- This table is indexed by the gimple code of `G'.
-
- When the compiler is built, this table is filled-in using the
- sizes of the structures used by each statement code defined in
- gimple.def. Since the operand vector is at the bottom of the
- structure, for a gimple code `C' the offset is computed as sizeof
- (struct-of `C') - sizeof (tree).
-
- This mechanism adds one memory indirection to every access when
- using `gimple_op'(), if this becomes a bottleneck, a pass can
- choose to memoize the result from `gimple_ops'() and use that to
- access the operands.
-
-12.5.7 Operand validation
--------------------------
-
-When adding a new operand to a gimple statement, the operand will be
-validated according to what each tuple accepts in its operand vector.
-These predicates are called by the `gimple_<name>_set_...()'. Each
-tuple will use one of the following predicates (Note, this list is not
-exhaustive):
-
- -- GIMPLE function: is_gimple_operand (tree t)
- This is the most permissive of the predicates. It essentially
- checks whether t has a `gimple_rhs_class' of `GIMPLE_SINGLE_RHS'.
-
- -- GIMPLE function: is_gimple_val (tree t)
- Returns true if t is a "GIMPLE value", which are all the
- non-addressable stack variables (variables for which
- `is_gimple_reg' returns true) and constants (expressions for which
- `is_gimple_min_invariant' returns true).
-
- -- GIMPLE function: is_gimple_addressable (tree t)
- Returns true if t is a symbol or memory reference whose address
- can be taken.
-
- -- GIMPLE function: is_gimple_asm_val (tree t)
- Similar to `is_gimple_val' but it also accepts hard registers.
-
- -- GIMPLE function: is_gimple_call_addr (tree t)
- Return true if t is a valid expression to use as the function
- called by a `GIMPLE_CALL'.
-
- -- GIMPLE function: is_gimple_constant (tree t)
- Return true if t is a valid gimple constant.
-
- -- GIMPLE function: is_gimple_min_invariant (tree t)
- Return true if t is a valid minimal invariant. This is different
- from constants, in that the specific value of t may not be known
- at compile time, but it is known that it doesn't change (e.g., the
- address of a function local variable).
-
- -- GIMPLE function: is_gimple_min_invariant_address (tree t)
- Return true if t is an `ADDR_EXPR' that does not change once the
- program is running.
-
-12.5.8 Statement validation
----------------------------
-
- -- GIMPLE function: is_gimple_assign (gimple g)
- Return true if the code of g is `GIMPLE_ASSIGN'.
-
- -- GIMPLE function: is_gimple_call (gimple g)
- Return true if the code of g is `GIMPLE_CALL'
-
- -- GIMPLE function: gimple_assign_cast_p (gimple g)
- Return true if g is a `GIMPLE_ASSIGN' that performs a type cast
- operation
-
-\1f
-File: gccint.info, Node: Manipulating GIMPLE statements, Next: Tuple specific accessors, Prev: Operands, Up: GIMPLE
-
-12.6 Manipulating GIMPLE statements
-===================================
-
-This section documents all the functions available to handle each of
-the GIMPLE instructions.
-
-12.6.1 Common accessors
------------------------
-
-The following are common accessors for gimple statements.
-
- -- GIMPLE function: enum gimple_code gimple_code (gimple g)
- Return the code for statement `G'.
-
- -- GIMPLE function: basic_block gimple_bb (gimple g)
- Return the basic block to which statement `G' belongs to.
-
- -- GIMPLE function: tree gimple_block (gimple g)
- Return the lexical scope block holding statement `G'.
-
- -- GIMPLE function: tree gimple_expr_type (gimple stmt)
- Return the type of the main expression computed by `STMT'. Return
- `void_type_node' if `STMT' computes nothing. This will only return
- something meaningful for `GIMPLE_ASSIGN', `GIMPLE_COND' and
- `GIMPLE_CALL'. For all other tuple codes, it will return
- `void_type_node'.
-
- -- GIMPLE function: enum tree_code gimple_expr_code (gimple stmt)
- Return the tree code for the expression computed by `STMT'. This
- is only meaningful for `GIMPLE_CALL', `GIMPLE_ASSIGN' and
- `GIMPLE_COND'. If `STMT' is `GIMPLE_CALL', it will return
- `CALL_EXPR'. For `GIMPLE_COND', it returns the code of the
- comparison predicate. For `GIMPLE_ASSIGN' it returns the code of
- the operation performed by the `RHS' of the assignment.
-
- -- GIMPLE function: void gimple_set_block (gimple g, tree block)
- Set the lexical scope block of `G' to `BLOCK'.
-
- -- GIMPLE function: location_t gimple_locus (gimple g)
- Return locus information for statement `G'.
-
- -- GIMPLE function: void gimple_set_locus (gimple g, location_t locus)
- Set locus information for statement `G'.
-
- -- GIMPLE function: bool gimple_locus_empty_p (gimple g)
- Return true if `G' does not have locus information.
-
- -- GIMPLE function: bool gimple_no_warning_p (gimple stmt)
- Return true if no warnings should be emitted for statement `STMT'.
-
- -- GIMPLE function: void gimple_set_visited (gimple stmt, bool
- visited_p)
- Set the visited status on statement `STMT' to `VISITED_P'.
-
- -- GIMPLE function: bool gimple_visited_p (gimple stmt)
- Return the visited status on statement `STMT'.
-
- -- GIMPLE function: void gimple_set_plf (gimple stmt, enum plf_mask
- plf, bool val_p)
- Set pass local flag `PLF' on statement `STMT' to `VAL_P'.
-
- -- GIMPLE function: unsigned int gimple_plf (gimple stmt, enum
- plf_mask plf)
- Return the value of pass local flag `PLF' on statement `STMT'.
-
- -- GIMPLE function: bool gimple_has_ops (gimple g)
- Return true if statement `G' has register or memory operands.
-
- -- GIMPLE function: bool gimple_has_mem_ops (gimple g)
- Return true if statement `G' has memory operands.
-
- -- GIMPLE function: unsigned gimple_num_ops (gimple g)
- Return the number of operands for statement `G'.
-
- -- GIMPLE function: tree *gimple_ops (gimple g)
- Return the array of operands for statement `G'.
-
- -- GIMPLE function: tree gimple_op (gimple g, unsigned i)
- Return operand `I' for statement `G'.
-
- -- GIMPLE function: tree *gimple_op_ptr (gimple g, unsigned i)
- Return a pointer to operand `I' for statement `G'.
-
- -- GIMPLE function: void gimple_set_op (gimple g, unsigned i, tree op)
- Set operand `I' of statement `G' to `OP'.
-
- -- GIMPLE function: bitmap gimple_addresses_taken (gimple stmt)
- Return the set of symbols that have had their address taken by
- `STMT'.
-
- -- GIMPLE function: struct def_optype_d *gimple_def_ops (gimple g)
- Return the set of `DEF' operands for statement `G'.
-
- -- GIMPLE function: void gimple_set_def_ops (gimple g, struct
- def_optype_d *def)
- Set `DEF' to be the set of `DEF' operands for statement `G'.
-
- -- GIMPLE function: struct use_optype_d *gimple_use_ops (gimple g)
- Return the set of `USE' operands for statement `G'.
-
- -- GIMPLE function: void gimple_set_use_ops (gimple g, struct
- use_optype_d *use)
- Set `USE' to be the set of `USE' operands for statement `G'.
-
- -- GIMPLE function: struct voptype_d *gimple_vuse_ops (gimple g)
- Return the set of `VUSE' operands for statement `G'.
-
- -- GIMPLE function: void gimple_set_vuse_ops (gimple g, struct
- voptype_d *ops)
- Set `OPS' to be the set of `VUSE' operands for statement `G'.
-
- -- GIMPLE function: struct voptype_d *gimple_vdef_ops (gimple g)
- Return the set of `VDEF' operands for statement `G'.
-
- -- GIMPLE function: void gimple_set_vdef_ops (gimple g, struct
- voptype_d *ops)
- Set `OPS' to be the set of `VDEF' operands for statement `G'.
-
- -- GIMPLE function: bitmap gimple_loaded_syms (gimple g)
- Return the set of symbols loaded by statement `G'. Each element of
- the set is the `DECL_UID' of the corresponding symbol.
-
- -- GIMPLE function: bitmap gimple_stored_syms (gimple g)
- Return the set of symbols stored by statement `G'. Each element of
- the set is the `DECL_UID' of the corresponding symbol.
-
- -- GIMPLE function: bool gimple_modified_p (gimple g)
- Return true if statement `G' has operands and the modified field
- has been set.
-
- -- GIMPLE function: bool gimple_has_volatile_ops (gimple stmt)
- Return true if statement `STMT' contains volatile operands.
-
- -- GIMPLE function: void gimple_set_has_volatile_ops (gimple stmt,
- bool volatilep)
- Return true if statement `STMT' contains volatile operands.
-
- -- GIMPLE function: void update_stmt (gimple s)
- Mark statement `S' as modified, and update it.
-
- -- GIMPLE function: void update_stmt_if_modified (gimple s)
- Update statement `S' if it has been marked modified.
-
- -- GIMPLE function: gimple gimple_copy (gimple stmt)
- Return a deep copy of statement `STMT'.
-
-\1f
-File: gccint.info, Node: Tuple specific accessors, Next: GIMPLE sequences, Prev: Manipulating GIMPLE statements, Up: GIMPLE
-
-12.7 Tuple specific accessors
-=============================
-
-* Menu:
-
-* `GIMPLE_ASM'::
-* `GIMPLE_ASSIGN'::
-* `GIMPLE_BIND'::
-* `GIMPLE_CALL'::
-* `GIMPLE_CATCH'::
-* `GIMPLE_CHANGE_DYNAMIC_TYPE'::
-* `GIMPLE_COND'::
-* `GIMPLE_EH_FILTER'::
-* `GIMPLE_LABEL'::
-* `GIMPLE_NOP'::
-* `GIMPLE_OMP_ATOMIC_LOAD'::
-* `GIMPLE_OMP_ATOMIC_STORE'::
-* `GIMPLE_OMP_CONTINUE'::
-* `GIMPLE_OMP_CRITICAL'::
-* `GIMPLE_OMP_FOR'::
-* `GIMPLE_OMP_MASTER'::
-* `GIMPLE_OMP_ORDERED'::
-* `GIMPLE_OMP_PARALLEL'::
-* `GIMPLE_OMP_RETURN'::
-* `GIMPLE_OMP_SECTION'::
-* `GIMPLE_OMP_SECTIONS'::
-* `GIMPLE_OMP_SINGLE'::
-* `GIMPLE_PHI'::
-* `GIMPLE_RESX'::
-* `GIMPLE_RETURN'::
-* `GIMPLE_SWITCH'::
-* `GIMPLE_TRY'::
-* `GIMPLE_WITH_CLEANUP_EXPR'::
-
-\1f
-File: gccint.info, Node: `GIMPLE_ASM', Next: `GIMPLE_ASSIGN', Up: Tuple specific accessors
-
-12.7.1 `GIMPLE_ASM'
--------------------
-
- -- GIMPLE function: gimple gimple_build_asm (const char *string,
- ninputs, noutputs, nclobbers, ...)
- Build a `GIMPLE_ASM' statement. This statement is used for
- building in-line assembly constructs. `STRING' is the assembly
- code. `NINPUT' is the number of register inputs. `NOUTPUT' is the
- number of register outputs. `NCLOBBERS' is the number of clobbered
- registers. The rest of the arguments trees for each input,
- output, and clobbered registers.
-
- -- GIMPLE function: gimple gimple_build_asm_vec (const char *,
- VEC(tree,gc) *, VEC(tree,gc) *, VEC(tree,gc) *)
- Identical to gimple_build_asm, but the arguments are passed in
- VECs.
-
- -- GIMPLE function: gimple_asm_ninputs (gimple g)
- Return the number of input operands for `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: gimple_asm_noutputs (gimple g)
- Return the number of output operands for `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: gimple_asm_nclobbers (gimple g)
- Return the number of clobber operands for `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: tree gimple_asm_input_op (gimple g, unsigned index)
- Return input operand `INDEX' of `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: void gimple_asm_set_input_op (gimple g, unsigned
- index, tree in_op)
- Set `IN_OP' to be input operand `INDEX' in `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: tree gimple_asm_output_op (gimple g, unsigned
- index)
- Return output operand `INDEX' of `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: void gimple_asm_set_output_op (gimple g, unsigned
- index, tree out_op)
- Set `OUT_OP' to be output operand `INDEX' in `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: tree gimple_asm_clobber_op (gimple g, unsigned
- index)
- Return clobber operand `INDEX' of `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: void gimple_asm_set_clobber_op (gimple g, unsigned
- index, tree clobber_op)
- Set `CLOBBER_OP' to be clobber operand `INDEX' in `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: const char *gimple_asm_string (gimple g)
- Return the string representing the assembly instruction in
- `GIMPLE_ASM' `G'.
-
- -- GIMPLE function: bool gimple_asm_volatile_p (gimple g)
- Return true if `G' is an asm statement marked volatile.
-
- -- GIMPLE function: void gimple_asm_set_volatile (gimple g)
- Mark asm statement `G' as volatile.
-
- -- GIMPLE function: void gimple_asm_clear_volatile (gimple g)
- Remove volatile marker from asm statement `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_ASSIGN', Next: `GIMPLE_BIND', Prev: `GIMPLE_ASM', Up: Tuple specific accessors
-
-12.7.2 `GIMPLE_ASSIGN'
-----------------------
-
- -- GIMPLE function: gimple gimple_build_assign (tree lhs, tree rhs)
- Build a `GIMPLE_ASSIGN' statement. The left-hand side is an lvalue
- passed in lhs. The right-hand side can be either a unary or
- binary tree expression. The expression tree rhs will be flattened
- and its operands assigned to the corresponding operand slots in
- the new statement. This function is useful when you already have
- a tree expression that you want to convert into a tuple. However,
- try to avoid building expression trees for the sole purpose of
- calling this function. If you already have the operands in
- separate trees, it is better to use `gimple_build_assign_with_ops'.
-
- -- GIMPLE function: gimple gimplify_assign (tree dst, tree src,
- gimple_seq *seq_p)
- Build a new `GIMPLE_ASSIGN' tuple and append it to the end of
- `*SEQ_P'.
-
- `DST'/`SRC' are the destination and source respectively. You can pass
-ungimplified trees in `DST' or `SRC', in which case they will be
-converted to a gimple operand if necessary.
-
- This function returns the newly created `GIMPLE_ASSIGN' tuple.
-
- -- GIMPLE function: gimple gimple_build_assign_with_ops (enum
- tree_code subcode, tree lhs, tree op1, tree op2)
- This function is similar to `gimple_build_assign', but is used to
- build a `GIMPLE_ASSIGN' statement when the operands of the
- right-hand side of the assignment are already split into different
- operands.
-
- The left-hand side is an lvalue passed in lhs. Subcode is the
- `tree_code' for the right-hand side of the assignment. Op1 and op2
- are the operands. If op2 is null, subcode must be a `tree_code'
- for a unary expression.
-
- -- GIMPLE function: enum tree_code gimple_assign_rhs_code (gimple g)
- Return the code of the expression computed on the `RHS' of
- assignment statement `G'.
-
- -- GIMPLE function: enum gimple_rhs_class gimple_assign_rhs_class
- (gimple g)
- Return the gimple rhs class of the code for the expression
- computed on the rhs of assignment statement `G'. This will never
- return `GIMPLE_INVALID_RHS'.
-
- -- GIMPLE function: tree gimple_assign_lhs (gimple g)
- Return the `LHS' of assignment statement `G'.
-
- -- GIMPLE function: tree *gimple_assign_lhs_ptr (gimple g)
- Return a pointer to the `LHS' of assignment statement `G'.
-
- -- GIMPLE function: tree gimple_assign_rhs1 (gimple g)
- Return the first operand on the `RHS' of assignment statement `G'.
-
- -- GIMPLE function: tree *gimple_assign_rhs1_ptr (gimple g)
- Return the address of the first operand on the `RHS' of assignment
- statement `G'.
-
- -- GIMPLE function: tree gimple_assign_rhs2 (gimple g)
- Return the second operand on the `RHS' of assignment statement `G'.
-
- -- GIMPLE function: tree *gimple_assign_rhs2_ptr (gimple g)
- Return the address of the second operand on the `RHS' of assignment
- statement `G'.
-
- -- GIMPLE function: void gimple_assign_set_lhs (gimple g, tree lhs)
- Set `LHS' to be the `LHS' operand of assignment statement `G'.
-
- -- GIMPLE function: void gimple_assign_set_rhs1 (gimple g, tree rhs)
- Set `RHS' to be the first operand on the `RHS' of assignment
- statement `G'.
-
- -- GIMPLE function: tree gimple_assign_rhs2 (gimple g)
- Return the second operand on the `RHS' of assignment statement `G'.
-
- -- GIMPLE function: tree *gimple_assign_rhs2_ptr (gimple g)
- Return a pointer to the second operand on the `RHS' of assignment
- statement `G'.
-
- -- GIMPLE function: void gimple_assign_set_rhs2 (gimple g, tree rhs)
- Set `RHS' to be the second operand on the `RHS' of assignment
- statement `G'.
-
- -- GIMPLE function: bool gimple_assign_cast_p (gimple s)
- Return true if `S' is an type-cast assignment.
-
-\1f
-File: gccint.info, Node: `GIMPLE_BIND', Next: `GIMPLE_CALL', Prev: `GIMPLE_ASSIGN', Up: Tuple specific accessors
-
-12.7.3 `GIMPLE_BIND'
---------------------
-
- -- GIMPLE function: gimple gimple_build_bind (tree vars, gimple_seq
- body)
- Build a `GIMPLE_BIND' statement with a list of variables in `VARS'
- and a body of statements in sequence `BODY'.
-
- -- GIMPLE function: tree gimple_bind_vars (gimple g)
- Return the variables declared in the `GIMPLE_BIND' statement `G'.
-
- -- GIMPLE function: void gimple_bind_set_vars (gimple g, tree vars)
- Set `VARS' to be the set of variables declared in the `GIMPLE_BIND'
- statement `G'.
-
- -- GIMPLE function: void gimple_bind_append_vars (gimple g, tree vars)
- Append `VARS' to the set of variables declared in the `GIMPLE_BIND'
- statement `G'.
-
- -- GIMPLE function: gimple_seq gimple_bind_body (gimple g)
- Return the GIMPLE sequence contained in the `GIMPLE_BIND' statement
- `G'.
-
- -- GIMPLE function: void gimple_bind_set_body (gimple g, gimple_seq
- seq)
- Set `SEQ' to be sequence contained in the `GIMPLE_BIND' statement
- `G'.
-
- -- GIMPLE function: void gimple_bind_add_stmt (gimple gs, gimple stmt)
- Append a statement to the end of a `GIMPLE_BIND''s body.
-
- -- GIMPLE function: void gimple_bind_add_seq (gimple gs, gimple_seq
- seq)
- Append a sequence of statements to the end of a `GIMPLE_BIND''s
- body.
-
- -- GIMPLE function: tree gimple_bind_block (gimple g)
- Return the `TREE_BLOCK' node associated with `GIMPLE_BIND'
- statement `G'. This is analogous to the `BIND_EXPR_BLOCK' field in
- trees.
-
- -- GIMPLE function: void gimple_bind_set_block (gimple g, tree block)
- Set `BLOCK' to be the `TREE_BLOCK' node associated with
- `GIMPLE_BIND' statement `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_CALL', Next: `GIMPLE_CATCH', Prev: `GIMPLE_BIND', Up: Tuple specific accessors
-
-12.7.4 `GIMPLE_CALL'
---------------------
-
- -- GIMPLE function: gimple gimple_build_call (tree fn, unsigned nargs,
- ...)
- Build a `GIMPLE_CALL' statement to function `FN'. The argument
- `FN' must be either a `FUNCTION_DECL' or a gimple call address as
- determined by `is_gimple_call_addr'. `NARGS' are the number of
- arguments. The rest of the arguments follow the argument `NARGS',
- and must be trees that are valid as rvalues in gimple (i.e., each
- operand is validated with `is_gimple_operand').
-
- -- GIMPLE function: gimple gimple_build_call_from_tree (tree call_expr)
- Build a `GIMPLE_CALL' from a `CALL_EXPR' node. The arguments and
- the function are taken from the expression directly. This routine
- assumes that `call_expr' is already in GIMPLE form. That is, its
- operands are GIMPLE values and the function call needs no further
- simplification. All the call flags in `call_expr' are copied over
- to the new `GIMPLE_CALL'.
-
- -- GIMPLE function: gimple gimple_build_call_vec (tree fn, `VEC'(tree,
- heap) *args)
- Identical to `gimple_build_call' but the arguments are stored in a
- `VEC'().
-
- -- GIMPLE function: tree gimple_call_lhs (gimple g)
- Return the `LHS' of call statement `G'.
-
- -- GIMPLE function: tree *gimple_call_lhs_ptr (gimple g)
- Return a pointer to the `LHS' of call statement `G'.
-
- -- GIMPLE function: void gimple_call_set_lhs (gimple g, tree lhs)
- Set `LHS' to be the `LHS' operand of call statement `G'.
-
- -- GIMPLE function: tree gimple_call_fn (gimple g)
- Return the tree node representing the function called by call
- statement `G'.
-
- -- GIMPLE function: void gimple_call_set_fn (gimple g, tree fn)
- Set `FN' to be the function called by call statement `G'. This has
- to be a gimple value specifying the address of the called function.
-
- -- GIMPLE function: tree gimple_call_fndecl (gimple g)
- If a given `GIMPLE_CALL''s callee is a `FUNCTION_DECL', return it.
- Otherwise return `NULL'. This function is analogous to
- `get_callee_fndecl' in `GENERIC'.
-
- -- GIMPLE function: tree gimple_call_set_fndecl (gimple g, tree fndecl)
- Set the called function to `FNDECL'.
-
- -- GIMPLE function: tree gimple_call_return_type (gimple g)
- Return the type returned by call statement `G'.
-
- -- GIMPLE function: tree gimple_call_chain (gimple g)
- Return the static chain for call statement `G'.
-
- -- GIMPLE function: void gimple_call_set_chain (gimple g, tree chain)
- Set `CHAIN' to be the static chain for call statement `G'.
-
- -- GIMPLE function: gimple_call_num_args (gimple g)
- Return the number of arguments used by call statement `G'.
-
- -- GIMPLE function: tree gimple_call_arg (gimple g, unsigned index)
- Return the argument at position `INDEX' for call statement `G'.
- The first argument is 0.
-
- -- GIMPLE function: tree *gimple_call_arg_ptr (gimple g, unsigned
- index)
- Return a pointer to the argument at position `INDEX' for call
- statement `G'.
-
- -- GIMPLE function: void gimple_call_set_arg (gimple g, unsigned
- index, tree arg)
- Set `ARG' to be the argument at position `INDEX' for call statement
- `G'.
-
- -- GIMPLE function: void gimple_call_set_tail (gimple s)
- Mark call statement `S' as being a tail call (i.e., a call just
- before the exit of a function). These calls are candidate for tail
- call optimization.
-
- -- GIMPLE function: bool gimple_call_tail_p (gimple s)
- Return true if `GIMPLE_CALL' `S' is marked as a tail call.
-
- -- GIMPLE function: void gimple_call_mark_uninlinable (gimple s)
- Mark `GIMPLE_CALL' `S' as being uninlinable.
-
- -- GIMPLE function: bool gimple_call_cannot_inline_p (gimple s)
- Return true if `GIMPLE_CALL' `S' cannot be inlined.
-
- -- GIMPLE function: bool gimple_call_noreturn_p (gimple s)
- Return true if `S' is a noreturn call.
-
- -- GIMPLE function: gimple gimple_call_copy_skip_args (gimple stmt,
- bitmap args_to_skip)
- Build a `GIMPLE_CALL' identical to `STMT' but skipping the
- arguments in the positions marked by the set `ARGS_TO_SKIP'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_CATCH', Next: `GIMPLE_CHANGE_DYNAMIC_TYPE', Prev: `GIMPLE_CALL', Up: Tuple specific accessors
-
-12.7.5 `GIMPLE_CATCH'
----------------------
-
- -- GIMPLE function: gimple gimple_build_catch (tree types, gimple_seq
- handler)
- Build a `GIMPLE_CATCH' statement. `TYPES' are the tree types this
- catch handles. `HANDLER' is a sequence of statements with the code
- for the handler.
-
- -- GIMPLE function: tree gimple_catch_types (gimple g)
- Return the types handled by `GIMPLE_CATCH' statement `G'.
-
- -- GIMPLE function: tree *gimple_catch_types_ptr (gimple g)
- Return a pointer to the types handled by `GIMPLE_CATCH' statement
- `G'.
-
- -- GIMPLE function: gimple_seq gimple_catch_handler (gimple g)
- Return the GIMPLE sequence representing the body of the handler of
- `GIMPLE_CATCH' statement `G'.
-
- -- GIMPLE function: void gimple_catch_set_types (gimple g, tree t)
- Set `T' to be the set of types handled by `GIMPLE_CATCH' `G'.
-
- -- GIMPLE function: void gimple_catch_set_handler (gimple g,
- gimple_seq handler)
- Set `HANDLER' to be the body of `GIMPLE_CATCH' `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_CHANGE_DYNAMIC_TYPE', Next: `GIMPLE_COND', Prev: `GIMPLE_CATCH', Up: Tuple specific accessors
-
-12.7.6 `GIMPLE_CHANGE_DYNAMIC_TYPE'
------------------------------------
-
- -- GIMPLE function: gimple gimple_build_cdt (tree type, tree ptr)
- Build a `GIMPLE_CHANGE_DYNAMIC_TYPE' statement. `TYPE' is the new
- type for the location `PTR'.
-
- -- GIMPLE function: tree gimple_cdt_new_type (gimple g)
- Return the new type set by `GIMPLE_CHANGE_DYNAMIC_TYPE' statement
- `G'.
-
- -- GIMPLE function: tree *gimple_cdt_new_type_ptr (gimple g)
- Return a pointer to the new type set by
- `GIMPLE_CHANGE_DYNAMIC_TYPE' statement `G'.
-
- -- GIMPLE function: void gimple_cdt_set_new_type (gimple g, tree
- new_type)
- Set `NEW_TYPE' to be the type returned by
- `GIMPLE_CHANGE_DYNAMIC_TYPE' statement `G'.
-
- -- GIMPLE function: tree gimple_cdt_location (gimple g)
- Return the location affected by `GIMPLE_CHANGE_DYNAMIC_TYPE'
- statement `G'.
-
- -- GIMPLE function: tree *gimple_cdt_location_ptr (gimple g)
- Return a pointer to the location affected by
- `GIMPLE_CHANGE_DYNAMIC_TYPE' statement `G'.
-
- -- GIMPLE function: void gimple_cdt_set_location (gimple g, tree ptr)
- Set `PTR' to be the location affected by
- `GIMPLE_CHANGE_DYNAMIC_TYPE' statement `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_COND', Next: `GIMPLE_EH_FILTER', Prev: `GIMPLE_CHANGE_DYNAMIC_TYPE', Up: Tuple specific accessors
-
-12.7.7 `GIMPLE_COND'
---------------------
-
- -- GIMPLE function: gimple gimple_build_cond (enum tree_code
- pred_code, tree lhs, tree rhs, tree t_label, tree f_label)
- Build a `GIMPLE_COND' statement. `A' `GIMPLE_COND' statement
- compares `LHS' and `RHS' and if the condition in `PRED_CODE' is
- true, jump to the label in `t_label', otherwise jump to the label
- in `f_label'. `PRED_CODE' are relational operator tree codes like
- `EQ_EXPR', `LT_EXPR', `LE_EXPR', `NE_EXPR', etc.
-
- -- GIMPLE function: gimple gimple_build_cond_from_tree (tree cond,
- tree t_label, tree f_label)
- Build a `GIMPLE_COND' statement from the conditional expression
- tree `COND'. `T_LABEL' and `F_LABEL' are as in
- `gimple_build_cond'.
-
- -- GIMPLE function: enum tree_code gimple_cond_code (gimple g)
- Return the code of the predicate computed by conditional statement
- `G'.
-
- -- GIMPLE function: void gimple_cond_set_code (gimple g, enum
- tree_code code)
- Set `CODE' to be the predicate code for the conditional statement
- `G'.
-
- -- GIMPLE function: tree gimple_cond_lhs (gimple g)
- Return the `LHS' of the predicate computed by conditional statement
- `G'.
-
- -- GIMPLE function: void gimple_cond_set_lhs (gimple g, tree lhs)
- Set `LHS' to be the `LHS' operand of the predicate computed by
- conditional statement `G'.
-
- -- GIMPLE function: tree gimple_cond_rhs (gimple g)
- Return the `RHS' operand of the predicate computed by conditional
- `G'.
-
- -- GIMPLE function: void gimple_cond_set_rhs (gimple g, tree rhs)
- Set `RHS' to be the `RHS' operand of the predicate computed by
- conditional statement `G'.
-
- -- GIMPLE function: tree gimple_cond_true_label (gimple g)
- Return the label used by conditional statement `G' when its
- predicate evaluates to true.
-
- -- GIMPLE function: void gimple_cond_set_true_label (gimple g, tree
- label)
- Set `LABEL' to be the label used by conditional statement `G' when
- its predicate evaluates to true.
-
- -- GIMPLE function: void gimple_cond_set_false_label (gimple g, tree
- label)
- Set `LABEL' to be the label used by conditional statement `G' when
- its predicate evaluates to false.
-
- -- GIMPLE function: tree gimple_cond_false_label (gimple g)
- Return the label used by conditional statement `G' when its
- predicate evaluates to false.
-
- -- GIMPLE function: void gimple_cond_make_false (gimple g)
- Set the conditional `COND_STMT' to be of the form 'if (1 == 0)'.
-
- -- GIMPLE function: void gimple_cond_make_true (gimple g)
- Set the conditional `COND_STMT' to be of the form 'if (1 == 1)'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_EH_FILTER', Next: `GIMPLE_LABEL', Prev: `GIMPLE_COND', Up: Tuple specific accessors
-
-12.7.8 `GIMPLE_EH_FILTER'
--------------------------
-
- -- GIMPLE function: gimple gimple_build_eh_filter (tree types,
- gimple_seq failure)
- Build a `GIMPLE_EH_FILTER' statement. `TYPES' are the filter's
- types. `FAILURE' is a sequence with the filter's failure action.
-
- -- GIMPLE function: tree gimple_eh_filter_types (gimple g)
- Return the types handled by `GIMPLE_EH_FILTER' statement `G'.
-
- -- GIMPLE function: tree *gimple_eh_filter_types_ptr (gimple g)
- Return a pointer to the types handled by `GIMPLE_EH_FILTER'
- statement `G'.
-
- -- GIMPLE function: gimple_seq gimple_eh_filter_failure (gimple g)
- Return the sequence of statement to execute when `GIMPLE_EH_FILTER'
- statement fails.
-
- -- GIMPLE function: void gimple_eh_filter_set_types (gimple g, tree
- types)
- Set `TYPES' to be the set of types handled by `GIMPLE_EH_FILTER'
- `G'.
-
- -- GIMPLE function: void gimple_eh_filter_set_failure (gimple g,
- gimple_seq failure)
- Set `FAILURE' to be the sequence of statements to execute on
- failure for `GIMPLE_EH_FILTER' `G'.
-
- -- GIMPLE function: bool gimple_eh_filter_must_not_throw (gimple g)
- Return the `EH_FILTER_MUST_NOT_THROW' flag.
-
- -- GIMPLE function: void gimple_eh_filter_set_must_not_throw (gimple
- g, bool mntp)
- Set the `EH_FILTER_MUST_NOT_THROW' flag.
-
-\1f
-File: gccint.info, Node: `GIMPLE_LABEL', Next: `GIMPLE_NOP', Prev: `GIMPLE_EH_FILTER', Up: Tuple specific accessors
-
-12.7.9 `GIMPLE_LABEL'
----------------------
-
- -- GIMPLE function: gimple gimple_build_label (tree label)
- Build a `GIMPLE_LABEL' statement with corresponding to the tree
- label, `LABEL'.
-
- -- GIMPLE function: tree gimple_label_label (gimple g)
- Return the `LABEL_DECL' node used by `GIMPLE_LABEL' statement `G'.
-
- -- GIMPLE function: void gimple_label_set_label (gimple g, tree label)
- Set `LABEL' to be the `LABEL_DECL' node used by `GIMPLE_LABEL'
- statement `G'.
-
- -- GIMPLE function: gimple gimple_build_goto (tree dest)
- Build a `GIMPLE_GOTO' statement to label `DEST'.
-
- -- GIMPLE function: tree gimple_goto_dest (gimple g)
- Return the destination of the unconditional jump `G'.
-
- -- GIMPLE function: void gimple_goto_set_dest (gimple g, tree dest)
- Set `DEST' to be the destination of the unconditional jump `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_NOP', Next: `GIMPLE_OMP_ATOMIC_LOAD', Prev: `GIMPLE_LABEL', Up: Tuple specific accessors
-
-12.7.10 `GIMPLE_NOP'
---------------------
-
- -- GIMPLE function: gimple gimple_build_nop (void)
- Build a `GIMPLE_NOP' statement.
-
- -- GIMPLE function: bool gimple_nop_p (gimple g)
- Returns `TRUE' if statement `G' is a `GIMPLE_NOP'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_ATOMIC_LOAD', Next: `GIMPLE_OMP_ATOMIC_STORE', Prev: `GIMPLE_NOP', Up: Tuple specific accessors
-
-12.7.11 `GIMPLE_OMP_ATOMIC_LOAD'
---------------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_atomic_load (tree lhs,
- tree rhs)
- Build a `GIMPLE_OMP_ATOMIC_LOAD' statement. `LHS' is the left-hand
- side of the assignment. `RHS' is the right-hand side of the
- assignment.
-
- -- GIMPLE function: void gimple_omp_atomic_load_set_lhs (gimple g,
- tree lhs)
- Set the `LHS' of an atomic load.
-
- -- GIMPLE function: tree gimple_omp_atomic_load_lhs (gimple g)
- Get the `LHS' of an atomic load.
-
- -- GIMPLE function: void gimple_omp_atomic_load_set_rhs (gimple g,
- tree rhs)
- Set the `RHS' of an atomic set.
-
- -- GIMPLE function: tree gimple_omp_atomic_load_rhs (gimple g)
- Get the `RHS' of an atomic set.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_ATOMIC_STORE', Next: `GIMPLE_OMP_CONTINUE', Prev: `GIMPLE_OMP_ATOMIC_LOAD', Up: Tuple specific accessors
-
-12.7.12 `GIMPLE_OMP_ATOMIC_STORE'
----------------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_atomic_store (tree val)
- Build a `GIMPLE_OMP_ATOMIC_STORE' statement. `VAL' is the value to
- be stored.
-
- -- GIMPLE function: void gimple_omp_atomic_store_set_val (gimple g,
- tree val)
- Set the value being stored in an atomic store.
-
- -- GIMPLE function: tree gimple_omp_atomic_store_val (gimple g)
- Return the value being stored in an atomic store.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_CONTINUE', Next: `GIMPLE_OMP_CRITICAL', Prev: `GIMPLE_OMP_ATOMIC_STORE', Up: Tuple specific accessors
-
-12.7.13 `GIMPLE_OMP_CONTINUE'
------------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_continue (tree
- control_def, tree control_use)
- Build a `GIMPLE_OMP_CONTINUE' statement. `CONTROL_DEF' is the
- definition of the control variable. `CONTROL_USE' is the use of
- the control variable.
-
- -- GIMPLE function: tree gimple_omp_continue_control_def (gimple s)
- Return the definition of the control variable on a
- `GIMPLE_OMP_CONTINUE' in `S'.
-
- -- GIMPLE function: tree gimple_omp_continue_control_def_ptr (gimple s)
- Same as above, but return the pointer.
-
- -- GIMPLE function: tree gimple_omp_continue_set_control_def (gimple s)
- Set the control variable definition for a `GIMPLE_OMP_CONTINUE'
- statement in `S'.
-
- -- GIMPLE function: tree gimple_omp_continue_control_use (gimple s)
- Return the use of the control variable on a `GIMPLE_OMP_CONTINUE'
- in `S'.
-
- -- GIMPLE function: tree gimple_omp_continue_control_use_ptr (gimple s)
- Same as above, but return the pointer.
-
- -- GIMPLE function: tree gimple_omp_continue_set_control_use (gimple s)
- Set the control variable use for a `GIMPLE_OMP_CONTINUE' statement
- in `S'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_CRITICAL', Next: `GIMPLE_OMP_FOR', Prev: `GIMPLE_OMP_CONTINUE', Up: Tuple specific accessors
-
-12.7.14 `GIMPLE_OMP_CRITICAL'
------------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_critical (gimple_seq body,
- tree name)
- Build a `GIMPLE_OMP_CRITICAL' statement. `BODY' is the sequence of
- statements for which only one thread can execute. `NAME' is an
- optional identifier for this critical block.
-
- -- GIMPLE function: tree gimple_omp_critical_name (gimple g)
- Return the name associated with `OMP_CRITICAL' statement `G'.
-
- -- GIMPLE function: tree *gimple_omp_critical_name_ptr (gimple g)
- Return a pointer to the name associated with `OMP' critical
- statement `G'.
-
- -- GIMPLE function: void gimple_omp_critical_set_name (gimple g, tree
- name)
- Set `NAME' to be the name associated with `OMP' critical statement
- `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_FOR', Next: `GIMPLE_OMP_MASTER', Prev: `GIMPLE_OMP_CRITICAL', Up: Tuple specific accessors
-
-12.7.15 `GIMPLE_OMP_FOR'
-------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_for (gimple_seq body, tree
- clauses, tree index, tree initial, tree final, tree incr,
- gimple_seq pre_body, enum tree_code omp_for_cond)
- Build a `GIMPLE_OMP_FOR' statement. `BODY' is sequence of
- statements inside the for loop. `CLAUSES', are any of the `OMP'
- loop construct's clauses: private, firstprivate, lastprivate,
- reductions, ordered, schedule, and nowait. `PRE_BODY' is the
- sequence of statements that are loop invariant. `INDEX' is the
- index variable. `INITIAL' is the initial value of `INDEX'.
- `FINAL' is final value of `INDEX'. OMP_FOR_COND is the predicate
- used to compare `INDEX' and `FINAL'. `INCR' is the increment
- expression.
-
- -- GIMPLE function: tree gimple_omp_for_clauses (gimple g)
- Return the clauses associated with `OMP_FOR' `G'.
-
- -- GIMPLE function: tree *gimple_omp_for_clauses_ptr (gimple g)
- Return a pointer to the `OMP_FOR' `G'.
-
- -- GIMPLE function: void gimple_omp_for_set_clauses (gimple g, tree
- clauses)
- Set `CLAUSES' to be the list of clauses associated with `OMP_FOR'
- `G'.
-
- -- GIMPLE function: tree gimple_omp_for_index (gimple g)
- Return the index variable for `OMP_FOR' `G'.
-
- -- GIMPLE function: tree *gimple_omp_for_index_ptr (gimple g)
- Return a pointer to the index variable for `OMP_FOR' `G'.
-
- -- GIMPLE function: void gimple_omp_for_set_index (gimple g, tree
- index)
- Set `INDEX' to be the index variable for `OMP_FOR' `G'.
-
- -- GIMPLE function: tree gimple_omp_for_initial (gimple g)
- Return the initial value for `OMP_FOR' `G'.
-
- -- GIMPLE function: tree *gimple_omp_for_initial_ptr (gimple g)
- Return a pointer to the initial value for `OMP_FOR' `G'.
-
- -- GIMPLE function: void gimple_omp_for_set_initial (gimple g, tree
- initial)
- Set `INITIAL' to be the initial value for `OMP_FOR' `G'.
-
- -- GIMPLE function: tree gimple_omp_for_final (gimple g)
- Return the final value for `OMP_FOR' `G'.
-
- -- GIMPLE function: tree *gimple_omp_for_final_ptr (gimple g)
- turn a pointer to the final value for `OMP_FOR' `G'.
-
- -- GIMPLE function: void gimple_omp_for_set_final (gimple g, tree
- final)
- Set `FINAL' to be the final value for `OMP_FOR' `G'.
-
- -- GIMPLE function: tree gimple_omp_for_incr (gimple g)
- Return the increment value for `OMP_FOR' `G'.
-
- -- GIMPLE function: tree *gimple_omp_for_incr_ptr (gimple g)
- Return a pointer to the increment value for `OMP_FOR' `G'.
-
- -- GIMPLE function: void gimple_omp_for_set_incr (gimple g, tree incr)
- Set `INCR' to be the increment value for `OMP_FOR' `G'.
-
- -- GIMPLE function: gimple_seq gimple_omp_for_pre_body (gimple g)
- Return the sequence of statements to execute before the `OMP_FOR'
- statement `G' starts.
-
- -- GIMPLE function: void gimple_omp_for_set_pre_body (gimple g,
- gimple_seq pre_body)
- Set `PRE_BODY' to be the sequence of statements to execute before
- the `OMP_FOR' statement `G' starts.
-
- -- GIMPLE function: void gimple_omp_for_set_cond (gimple g, enum
- tree_code cond)
- Set `COND' to be the condition code for `OMP_FOR' `G'.
-
- -- GIMPLE function: enum tree_code gimple_omp_for_cond (gimple g)
- Return the condition code associated with `OMP_FOR' `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_MASTER', Next: `GIMPLE_OMP_ORDERED', Prev: `GIMPLE_OMP_FOR', Up: Tuple specific accessors
-
-12.7.16 `GIMPLE_OMP_MASTER'
----------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_master (gimple_seq body)
- Build a `GIMPLE_OMP_MASTER' statement. `BODY' is the sequence of
- statements to be executed by just the master.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_ORDERED', Next: `GIMPLE_OMP_PARALLEL', Prev: `GIMPLE_OMP_MASTER', Up: Tuple specific accessors
-
-12.7.17 `GIMPLE_OMP_ORDERED'
-----------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_ordered (gimple_seq body)
- Build a `GIMPLE_OMP_ORDERED' statement.
-
- `BODY' is the sequence of statements inside a loop that will executed
-in sequence.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_PARALLEL', Next: `GIMPLE_OMP_RETURN', Prev: `GIMPLE_OMP_ORDERED', Up: Tuple specific accessors
-
-12.7.18 `GIMPLE_OMP_PARALLEL'
------------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_parallel (gimple_seq body,
- tree clauses, tree child_fn, tree data_arg)
- Build a `GIMPLE_OMP_PARALLEL' statement.
-
- `BODY' is sequence of statements which are executed in parallel.
-`CLAUSES', are the `OMP' parallel construct's clauses. `CHILD_FN' is
-the function created for the parallel threads to execute. `DATA_ARG'
-are the shared data argument(s).
-
- -- GIMPLE function: bool gimple_omp_parallel_combined_p (gimple g)
- Return true if `OMP' parallel statement `G' has the
- `GF_OMP_PARALLEL_COMBINED' flag set.
-
- -- GIMPLE function: void gimple_omp_parallel_set_combined_p (gimple g)
- Set the `GF_OMP_PARALLEL_COMBINED' field in `OMP' parallel
- statement `G'.
-
- -- GIMPLE function: gimple_seq gimple_omp_body (gimple g)
- Return the body for the `OMP' statement `G'.
-
- -- GIMPLE function: void gimple_omp_set_body (gimple g, gimple_seq
- body)
- Set `BODY' to be the body for the `OMP' statement `G'.
-
- -- GIMPLE function: tree gimple_omp_parallel_clauses (gimple g)
- Return the clauses associated with `OMP_PARALLEL' `G'.
-
- -- GIMPLE function: tree *gimple_omp_parallel_clauses_ptr (gimple g)
- Return a pointer to the clauses associated with `OMP_PARALLEL' `G'.
-
- -- GIMPLE function: void gimple_omp_parallel_set_clauses (gimple g,
- tree clauses)
- Set `CLAUSES' to be the list of clauses associated with
- `OMP_PARALLEL' `G'.
-
- -- GIMPLE function: tree gimple_omp_parallel_child_fn (gimple g)
- Return the child function used to hold the body of `OMP_PARALLEL'
- `G'.
-
- -- GIMPLE function: tree *gimple_omp_parallel_child_fn_ptr (gimple g)
- Return a pointer to the child function used to hold the body of
- `OMP_PARALLEL' `G'.
-
- -- GIMPLE function: void gimple_omp_parallel_set_child_fn (gimple g,
- tree child_fn)
- Set `CHILD_FN' to be the child function for `OMP_PARALLEL' `G'.
-
- -- GIMPLE function: tree gimple_omp_parallel_data_arg (gimple g)
- Return the artificial argument used to send variables and values
- from the parent to the children threads in `OMP_PARALLEL' `G'.
-
- -- GIMPLE function: tree *gimple_omp_parallel_data_arg_ptr (gimple g)
- Return a pointer to the data argument for `OMP_PARALLEL' `G'.
-
- -- GIMPLE function: void gimple_omp_parallel_set_data_arg (gimple g,
- tree data_arg)
- Set `DATA_ARG' to be the data argument for `OMP_PARALLEL' `G'.
-
- -- GIMPLE function: bool is_gimple_omp (gimple stmt)
- Returns true when the gimple statement `STMT' is any of the OpenMP
- types.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_RETURN', Next: `GIMPLE_OMP_SECTION', Prev: `GIMPLE_OMP_PARALLEL', Up: Tuple specific accessors
-
-12.7.19 `GIMPLE_OMP_RETURN'
----------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_return (bool wait_p)
- Build a `GIMPLE_OMP_RETURN' statement. `WAIT_P' is true if this is
- a non-waiting return.
-
- -- GIMPLE function: void gimple_omp_return_set_nowait (gimple s)
- Set the nowait flag on `GIMPLE_OMP_RETURN' statement `S'.
-
- -- GIMPLE function: bool gimple_omp_return_nowait_p (gimple g)
- Return true if `OMP' return statement `G' has the
- `GF_OMP_RETURN_NOWAIT' flag set.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_SECTION', Next: `GIMPLE_OMP_SECTIONS', Prev: `GIMPLE_OMP_RETURN', Up: Tuple specific accessors
-
-12.7.20 `GIMPLE_OMP_SECTION'
-----------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_section (gimple_seq body)
- Build a `GIMPLE_OMP_SECTION' statement for a sections statement.
-
- `BODY' is the sequence of statements in the section.
-
- -- GIMPLE function: bool gimple_omp_section_last_p (gimple g)
- Return true if `OMP' section statement `G' has the
- `GF_OMP_SECTION_LAST' flag set.
-
- -- GIMPLE function: void gimple_omp_section_set_last (gimple g)
- Set the `GF_OMP_SECTION_LAST' flag on `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_SECTIONS', Next: `GIMPLE_OMP_SINGLE', Prev: `GIMPLE_OMP_SECTION', Up: Tuple specific accessors
-
-12.7.21 `GIMPLE_OMP_SECTIONS'
------------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_sections (gimple_seq body,
- tree clauses)
- Build a `GIMPLE_OMP_SECTIONS' statement. `BODY' is a sequence of
- section statements. `CLAUSES' are any of the `OMP' sections
- construct's clauses: private, firstprivate, lastprivate,
- reduction, and nowait.
-
- -- GIMPLE function: gimple gimple_build_omp_sections_switch (void)
- Build a `GIMPLE_OMP_SECTIONS_SWITCH' statement.
-
- -- GIMPLE function: tree gimple_omp_sections_control (gimple g)
- Return the control variable associated with the
- `GIMPLE_OMP_SECTIONS' in `G'.
-
- -- GIMPLE function: tree *gimple_omp_sections_control_ptr (gimple g)
- Return a pointer to the clauses associated with the
- `GIMPLE_OMP_SECTIONS' in `G'.
-
- -- GIMPLE function: void gimple_omp_sections_set_control (gimple g,
- tree control)
- Set `CONTROL' to be the set of clauses associated with the
- `GIMPLE_OMP_SECTIONS' in `G'.
-
- -- GIMPLE function: tree gimple_omp_sections_clauses (gimple g)
- Return the clauses associated with `OMP_SECTIONS' `G'.
-
- -- GIMPLE function: tree *gimple_omp_sections_clauses_ptr (gimple g)
- Return a pointer to the clauses associated with `OMP_SECTIONS' `G'.
-
- -- GIMPLE function: void gimple_omp_sections_set_clauses (gimple g,
- tree clauses)
- Set `CLAUSES' to be the set of clauses associated with
- `OMP_SECTIONS' `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_OMP_SINGLE', Next: `GIMPLE_PHI', Prev: `GIMPLE_OMP_SECTIONS', Up: Tuple specific accessors
-
-12.7.22 `GIMPLE_OMP_SINGLE'
----------------------------
-
- -- GIMPLE function: gimple gimple_build_omp_single (gimple_seq body,
- tree clauses)
- Build a `GIMPLE_OMP_SINGLE' statement. `BODY' is the sequence of
- statements that will be executed once. `CLAUSES' are any of the
- `OMP' single construct's clauses: private, firstprivate,
- copyprivate, nowait.
-
- -- GIMPLE function: tree gimple_omp_single_clauses (gimple g)
- Return the clauses associated with `OMP_SINGLE' `G'.
-
- -- GIMPLE function: tree *gimple_omp_single_clauses_ptr (gimple g)
- Return a pointer to the clauses associated with `OMP_SINGLE' `G'.
-
- -- GIMPLE function: void gimple_omp_single_set_clauses (gimple g, tree
- clauses)
- Set `CLAUSES' to be the clauses associated with `OMP_SINGLE' `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_PHI', Next: `GIMPLE_RESX', Prev: `GIMPLE_OMP_SINGLE', Up: Tuple specific accessors
-
-12.7.23 `GIMPLE_PHI'
---------------------
-
- -- GIMPLE function: gimple make_phi_node (tree var, int len)
- Build a `PHI' node with len argument slots for variable var.
-
- -- GIMPLE function: unsigned gimple_phi_capacity (gimple g)
- Return the maximum number of arguments supported by `GIMPLE_PHI'
- `G'.
-
- -- GIMPLE function: unsigned gimple_phi_num_args (gimple g)
- Return the number of arguments in `GIMPLE_PHI' `G'. This must
- always be exactly the number of incoming edges for the basic block
- holding `G'.
-
- -- GIMPLE function: tree gimple_phi_result (gimple g)
- Return the `SSA' name created by `GIMPLE_PHI' `G'.
-
- -- GIMPLE function: tree *gimple_phi_result_ptr (gimple g)
- Return a pointer to the `SSA' name created by `GIMPLE_PHI' `G'.
-
- -- GIMPLE function: void gimple_phi_set_result (gimple g, tree result)
- Set `RESULT' to be the `SSA' name created by `GIMPLE_PHI' `G'.
-
- -- GIMPLE function: struct phi_arg_d *gimple_phi_arg (gimple g, index)
- Return the `PHI' argument corresponding to incoming edge `INDEX'
- for `GIMPLE_PHI' `G'.
-
- -- GIMPLE function: void gimple_phi_set_arg (gimple g, index, struct
- phi_arg_d * phiarg)
- Set `PHIARG' to be the argument corresponding to incoming edge
- `INDEX' for `GIMPLE_PHI' `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_RESX', Next: `GIMPLE_RETURN', Prev: `GIMPLE_PHI', Up: Tuple specific accessors
-
-12.7.24 `GIMPLE_RESX'
----------------------
-
- -- GIMPLE function: gimple gimple_build_resx (int region)
- Build a `GIMPLE_RESX' statement which is a statement. This
- statement is a placeholder for _Unwind_Resume before we know if a
- function call or a branch is needed. `REGION' is the exception
- region from which control is flowing.
-
- -- GIMPLE function: int gimple_resx_region (gimple g)
- Return the region number for `GIMPLE_RESX' `G'.
-
- -- GIMPLE function: void gimple_resx_set_region (gimple g, int region)
- Set `REGION' to be the region number for `GIMPLE_RESX' `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_RETURN', Next: `GIMPLE_SWITCH', Prev: `GIMPLE_RESX', Up: Tuple specific accessors
-
-12.7.25 `GIMPLE_RETURN'
------------------------
-
- -- GIMPLE function: gimple gimple_build_return (tree retval)
- Build a `GIMPLE_RETURN' statement whose return value is retval.
-
- -- GIMPLE function: tree gimple_return_retval (gimple g)
- Return the return value for `GIMPLE_RETURN' `G'.
-
- -- GIMPLE function: void gimple_return_set_retval (gimple g, tree
- retval)
- Set `RETVAL' to be the return value for `GIMPLE_RETURN' `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_SWITCH', Next: `GIMPLE_TRY', Prev: `GIMPLE_RETURN', Up: Tuple specific accessors
-
-12.7.26 `GIMPLE_SWITCH'
------------------------
-
- -- GIMPLE function: gimple gimple_build_switch ( nlabels, tree index,
- tree default_label, ...)
- Build a `GIMPLE_SWITCH' statement. `NLABELS' are the number of
- labels excluding the default label. The default label is passed
- in `DEFAULT_LABEL'. The rest of the arguments are trees
- representing the labels. Each label is a tree of code
- `CASE_LABEL_EXPR'.
-
- -- GIMPLE function: gimple gimple_build_switch_vec (tree index, tree
- default_label, `VEC'(tree,heap) *args)
- This function is an alternate way of building `GIMPLE_SWITCH'
- statements. `INDEX' and `DEFAULT_LABEL' are as in
- gimple_build_switch. `ARGS' is a vector of `CASE_LABEL_EXPR' trees
- that contain the labels.
-
- -- GIMPLE function: unsigned gimple_switch_num_labels (gimple g)
- Return the number of labels associated with the switch statement
- `G'.
-
- -- GIMPLE function: void gimple_switch_set_num_labels (gimple g,
- unsigned nlabels)
- Set `NLABELS' to be the number of labels for the switch statement
- `G'.
-
- -- GIMPLE function: tree gimple_switch_index (gimple g)
- Return the index variable used by the switch statement `G'.
-
- -- GIMPLE function: void gimple_switch_set_index (gimple g, tree index)
- Set `INDEX' to be the index variable for switch statement `G'.
-
- -- GIMPLE function: tree gimple_switch_label (gimple g, unsigned index)
- Return the label numbered `INDEX'. The default label is 0, followed
- by any labels in a switch statement.
-
- -- GIMPLE function: void gimple_switch_set_label (gimple g, unsigned
- index, tree label)
- Set the label number `INDEX' to `LABEL'. 0 is always the default
- label.
-
- -- GIMPLE function: tree gimple_switch_default_label (gimple g)
- Return the default label for a switch statement.
-
- -- GIMPLE function: void gimple_switch_set_default_label (gimple g,
- tree label)
- Set the default label for a switch statement.
-
-\1f
-File: gccint.info, Node: `GIMPLE_TRY', Next: `GIMPLE_WITH_CLEANUP_EXPR', Prev: `GIMPLE_SWITCH', Up: Tuple specific accessors
-
-12.7.27 `GIMPLE_TRY'
---------------------
-
- -- GIMPLE function: gimple gimple_build_try (gimple_seq eval,
- gimple_seq cleanup, unsigned int kind)
- Build a `GIMPLE_TRY' statement. `EVAL' is a sequence with the
- expression to evaluate. `CLEANUP' is a sequence of statements to
- run at clean-up time. `KIND' is the enumeration value
- `GIMPLE_TRY_CATCH' if this statement denotes a try/catch construct
- or `GIMPLE_TRY_FINALLY' if this statement denotes a try/finally
- construct.
-
- -- GIMPLE function: enum gimple_try_flags gimple_try_kind (gimple g)
- Return the kind of try block represented by `GIMPLE_TRY' `G'. This
- is either `GIMPLE_TRY_CATCH' or `GIMPLE_TRY_FINALLY'.
-
- -- GIMPLE function: bool gimple_try_catch_is_cleanup (gimple g)
- Return the `GIMPLE_TRY_CATCH_IS_CLEANUP' flag.
-
- -- GIMPLE function: gimple_seq gimple_try_eval (gimple g)
- Return the sequence of statements used as the body for `GIMPLE_TRY'
- `G'.
-
- -- GIMPLE function: gimple_seq gimple_try_cleanup (gimple g)
- Return the sequence of statements used as the cleanup body for
- `GIMPLE_TRY' `G'.
-
- -- GIMPLE function: void gimple_try_set_catch_is_cleanup (gimple g,
- bool catch_is_cleanup)
- Set the `GIMPLE_TRY_CATCH_IS_CLEANUP' flag.
-
- -- GIMPLE function: void gimple_try_set_eval (gimple g, gimple_seq
- eval)
- Set `EVAL' to be the sequence of statements to use as the body for
- `GIMPLE_TRY' `G'.
-
- -- GIMPLE function: void gimple_try_set_cleanup (gimple g, gimple_seq
- cleanup)
- Set `CLEANUP' to be the sequence of statements to use as the
- cleanup body for `GIMPLE_TRY' `G'.
-
-\1f
-File: gccint.info, Node: `GIMPLE_WITH_CLEANUP_EXPR', Prev: `GIMPLE_TRY', Up: Tuple specific accessors
-
-12.7.28 `GIMPLE_WITH_CLEANUP_EXPR'
-----------------------------------
-
- -- GIMPLE function: gimple gimple_build_wce (gimple_seq cleanup)
- Build a `GIMPLE_WITH_CLEANUP_EXPR' statement. `CLEANUP' is the
- clean-up expression.
-
- -- GIMPLE function: gimple_seq gimple_wce_cleanup (gimple g)
- Return the cleanup sequence for cleanup statement `G'.
-
- -- GIMPLE function: void gimple_wce_set_cleanup (gimple g, gimple_seq
- cleanup)
- Set `CLEANUP' to be the cleanup sequence for `G'.
-
- -- GIMPLE function: bool gimple_wce_cleanup_eh_only (gimple g)
- Return the `CLEANUP_EH_ONLY' flag for a `WCE' tuple.
-
- -- GIMPLE function: void gimple_wce_set_cleanup_eh_only (gimple g,
- bool eh_only_p)
- Set the `CLEANUP_EH_ONLY' flag for a `WCE' tuple.
-
-\1f
-File: gccint.info, Node: GIMPLE sequences, Next: Sequence iterators, Prev: Tuple specific accessors, Up: GIMPLE
-
-12.8 GIMPLE sequences
-=====================
-
-GIMPLE sequences are the tuple equivalent of `STATEMENT_LIST''s used in
-`GENERIC'. They are used to chain statements together, and when used
-in conjunction with sequence iterators, provide a framework for
-iterating through statements.
-
- GIMPLE sequences are of type struct `gimple_sequence', but are more
-commonly passed by reference to functions dealing with sequences. The
-type for a sequence pointer is `gimple_seq' which is the same as struct
-`gimple_sequence' *. When declaring a local sequence, you can define a
-local variable of type struct `gimple_sequence'. When declaring a
-sequence allocated on the garbage collected heap, use the function
-`gimple_seq_alloc' documented below.
-
- There are convenience functions for iterating through sequences in the
-section entitled Sequence Iterators.
-
- Below is a list of functions to manipulate and query sequences.
-
- -- GIMPLE function: void gimple_seq_add_stmt (gimple_seq *seq, gimple
- g)
- Link a gimple statement to the end of the sequence *`SEQ' if `G' is
- not `NULL'. If *`SEQ' is `NULL', allocate a sequence before
- linking.
-
- -- GIMPLE function: void gimple_seq_add_seq (gimple_seq *dest,
- gimple_seq src)
- Append sequence `SRC' to the end of sequence *`DEST' if `SRC' is
- not `NULL'. If *`DEST' is `NULL', allocate a new sequence before
- appending.
-
- -- GIMPLE function: gimple_seq gimple_seq_deep_copy (gimple_seq src)
- Perform a deep copy of sequence `SRC' and return the result.
-
- -- GIMPLE function: gimple_seq gimple_seq_reverse (gimple_seq seq)
- Reverse the order of the statements in the sequence `SEQ'. Return
- `SEQ'.
-
- -- GIMPLE function: gimple gimple_seq_first (gimple_seq s)
- Return the first statement in sequence `S'.
-
- -- GIMPLE function: gimple gimple_seq_last (gimple_seq s)
- Return the last statement in sequence `S'.
-
- -- GIMPLE function: void gimple_seq_set_last (gimple_seq s, gimple
- last)
- Set the last statement in sequence `S' to the statement in `LAST'.
-
- -- GIMPLE function: void gimple_seq_set_first (gimple_seq s, gimple
- first)
- Set the first statement in sequence `S' to the statement in
- `FIRST'.
-
- -- GIMPLE function: void gimple_seq_init (gimple_seq s)
- Initialize sequence `S' to an empty sequence.
-
- -- GIMPLE function: gimple_seq gimple_seq_alloc (void)
- Allocate a new sequence in the garbage collected store and return
- it.
-
- -- GIMPLE function: void gimple_seq_copy (gimple_seq dest, gimple_seq
- src)
- Copy the sequence `SRC' into the sequence `DEST'.
-
- -- GIMPLE function: bool gimple_seq_empty_p (gimple_seq s)
- Return true if the sequence `S' is empty.
-
- -- GIMPLE function: gimple_seq bb_seq (basic_block bb)
- Returns the sequence of statements in `BB'.
-
- -- GIMPLE function: void set_bb_seq (basic_block bb, gimple_seq seq)
- Sets the sequence of statements in `BB' to `SEQ'.
-
- -- GIMPLE function: bool gimple_seq_singleton_p (gimple_seq seq)
- Determine whether `SEQ' contains exactly one statement.
-
-\1f
-File: gccint.info, Node: Sequence iterators, Next: Adding a new GIMPLE statement code, Prev: GIMPLE sequences, Up: GIMPLE
-
-12.9 Sequence iterators
-=======================
-
-Sequence iterators are convenience constructs for iterating through
-statements in a sequence. Given a sequence `SEQ', here is a typical
-use of gimple sequence iterators:
-
- gimple_stmt_iterator gsi;
-
- for (gsi = gsi_start (seq); !gsi_end_p (gsi); gsi_next (&gsi))
- {
- gimple g = gsi_stmt (gsi);
- /* Do something with gimple statement `G'. */
- }
-
- Backward iterations are possible:
-
- for (gsi = gsi_last (seq); !gsi_end_p (gsi); gsi_prev (&gsi))
-
- Forward and backward iterations on basic blocks are possible with
-`gsi_start_bb' and `gsi_last_bb'.
-
- In the documentation below we sometimes refer to enum
-`gsi_iterator_update'. The valid options for this enumeration are:
-
- * `GSI_NEW_STMT' Only valid when a single statement is added. Move
- the iterator to it.
-
- * `GSI_SAME_STMT' Leave the iterator at the same statement.
-
- * `GSI_CONTINUE_LINKING' Move iterator to whatever position is
- suitable for linking other statements in the same direction.
-
- Below is a list of the functions used to manipulate and use statement
-iterators.
-
- -- GIMPLE function: gimple_stmt_iterator gsi_start (gimple_seq seq)
- Return a new iterator pointing to the sequence `SEQ''s first
- statement. If `SEQ' is empty, the iterator's basic block is
- `NULL'. Use `gsi_start_bb' instead when the iterator needs to
- always have the correct basic block set.
-
- -- GIMPLE function: gimple_stmt_iterator gsi_start_bb (basic_block bb)
- Return a new iterator pointing to the first statement in basic
- block `BB'.
-
- -- GIMPLE function: gimple_stmt_iterator gsi_last (gimple_seq seq)
- Return a new iterator initially pointing to the last statement of
- sequence `SEQ'. If `SEQ' is empty, the iterator's basic block is
- `NULL'. Use `gsi_last_bb' instead when the iterator needs to
- always have the correct basic block set.
-
- -- GIMPLE function: gimple_stmt_iterator gsi_last_bb (basic_block bb)
- Return a new iterator pointing to the last statement in basic
- block `BB'.
-
- -- GIMPLE function: bool gsi_end_p (gimple_stmt_iterator i)
- Return `TRUE' if at the end of `I'.
-
- -- GIMPLE function: bool gsi_one_before_end_p (gimple_stmt_iterator i)
- Return `TRUE' if we're one statement before the end of `I'.
-
- -- GIMPLE function: void gsi_next (gimple_stmt_iterator *i)
- Advance the iterator to the next gimple statement.
-
- -- GIMPLE function: void gsi_prev (gimple_stmt_iterator *i)
- Advance the iterator to the previous gimple statement.
-
- -- GIMPLE function: gimple gsi_stmt (gimple_stmt_iterator i)
- Return the current stmt.
-
- -- GIMPLE function: gimple_stmt_iterator gsi_after_labels (basic_block
- bb)
- Return a block statement iterator that points to the first
- non-label statement in block `BB'.
-
- -- GIMPLE function: gimple *gsi_stmt_ptr (gimple_stmt_iterator *i)
- Return a pointer to the current stmt.
-
- -- GIMPLE function: basic_block gsi_bb (gimple_stmt_iterator i)
- Return the basic block associated with this iterator.
-
- -- GIMPLE function: gimple_seq gsi_seq (gimple_stmt_iterator i)
- Return the sequence associated with this iterator.
-
- -- GIMPLE function: void gsi_remove (gimple_stmt_iterator *i, bool
- remove_eh_info)
- Remove the current stmt from the sequence. The iterator is
- updated to point to the next statement. When `REMOVE_EH_INFO' is
- true we remove the statement pointed to by iterator `I' from the
- `EH' tables. Otherwise we do not modify the `EH' tables.
- Generally, `REMOVE_EH_INFO' should be true when the statement is
- going to be removed from the `IL' and not reinserted elsewhere.
-
- -- GIMPLE function: void gsi_link_seq_before (gimple_stmt_iterator *i,
- gimple_seq seq, enum gsi_iterator_update mode)
- Links the sequence of statements `SEQ' before the statement pointed
- by iterator `I'. `MODE' indicates what to do with the iterator
- after insertion (see `enum gsi_iterator_update' above).
-
- -- GIMPLE function: void gsi_link_before (gimple_stmt_iterator *i,
- gimple g, enum gsi_iterator_update mode)
- Links statement `G' before the statement pointed-to by iterator
- `I'. Updates iterator `I' according to `MODE'.
-
- -- GIMPLE function: void gsi_link_seq_after (gimple_stmt_iterator *i,
- gimple_seq seq, enum gsi_iterator_update mode)
- Links sequence `SEQ' after the statement pointed-to by iterator
- `I'. `MODE' is as in `gsi_insert_after'.
-
- -- GIMPLE function: void gsi_link_after (gimple_stmt_iterator *i,
- gimple g, enum gsi_iterator_update mode)
- Links statement `G' after the statement pointed-to by iterator `I'.
- `MODE' is as in `gsi_insert_after'.
-
- -- GIMPLE function: gimple_seq gsi_split_seq_after
- (gimple_stmt_iterator i)
- Move all statements in the sequence after `I' to a new sequence.
- Return this new sequence.
-
- -- GIMPLE function: gimple_seq gsi_split_seq_before
- (gimple_stmt_iterator *i)
- Move all statements in the sequence before `I' to a new sequence.
- Return this new sequence.
-
- -- GIMPLE function: void gsi_replace (gimple_stmt_iterator *i, gimple
- stmt, bool update_eh_info)
- Replace the statement pointed-to by `I' to `STMT'. If
- `UPDATE_EH_INFO' is true, the exception handling information of
- the original statement is moved to the new statement.
-
- -- GIMPLE function: void gsi_insert_before (gimple_stmt_iterator *i,
- gimple stmt, enum gsi_iterator_update mode)
- Insert statement `STMT' before the statement pointed-to by iterator
- `I', update `STMT''s basic block and scan it for new operands.
- `MODE' specifies how to update iterator `I' after insertion (see
- enum `gsi_iterator_update').
-
- -- GIMPLE function: void gsi_insert_seq_before (gimple_stmt_iterator
- *i, gimple_seq seq, enum gsi_iterator_update mode)
- Like `gsi_insert_before', but for all the statements in `SEQ'.
-
- -- GIMPLE function: void gsi_insert_after (gimple_stmt_iterator *i,
- gimple stmt, enum gsi_iterator_update mode)
- Insert statement `STMT' after the statement pointed-to by iterator
- `I', update `STMT''s basic block and scan it for new operands.
- `MODE' specifies how to update iterator `I' after insertion (see
- enum `gsi_iterator_update').
-
- -- GIMPLE function: void gsi_insert_seq_after (gimple_stmt_iterator
- *i, gimple_seq seq, enum gsi_iterator_update mode)
- Like `gsi_insert_after', but for all the statements in `SEQ'.
-
- -- GIMPLE function: gimple_stmt_iterator gsi_for_stmt (gimple stmt)
- Finds iterator for `STMT'.
-
- -- GIMPLE function: void gsi_move_after (gimple_stmt_iterator *from,
- gimple_stmt_iterator *to)
- Move the statement at `FROM' so it comes right after the statement
- at `TO'.
-
- -- GIMPLE function: void gsi_move_before (gimple_stmt_iterator *from,
- gimple_stmt_iterator *to)
- Move the statement at `FROM' so it comes right before the statement
- at `TO'.
-
- -- GIMPLE function: void gsi_move_to_bb_end (gimple_stmt_iterator
- *from, basic_block bb)
- Move the statement at `FROM' to the end of basic block `BB'.
-
- -- GIMPLE function: void gsi_insert_on_edge (edge e, gimple stmt)
- Add `STMT' to the pending list of edge `E'. No actual insertion is
- made until a call to `gsi_commit_edge_inserts'() is made.
-
- -- GIMPLE function: void gsi_insert_seq_on_edge (edge e, gimple_seq
- seq)
- Add the sequence of statements in `SEQ' to the pending list of edge
- `E'. No actual insertion is made until a call to
- `gsi_commit_edge_inserts'() is made.
-
- -- GIMPLE function: basic_block gsi_insert_on_edge_immediate (edge e,
- gimple stmt)
- Similar to `gsi_insert_on_edge'+`gsi_commit_edge_inserts'. If a
- new block has to be created, it is returned.
-
- -- GIMPLE function: void gsi_commit_one_edge_insert (edge e,
- basic_block *new_bb)
- Commit insertions pending at edge `E'. If a new block is created,
- set `NEW_BB' to this block, otherwise set it to `NULL'.
-
- -- GIMPLE function: void gsi_commit_edge_inserts (void)
- This routine will commit all pending edge insertions, creating any
- new basic blocks which are necessary.
-
-\1f
-File: gccint.info, Node: Adding a new GIMPLE statement code, Next: Statement and operand traversals, Prev: Sequence iterators, Up: GIMPLE
-
-12.10 Adding a new GIMPLE statement code
-========================================
-
-The first step in adding a new GIMPLE statement code, is modifying the
-file `gimple.def', which contains all the GIMPLE codes. Then you must
-add a corresponding structure, and an entry in `union
-gimple_statement_d', both of which are located in `gimple.h'. This in
-turn, will require you to add a corresponding `GTY' tag in
-`gsstruct.def', and code to handle this tag in `gss_for_code' which is
-located in `gimple.c'.
-
- In order for the garbage collector to know the size of the structure
-you created in `gimple.h', you need to add a case to handle your new
-GIMPLE statement in `gimple_size' which is located in `gimple.c'.
-
- You will probably want to create a function to build the new gimple
-statement in `gimple.c'. The function should be called
-`gimple_build_<`NEW_TUPLE_NAME'>', and should return the new tuple of
-type gimple.
-
- If your new statement requires accessors for any members or operands
-it may have, put simple inline accessors in `gimple.h' and any
-non-trivial accessors in `gimple.c' with a corresponding prototype in
-`gimple.h'.
-
-\1f
-File: gccint.info, Node: Statement and operand traversals, Prev: Adding a new GIMPLE statement code, Up: GIMPLE
-
-12.11 Statement and operand traversals
-======================================
-
-There are two functions available for walking statements and sequences:
-`walk_gimple_stmt' and `walk_gimple_seq', accordingly, and a third
-function for walking the operands in a statement: `walk_gimple_op'.
-
- -- GIMPLE function: tree walk_gimple_stmt (gimple_stmt_iterator *gsi,
- walk_stmt_fn callback_stmt, walk_tree_fn callback_op, struct
- walk_stmt_info *wi)
- This function is used to walk the current statement in `GSI',
- optionally using traversal state stored in `WI'. If `WI' is
- `NULL', no state is kept during the traversal.
-
- The callback `CALLBACK_STMT' is called. If `CALLBACK_STMT' returns
- true, it means that the callback function has handled all the
- operands of the statement and it is not necessary to walk its
- operands.
-
- If `CALLBACK_STMT' is `NULL' or it returns false, `CALLBACK_OP' is
- called on each operand of the statement via `walk_gimple_op'. If
- `walk_gimple_op' returns non-`NULL' for any operand, the remaining
- operands are not scanned.
-
- The return value is that returned by the last call to
- `walk_gimple_op', or `NULL_TREE' if no `CALLBACK_OP' is specified.
-
- -- GIMPLE function: tree walk_gimple_op (gimple stmt, walk_tree_fn
- callback_op, struct walk_stmt_info *wi)
- Use this function to walk the operands of statement `STMT'. Every
- operand is walked via `walk_tree' with optional state information
- in `WI'.
-
- `CALLBACK_OP' is called on each operand of `STMT' via `walk_tree'.
- Additional parameters to `walk_tree' must be stored in `WI'. For
- each operand `OP', `walk_tree' is called as:
-
- walk_tree (&`OP', `CALLBACK_OP', `WI', `WI'- `PSET')
-
- If `CALLBACK_OP' returns non-`NULL' for an operand, the remaining
- operands are not scanned. The return value is that returned by
- the last call to `walk_tree', or `NULL_TREE' if no `CALLBACK_OP' is
- specified.
-
- -- GIMPLE function: tree walk_gimple_seq (gimple_seq seq, walk_stmt_fn
- callback_stmt, walk_tree_fn callback_op, struct
- walk_stmt_info *wi)
- This function walks all the statements in the sequence `SEQ'
- calling `walk_gimple_stmt' on each one. `WI' is as in
- `walk_gimple_stmt'. If `walk_gimple_stmt' returns non-`NULL', the
- walk is stopped and the value returned. Otherwise, all the
- statements are walked and `NULL_TREE' returned.
-
-\1f
-File: gccint.info, Node: Tree SSA, Next: RTL, Prev: GIMPLE, Up: Top
-
-13 Analysis and Optimization of GIMPLE tuples
-*********************************************
-
-GCC uses three main intermediate languages to represent the program
-during compilation: GENERIC, GIMPLE and RTL. GENERIC is a
-language-independent representation generated by each front end. It is
-used to serve as an interface between the parser and optimizer.
-GENERIC is a common representation that is able to represent programs
-written in all the languages supported by GCC.
-
- GIMPLE and RTL are used to optimize the program. GIMPLE is used for
-target and language independent optimizations (e.g., inlining, constant
-propagation, tail call elimination, redundancy elimination, etc). Much
-like GENERIC, GIMPLE is a language independent, tree based
-representation. However, it differs from GENERIC in that the GIMPLE
-grammar is more restrictive: expressions contain no more than 3
-operands (except function calls), it has no control flow structures and
-expressions with side-effects are only allowed on the right hand side
-of assignments. See the chapter describing GENERIC and GIMPLE for more
-details.
-
- This chapter describes the data structures and functions used in the
-GIMPLE optimizers (also known as "tree optimizers" or "middle end").
-In particular, it focuses on all the macros, data structures, functions
-and programming constructs needed to implement optimization passes for
-GIMPLE.
-
-* Menu:
-
-* Annotations:: Attributes for variables.
-* SSA Operands:: SSA names referenced by GIMPLE statements.
-* SSA:: Static Single Assignment representation.
-* Alias analysis:: Representing aliased loads and stores.
-
-\1f
-File: gccint.info, Node: Annotations, Next: SSA Operands, Up: Tree SSA
-
-13.1 Annotations
-================
-
-The optimizers need to associate attributes with variables during the
-optimization process. For instance, we need to know whether a variable
-has aliases. All these attributes are stored in data structures called
-annotations which are then linked to the field `ann' in `struct
-tree_common'.
-
- Presently, we define annotations for variables (`var_ann_t').
-Annotations are defined and documented in `tree-flow.h'.
-
-\1f
-File: gccint.info, Node: SSA Operands, Next: SSA, Prev: Annotations, Up: Tree SSA
-
-13.2 SSA Operands
-=================
-
-Almost every GIMPLE statement will contain a reference to a variable or
-memory location. Since statements come in different shapes and sizes,
-their operands are going to be located at various spots inside the
-statement's tree. To facilitate access to the statement's operands,
-they are organized into lists associated inside each statement's
-annotation. Each element in an operand list is a pointer to a
-`VAR_DECL', `PARM_DECL' or `SSA_NAME' tree node. This provides a very
-convenient way of examining and replacing operands.
-
- Data flow analysis and optimization is done on all tree nodes
-representing variables. Any node for which `SSA_VAR_P' returns nonzero
-is considered when scanning statement operands. However, not all
-`SSA_VAR_P' variables are processed in the same way. For the purposes
-of optimization, we need to distinguish between references to local
-scalar variables and references to globals, statics, structures,
-arrays, aliased variables, etc. The reason is simple, the compiler can
-gather complete data flow information for a local scalar. On the other
-hand, a global variable may be modified by a function call, it may not
-be possible to keep track of all the elements of an array or the fields
-of a structure, etc.
-
- The operand scanner gathers two kinds of operands: "real" and
-"virtual". An operand for which `is_gimple_reg' returns true is
-considered real, otherwise it is a virtual operand. We also
-distinguish between uses and definitions. An operand is used if its
-value is loaded by the statement (e.g., the operand at the RHS of an
-assignment). If the statement assigns a new value to the operand, the
-operand is considered a definition (e.g., the operand at the LHS of an
-assignment).
-
- Virtual and real operands also have very different data flow
-properties. Real operands are unambiguous references to the full
-object that they represent. For instance, given
-
- {
- int a, b;
- a = b
- }
-
- Since `a' and `b' are non-aliased locals, the statement `a = b' will
-have one real definition and one real use because variable `b' is
-completely modified with the contents of variable `a'. Real definition
-are also known as "killing definitions". Similarly, the use of `a'
-reads all its bits.
-
- In contrast, virtual operands are used with variables that can have a
-partial or ambiguous reference. This includes structures, arrays,
-globals, and aliased variables. In these cases, we have two types of
-definitions. For globals, structures, and arrays, we can determine from
-a statement whether a variable of these types has a killing definition.
-If the variable does, then the statement is marked as having a "must
-definition" of that variable. However, if a statement is only defining
-a part of the variable (i.e. a field in a structure), or if we know
-that a statement might define the variable but we cannot say for sure,
-then we mark that statement as having a "may definition". For
-instance, given
-
- {
- int a, b, *p;
-
- if (...)
- p = &a;
- else
- p = &b;
- *p = 5;
- return *p;
- }
-
- The assignment `*p = 5' may be a definition of `a' or `b'. If we
-cannot determine statically where `p' is pointing to at the time of the
-store operation, we create virtual definitions to mark that statement
-as a potential definition site for `a' and `b'. Memory loads are
-similarly marked with virtual use operands. Virtual operands are shown
-in tree dumps right before the statement that contains them. To
-request a tree dump with virtual operands, use the `-vops' option to
-`-fdump-tree':
-
- {
- int a, b, *p;
-
- if (...)
- p = &a;
- else
- p = &b;
- # a = VDEF <a>
- # b = VDEF <b>
- *p = 5;
-
- # VUSE <a>
- # VUSE <b>
- return *p;
- }
-
- Notice that `VDEF' operands have two copies of the referenced
-variable. This indicates that this is not a killing definition of that
-variable. In this case we refer to it as a "may definition" or
-"aliased store". The presence of the second copy of the variable in
-the `VDEF' operand will become important when the function is converted
-into SSA form. This will be used to link all the non-killing
-definitions to prevent optimizations from making incorrect assumptions
-about them.
-
- Operands are updated as soon as the statement is finished via a call
-to `update_stmt'. If statement elements are changed via `SET_USE' or
-`SET_DEF', then no further action is required (i.e., those macros take
-care of updating the statement). If changes are made by manipulating
-the statement's tree directly, then a call must be made to
-`update_stmt' when complete. Calling one of the `bsi_insert' routines
-or `bsi_replace' performs an implicit call to `update_stmt'.
-
-13.2.1 Operand Iterators And Access Routines
---------------------------------------------
-
-Operands are collected by `tree-ssa-operands.c'. They are stored
-inside each statement's annotation and can be accessed through either
-the operand iterators or an access routine.
-
- The following access routines are available for examining operands:
-
- 1. `SINGLE_SSA_{USE,DEF,TREE}_OPERAND': These accessors will return
- NULL unless there is exactly one operand matching the specified
- flags. If there is exactly one operand, the operand is returned
- as either a `tree', `def_operand_p', or `use_operand_p'.
-
- tree t = SINGLE_SSA_TREE_OPERAND (stmt, flags);
- use_operand_p u = SINGLE_SSA_USE_OPERAND (stmt, SSA_ALL_VIRTUAL_USES);
- def_operand_p d = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_ALL_DEFS);
-
- 2. `ZERO_SSA_OPERANDS': This macro returns true if there are no
- operands matching the specified flags.
-
- if (ZERO_SSA_OPERANDS (stmt, SSA_OP_ALL_VIRTUALS))
- return;
-
- 3. `NUM_SSA_OPERANDS': This macro Returns the number of operands
- matching 'flags'. This actually executes a loop to perform the
- count, so only use this if it is really needed.
-
- int count = NUM_SSA_OPERANDS (stmt, flags)
-
- If you wish to iterate over some or all operands, use the
-`FOR_EACH_SSA_{USE,DEF,TREE}_OPERAND' iterator. For example, to print
-all the operands for a statement:
-
- void
- print_ops (tree stmt)
- {
- ssa_op_iter;
- tree var;
-
- FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_OPERANDS)
- print_generic_expr (stderr, var, TDF_SLIM);
- }
-
- How to choose the appropriate iterator:
-
- 1. Determine whether you are need to see the operand pointers, or
- just the trees, and choose the appropriate macro:
-
- Need Macro:
- ---- -------
- use_operand_p FOR_EACH_SSA_USE_OPERAND
- def_operand_p FOR_EACH_SSA_DEF_OPERAND
- tree FOR_EACH_SSA_TREE_OPERAND
-
- 2. You need to declare a variable of the type you are interested in,
- and an ssa_op_iter structure which serves as the loop controlling
- variable.
-
- 3. Determine which operands you wish to use, and specify the flags of
- those you are interested in. They are documented in
- `tree-ssa-operands.h':
-
- #define SSA_OP_USE 0x01 /* Real USE operands. */
- #define SSA_OP_DEF 0x02 /* Real DEF operands. */
- #define SSA_OP_VUSE 0x04 /* VUSE operands. */
- #define SSA_OP_VMAYUSE 0x08 /* USE portion of VDEFS. */
- #define SSA_OP_VDEF 0x10 /* DEF portion of VDEFS. */
-
- /* These are commonly grouped operand flags. */
- #define SSA_OP_VIRTUAL_USES (SSA_OP_VUSE | SSA_OP_VMAYUSE)
- #define SSA_OP_VIRTUAL_DEFS (SSA_OP_VDEF)
- #define SSA_OP_ALL_USES (SSA_OP_VIRTUAL_USES | SSA_OP_USE)
- #define SSA_OP_ALL_DEFS (SSA_OP_VIRTUAL_DEFS | SSA_OP_DEF)
- #define SSA_OP_ALL_OPERANDS (SSA_OP_ALL_USES | SSA_OP_ALL_DEFS)
-
- So if you want to look at the use pointers for all the `USE' and
-`VUSE' operands, you would do something like:
-
- use_operand_p use_p;
- ssa_op_iter iter;
-
- FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, (SSA_OP_USE | SSA_OP_VUSE))
- {
- process_use_ptr (use_p);
- }
-
- The `TREE' macro is basically the same as the `USE' and `DEF' macros,
-only with the use or def dereferenced via `USE_FROM_PTR (use_p)' and
-`DEF_FROM_PTR (def_p)'. Since we aren't using operand pointers, use
-and defs flags can be mixed.
-
- tree var;
- ssa_op_iter iter;
-
- FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_VUSE)
- {
- print_generic_expr (stderr, var, TDF_SLIM);
- }
-
- `VDEF's are broken into two flags, one for the `DEF' portion
-(`SSA_OP_VDEF') and one for the USE portion (`SSA_OP_VMAYUSE'). If all
-you want to look at are the `VDEF's together, there is a fourth
-iterator macro for this, which returns both a def_operand_p and a
-use_operand_p for each `VDEF' in the statement. Note that you don't
-need any flags for this one.
-
- use_operand_p use_p;
- def_operand_p def_p;
- ssa_op_iter iter;
-
- FOR_EACH_SSA_MAYDEF_OPERAND (def_p, use_p, stmt, iter)
- {
- my_code;
- }
-
- There are many examples in the code as well, as well as the
-documentation in `tree-ssa-operands.h'.
-
- There are also a couple of variants on the stmt iterators regarding PHI
-nodes.
-
- `FOR_EACH_PHI_ARG' Works exactly like `FOR_EACH_SSA_USE_OPERAND',
-except it works over `PHI' arguments instead of statement operands.
-
- /* Look at every virtual PHI use. */
- FOR_EACH_PHI_ARG (use_p, phi_stmt, iter, SSA_OP_VIRTUAL_USES)
- {
- my_code;
- }
-
- /* Look at every real PHI use. */
- FOR_EACH_PHI_ARG (use_p, phi_stmt, iter, SSA_OP_USES)
- my_code;
-
- /* Look at every PHI use. */
- FOR_EACH_PHI_ARG (use_p, phi_stmt, iter, SSA_OP_ALL_USES)
- my_code;
-
- `FOR_EACH_PHI_OR_STMT_{USE,DEF}' works exactly like
-`FOR_EACH_SSA_{USE,DEF}_OPERAND', except it will function on either a
-statement or a `PHI' node. These should be used when it is appropriate
-but they are not quite as efficient as the individual `FOR_EACH_PHI'
-and `FOR_EACH_SSA' routines.
-
- FOR_EACH_PHI_OR_STMT_USE (use_operand_p, stmt, iter, flags)
- {
- my_code;
- }
-
- FOR_EACH_PHI_OR_STMT_DEF (def_operand_p, phi, iter, flags)
- {
- my_code;
- }
-
-13.2.2 Immediate Uses
----------------------
-
-Immediate use information is now always available. Using the immediate
-use iterators, you may examine every use of any `SSA_NAME'. For
-instance, to change each use of `ssa_var' to `ssa_var2' and call
-fold_stmt on each stmt after that is done:
-
- use_operand_p imm_use_p;
- imm_use_iterator iterator;
- tree ssa_var, stmt;
-
-
- FOR_EACH_IMM_USE_STMT (stmt, iterator, ssa_var)
- {
- FOR_EACH_IMM_USE_ON_STMT (imm_use_p, iterator)
- SET_USE (imm_use_p, ssa_var_2);
- fold_stmt (stmt);
- }
-
- There are 2 iterators which can be used. `FOR_EACH_IMM_USE_FAST' is
-used when the immediate uses are not changed, i.e., you are looking at
-the uses, but not setting them.
-
- If they do get changed, then care must be taken that things are not
-changed under the iterators, so use the `FOR_EACH_IMM_USE_STMT' and
-`FOR_EACH_IMM_USE_ON_STMT' iterators. They attempt to preserve the
-sanity of the use list by moving all the uses for a statement into a
-controlled position, and then iterating over those uses. Then the
-optimization can manipulate the stmt when all the uses have been
-processed. This is a little slower than the FAST version since it adds
-a placeholder element and must sort through the list a bit for each
-statement. This placeholder element must be also be removed if the
-loop is terminated early. The macro `BREAK_FROM_IMM_USE_SAFE' is
-provided to do this :
-
- FOR_EACH_IMM_USE_STMT (stmt, iterator, ssa_var)
- {
- if (stmt == last_stmt)
- BREAK_FROM_SAFE_IMM_USE (iter);
-
- FOR_EACH_IMM_USE_ON_STMT (imm_use_p, iterator)
- SET_USE (imm_use_p, ssa_var_2);
- fold_stmt (stmt);
- }
-
- There are checks in `verify_ssa' which verify that the immediate use
-list is up to date, as well as checking that an optimization didn't
-break from the loop without using this macro. It is safe to simply
-'break'; from a `FOR_EACH_IMM_USE_FAST' traverse.
-
- Some useful functions and macros:
- 1. `has_zero_uses (ssa_var)' : Returns true if there are no uses of
- `ssa_var'.
-
- 2. `has_single_use (ssa_var)' : Returns true if there is only a
- single use of `ssa_var'.
-
- 3. `single_imm_use (ssa_var, use_operand_p *ptr, tree *stmt)' :
- Returns true if there is only a single use of `ssa_var', and also
- returns the use pointer and statement it occurs in, in the second
- and third parameters.
-
- 4. `num_imm_uses (ssa_var)' : Returns the number of immediate uses of
- `ssa_var'. It is better not to use this if possible since it simply
- utilizes a loop to count the uses.
-
- 5. `PHI_ARG_INDEX_FROM_USE (use_p)' : Given a use within a `PHI'
- node, return the index number for the use. An assert is triggered
- if the use isn't located in a `PHI' node.
-
- 6. `USE_STMT (use_p)' : Return the statement a use occurs in.
-
- Note that uses are not put into an immediate use list until their
-statement is actually inserted into the instruction stream via a
-`bsi_*' routine.
-
- It is also still possible to utilize lazy updating of statements, but
-this should be used only when absolutely required. Both alias analysis
-and the dominator optimizations currently do this.
-
- When lazy updating is being used, the immediate use information is out
-of date and cannot be used reliably. Lazy updating is achieved by
-simply marking statements modified via calls to `mark_stmt_modified'
-instead of `update_stmt'. When lazy updating is no longer required,
-all the modified statements must have `update_stmt' called in order to
-bring them up to date. This must be done before the optimization is
-finished, or `verify_ssa' will trigger an abort.
-
- This is done with a simple loop over the instruction stream:
- block_stmt_iterator bsi;
- basic_block bb;
- FOR_EACH_BB (bb)
- {
- for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
- update_stmt_if_modified (bsi_stmt (bsi));
- }
-
-\1f
-File: gccint.info, Node: SSA, Next: Alias analysis, Prev: SSA Operands, Up: Tree SSA
-
-13.3 Static Single Assignment
-=============================
-
-Most of the tree optimizers rely on the data flow information provided
-by the Static Single Assignment (SSA) form. We implement the SSA form
-as described in `R. Cytron, J. Ferrante, B. Rosen, M. Wegman, and K.
-Zadeck. Efficiently Computing Static Single Assignment Form and the
-Control Dependence Graph. ACM Transactions on Programming Languages
-and Systems, 13(4):451-490, October 1991'.
-
- The SSA form is based on the premise that program variables are
-assigned in exactly one location in the program. Multiple assignments
-to the same variable create new versions of that variable. Naturally,
-actual programs are seldom in SSA form initially because variables tend
-to be assigned multiple times. The compiler modifies the program
-representation so that every time a variable is assigned in the code, a
-new version of the variable is created. Different versions of the same
-variable are distinguished by subscripting the variable name with its
-version number. Variables used in the right-hand side of expressions
-are renamed so that their version number matches that of the most
-recent assignment.
-
- We represent variable versions using `SSA_NAME' nodes. The renaming
-process in `tree-ssa.c' wraps every real and virtual operand with an
-`SSA_NAME' node which contains the version number and the statement
-that created the `SSA_NAME'. Only definitions and virtual definitions
-may create new `SSA_NAME' nodes.
-
- Sometimes, flow of control makes it impossible to determine the most
-recent version of a variable. In these cases, the compiler inserts an
-artificial definition for that variable called "PHI function" or "PHI
-node". This new definition merges all the incoming versions of the
-variable to create a new name for it. For instance,
-
- if (...)
- a_1 = 5;
- else if (...)
- a_2 = 2;
- else
- a_3 = 13;
-
- # a_4 = PHI <a_1, a_2, a_3>
- return a_4;
-
- Since it is not possible to determine which of the three branches will
-be taken at runtime, we don't know which of `a_1', `a_2' or `a_3' to
-use at the return statement. So, the SSA renamer creates a new version
-`a_4' which is assigned the result of "merging" `a_1', `a_2' and `a_3'.
-Hence, PHI nodes mean "one of these operands. I don't know which".
-
- The following macros can be used to examine PHI nodes
-
- -- Macro: PHI_RESULT (PHI)
- Returns the `SSA_NAME' created by PHI node PHI (i.e., PHI's LHS).
-
- -- Macro: PHI_NUM_ARGS (PHI)
- Returns the number of arguments in PHI. This number is exactly
- the number of incoming edges to the basic block holding PHI.
-
- -- Macro: PHI_ARG_ELT (PHI, I)
- Returns a tuple representing the Ith argument of PHI. Each
- element of this tuple contains an `SSA_NAME' VAR and the incoming
- edge through which VAR flows.
-
- -- Macro: PHI_ARG_EDGE (PHI, I)
- Returns the incoming edge for the Ith argument of PHI.
-
- -- Macro: PHI_ARG_DEF (PHI, I)
- Returns the `SSA_NAME' for the Ith argument of PHI.
-
-13.3.1 Preserving the SSA form
-------------------------------
-
-Some optimization passes make changes to the function that invalidate
-the SSA property. This can happen when a pass has added new symbols or
-changed the program so that variables that were previously aliased
-aren't anymore. Whenever something like this happens, the affected
-symbols must be renamed into SSA form again. Transformations that emit
-new code or replicate existing statements will also need to update the
-SSA form.
-
- Since GCC implements two different SSA forms for register and virtual
-variables, keeping the SSA form up to date depends on whether you are
-updating register or virtual names. In both cases, the general idea
-behind incremental SSA updates is similar: when new SSA names are
-created, they typically are meant to replace other existing names in
-the program.
-
- For instance, given the following code:
-
- 1 L0:
- 2 x_1 = PHI (0, x_5)
- 3 if (x_1 < 10)
- 4 if (x_1 > 7)
- 5 y_2 = 0
- 6 else
- 7 y_3 = x_1 + x_7
- 8 endif
- 9 x_5 = x_1 + 1
- 10 goto L0;
- 11 endif
-
- Suppose that we insert new names `x_10' and `x_11' (lines `4' and `8').
-
- 1 L0:
- 2 x_1 = PHI (0, x_5)
- 3 if (x_1 < 10)
- 4 x_10 = ...
- 5 if (x_1 > 7)
- 6 y_2 = 0
- 7 else
- 8 x_11 = ...
- 9 y_3 = x_1 + x_7
- 10 endif
- 11 x_5 = x_1 + 1
- 12 goto L0;
- 13 endif
-
- We want to replace all the uses of `x_1' with the new definitions of
-`x_10' and `x_11'. Note that the only uses that should be replaced are
-those at lines `5', `9' and `11'. Also, the use of `x_7' at line `9'
-should _not_ be replaced (this is why we cannot just mark symbol `x' for
-renaming).
-
- Additionally, we may need to insert a PHI node at line `11' because
-that is a merge point for `x_10' and `x_11'. So the use of `x_1' at
-line `11' will be replaced with the new PHI node. The insertion of PHI
-nodes is optional. They are not strictly necessary to preserve the SSA
-form, and depending on what the caller inserted, they may not even be
-useful for the optimizers.
-
- Updating the SSA form is a two step process. First, the pass has to
-identify which names need to be updated and/or which symbols need to be
-renamed into SSA form for the first time. When new names are
-introduced to replace existing names in the program, the mapping
-between the old and the new names are registered by calling
-`register_new_name_mapping' (note that if your pass creates new code by
-duplicating basic blocks, the call to `tree_duplicate_bb' will set up
-the necessary mappings automatically). On the other hand, if your pass
-exposes a new symbol that should be put in SSA form for the first time,
-the new symbol should be registered with `mark_sym_for_renaming'.
-
- After the replacement mappings have been registered and new symbols
-marked for renaming, a call to `update_ssa' makes the registered
-changes. This can be done with an explicit call or by creating `TODO'
-flags in the `tree_opt_pass' structure for your pass. There are
-several `TODO' flags that control the behavior of `update_ssa':
-
- * `TODO_update_ssa'. Update the SSA form inserting PHI nodes for
- newly exposed symbols and virtual names marked for updating. When
- updating real names, only insert PHI nodes for a real name `O_j'
- in blocks reached by all the new and old definitions for `O_j'.
- If the iterated dominance frontier for `O_j' is not pruned, we may
- end up inserting PHI nodes in blocks that have one or more edges
- with no incoming definition for `O_j'. This would lead to
- uninitialized warnings for `O_j''s symbol.
-
- * `TODO_update_ssa_no_phi'. Update the SSA form without inserting
- any new PHI nodes at all. This is used by passes that have either
- inserted all the PHI nodes themselves or passes that need only to
- patch use-def and def-def chains for virtuals (e.g., DCE).
-
- * `TODO_update_ssa_full_phi'. Insert PHI nodes everywhere they are
- needed. No pruning of the IDF is done. This is used by passes
- that need the PHI nodes for `O_j' even if it means that some
- arguments will come from the default definition of `O_j''s symbol
- (e.g., `pass_linear_transform').
-
- WARNING: If you need to use this flag, chances are that your pass
- may be doing something wrong. Inserting PHI nodes for an old name
- where not all edges carry a new replacement may lead to silent
- codegen errors or spurious uninitialized warnings.
-
- * `TODO_update_ssa_only_virtuals'. Passes that update the SSA form
- on their own may want to delegate the updating of virtual names to
- the generic updater. Since FUD chains are easier to maintain,
- this simplifies the work they need to do. NOTE: If this flag is
- used, any OLD->NEW mappings for real names are explicitly
- destroyed and only the symbols marked for renaming are processed.
-
-13.3.2 Preserving the virtual SSA form
---------------------------------------
-
-The virtual SSA form is harder to preserve than the non-virtual SSA form
-mainly because the set of virtual operands for a statement may change at
-what some would consider unexpected times. In general, statement
-modifications should be bracketed between calls to `push_stmt_changes'
-and `pop_stmt_changes'. For example,
-
- munge_stmt (tree stmt)
- {
- push_stmt_changes (&stmt);
- ... rewrite STMT ...
- pop_stmt_changes (&stmt);
- }
-
- The call to `push_stmt_changes' saves the current state of the
-statement operands and the call to `pop_stmt_changes' compares the
-saved state with the current one and does the appropriate symbol
-marking for the SSA renamer.
-
- It is possible to modify several statements at a time, provided that
-`push_stmt_changes' and `pop_stmt_changes' are called in LIFO order, as
-when processing a stack of statements.
-
- Additionally, if the pass discovers that it did not need to make
-changes to the statement after calling `push_stmt_changes', it can
-simply discard the topmost change buffer by calling
-`discard_stmt_changes'. This will avoid the expensive operand re-scan
-operation and the buffer comparison that determines if symbols need to
-be marked for renaming.
-
-13.3.3 Examining `SSA_NAME' nodes
----------------------------------
-
-The following macros can be used to examine `SSA_NAME' nodes
-
- -- Macro: SSA_NAME_DEF_STMT (VAR)
- Returns the statement S that creates the `SSA_NAME' VAR. If S is
- an empty statement (i.e., `IS_EMPTY_STMT (S)' returns `true'), it
- means that the first reference to this variable is a USE or a VUSE.
-
- -- Macro: SSA_NAME_VERSION (VAR)
- Returns the version number of the `SSA_NAME' object VAR.
-
-13.3.4 Walking use-def chains
------------------------------
-
- -- Tree SSA function: void walk_use_def_chains (VAR, FN, DATA)
- Walks use-def chains starting at the `SSA_NAME' node VAR. Calls
- function FN at each reaching definition found. Function FN takes
- three arguments: VAR, its defining statement (DEF_STMT) and a
- generic pointer to whatever state information that FN may want to
- maintain (DATA). Function FN is able to stop the walk by
- returning `true', otherwise in order to continue the walk, FN
- should return `false'.
-
- Note, that if DEF_STMT is a `PHI' node, the semantics are slightly
- different. For each argument ARG of the PHI node, this function
- will:
-
- 1. Walk the use-def chains for ARG.
-
- 2. Call `FN (ARG, PHI, DATA)'.
-
- Note how the first argument to FN is no longer the original
- variable VAR, but the PHI argument currently being examined. If
- FN wants to get at VAR, it should call `PHI_RESULT' (PHI).
-
-13.3.5 Walking the dominator tree
----------------------------------
-
- -- Tree SSA function: void walk_dominator_tree (WALK_DATA, BB)
- This function walks the dominator tree for the current CFG calling
- a set of callback functions defined in STRUCT DOM_WALK_DATA in
- `domwalk.h'. The call back functions you need to define give you
- hooks to execute custom code at various points during traversal:
-
- 1. Once to initialize any local data needed while processing BB
- and its children. This local data is pushed into an internal
- stack which is automatically pushed and popped as the walker
- traverses the dominator tree.
-
- 2. Once before traversing all the statements in the BB.
-
- 3. Once for every statement inside BB.
-
- 4. Once after traversing all the statements and before recursing
- into BB's dominator children.
-
- 5. It then recurses into all the dominator children of BB.
-
- 6. After recursing into all the dominator children of BB it can,
- optionally, traverse every statement in BB again (i.e.,
- repeating steps 2 and 3).
-
- 7. Once after walking the statements in BB and BB's dominator
- children. At this stage, the block local data stack is
- popped.
-
-\1f
-File: gccint.info, Node: Alias analysis, Prev: SSA, Up: Tree SSA
-
-13.4 Alias analysis
-===================
-
-Alias analysis proceeds in 4 main phases:
-
- 1. Structural alias analysis.
-
- This phase walks the types for structure variables, and determines
- which of the fields can overlap using offset and size of each
- field. For each field, a "subvariable" called a "Structure field
- tag" (SFT) is created, which represents that field as a separate
- variable. All accesses that could possibly overlap with a given
- field will have virtual operands for the SFT of that field.
-
- struct foo
- {
- int a;
- int b;
- }
- struct foo temp;
- int bar (void)
- {
- int tmp1, tmp2, tmp3;
- SFT.0_2 = VDEF <SFT.0_1>
- temp.a = 5;
- SFT.1_4 = VDEF <SFT.1_3>
- temp.b = 6;
-
- VUSE <SFT.1_4>
- tmp1_5 = temp.b;
- VUSE <SFT.0_2>
- tmp2_6 = temp.a;
-
- tmp3_7 = tmp1_5 + tmp2_6;
- return tmp3_7;
- }
-
- If you copy the symbol tag for a variable for some reason, you
- probably also want to copy the subvariables for that variable.
-
- 2. Points-to and escape analysis.
-
- This phase walks the use-def chains in the SSA web looking for
- three things:
-
- * Assignments of the form `P_i = &VAR'
-
- * Assignments of the form P_i = malloc()
-
- * Pointers and ADDR_EXPR that escape the current function.
-
- The concept of `escaping' is the same one used in the Java world.
- When a pointer or an ADDR_EXPR escapes, it means that it has been
- exposed outside of the current function. So, assignment to global
- variables, function arguments and returning a pointer are all
- escape sites.
-
- This is where we are currently limited. Since not everything is
- renamed into SSA, we lose track of escape properties when a
- pointer is stashed inside a field in a structure, for instance.
- In those cases, we are assuming that the pointer does escape.
-
- We use escape analysis to determine whether a variable is
- call-clobbered. Simply put, if an ADDR_EXPR escapes, then the
- variable is call-clobbered. If a pointer P_i escapes, then all
- the variables pointed-to by P_i (and its memory tag) also escape.
-
- 3. Compute flow-sensitive aliases
-
- We have two classes of memory tags. Memory tags associated with
- the pointed-to data type of the pointers in the program. These
- tags are called "symbol memory tag" (SMT). The other class are
- those associated with SSA_NAMEs, called "name memory tag" (NMT).
- The basic idea is that when adding operands for an INDIRECT_REF
- *P_i, we will first check whether P_i has a name tag, if it does
- we use it, because that will have more precise aliasing
- information. Otherwise, we use the standard symbol tag.
-
- In this phase, we go through all the pointers we found in
- points-to analysis and create alias sets for the name memory tags
- associated with each pointer P_i. If P_i escapes, we mark
- call-clobbered the variables it points to and its tag.
-
- 4. Compute flow-insensitive aliases
-
- This pass will compare the alias set of every symbol memory tag and
- every addressable variable found in the program. Given a symbol
- memory tag SMT and an addressable variable V. If the alias sets
- of SMT and V conflict (as computed by may_alias_p), then V is
- marked as an alias tag and added to the alias set of SMT.
-
- Every language that wishes to perform language-specific alias
- analysis should define a function that computes, given a `tree'
- node, an alias set for the node. Nodes in different alias sets
- are not allowed to alias. For an example, see the C front-end
- function `c_get_alias_set'.
-
- For instance, consider the following function:
-
- foo (int i)
- {
- int *p, *q, a, b;
-
- if (i > 10)
- p = &a;
- else
- q = &b;
-
- *p = 3;
- *q = 5;
- a = b + 2;
- return *p;
- }
-
- After aliasing analysis has finished, the symbol memory tag for
-pointer `p' will have two aliases, namely variables `a' and `b'. Every
-time pointer `p' is dereferenced, we want to mark the operation as a
-potential reference to `a' and `b'.
-
- foo (int i)
- {
- int *p, a, b;
-
- if (i_2 > 10)
- p_4 = &a;
- else
- p_6 = &b;
- # p_1 = PHI <p_4(1), p_6(2)>;
-
- # a_7 = VDEF <a_3>;
- # b_8 = VDEF <b_5>;
- *p_1 = 3;
-
- # a_9 = VDEF <a_7>
- # VUSE <b_8>
- a_9 = b_8 + 2;
-
- # VUSE <a_9>;
- # VUSE <b_8>;
- return *p_1;
- }
-
- In certain cases, the list of may aliases for a pointer may grow too
-large. This may cause an explosion in the number of virtual operands
-inserted in the code. Resulting in increased memory consumption and
-compilation time.
-
- When the number of virtual operands needed to represent aliased loads
-and stores grows too large (configurable with `--param
-max-aliased-vops'), alias sets are grouped to avoid severe compile-time
-slow downs and memory consumption. The alias grouping heuristic
-proceeds as follows:
-
- 1. Sort the list of pointers in decreasing number of contributed
- virtual operands.
-
- 2. Take the first pointer from the list and reverse the role of the
- memory tag and its aliases. Usually, whenever an aliased variable
- Vi is found to alias with a memory tag T, we add Vi to the
- may-aliases set for T. Meaning that after alias analysis, we will
- have:
-
- may-aliases(T) = { V1, V2, V3, ..., Vn }
-
- This means that every statement that references T, will get `n'
- virtual operands for each of the Vi tags. But, when alias
- grouping is enabled, we make T an alias tag and add it to the
- alias set of all the Vi variables:
-
- may-aliases(V1) = { T }
- may-aliases(V2) = { T }
- ...
- may-aliases(Vn) = { T }
-
- This has two effects: (a) statements referencing T will only get a
- single virtual operand, and, (b) all the variables Vi will now
- appear to alias each other. So, we lose alias precision to
- improve compile time. But, in theory, a program with such a high
- level of aliasing should not be very optimizable in the first
- place.
-
- 3. Since variables may be in the alias set of more than one memory
- tag, the grouping done in step (2) needs to be extended to all the
- memory tags that have a non-empty intersection with the
- may-aliases set of tag T. For instance, if we originally had
- these may-aliases sets:
-
- may-aliases(T) = { V1, V2, V3 }
- may-aliases(R) = { V2, V4 }
-
- In step (2) we would have reverted the aliases for T as:
-
- may-aliases(V1) = { T }
- may-aliases(V2) = { T }
- may-aliases(V3) = { T }
-
- But note that now V2 is no longer aliased with R. We could add R
- to may-aliases(V2), but we are in the process of grouping aliases
- to reduce virtual operands so what we do is add V4 to the grouping
- to obtain:
-
- may-aliases(V1) = { T }
- may-aliases(V2) = { T }
- may-aliases(V3) = { T }
- may-aliases(V4) = { T }
-
- 4. If the total number of virtual operands due to aliasing is still
- above the threshold set by max-alias-vops, go back to (2).
-
-\1f
-File: gccint.info, Node: Loop Analysis and Representation, Next: Machine Desc, Prev: Control Flow, Up: Top
-
-14 Analysis and Representation of Loops
-***************************************
-
-GCC provides extensive infrastructure for work with natural loops, i.e.,
-strongly connected components of CFG with only one entry block. This
-chapter describes representation of loops in GCC, both on GIMPLE and in
-RTL, as well as the interfaces to loop-related analyses (induction
-variable analysis and number of iterations analysis).
-
-* Menu:
-
-* Loop representation:: Representation and analysis of loops.
-* Loop querying:: Getting information about loops.
-* Loop manipulation:: Loop manipulation functions.
-* LCSSA:: Loop-closed SSA form.
-* Scalar evolutions:: Induction variables on GIMPLE.
-* loop-iv:: Induction variables on RTL.
-* Number of iterations:: Number of iterations analysis.
-* Dependency analysis:: Data dependency analysis.
-* Lambda:: Linear loop transformations framework.
-* Omega:: A solver for linear programming problems.
-
-\1f
-File: gccint.info, Node: Loop representation, Next: Loop querying, Up: Loop Analysis and Representation
-
-14.1 Loop representation
-========================
-
-This chapter describes the representation of loops in GCC, and functions
-that can be used to build, modify and analyze this representation. Most
-of the interfaces and data structures are declared in `cfgloop.h'. At
-the moment, loop structures are analyzed and this information is
-updated only by the optimization passes that deal with loops, but some
-efforts are being made to make it available throughout most of the
-optimization passes.
-
- In general, a natural loop has one entry block (header) and possibly
-several back edges (latches) leading to the header from the inside of
-the loop. Loops with several latches may appear if several loops share
-a single header, or if there is a branching in the middle of the loop.
-The representation of loops in GCC however allows only loops with a
-single latch. During loop analysis, headers of such loops are split and
-forwarder blocks are created in order to disambiguate their structures.
-Heuristic based on profile information and structure of the induction
-variables in the loops is used to determine whether the latches
-correspond to sub-loops or to control flow in a single loop. This means
-that the analysis sometimes changes the CFG, and if you run it in the
-middle of an optimization pass, you must be able to deal with the new
-blocks. You may avoid CFG changes by passing
-`LOOPS_MAY_HAVE_MULTIPLE_LATCHES' flag to the loop discovery, note
-however that most other loop manipulation functions will not work
-correctly for loops with multiple latch edges (the functions that only
-query membership of blocks to loops and subloop relationships, or
-enumerate and test loop exits, can be expected to work).
-
- Body of the loop is the set of blocks that are dominated by its header,
-and reachable from its latch against the direction of edges in CFG. The
-loops are organized in a containment hierarchy (tree) such that all the
-loops immediately contained inside loop L are the children of L in the
-tree. This tree is represented by the `struct loops' structure. The
-root of this tree is a fake loop that contains all blocks in the
-function. Each of the loops is represented in a `struct loop'
-structure. Each loop is assigned an index (`num' field of the `struct
-loop' structure), and the pointer to the loop is stored in the
-corresponding field of the `larray' vector in the loops structure. The
-indices do not have to be continuous, there may be empty (`NULL')
-entries in the `larray' created by deleting loops. Also, there is no
-guarantee on the relative order of a loop and its subloops in the
-numbering. The index of a loop never changes.
-
- The entries of the `larray' field should not be accessed directly.
-The function `get_loop' returns the loop description for a loop with
-the given index. `number_of_loops' function returns number of loops in
-the function. To traverse all loops, use `FOR_EACH_LOOP' macro. The
-`flags' argument of the macro is used to determine the direction of
-traversal and the set of loops visited. Each loop is guaranteed to be
-visited exactly once, regardless of the changes to the loop tree, and
-the loops may be removed during the traversal. The newly created loops
-are never traversed, if they need to be visited, this must be done
-separately after their creation. The `FOR_EACH_LOOP' macro allocates
-temporary variables. If the `FOR_EACH_LOOP' loop were ended using
-break or goto, they would not be released; `FOR_EACH_LOOP_BREAK' macro
-must be used instead.
-
- Each basic block contains the reference to the innermost loop it
-belongs to (`loop_father'). For this reason, it is only possible to
-have one `struct loops' structure initialized at the same time for each
-CFG. The global variable `current_loops' contains the `struct loops'
-structure. Many of the loop manipulation functions assume that
-dominance information is up-to-date.
-
- The loops are analyzed through `loop_optimizer_init' function. The
-argument of this function is a set of flags represented in an integer
-bitmask. These flags specify what other properties of the loop
-structures should be calculated/enforced and preserved later:
-
- * `LOOPS_MAY_HAVE_MULTIPLE_LATCHES': If this flag is set, no changes
- to CFG will be performed in the loop analysis, in particular,
- loops with multiple latch edges will not be disambiguated. If a
- loop has multiple latches, its latch block is set to NULL. Most of
- the loop manipulation functions will not work for loops in this
- shape. No other flags that require CFG changes can be passed to
- loop_optimizer_init.
-
- * `LOOPS_HAVE_PREHEADERS': Forwarder blocks are created in such a
- way that each loop has only one entry edge, and additionally, the
- source block of this entry edge has only one successor. This
- creates a natural place where the code can be moved out of the
- loop, and ensures that the entry edge of the loop leads from its
- immediate super-loop.
-
- * `LOOPS_HAVE_SIMPLE_LATCHES': Forwarder blocks are created to force
- the latch block of each loop to have only one successor. This
- ensures that the latch of the loop does not belong to any of its
- sub-loops, and makes manipulation with the loops significantly
- easier. Most of the loop manipulation functions assume that the
- loops are in this shape. Note that with this flag, the "normal"
- loop without any control flow inside and with one exit consists of
- two basic blocks.
-
- * `LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS': Basic blocks and edges in
- the strongly connected components that are not natural loops (have
- more than one entry block) are marked with `BB_IRREDUCIBLE_LOOP'
- and `EDGE_IRREDUCIBLE_LOOP' flags. The flag is not set for blocks
- and edges that belong to natural loops that are in such an
- irreducible region (but it is set for the entry and exit edges of
- such a loop, if they lead to/from this region).
-
- * `LOOPS_HAVE_RECORDED_EXITS': The lists of exits are recorded and
- updated for each loop. This makes some functions (e.g.,
- `get_loop_exit_edges') more efficient. Some functions (e.g.,
- `single_exit') can be used only if the lists of exits are recorded.
-
- These properties may also be computed/enforced later, using functions
-`create_preheaders', `force_single_succ_latches',
-`mark_irreducible_loops' and `record_loop_exits'.
-
- The memory occupied by the loops structures should be freed with
-`loop_optimizer_finalize' function.
-
- The CFG manipulation functions in general do not update loop
-structures. Specialized versions that additionally do so are provided
-for the most common tasks. On GIMPLE, `cleanup_tree_cfg_loop' function
-can be used to cleanup CFG while updating the loops structures if
-`current_loops' is set.
-
-\1f
-File: gccint.info, Node: Loop querying, Next: Loop manipulation, Prev: Loop representation, Up: Loop Analysis and Representation
-
-14.2 Loop querying
-==================
-
-The functions to query the information about loops are declared in
-`cfgloop.h'. Some of the information can be taken directly from the
-structures. `loop_father' field of each basic block contains the
-innermost loop to that the block belongs. The most useful fields of
-loop structure (that are kept up-to-date at all times) are:
-
- * `header', `latch': Header and latch basic blocks of the loop.
-
- * `num_nodes': Number of basic blocks in the loop (including the
- basic blocks of the sub-loops).
-
- * `depth': The depth of the loop in the loops tree, i.e., the number
- of super-loops of the loop.
-
- * `outer', `inner', `next': The super-loop, the first sub-loop, and
- the sibling of the loop in the loops tree.
-
- There are other fields in the loop structures, many of them used only
-by some of the passes, or not updated during CFG changes; in general,
-they should not be accessed directly.
-
- The most important functions to query loop structures are:
-
- * `flow_loops_dump': Dumps the information about loops to a file.
-
- * `verify_loop_structure': Checks consistency of the loop structures.
-
- * `loop_latch_edge': Returns the latch edge of a loop.
-
- * `loop_preheader_edge': If loops have preheaders, returns the
- preheader edge of a loop.
-
- * `flow_loop_nested_p': Tests whether loop is a sub-loop of another
- loop.
-
- * `flow_bb_inside_loop_p': Tests whether a basic block belongs to a
- loop (including its sub-loops).
-
- * `find_common_loop': Finds the common super-loop of two loops.
-
- * `superloop_at_depth': Returns the super-loop of a loop with the
- given depth.
-
- * `tree_num_loop_insns', `num_loop_insns': Estimates the number of
- insns in the loop, on GIMPLE and on RTL.
-
- * `loop_exit_edge_p': Tests whether edge is an exit from a loop.
-
- * `mark_loop_exit_edges': Marks all exit edges of all loops with
- `EDGE_LOOP_EXIT' flag.
-
- * `get_loop_body', `get_loop_body_in_dom_order',
- `get_loop_body_in_bfs_order': Enumerates the basic blocks in the
- loop in depth-first search order in reversed CFG, ordered by
- dominance relation, and breath-first search order, respectively.
-
- * `single_exit': Returns the single exit edge of the loop, or `NULL'
- if the loop has more than one exit. You can only use this
- function if LOOPS_HAVE_MARKED_SINGLE_EXITS property is used.
-
- * `get_loop_exit_edges': Enumerates the exit edges of a loop.
-
- * `just_once_each_iteration_p': Returns true if the basic block is
- executed exactly once during each iteration of a loop (that is, it
- does not belong to a sub-loop, and it dominates the latch of the
- loop).
-
-\1f
-File: gccint.info, Node: Loop manipulation, Next: LCSSA, Prev: Loop querying, Up: Loop Analysis and Representation
-
-14.3 Loop manipulation
-======================
-
-The loops tree can be manipulated using the following functions:
-
- * `flow_loop_tree_node_add': Adds a node to the tree.
-
- * `flow_loop_tree_node_remove': Removes a node from the tree.
-
- * `add_bb_to_loop': Adds a basic block to a loop.
-
- * `remove_bb_from_loops': Removes a basic block from loops.
-
- Most low-level CFG functions update loops automatically. The following
-functions handle some more complicated cases of CFG manipulations:
-
- * `remove_path': Removes an edge and all blocks it dominates.
-
- * `split_loop_exit_edge': Splits exit edge of the loop, ensuring
- that PHI node arguments remain in the loop (this ensures that
- loop-closed SSA form is preserved). Only useful on GIMPLE.
-
- Finally, there are some higher-level loop transformations implemented.
-While some of them are written so that they should work on non-innermost
-loops, they are mostly untested in that case, and at the moment, they
-are only reliable for the innermost loops:
-
- * `create_iv': Creates a new induction variable. Only works on
- GIMPLE. `standard_iv_increment_position' can be used to find a
- suitable place for the iv increment.
-
- * `duplicate_loop_to_header_edge',
- `tree_duplicate_loop_to_header_edge': These functions (on RTL and
- on GIMPLE) duplicate the body of the loop prescribed number of
- times on one of the edges entering loop header, thus performing
- either loop unrolling or loop peeling. `can_duplicate_loop_p'
- (`can_unroll_loop_p' on GIMPLE) must be true for the duplicated
- loop.
-
- * `loop_version', `tree_ssa_loop_version': These function create a
- copy of a loop, and a branch before them that selects one of them
- depending on the prescribed condition. This is useful for
- optimizations that need to verify some assumptions in runtime (one
- of the copies of the loop is usually left unchanged, while the
- other one is transformed in some way).
-
- * `tree_unroll_loop': Unrolls the loop, including peeling the extra
- iterations to make the number of iterations divisible by unroll
- factor, updating the exit condition, and removing the exits that
- now cannot be taken. Works only on GIMPLE.
-
-\1f
-File: gccint.info, Node: LCSSA, Next: Scalar evolutions, Prev: Loop manipulation, Up: Loop Analysis and Representation
-
-14.4 Loop-closed SSA form
-=========================
-
-Throughout the loop optimizations on tree level, one extra condition is
-enforced on the SSA form: No SSA name is used outside of the loop in
-that it is defined. The SSA form satisfying this condition is called
-"loop-closed SSA form" - LCSSA. To enforce LCSSA, PHI nodes must be
-created at the exits of the loops for the SSA names that are used
-outside of them. Only the real operands (not virtual SSA names) are
-held in LCSSA, in order to save memory.
-
- There are various benefits of LCSSA:
-
- * Many optimizations (value range analysis, final value replacement)
- are interested in the values that are defined in the loop and used
- outside of it, i.e., exactly those for that we create new PHI
- nodes.
-
- * In induction variable analysis, it is not necessary to specify the
- loop in that the analysis should be performed - the scalar
- evolution analysis always returns the results with respect to the
- loop in that the SSA name is defined.
-
- * It makes updating of SSA form during loop transformations simpler.
- Without LCSSA, operations like loop unrolling may force creation
- of PHI nodes arbitrarily far from the loop, while in LCSSA, the
- SSA form can be updated locally. However, since we only keep real
- operands in LCSSA, we cannot use this advantage (we could have
- local updating of real operands, but it is not much more efficient
- than to use generic SSA form updating for it as well; the amount
- of changes to SSA is the same).
-
- However, it also means LCSSA must be updated. This is usually
-straightforward, unless you create a new value in loop and use it
-outside, or unless you manipulate loop exit edges (functions are
-provided to make these manipulations simple).
-`rewrite_into_loop_closed_ssa' is used to rewrite SSA form to LCSSA,
-and `verify_loop_closed_ssa' to check that the invariant of LCSSA is
-preserved.
-
-\1f
-File: gccint.info, Node: Scalar evolutions, Next: loop-iv, Prev: LCSSA, Up: Loop Analysis and Representation
-
-14.5 Scalar evolutions
-======================
-
-Scalar evolutions (SCEV) are used to represent results of induction
-variable analysis on GIMPLE. They enable us to represent variables with
-complicated behavior in a simple and consistent way (we only use it to
-express values of polynomial induction variables, but it is possible to
-extend it). The interfaces to SCEV analysis are declared in
-`tree-scalar-evolution.h'. To use scalar evolutions analysis,
-`scev_initialize' must be used. To stop using SCEV, `scev_finalize'
-should be used. SCEV analysis caches results in order to save time and
-memory. This cache however is made invalid by most of the loop
-transformations, including removal of code. If such a transformation
-is performed, `scev_reset' must be called to clean the caches.
-
- Given an SSA name, its behavior in loops can be analyzed using the
-`analyze_scalar_evolution' function. The returned SCEV however does
-not have to be fully analyzed and it may contain references to other
-SSA names defined in the loop. To resolve these (potentially
-recursive) references, `instantiate_parameters' or `resolve_mixers'
-functions must be used. `instantiate_parameters' is useful when you
-use the results of SCEV only for some analysis, and when you work with
-whole nest of loops at once. It will try replacing all SSA names by
-their SCEV in all loops, including the super-loops of the current loop,
-thus providing a complete information about the behavior of the
-variable in the loop nest. `resolve_mixers' is useful if you work with
-only one loop at a time, and if you possibly need to create code based
-on the value of the induction variable. It will only resolve the SSA
-names defined in the current loop, leaving the SSA names defined
-outside unchanged, even if their evolution in the outer loops is known.
-
- The SCEV is a normal tree expression, except for the fact that it may
-contain several special tree nodes. One of them is `SCEV_NOT_KNOWN',
-used for SSA names whose value cannot be expressed. The other one is
-`POLYNOMIAL_CHREC'. Polynomial chrec has three arguments - base, step
-and loop (both base and step may contain further polynomial chrecs).
-Type of the expression and of base and step must be the same. A
-variable has evolution `POLYNOMIAL_CHREC(base, step, loop)' if it is
-(in the specified loop) equivalent to `x_1' in the following example
-
- while (...)
- {
- x_1 = phi (base, x_2);
- x_2 = x_1 + step;
- }
-
- Note that this includes the language restrictions on the operations.
-For example, if we compile C code and `x' has signed type, then the
-overflow in addition would cause undefined behavior, and we may assume
-that this does not happen. Hence, the value with this SCEV cannot
-overflow (which restricts the number of iterations of such a loop).
-
- In many cases, one wants to restrict the attention just to affine
-induction variables. In this case, the extra expressive power of SCEV
-is not useful, and may complicate the optimizations. In this case,
-`simple_iv' function may be used to analyze a value - the result is a
-loop-invariant base and step.
-
-\1f
-File: gccint.info, Node: loop-iv, Next: Number of iterations, Prev: Scalar evolutions, Up: Loop Analysis and Representation
-
-14.6 IV analysis on RTL
-=======================
-
-The induction variable on RTL is simple and only allows analysis of
-affine induction variables, and only in one loop at once. The interface
-is declared in `cfgloop.h'. Before analyzing induction variables in a
-loop L, `iv_analysis_loop_init' function must be called on L. After
-the analysis (possibly calling `iv_analysis_loop_init' for several
-loops) is finished, `iv_analysis_done' should be called. The following
-functions can be used to access the results of the analysis:
-
- * `iv_analyze': Analyzes a single register used in the given insn.
- If no use of the register in this insn is found, the following
- insns are scanned, so that this function can be called on the insn
- returned by get_condition.
-
- * `iv_analyze_result': Analyzes result of the assignment in the
- given insn.
-
- * `iv_analyze_expr': Analyzes a more complicated expression. All
- its operands are analyzed by `iv_analyze', and hence they must be
- used in the specified insn or one of the following insns.
-
- The description of the induction variable is provided in `struct
-rtx_iv'. In order to handle subregs, the representation is a bit
-complicated; if the value of the `extend' field is not `UNKNOWN', the
-value of the induction variable in the i-th iteration is
-
- delta + mult * extend_{extend_mode} (subreg_{mode} (base + i * step)),
-
- with the following exception: if `first_special' is true, then the
-value in the first iteration (when `i' is zero) is `delta + mult *
-base'. However, if `extend' is equal to `UNKNOWN', then
-`first_special' must be false, `delta' 0, `mult' 1 and the value in the
-i-th iteration is
-
- subreg_{mode} (base + i * step)
-
- The function `get_iv_value' can be used to perform these calculations.
-
-\1f
-File: gccint.info, Node: Number of iterations, Next: Dependency analysis, Prev: loop-iv, Up: Loop Analysis and Representation
-
-14.7 Number of iterations analysis
-==================================
-
-Both on GIMPLE and on RTL, there are functions available to determine
-the number of iterations of a loop, with a similar interface. The
-number of iterations of a loop in GCC is defined as the number of
-executions of the loop latch. In many cases, it is not possible to
-determine the number of iterations unconditionally - the determined
-number is correct only if some assumptions are satisfied. The analysis
-tries to verify these conditions using the information contained in the
-program; if it fails, the conditions are returned together with the
-result. The following information and conditions are provided by the
-analysis:
-
- * `assumptions': If this condition is false, the rest of the
- information is invalid.
-
- * `noloop_assumptions' on RTL, `may_be_zero' on GIMPLE: If this
- condition is true, the loop exits in the first iteration.
-
- * `infinite': If this condition is true, the loop is infinite. This
- condition is only available on RTL. On GIMPLE, conditions for
- finiteness of the loop are included in `assumptions'.
-
- * `niter_expr' on RTL, `niter' on GIMPLE: The expression that gives
- number of iterations. The number of iterations is defined as the
- number of executions of the loop latch.
-
- Both on GIMPLE and on RTL, it necessary for the induction variable
-analysis framework to be initialized (SCEV on GIMPLE, loop-iv on RTL).
-On GIMPLE, the results are stored to `struct tree_niter_desc'
-structure. Number of iterations before the loop is exited through a
-given exit can be determined using `number_of_iterations_exit'
-function. On RTL, the results are returned in `struct niter_desc'
-structure. The corresponding function is named `check_simple_exit'.
-There are also functions that pass through all the exits of a loop and
-try to find one with easy to determine number of iterations -
-`find_loop_niter' on GIMPLE and `find_simple_exit' on RTL. Finally,
-there are functions that provide the same information, but additionally
-cache it, so that repeated calls to number of iterations are not so
-costly - `number_of_latch_executions' on GIMPLE and
-`get_simple_loop_desc' on RTL.
-
- Note that some of these functions may behave slightly differently than
-others - some of them return only the expression for the number of
-iterations, and fail if there are some assumptions. The function
-`number_of_latch_executions' works only for single-exit loops. The
-function `number_of_cond_exit_executions' can be used to determine
-number of executions of the exit condition of a single-exit loop (i.e.,
-the `number_of_latch_executions' increased by one).
-
-\1f
-File: gccint.info, Node: Dependency analysis, Next: Lambda, Prev: Number of iterations, Up: Loop Analysis and Representation
-
-14.8 Data Dependency Analysis
-=============================
-
-The code for the data dependence analysis can be found in
-`tree-data-ref.c' and its interface and data structures are described
-in `tree-data-ref.h'. The function that computes the data dependences
-for all the array and pointer references for a given loop is
-`compute_data_dependences_for_loop'. This function is currently used
-by the linear loop transform and the vectorization passes. Before
-calling this function, one has to allocate two vectors: a first vector
-will contain the set of data references that are contained in the
-analyzed loop body, and the second vector will contain the dependence
-relations between the data references. Thus if the vector of data
-references is of size `n', the vector containing the dependence
-relations will contain `n*n' elements. However if the analyzed loop
-contains side effects, such as calls that potentially can interfere
-with the data references in the current analyzed loop, the analysis
-stops while scanning the loop body for data references, and inserts a
-single `chrec_dont_know' in the dependence relation array.
-
- The data references are discovered in a particular order during the
-scanning of the loop body: the loop body is analyzed in execution order,
-and the data references of each statement are pushed at the end of the
-data reference array. Two data references syntactically occur in the
-program in the same order as in the array of data references. This
-syntactic order is important in some classical data dependence tests,
-and mapping this order to the elements of this array avoids costly
-queries to the loop body representation.
-
- Three types of data references are currently handled: ARRAY_REF,
-INDIRECT_REF and COMPONENT_REF. The data structure for the data
-reference is `data_reference', where `data_reference_p' is a name of a
-pointer to the data reference structure. The structure contains the
-following elements:
-
- * `base_object_info': Provides information about the base object of
- the data reference and its access functions. These access functions
- represent the evolution of the data reference in the loop relative
- to its base, in keeping with the classical meaning of the data
- reference access function for the support of arrays. For example,
- for a reference `a.b[i][j]', the base object is `a.b' and the
- access functions, one for each array subscript, are: `{i_init, +
- i_step}_1, {j_init, +, j_step}_2'.
-
- * `first_location_in_loop': Provides information about the first
- location accessed by the data reference in the loop and about the
- access function used to represent evolution relative to this
- location. This data is used to support pointers, and is not used
- for arrays (for which we have base objects). Pointer accesses are
- represented as a one-dimensional access that starts from the first
- location accessed in the loop. For example:
-
- for1 i
- for2 j
- *((int *)p + i + j) = a[i][j];
-
- The access function of the pointer access is `{0, + 4B}_for2'
- relative to `p + i'. The access functions of the array are
- `{i_init, + i_step}_for1' and `{j_init, +, j_step}_for2' relative
- to `a'.
-
- Usually, the object the pointer refers to is either unknown, or we
- can't prove that the access is confined to the boundaries of a
- certain object.
-
- Two data references can be compared only if at least one of these
- two representations has all its fields filled for both data
- references.
-
- The current strategy for data dependence tests is as follows: If
- both `a' and `b' are represented as arrays, compare
- `a.base_object' and `b.base_object'; if they are equal, apply
- dependence tests (use access functions based on base_objects).
- Else if both `a' and `b' are represented as pointers, compare
- `a.first_location' and `b.first_location'; if they are equal,
- apply dependence tests (use access functions based on first
- location). However, if `a' and `b' are represented differently,
- only try to prove that the bases are definitely different.
-
- * Aliasing information.
-
- * Alignment information.
-
- The structure describing the relation between two data references is
-`data_dependence_relation' and the shorter name for a pointer to such a
-structure is `ddr_p'. This structure contains:
-
- * a pointer to each data reference,
-
- * a tree node `are_dependent' that is set to `chrec_known' if the
- analysis has proved that there is no dependence between these two
- data references, `chrec_dont_know' if the analysis was not able to
- determine any useful result and potentially there could exist a
- dependence between these data references, and `are_dependent' is
- set to `NULL_TREE' if there exist a dependence relation between the
- data references, and the description of this dependence relation is
- given in the `subscripts', `dir_vects', and `dist_vects' arrays,
-
- * a boolean that determines whether the dependence relation can be
- represented by a classical distance vector,
-
- * an array `subscripts' that contains a description of each
- subscript of the data references. Given two array accesses a
- subscript is the tuple composed of the access functions for a given
- dimension. For example, given `A[f1][f2][f3]' and
- `B[g1][g2][g3]', there are three subscripts: `(f1, g1), (f2, g2),
- (f3, g3)'.
-
- * two arrays `dir_vects' and `dist_vects' that contain classical
- representations of the data dependences under the form of
- direction and distance dependence vectors,
-
- * an array of loops `loop_nest' that contains the loops to which the
- distance and direction vectors refer to.
-
- Several functions for pretty printing the information extracted by the
-data dependence analysis are available: `dump_ddrs' prints with a
-maximum verbosity the details of a data dependence relations array,
-`dump_dist_dir_vectors' prints only the classical distance and
-direction vectors for a data dependence relations array, and
-`dump_data_references' prints the details of the data references
-contained in a data reference array.
-
-\1f
-File: gccint.info, Node: Lambda, Next: Omega, Prev: Dependency analysis, Up: Loop Analysis and Representation
-
-14.9 Linear loop transformations framework
-==========================================
-
-Lambda is a framework that allows transformations of loops using
-non-singular matrix based transformations of the iteration space and
-loop bounds. This allows compositions of skewing, scaling, interchange,
-and reversal transformations. These transformations are often used to
-improve cache behavior or remove inner loop dependencies to allow
-parallelization and vectorization to take place.
-
- To perform these transformations, Lambda requires that the loopnest be
-converted into a internal form that can be matrix transformed easily.
-To do this conversion, the function `gcc_loopnest_to_lambda_loopnest'
-is provided. If the loop cannot be transformed using lambda, this
-function will return NULL.
-
- Once a `lambda_loopnest' is obtained from the conversion function, it
-can be transformed by using `lambda_loopnest_transform', which takes a
-transformation matrix to apply. Note that it is up to the caller to
-verify that the transformation matrix is legal to apply to the loop
-(dependence respecting, etc). Lambda simply applies whatever matrix it
-is told to provide. It can be extended to make legal matrices out of
-any non-singular matrix, but this is not currently implemented.
-Legality of a matrix for a given loopnest can be verified using
-`lambda_transform_legal_p'.
-
- Given a transformed loopnest, conversion back into gcc IR is done by
-`lambda_loopnest_to_gcc_loopnest'. This function will modify the loops
-so that they match the transformed loopnest.
-
-\1f
-File: gccint.info, Node: Omega, Prev: Lambda, Up: Loop Analysis and Representation
-
-14.10 Omega a solver for linear programming problems
-====================================================
-
-The data dependence analysis contains several solvers triggered
-sequentially from the less complex ones to the more sophisticated. For
-ensuring the consistency of the results of these solvers, a data
-dependence check pass has been implemented based on two different
-solvers. The second method that has been integrated to GCC is based on
-the Omega dependence solver, written in the 1990's by William Pugh and
-David Wonnacott. Data dependence tests can be formulated using a
-subset of the Presburger arithmetics that can be translated to linear
-constraint systems. These linear constraint systems can then be solved
-using the Omega solver.
-
- The Omega solver is using Fourier-Motzkin's algorithm for variable
-elimination: a linear constraint system containing `n' variables is
-reduced to a linear constraint system with `n-1' variables. The Omega
-solver can also be used for solving other problems that can be
-expressed under the form of a system of linear equalities and
-inequalities. The Omega solver is known to have an exponential worst
-case, also known under the name of "omega nightmare" in the literature,
-but in practice, the omega test is known to be efficient for the common
-data dependence tests.
-
- The interface used by the Omega solver for describing the linear
-programming problems is described in `omega.h', and the solver is
-`omega_solve_problem'.
-
-\1f
-File: gccint.info, Node: Control Flow, Next: Loop Analysis and Representation, Prev: RTL, Up: Top
-
-15 Control Flow Graph
-*********************
-
-A control flow graph (CFG) is a data structure built on top of the
-intermediate code representation (the RTL or `tree' instruction stream)
-abstracting the control flow behavior of a function that is being
-compiled. The CFG is a directed graph where the vertices represent
-basic blocks and edges represent possible transfer of control flow from
-one basic block to another. The data structures used to represent the
-control flow graph are defined in `basic-block.h'.
-
-* Menu:
-
-* Basic Blocks:: The definition and representation of basic blocks.
-* Edges:: Types of edges and their representation.
-* Profile information:: Representation of frequencies and probabilities.
-* Maintaining the CFG:: Keeping the control flow graph and up to date.
-* Liveness information:: Using and maintaining liveness information.
-
-\1f
-File: gccint.info, Node: Basic Blocks, Next: Edges, Up: Control Flow
-
-15.1 Basic Blocks
-=================
-
-A basic block is a straight-line sequence of code with only one entry
-point and only one exit. In GCC, basic blocks are represented using
-the `basic_block' data type.
-
- Two pointer members of the `basic_block' structure are the pointers
-`next_bb' and `prev_bb'. These are used to keep doubly linked chain of
-basic blocks in the same order as the underlying instruction stream.
-The chain of basic blocks is updated transparently by the provided API
-for manipulating the CFG. The macro `FOR_EACH_BB' can be used to visit
-all the basic blocks in lexicographical order. Dominator traversals
-are also possible using `walk_dominator_tree'. Given two basic blocks
-A and B, block A dominates block B if A is _always_ executed before B.
-
- The `BASIC_BLOCK' array contains all basic blocks in an unspecified
-order. Each `basic_block' structure has a field that holds a unique
-integer identifier `index' that is the index of the block in the
-`BASIC_BLOCK' array. The total number of basic blocks in the function
-is `n_basic_blocks'. Both the basic block indices and the total number
-of basic blocks may vary during the compilation process, as passes
-reorder, create, duplicate, and destroy basic blocks. The index for
-any block should never be greater than `last_basic_block'.
-
- Special basic blocks represent possible entry and exit points of a
-function. These blocks are called `ENTRY_BLOCK_PTR' and
-`EXIT_BLOCK_PTR'. These blocks do not contain any code, and are not
-elements of the `BASIC_BLOCK' array. Therefore they have been assigned
-unique, negative index numbers.
-
- Each `basic_block' also contains pointers to the first instruction
-(the "head") and the last instruction (the "tail") or "end" of the
-instruction stream contained in a basic block. In fact, since the
-`basic_block' data type is used to represent blocks in both major
-intermediate representations of GCC (`tree' and RTL), there are
-pointers to the head and end of a basic block for both representations.
-
- For RTL, these pointers are `rtx head, end'. In the RTL function
-representation, the head pointer always points either to a
-`NOTE_INSN_BASIC_BLOCK' or to a `CODE_LABEL', if present. In the RTL
-representation of a function, the instruction stream contains not only
-the "real" instructions, but also "notes". Any function that moves or
-duplicates the basic blocks needs to take care of updating of these
-notes. Many of these notes expect that the instruction stream consists
-of linear regions, making such updates difficult. The
-`NOTE_INSN_BASIC_BLOCK' note is the only kind of note that may appear
-in the instruction stream contained in a basic block. The instruction
-stream of a basic block always follows a `NOTE_INSN_BASIC_BLOCK', but
-zero or more `CODE_LABEL' nodes can precede the block note. A basic
-block ends by control flow instruction or last instruction before
-following `CODE_LABEL' or `NOTE_INSN_BASIC_BLOCK'. A `CODE_LABEL'
-cannot appear in the instruction stream of a basic block.
-
- In addition to notes, the jump table vectors are also represented as
-"pseudo-instructions" inside the insn stream. These vectors never
-appear in the basic block and should always be placed just after the
-table jump instructions referencing them. After removing the
-table-jump it is often difficult to eliminate the code computing the
-address and referencing the vector, so cleaning up these vectors is
-postponed until after liveness analysis. Thus the jump table vectors
-may appear in the insn stream unreferenced and without any purpose.
-Before any edge is made "fall-thru", the existence of such construct in
-the way needs to be checked by calling `can_fallthru' function.
-
- For the `tree' representation, the head and end of the basic block are
-being pointed to by the `stmt_list' field, but this special `tree'
-should never be referenced directly. Instead, at the tree level
-abstract containers and iterators are used to access statements and
-expressions in basic blocks. These iterators are called "block
-statement iterators" (BSIs). Grep for `^bsi' in the various `tree-*'
-files. The following snippet will pretty-print all the statements of
-the program in the GIMPLE representation.
-
- FOR_EACH_BB (bb)
- {
- block_stmt_iterator si;
-
- for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si))
- {
- tree stmt = bsi_stmt (si);
- print_generic_stmt (stderr, stmt, 0);
- }
- }
-
-\1f
-File: gccint.info, Node: Edges, Next: Profile information, Prev: Basic Blocks, Up: Control Flow
-
-15.2 Edges
-==========
-
-Edges represent possible control flow transfers from the end of some
-basic block A to the head of another basic block B. We say that A is a
-predecessor of B, and B is a successor of A. Edges are represented in
-GCC with the `edge' data type. Each `edge' acts as a link between two
-basic blocks: the `src' member of an edge points to the predecessor
-basic block of the `dest' basic block. The members `preds' and `succs'
-of the `basic_block' data type point to type-safe vectors of edges to
-the predecessors and successors of the block.
-
- When walking the edges in an edge vector, "edge iterators" should be
-used. Edge iterators are constructed using the `edge_iterator' data
-structure and several methods are available to operate on them:
-
-`ei_start'
- This function initializes an `edge_iterator' that points to the
- first edge in a vector of edges.
-
-`ei_last'
- This function initializes an `edge_iterator' that points to the
- last edge in a vector of edges.
-
-`ei_end_p'
- This predicate is `true' if an `edge_iterator' represents the last
- edge in an edge vector.
-
-`ei_one_before_end_p'
- This predicate is `true' if an `edge_iterator' represents the
- second last edge in an edge vector.
-
-`ei_next'
- This function takes a pointer to an `edge_iterator' and makes it
- point to the next edge in the sequence.
-
-`ei_prev'
- This function takes a pointer to an `edge_iterator' and makes it
- point to the previous edge in the sequence.
-
-`ei_edge'
- This function returns the `edge' currently pointed to by an
- `edge_iterator'.
-
-`ei_safe_safe'
- This function returns the `edge' currently pointed to by an
- `edge_iterator', but returns `NULL' if the iterator is pointing at
- the end of the sequence. This function has been provided for
- existing code makes the assumption that a `NULL' edge indicates
- the end of the sequence.
-
-
- The convenience macro `FOR_EACH_EDGE' can be used to visit all of the
-edges in a sequence of predecessor or successor edges. It must not be
-used when an element might be removed during the traversal, otherwise
-elements will be missed. Here is an example of how to use the macro:
-
- edge e;
- edge_iterator ei;
-
- FOR_EACH_EDGE (e, ei, bb->succs)
- {
- if (e->flags & EDGE_FALLTHRU)
- break;
- }
-
- There are various reasons why control flow may transfer from one block
-to another. One possibility is that some instruction, for example a
-`CODE_LABEL', in a linearized instruction stream just always starts a
-new basic block. In this case a "fall-thru" edge links the basic block
-to the first following basic block. But there are several other
-reasons why edges may be created. The `flags' field of the `edge' data
-type is used to store information about the type of edge we are dealing
-with. Each edge is of one of the following types:
-
-_jump_
- No type flags are set for edges corresponding to jump instructions.
- These edges are used for unconditional or conditional jumps and in
- RTL also for table jumps. They are the easiest to manipulate as
- they may be freely redirected when the flow graph is not in SSA
- form.
-
-_fall-thru_
- Fall-thru edges are present in case where the basic block may
- continue execution to the following one without branching. These
- edges have the `EDGE_FALLTHRU' flag set. Unlike other types of
- edges, these edges must come into the basic block immediately
- following in the instruction stream. The function
- `force_nonfallthru' is available to insert an unconditional jump
- in the case that redirection is needed. Note that this may
- require creation of a new basic block.
-
-_exception handling_
- Exception handling edges represent possible control transfers from
- a trapping instruction to an exception handler. The definition of
- "trapping" varies. In C++, only function calls can throw, but for
- Java, exceptions like division by zero or segmentation fault are
- defined and thus each instruction possibly throwing this kind of
- exception needs to be handled as control flow instruction.
- Exception edges have the `EDGE_ABNORMAL' and `EDGE_EH' flags set.
-
- When updating the instruction stream it is easy to change possibly
- trapping instruction to non-trapping, by simply removing the
- exception edge. The opposite conversion is difficult, but should
- not happen anyway. The edges can be eliminated via
- `purge_dead_edges' call.
-
- In the RTL representation, the destination of an exception edge is
- specified by `REG_EH_REGION' note attached to the insn. In case
- of a trapping call the `EDGE_ABNORMAL_CALL' flag is set too. In
- the `tree' representation, this extra flag is not set.
-
- In the RTL representation, the predicate `may_trap_p' may be used
- to check whether instruction still may trap or not. For the tree
- representation, the `tree_could_trap_p' predicate is available,
- but this predicate only checks for possible memory traps, as in
- dereferencing an invalid pointer location.
-
-_sibling calls_
- Sibling calls or tail calls terminate the function in a
- non-standard way and thus an edge to the exit must be present.
- `EDGE_SIBCALL' and `EDGE_ABNORMAL' are set in such case. These
- edges only exist in the RTL representation.
-
-_computed jumps_
- Computed jumps contain edges to all labels in the function
- referenced from the code. All those edges have `EDGE_ABNORMAL'
- flag set. The edges used to represent computed jumps often cause
- compile time performance problems, since functions consisting of
- many taken labels and many computed jumps may have _very_ dense
- flow graphs, so these edges need to be handled with special care.
- During the earlier stages of the compilation process, GCC tries to
- avoid such dense flow graphs by factoring computed jumps. For
- example, given the following series of jumps,
-
- goto *x;
- [ ... ]
-
- goto *x;
- [ ... ]
-
- goto *x;
- [ ... ]
-
- factoring the computed jumps results in the following code sequence
- which has a much simpler flow graph:
-
- goto y;
- [ ... ]
-
- goto y;
- [ ... ]
-
- goto y;
- [ ... ]
-
- y:
- goto *x;
-
- However, the classic problem with this transformation is that it
- has a runtime cost in there resulting code: An extra jump.
- Therefore, the computed jumps are un-factored in the later passes
- of the compiler. Be aware of that when you work on passes in that
- area. There have been numerous examples already where the compile
- time for code with unfactored computed jumps caused some serious
- headaches.
-
-_nonlocal goto handlers_
- GCC allows nested functions to return into caller using a `goto'
- to a label passed to as an argument to the callee. The labels
- passed to nested functions contain special code to cleanup after
- function call. Such sections of code are referred to as "nonlocal
- goto receivers". If a function contains such nonlocal goto
- receivers, an edge from the call to the label is created with the
- `EDGE_ABNORMAL' and `EDGE_ABNORMAL_CALL' flags set.
-
-_function entry points_
- By definition, execution of function starts at basic block 0, so
- there is always an edge from the `ENTRY_BLOCK_PTR' to basic block
- 0. There is no `tree' representation for alternate entry points at
- this moment. In RTL, alternate entry points are specified by
- `CODE_LABEL' with `LABEL_ALTERNATE_NAME' defined. This feature is
- currently used for multiple entry point prologues and is limited
- to post-reload passes only. This can be used by back-ends to emit
- alternate prologues for functions called from different contexts.
- In future full support for multiple entry functions defined by
- Fortran 90 needs to be implemented.
-
-_function exits_
- In the pre-reload representation a function terminates after the
- last instruction in the insn chain and no explicit return
- instructions are used. This corresponds to the fall-thru edge
- into exit block. After reload, optimal RTL epilogues are used
- that use explicit (conditional) return instructions that are
- represented by edges with no flags set.
-
-
-\1f
-File: gccint.info, Node: Profile information, Next: Maintaining the CFG, Prev: Edges, Up: Control Flow
-
-15.3 Profile information
-========================
-
-In many cases a compiler must make a choice whether to trade speed in
-one part of code for speed in another, or to trade code size for code
-speed. In such cases it is useful to know information about how often
-some given block will be executed. That is the purpose for maintaining
-profile within the flow graph. GCC can handle profile information
-obtained through "profile feedback", but it can also estimate branch
-probabilities based on statics and heuristics.
-
- The feedback based profile is produced by compiling the program with
-instrumentation, executing it on a train run and reading the numbers of
-executions of basic blocks and edges back to the compiler while
-re-compiling the program to produce the final executable. This method
-provides very accurate information about where a program spends most of
-its time on the train run. Whether it matches the average run of
-course depends on the choice of train data set, but several studies
-have shown that the behavior of a program usually changes just
-marginally over different data sets.
-
- When profile feedback is not available, the compiler may be asked to
-attempt to predict the behavior of each branch in the program using a
-set of heuristics (see `predict.def' for details) and compute estimated
-frequencies of each basic block by propagating the probabilities over
-the graph.
-
- Each `basic_block' contains two integer fields to represent profile
-information: `frequency' and `count'. The `frequency' is an estimation
-how often is basic block executed within a function. It is represented
-as an integer scaled in the range from 0 to `BB_FREQ_BASE'. The most
-frequently executed basic block in function is initially set to
-`BB_FREQ_BASE' and the rest of frequencies are scaled accordingly.
-During optimization, the frequency of the most frequent basic block can
-both decrease (for instance by loop unrolling) or grow (for instance by
-cross-jumping optimization), so scaling sometimes has to be performed
-multiple times.
-
- The `count' contains hard-counted numbers of execution measured during
-training runs and is nonzero only when profile feedback is available.
-This value is represented as the host's widest integer (typically a 64
-bit integer) of the special type `gcov_type'.
-
- Most optimization passes can use only the frequency information of a
-basic block, but a few passes may want to know hard execution counts.
-The frequencies should always match the counts after scaling, however
-during updating of the profile information numerical error may
-accumulate into quite large errors.
-
- Each edge also contains a branch probability field: an integer in the
-range from 0 to `REG_BR_PROB_BASE'. It represents probability of
-passing control from the end of the `src' basic block to the `dest'
-basic block, i.e. the probability that control will flow along this
-edge. The `EDGE_FREQUENCY' macro is available to compute how
-frequently a given edge is taken. There is a `count' field for each
-edge as well, representing same information as for a basic block.
-
- The basic block frequencies are not represented in the instruction
-stream, but in the RTL representation the edge frequencies are
-represented for conditional jumps (via the `REG_BR_PROB' macro) since
-they are used when instructions are output to the assembly file and the
-flow graph is no longer maintained.
-
- The probability that control flow arrives via a given edge to its
-destination basic block is called "reverse probability" and is not
-directly represented, but it may be easily computed from frequencies of
-basic blocks.
-
- Updating profile information is a delicate task that can unfortunately
-not be easily integrated with the CFG manipulation API. Many of the
-functions and hooks to modify the CFG, such as
-`redirect_edge_and_branch', do not have enough information to easily
-update the profile, so updating it is in the majority of cases left up
-to the caller. It is difficult to uncover bugs in the profile updating
-code, because they manifest themselves only by producing worse code,
-and checking profile consistency is not possible because of numeric
-error accumulation. Hence special attention needs to be given to this
-issue in each pass that modifies the CFG.
-
- It is important to point out that `REG_BR_PROB_BASE' and
-`BB_FREQ_BASE' are both set low enough to be possible to compute second
-power of any frequency or probability in the flow graph, it is not
-possible to even square the `count' field, as modern CPUs are fast
-enough to execute $2^32$ operations quickly.
-
-\1f
-File: gccint.info, Node: Maintaining the CFG, Next: Liveness information, Prev: Profile information, Up: Control Flow
-
-15.4 Maintaining the CFG
-========================
-
-An important task of each compiler pass is to keep both the control
-flow graph and all profile information up-to-date. Reconstruction of
-the control flow graph after each pass is not an option, since it may be
-very expensive and lost profile information cannot be reconstructed at
-all.
-
- GCC has two major intermediate representations, and both use the
-`basic_block' and `edge' data types to represent control flow. Both
-representations share as much of the CFG maintenance code as possible.
-For each representation, a set of "hooks" is defined so that each
-representation can provide its own implementation of CFG manipulation
-routines when necessary. These hooks are defined in `cfghooks.h'.
-There are hooks for almost all common CFG manipulations, including
-block splitting and merging, edge redirection and creating and deleting
-basic blocks. These hooks should provide everything you need to
-maintain and manipulate the CFG in both the RTL and `tree'
-representation.
-
- At the moment, the basic block boundaries are maintained transparently
-when modifying instructions, so there rarely is a need to move them
-manually (such as in case someone wants to output instruction outside
-basic block explicitly). Often the CFG may be better viewed as
-integral part of instruction chain, than structure built on the top of
-it. However, in principle the control flow graph for the `tree'
-representation is _not_ an integral part of the representation, in that
-a function tree may be expanded without first building a flow graph
-for the `tree' representation at all. This happens when compiling
-without any `tree' optimization enabled. When the `tree' optimizations
-are enabled and the instruction stream is rewritten in SSA form, the
-CFG is very tightly coupled with the instruction stream. In
-particular, statement insertion and removal has to be done with care.
-In fact, the whole `tree' representation can not be easily used or
-maintained without proper maintenance of the CFG simultaneously.
-
- In the RTL representation, each instruction has a `BLOCK_FOR_INSN'
-value that represents pointer to the basic block that contains the
-instruction. In the `tree' representation, the function `bb_for_stmt'
-returns a pointer to the basic block containing the queried statement.
-
- When changes need to be applied to a function in its `tree'
-representation, "block statement iterators" should be used. These
-iterators provide an integrated abstraction of the flow graph and the
-instruction stream. Block statement iterators are constructed using
-the `block_stmt_iterator' data structure and several modifier are
-available, including the following:
-
-`bsi_start'
- This function initializes a `block_stmt_iterator' that points to
- the first non-empty statement in a basic block.
-
-`bsi_last'
- This function initializes a `block_stmt_iterator' that points to
- the last statement in a basic block.
-
-`bsi_end_p'
- This predicate is `true' if a `block_stmt_iterator' represents the
- end of a basic block.
-
-`bsi_next'
- This function takes a `block_stmt_iterator' and makes it point to
- its successor.
-
-`bsi_prev'
- This function takes a `block_stmt_iterator' and makes it point to
- its predecessor.
-
-`bsi_insert_after'
- This function inserts a statement after the `block_stmt_iterator'
- passed in. The final parameter determines whether the statement
- iterator is updated to point to the newly inserted statement, or
- left pointing to the original statement.
-
-`bsi_insert_before'
- This function inserts a statement before the `block_stmt_iterator'
- passed in. The final parameter determines whether the statement
- iterator is updated to point to the newly inserted statement, or
- left pointing to the original statement.
-
-`bsi_remove'
- This function removes the `block_stmt_iterator' passed in and
- rechains the remaining statements in a basic block, if any.
-
- In the RTL representation, the macros `BB_HEAD' and `BB_END' may be
-used to get the head and end `rtx' of a basic block. No abstract
-iterators are defined for traversing the insn chain, but you can just
-use `NEXT_INSN' and `PREV_INSN' instead. See *Note Insns::.
-
- Usually a code manipulating pass simplifies the instruction stream and
-the flow of control, possibly eliminating some edges. This may for
-example happen when a conditional jump is replaced with an
-unconditional jump, but also when simplifying possibly trapping
-instruction to non-trapping while compiling Java. Updating of edges is
-not transparent and each optimization pass is required to do so
-manually. However only few cases occur in practice. The pass may call
-`purge_dead_edges' on a given basic block to remove superfluous edges,
-if any.
-
- Another common scenario is redirection of branch instructions, but
-this is best modeled as redirection of edges in the control flow graph
-and thus use of `redirect_edge_and_branch' is preferred over more low
-level functions, such as `redirect_jump' that operate on RTL chain
-only. The CFG hooks defined in `cfghooks.h' should provide the
-complete API required for manipulating and maintaining the CFG.
-
- It is also possible that a pass has to insert control flow instruction
-into the middle of a basic block, thus creating an entry point in the
-middle of the basic block, which is impossible by definition: The block
-must be split to make sure it only has one entry point, i.e. the head
-of the basic block. The CFG hook `split_block' may be used when an
-instruction in the middle of a basic block has to become the target of
-a jump or branch instruction.
-
- For a global optimizer, a common operation is to split edges in the
-flow graph and insert instructions on them. In the RTL representation,
-this can be easily done using the `insert_insn_on_edge' function that
-emits an instruction "on the edge", caching it for a later
-`commit_edge_insertions' call that will take care of moving the
-inserted instructions off the edge into the instruction stream
-contained in a basic block. This includes the creation of new basic
-blocks where needed. In the `tree' representation, the equivalent
-functions are `bsi_insert_on_edge' which inserts a block statement
-iterator on an edge, and `bsi_commit_edge_inserts' which flushes the
-instruction to actual instruction stream.
-
- While debugging the optimization pass, an `verify_flow_info' function
-may be useful to find bugs in the control flow graph updating code.
-
- Note that at present, the representation of control flow in the `tree'
-representation is discarded before expanding to RTL. Long term the CFG
-should be maintained and "expanded" to the RTL representation along
-with the function `tree' itself.
-
-\1f
-File: gccint.info, Node: Liveness information, Prev: Maintaining the CFG, Up: Control Flow
-
-15.5 Liveness information
-=========================
-
-Liveness information is useful to determine whether some register is
-"live" at given point of program, i.e. that it contains a value that
-may be used at a later point in the program. This information is used,
-for instance, during register allocation, as the pseudo registers only
-need to be assigned to a unique hard register or to a stack slot if
-they are live. The hard registers and stack slots may be freely reused
-for other values when a register is dead.
-
- Liveness information is available in the back end starting with
-`pass_df_initialize' and ending with `pass_df_finish'. Three flavors
-of live analysis are available: With `LR', it is possible to determine
-at any point `P' in the function if the register may be used on some
-path from `P' to the end of the function. With `UR', it is possible to
-determine if there is a path from the beginning of the function to `P'
-that defines the variable. `LIVE' is the intersection of the `LR' and
-`UR' and a variable is live at `P' if there is both an assignment that
-reaches it from the beginning of the function and a uses that can be
-reached on some path from `P' to the end of the function.
-
- In general `LIVE' is the most useful of the three. The macros
-`DF_[LR,UR,LIVE]_[IN,OUT]' can be used to access this information. The
-macros take a basic block number and return a bitmap that is indexed by
-the register number. This information is only guaranteed to be up to
-date after calls are made to `df_analyze'. See the file `df-core.c'
-for details on using the dataflow.
-
- The liveness information is stored partly in the RTL instruction stream
-and partly in the flow graph. Local information is stored in the
-instruction stream: Each instruction may contain `REG_DEAD' notes
-representing that the value of a given register is no longer needed, or
-`REG_UNUSED' notes representing that the value computed by the
-instruction is never used. The second is useful for instructions
-computing multiple values at once.
-
-\1f
-File: gccint.info, Node: Machine Desc, Next: Target Macros, Prev: Loop Analysis and Representation, Up: Top
-
-16 Machine Descriptions
-***********************
-
-A machine description has two parts: a file of instruction patterns
-(`.md' file) and a C header file of macro definitions.
-
- The `.md' file for a target machine contains a pattern for each
-instruction that the target machine supports (or at least each
-instruction that is worth telling the compiler about). It may also
-contain comments. A semicolon causes the rest of the line to be a
-comment, unless the semicolon is inside a quoted string.
-
- See the next chapter for information on the C header file.
-
-* Menu:
-
-* Overview:: How the machine description is used.
-* Patterns:: How to write instruction patterns.
-* Example:: An explained example of a `define_insn' pattern.
-* RTL Template:: The RTL template defines what insns match a pattern.
-* Output Template:: The output template says how to make assembler code
- from such an insn.
-* Output Statement:: For more generality, write C code to output
- the assembler code.
-* Predicates:: Controlling what kinds of operands can be used
- for an insn.
-* Constraints:: Fine-tuning operand selection.
-* Standard Names:: Names mark patterns to use for code generation.
-* Pattern Ordering:: When the order of patterns makes a difference.
-* Dependent Patterns:: Having one pattern may make you need another.
-* Jump Patterns:: Special considerations for patterns for jump insns.
-* Looping Patterns:: How to define patterns for special looping insns.
-* Insn Canonicalizations::Canonicalization of Instructions
-* Expander Definitions::Generating a sequence of several RTL insns
- for a standard operation.
-* Insn Splitting:: Splitting Instructions into Multiple Instructions.
-* Including Patterns:: Including Patterns in Machine Descriptions.
-* Peephole Definitions::Defining machine-specific peephole optimizations.
-* Insn Attributes:: Specifying the value of attributes for generated insns.
-* Conditional Execution::Generating `define_insn' patterns for
- predication.
-* Constant Definitions::Defining symbolic constants that can be used in the
- md file.
-* Iterators:: Using iterators to generate patterns from a template.
-
-\1f
-File: gccint.info, Node: Overview, Next: Patterns, Up: Machine Desc
-
-16.1 Overview of How the Machine Description is Used
-====================================================
-
-There are three main conversions that happen in the compiler:
-
- 1. The front end reads the source code and builds a parse tree.
-
- 2. The parse tree is used to generate an RTL insn list based on named
- instruction patterns.
-
- 3. The insn list is matched against the RTL templates to produce
- assembler code.
-
-
- For the generate pass, only the names of the insns matter, from either
-a named `define_insn' or a `define_expand'. The compiler will choose
-the pattern with the right name and apply the operands according to the
-documentation later in this chapter, without regard for the RTL
-template or operand constraints. Note that the names the compiler looks
-for are hard-coded in the compiler--it will ignore unnamed patterns and
-patterns with names it doesn't know about, but if you don't provide a
-named pattern it needs, it will abort.
-
- If a `define_insn' is used, the template given is inserted into the
-insn list. If a `define_expand' is used, one of three things happens,
-based on the condition logic. The condition logic may manually create
-new insns for the insn list, say via `emit_insn()', and invoke `DONE'.
-For certain named patterns, it may invoke `FAIL' to tell the compiler
-to use an alternate way of performing that task. If it invokes neither
-`DONE' nor `FAIL', the template given in the pattern is inserted, as if
-the `define_expand' were a `define_insn'.
-
- Once the insn list is generated, various optimization passes convert,
-replace, and rearrange the insns in the insn list. This is where the
-`define_split' and `define_peephole' patterns get used, for example.
-
- Finally, the insn list's RTL is matched up with the RTL templates in
-the `define_insn' patterns, and those patterns are used to emit the
-final assembly code. For this purpose, each named `define_insn' acts
-like it's unnamed, since the names are ignored.
-
-\1f
-File: gccint.info, Node: Patterns, Next: Example, Prev: Overview, Up: Machine Desc
-
-16.2 Everything about Instruction Patterns
-==========================================
-
-Each instruction pattern contains an incomplete RTL expression, with
-pieces to be filled in later, operand constraints that restrict how the
-pieces can be filled in, and an output pattern or C code to generate
-the assembler output, all wrapped up in a `define_insn' expression.
-
- A `define_insn' is an RTL expression containing four or five operands:
-
- 1. An optional name. The presence of a name indicate that this
- instruction pattern can perform a certain standard job for the
- RTL-generation pass of the compiler. This pass knows certain
- names and will use the instruction patterns with those names, if
- the names are defined in the machine description.
-
- The absence of a name is indicated by writing an empty string
- where the name should go. Nameless instruction patterns are never
- used for generating RTL code, but they may permit several simpler
- insns to be combined later on.
-
- Names that are not thus known and used in RTL-generation have no
- effect; they are equivalent to no name at all.
-
- For the purpose of debugging the compiler, you may also specify a
- name beginning with the `*' character. Such a name is used only
- for identifying the instruction in RTL dumps; it is entirely
- equivalent to having a nameless pattern for all other purposes.
-
- 2. The "RTL template" (*note RTL Template::) is a vector of incomplete
- RTL expressions which show what the instruction should look like.
- It is incomplete because it may contain `match_operand',
- `match_operator', and `match_dup' expressions that stand for
- operands of the instruction.
-
- If the vector has only one element, that element is the template
- for the instruction pattern. If the vector has multiple elements,
- then the instruction pattern is a `parallel' expression containing
- the elements described.
-
- 3. A condition. This is a string which contains a C expression that
- is the final test to decide whether an insn body matches this
- pattern.
-
- For a named pattern, the condition (if present) may not depend on
- the data in the insn being matched, but only the
- target-machine-type flags. The compiler needs to test these
- conditions during initialization in order to learn exactly which
- named instructions are available in a particular run.
-
- For nameless patterns, the condition is applied only when matching
- an individual insn, and only after the insn has matched the
- pattern's recognition template. The insn's operands may be found
- in the vector `operands'. For an insn where the condition has
- once matched, it can't be used to control register allocation, for
- example by excluding certain hard registers or hard register
- combinations.
-
- 4. The "output template": a string that says how to output matching
- insns as assembler code. `%' in this string specifies where to
- substitute the value of an operand. *Note Output Template::.
-
- When simple substitution isn't general enough, you can specify a
- piece of C code to compute the output. *Note Output Statement::.
-
- 5. Optionally, a vector containing the values of attributes for insns
- matching this pattern. *Note Insn Attributes::.
-
-\1f
-File: gccint.info, Node: Example, Next: RTL Template, Prev: Patterns, Up: Machine Desc
-
-16.3 Example of `define_insn'
-=============================
-
-Here is an actual example of an instruction pattern, for the
-68000/68020.
-
- (define_insn "tstsi"
- [(set (cc0)
- (match_operand:SI 0 "general_operand" "rm"))]
- ""
- "*
- {
- if (TARGET_68020 || ! ADDRESS_REG_P (operands[0]))
- return \"tstl %0\";
- return \"cmpl #0,%0\";
- }")
-
-This can also be written using braced strings:
-
- (define_insn "tstsi"
- [(set (cc0)
- (match_operand:SI 0 "general_operand" "rm"))]
- ""
- {
- if (TARGET_68020 || ! ADDRESS_REG_P (operands[0]))
- return "tstl %0";
- return "cmpl #0,%0";
- })
-
- This is an instruction that sets the condition codes based on the
-value of a general operand. It has no condition, so any insn whose RTL
-description has the form shown may be handled according to this
-pattern. The name `tstsi' means "test a `SImode' value" and tells the
-RTL generation pass that, when it is necessary to test such a value, an
-insn to do so can be constructed using this pattern.
-
- The output control string is a piece of C code which chooses which
-output template to return based on the kind of operand and the specific
-type of CPU for which code is being generated.
-
- `"rm"' is an operand constraint. Its meaning is explained below.
-
-\1f
-File: gccint.info, Node: RTL Template, Next: Output Template, Prev: Example, Up: Machine Desc
-
-16.4 RTL Template
-=================
-
-The RTL template is used to define which insns match the particular
-pattern and how to find their operands. For named patterns, the RTL
-template also says how to construct an insn from specified operands.
-
- Construction involves substituting specified operands into a copy of
-the template. Matching involves determining the values that serve as
-the operands in the insn being matched. Both of these activities are
-controlled by special expression types that direct matching and
-substitution of the operands.
-
-`(match_operand:M N PREDICATE CONSTRAINT)'
- This expression is a placeholder for operand number N of the insn.
- When constructing an insn, operand number N will be substituted at
- this point. When matching an insn, whatever appears at this
- position in the insn will be taken as operand number N; but it
- must satisfy PREDICATE or this instruction pattern will not match
- at all.
-
- Operand numbers must be chosen consecutively counting from zero in
- each instruction pattern. There may be only one `match_operand'
- expression in the pattern for each operand number. Usually
- operands are numbered in the order of appearance in `match_operand'
- expressions. In the case of a `define_expand', any operand numbers
- used only in `match_dup' expressions have higher values than all
- other operand numbers.
-
- PREDICATE is a string that is the name of a function that accepts
- two arguments, an expression and a machine mode. *Note
- Predicates::. During matching, the function will be called with
- the putative operand as the expression and M as the mode argument
- (if M is not specified, `VOIDmode' will be used, which normally
- causes PREDICATE to accept any mode). If it returns zero, this
- instruction pattern fails to match. PREDICATE may be an empty
- string; then it means no test is to be done on the operand, so
- anything which occurs in this position is valid.
-
- Most of the time, PREDICATE will reject modes other than M--but
- not always. For example, the predicate `address_operand' uses M
- as the mode of memory ref that the address should be valid for.
- Many predicates accept `const_int' nodes even though their mode is
- `VOIDmode'.
-
- CONSTRAINT controls reloading and the choice of the best register
- class to use for a value, as explained later (*note Constraints::).
- If the constraint would be an empty string, it can be omitted.
-
- People are often unclear on the difference between the constraint
- and the predicate. The predicate helps decide whether a given
- insn matches the pattern. The constraint plays no role in this
- decision; instead, it controls various decisions in the case of an
- insn which does match.
-
-`(match_scratch:M N CONSTRAINT)'
- This expression is also a placeholder for operand number N and
- indicates that operand must be a `scratch' or `reg' expression.
-
- When matching patterns, this is equivalent to
-
- (match_operand:M N "scratch_operand" PRED)
-
- but, when generating RTL, it produces a (`scratch':M) expression.
-
- If the last few expressions in a `parallel' are `clobber'
- expressions whose operands are either a hard register or
- `match_scratch', the combiner can add or delete them when
- necessary. *Note Side Effects::.
-
-`(match_dup N)'
- This expression is also a placeholder for operand number N. It is
- used when the operand needs to appear more than once in the insn.
-
- In construction, `match_dup' acts just like `match_operand': the
- operand is substituted into the insn being constructed. But in
- matching, `match_dup' behaves differently. It assumes that operand
- number N has already been determined by a `match_operand'
- appearing earlier in the recognition template, and it matches only
- an identical-looking expression.
-
- Note that `match_dup' should not be used to tell the compiler that
- a particular register is being used for two operands (example:
- `add' that adds one register to another; the second register is
- both an input operand and the output operand). Use a matching
- constraint (*note Simple Constraints::) for those. `match_dup' is
- for the cases where one operand is used in two places in the
- template, such as an instruction that computes both a quotient and
- a remainder, where the opcode takes two input operands but the RTL
- template has to refer to each of those twice; once for the
- quotient pattern and once for the remainder pattern.
-
-`(match_operator:M N PREDICATE [OPERANDS...])'
- This pattern is a kind of placeholder for a variable RTL expression
- code.
-
- When constructing an insn, it stands for an RTL expression whose
- expression code is taken from that of operand N, and whose
- operands are constructed from the patterns OPERANDS.
-
- When matching an expression, it matches an expression if the
- function PREDICATE returns nonzero on that expression _and_ the
- patterns OPERANDS match the operands of the expression.
-
- Suppose that the function `commutative_operator' is defined as
- follows, to match any expression whose operator is one of the
- commutative arithmetic operators of RTL and whose mode is MODE:
-
- int
- commutative_integer_operator (x, mode)
- rtx x;
- enum machine_mode mode;
- {
- enum rtx_code code = GET_CODE (x);
- if (GET_MODE (x) != mode)
- return 0;
- return (GET_RTX_CLASS (code) == RTX_COMM_ARITH
- || code == EQ || code == NE);
- }
-
- Then the following pattern will match any RTL expression consisting
- of a commutative operator applied to two general operands:
-
- (match_operator:SI 3 "commutative_operator"
- [(match_operand:SI 1 "general_operand" "g")
- (match_operand:SI 2 "general_operand" "g")])
-
- Here the vector `[OPERANDS...]' contains two patterns because the
- expressions to be matched all contain two operands.
-
- When this pattern does match, the two operands of the commutative
- operator are recorded as operands 1 and 2 of the insn. (This is
- done by the two instances of `match_operand'.) Operand 3 of the
- insn will be the entire commutative expression: use `GET_CODE
- (operands[3])' to see which commutative operator was used.
-
- The machine mode M of `match_operator' works like that of
- `match_operand': it is passed as the second argument to the
- predicate function, and that function is solely responsible for
- deciding whether the expression to be matched "has" that mode.
-
- When constructing an insn, argument 3 of the gen-function will
- specify the operation (i.e. the expression code) for the
- expression to be made. It should be an RTL expression, whose
- expression code is copied into a new expression whose operands are
- arguments 1 and 2 of the gen-function. The subexpressions of
- argument 3 are not used; only its expression code matters.
-
- When `match_operator' is used in a pattern for matching an insn,
- it usually best if the operand number of the `match_operator' is
- higher than that of the actual operands of the insn. This improves
- register allocation because the register allocator often looks at
- operands 1 and 2 of insns to see if it can do register tying.
-
- There is no way to specify constraints in `match_operator'. The
- operand of the insn which corresponds to the `match_operator'
- never has any constraints because it is never reloaded as a whole.
- However, if parts of its OPERANDS are matched by `match_operand'
- patterns, those parts may have constraints of their own.
-
-`(match_op_dup:M N[OPERANDS...])'
- Like `match_dup', except that it applies to operators instead of
- operands. When constructing an insn, operand number N will be
- substituted at this point. But in matching, `match_op_dup' behaves
- differently. It assumes that operand number N has already been
- determined by a `match_operator' appearing earlier in the
- recognition template, and it matches only an identical-looking
- expression.
-
-`(match_parallel N PREDICATE [SUBPAT...])'
- This pattern is a placeholder for an insn that consists of a
- `parallel' expression with a variable number of elements. This
- expression should only appear at the top level of an insn pattern.
-
- When constructing an insn, operand number N will be substituted at
- this point. When matching an insn, it matches if the body of the
- insn is a `parallel' expression with at least as many elements as
- the vector of SUBPAT expressions in the `match_parallel', if each
- SUBPAT matches the corresponding element of the `parallel', _and_
- the function PREDICATE returns nonzero on the `parallel' that is
- the body of the insn. It is the responsibility of the predicate
- to validate elements of the `parallel' beyond those listed in the
- `match_parallel'.
-
- A typical use of `match_parallel' is to match load and store
- multiple expressions, which can contain a variable number of
- elements in a `parallel'. For example,
-
- (define_insn ""
- [(match_parallel 0 "load_multiple_operation"
- [(set (match_operand:SI 1 "gpc_reg_operand" "=r")
- (match_operand:SI 2 "memory_operand" "m"))
- (use (reg:SI 179))
- (clobber (reg:SI 179))])]
- ""
- "loadm 0,0,%1,%2")
-
- This example comes from `a29k.md'. The function
- `load_multiple_operation' is defined in `a29k.c' and checks that
- subsequent elements in the `parallel' are the same as the `set' in
- the pattern, except that they are referencing subsequent registers
- and memory locations.
-
- An insn that matches this pattern might look like:
-
- (parallel
- [(set (reg:SI 20) (mem:SI (reg:SI 100)))
- (use (reg:SI 179))
- (clobber (reg:SI 179))
- (set (reg:SI 21)
- (mem:SI (plus:SI (reg:SI 100)
- (const_int 4))))
- (set (reg:SI 22)
- (mem:SI (plus:SI (reg:SI 100)
- (const_int 8))))])
-
-`(match_par_dup N [SUBPAT...])'
- Like `match_op_dup', but for `match_parallel' instead of
- `match_operator'.
-
-
-\1f
-File: gccint.info, Node: Output Template, Next: Output Statement, Prev: RTL Template, Up: Machine Desc
-
-16.5 Output Templates and Operand Substitution
-==============================================
-
-The "output template" is a string which specifies how to output the
-assembler code for an instruction pattern. Most of the template is a
-fixed string which is output literally. The character `%' is used to
-specify where to substitute an operand; it can also be used to identify
-places where different variants of the assembler require different
-syntax.
-
- In the simplest case, a `%' followed by a digit N says to output
-operand N at that point in the string.
-
- `%' followed by a letter and a digit says to output an operand in an
-alternate fashion. Four letters have standard, built-in meanings
-described below. The machine description macro `PRINT_OPERAND' can
-define additional letters with nonstandard meanings.
-
- `%cDIGIT' can be used to substitute an operand that is a constant
-value without the syntax that normally indicates an immediate operand.
-
- `%nDIGIT' is like `%cDIGIT' except that the value of the constant is
-negated before printing.
-
- `%aDIGIT' can be used to substitute an operand as if it were a memory
-reference, with the actual operand treated as the address. This may be
-useful when outputting a "load address" instruction, because often the
-assembler syntax for such an instruction requires you to write the
-operand as if it were a memory reference.
-
- `%lDIGIT' is used to substitute a `label_ref' into a jump instruction.
-
- `%=' outputs a number which is unique to each instruction in the
-entire compilation. This is useful for making local labels to be
-referred to more than once in a single template that generates multiple
-assembler instructions.
-
- `%' followed by a punctuation character specifies a substitution that
-does not use an operand. Only one case is standard: `%%' outputs a `%'
-into the assembler code. Other nonstandard cases can be defined in the
-`PRINT_OPERAND' macro. You must also define which punctuation
-characters are valid with the `PRINT_OPERAND_PUNCT_VALID_P' macro.
-
- The template may generate multiple assembler instructions. Write the
-text for the instructions, with `\;' between them.
-
- When the RTL contains two operands which are required by constraint to
-match each other, the output template must refer only to the
-lower-numbered operand. Matching operands are not always identical,
-and the rest of the compiler arranges to put the proper RTL expression
-for printing into the lower-numbered operand.
-
- One use of nonstandard letters or punctuation following `%' is to
-distinguish between different assembler languages for the same machine;
-for example, Motorola syntax versus MIT syntax for the 68000. Motorola
-syntax requires periods in most opcode names, while MIT syntax does
-not. For example, the opcode `movel' in MIT syntax is `move.l' in
-Motorola syntax. The same file of patterns is used for both kinds of
-output syntax, but the character sequence `%.' is used in each place
-where Motorola syntax wants a period. The `PRINT_OPERAND' macro for
-Motorola syntax defines the sequence to output a period; the macro for
-MIT syntax defines it to do nothing.
-
- As a special case, a template consisting of the single character `#'
-instructs the compiler to first split the insn, and then output the
-resulting instructions separately. This helps eliminate redundancy in
-the output templates. If you have a `define_insn' that needs to emit
-multiple assembler instructions, and there is an matching `define_split'
-already defined, then you can simply use `#' as the output template
-instead of writing an output template that emits the multiple assembler
-instructions.
-
- If the macro `ASSEMBLER_DIALECT' is defined, you can use construct of
-the form `{option0|option1|option2}' in the templates. These describe
-multiple variants of assembler language syntax. *Note Instruction
-Output::.
-
-\1f
-File: gccint.info, Node: Output Statement, Next: Predicates, Prev: Output Template, Up: Machine Desc
-
-16.6 C Statements for Assembler Output
-======================================
-
-Often a single fixed template string cannot produce correct and
-efficient assembler code for all the cases that are recognized by a
-single instruction pattern. For example, the opcodes may depend on the
-kinds of operands; or some unfortunate combinations of operands may
-require extra machine instructions.
-
- If the output control string starts with a `@', then it is actually a
-series of templates, each on a separate line. (Blank lines and leading
-spaces and tabs are ignored.) The templates correspond to the
-pattern's constraint alternatives (*note Multi-Alternative::). For
-example, if a target machine has a two-address add instruction `addr'
-to add into a register and another `addm' to add a register to memory,
-you might write this pattern:
-
- (define_insn "addsi3"
- [(set (match_operand:SI 0 "general_operand" "=r,m")
- (plus:SI (match_operand:SI 1 "general_operand" "0,0")
- (match_operand:SI 2 "general_operand" "g,r")))]
- ""
- "@
- addr %2,%0
- addm %2,%0")
-
- If the output control string starts with a `*', then it is not an
-output template but rather a piece of C program that should compute a
-template. It should execute a `return' statement to return the
-template-string you want. Most such templates use C string literals,
-which require doublequote characters to delimit them. To include these
-doublequote characters in the string, prefix each one with `\'.
-
- If the output control string is written as a brace block instead of a
-double-quoted string, it is automatically assumed to be C code. In that
-case, it is not necessary to put in a leading asterisk, or to escape the
-doublequotes surrounding C string literals.
-
- The operands may be found in the array `operands', whose C data type
-is `rtx []'.
-
- It is very common to select different ways of generating assembler code
-based on whether an immediate operand is within a certain range. Be
-careful when doing this, because the result of `INTVAL' is an integer
-on the host machine. If the host machine has more bits in an `int'
-than the target machine has in the mode in which the constant will be
-used, then some of the bits you get from `INTVAL' will be superfluous.
-For proper results, you must carefully disregard the values of those
-bits.
-
- It is possible to output an assembler instruction and then go on to
-output or compute more of them, using the subroutine `output_asm_insn'.
-This receives two arguments: a template-string and a vector of
-operands. The vector may be `operands', or it may be another array of
-`rtx' that you declare locally and initialize yourself.
-
- When an insn pattern has multiple alternatives in its constraints,
-often the appearance of the assembler code is determined mostly by
-which alternative was matched. When this is so, the C code can test
-the variable `which_alternative', which is the ordinal number of the
-alternative that was actually satisfied (0 for the first, 1 for the
-second alternative, etc.).
-
- For example, suppose there are two opcodes for storing zero, `clrreg'
-for registers and `clrmem' for memory locations. Here is how a pattern
-could use `which_alternative' to choose between them:
-
- (define_insn ""
- [(set (match_operand:SI 0 "general_operand" "=r,m")
- (const_int 0))]
- ""
- {
- return (which_alternative == 0
- ? "clrreg %0" : "clrmem %0");
- })
-
- The example above, where the assembler code to generate was _solely_
-determined by the alternative, could also have been specified as
-follows, having the output control string start with a `@':
-
- (define_insn ""
- [(set (match_operand:SI 0 "general_operand" "=r,m")
- (const_int 0))]
- ""
- "@
- clrreg %0
- clrmem %0")
-
-\1f
-File: gccint.info, Node: Predicates, Next: Constraints, Prev: Output Statement, Up: Machine Desc
-
-16.7 Predicates
-===============
-
-A predicate determines whether a `match_operand' or `match_operator'
-expression matches, and therefore whether the surrounding instruction
-pattern will be used for that combination of operands. GCC has a
-number of machine-independent predicates, and you can define
-machine-specific predicates as needed. By convention, predicates used
-with `match_operand' have names that end in `_operand', and those used
-with `match_operator' have names that end in `_operator'.
-
- All predicates are Boolean functions (in the mathematical sense) of
-two arguments: the RTL expression that is being considered at that
-position in the instruction pattern, and the machine mode that the
-`match_operand' or `match_operator' specifies. In this section, the
-first argument is called OP and the second argument MODE. Predicates
-can be called from C as ordinary two-argument functions; this can be
-useful in output templates or other machine-specific code.
-
- Operand predicates can allow operands that are not actually acceptable
-to the hardware, as long as the constraints give reload the ability to
-fix them up (*note Constraints::). However, GCC will usually generate
-better code if the predicates specify the requirements of the machine
-instructions as closely as possible. Reload cannot fix up operands
-that must be constants ("immediate operands"); you must use a predicate
-that allows only constants, or else enforce the requirement in the
-extra condition.
-
- Most predicates handle their MODE argument in a uniform manner. If
-MODE is `VOIDmode' (unspecified), then OP can have any mode. If MODE
-is anything else, then OP must have the same mode, unless OP is a
-`CONST_INT' or integer `CONST_DOUBLE'. These RTL expressions always
-have `VOIDmode', so it would be counterproductive to check that their
-mode matches. Instead, predicates that accept `CONST_INT' and/or
-integer `CONST_DOUBLE' check that the value stored in the constant will
-fit in the requested mode.
-
- Predicates with this behavior are called "normal". `genrecog' can
-optimize the instruction recognizer based on knowledge of how normal
-predicates treat modes. It can also diagnose certain kinds of common
-errors in the use of normal predicates; for instance, it is almost
-always an error to use a normal predicate without specifying a mode.
-
- Predicates that do something different with their MODE argument are
-called "special". The generic predicates `address_operand' and
-`pmode_register_operand' are special predicates. `genrecog' does not
-do any optimizations or diagnosis when special predicates are used.
-
-* Menu:
-
-* Machine-Independent Predicates:: Predicates available to all back ends.
-* Defining Predicates:: How to write machine-specific predicate
- functions.
-
-\1f
-File: gccint.info, Node: Machine-Independent Predicates, Next: Defining Predicates, Up: Predicates
-
-16.7.1 Machine-Independent Predicates
--------------------------------------
-
-These are the generic predicates available to all back ends. They are
-defined in `recog.c'. The first category of predicates allow only
-constant, or "immediate", operands.
-
- -- Function: immediate_operand
- This predicate allows any sort of constant that fits in MODE. It
- is an appropriate choice for instructions that take operands that
- must be constant.
-
- -- Function: const_int_operand
- This predicate allows any `CONST_INT' expression that fits in
- MODE. It is an appropriate choice for an immediate operand that
- does not allow a symbol or label.
-
- -- Function: const_double_operand
- This predicate accepts any `CONST_DOUBLE' expression that has
- exactly MODE. If MODE is `VOIDmode', it will also accept
- `CONST_INT'. It is intended for immediate floating point
- constants.
-
-The second category of predicates allow only some kind of machine
-register.
-
- -- Function: register_operand
- This predicate allows any `REG' or `SUBREG' expression that is
- valid for MODE. It is often suitable for arithmetic instruction
- operands on a RISC machine.
-
- -- Function: pmode_register_operand
- This is a slight variant on `register_operand' which works around
- a limitation in the machine-description reader.
-
- (match_operand N "pmode_register_operand" CONSTRAINT)
-
- means exactly what
-
- (match_operand:P N "register_operand" CONSTRAINT)
-
- would mean, if the machine-description reader accepted `:P' mode
- suffixes. Unfortunately, it cannot, because `Pmode' is an alias
- for some other mode, and might vary with machine-specific options.
- *Note Misc::.
-
- -- Function: scratch_operand
- This predicate allows hard registers and `SCRATCH' expressions,
- but not pseudo-registers. It is used internally by
- `match_scratch'; it should not be used directly.
-
-The third category of predicates allow only some kind of memory
-reference.
-
- -- Function: memory_operand
- This predicate allows any valid reference to a quantity of mode
- MODE in memory, as determined by the weak form of
- `GO_IF_LEGITIMATE_ADDRESS' (*note Addressing Modes::).
-
- -- Function: address_operand
- This predicate is a little unusual; it allows any operand that is a
- valid expression for the _address_ of a quantity of mode MODE,
- again determined by the weak form of `GO_IF_LEGITIMATE_ADDRESS'.
- To first order, if `(mem:MODE (EXP))' is acceptable to
- `memory_operand', then EXP is acceptable to `address_operand'.
- Note that EXP does not necessarily have the mode MODE.
-
- -- Function: indirect_operand
- This is a stricter form of `memory_operand' which allows only
- memory references with a `general_operand' as the address
- expression. New uses of this predicate are discouraged, because
- `general_operand' is very permissive, so it's hard to tell what an
- `indirect_operand' does or does not allow. If a target has
- different requirements for memory operands for different
- instructions, it is better to define target-specific predicates
- which enforce the hardware's requirements explicitly.
-
- -- Function: push_operand
- This predicate allows a memory reference suitable for pushing a
- value onto the stack. This will be a `MEM' which refers to
- `stack_pointer_rtx', with a side-effect in its address expression
- (*note Incdec::); which one is determined by the `STACK_PUSH_CODE'
- macro (*note Frame Layout::).
-
- -- Function: pop_operand
- This predicate allows a memory reference suitable for popping a
- value off the stack. Again, this will be a `MEM' referring to
- `stack_pointer_rtx', with a side-effect in its address expression.
- However, this time `STACK_POP_CODE' is expected.
-
-The fourth category of predicates allow some combination of the above
-operands.
-
- -- Function: nonmemory_operand
- This predicate allows any immediate or register operand valid for
- MODE.
-
- -- Function: nonimmediate_operand
- This predicate allows any register or memory operand valid for
- MODE.
-
- -- Function: general_operand
- This predicate allows any immediate, register, or memory operand
- valid for MODE.
-
-Finally, there is one generic operator predicate.
-
- -- Function: comparison_operator
- This predicate matches any expression which performs an arithmetic
- comparison in MODE; that is, `COMPARISON_P' is true for the
- expression code.
-
-\1f
-File: gccint.info, Node: Defining Predicates, Prev: Machine-Independent Predicates, Up: Predicates
-
-16.7.2 Defining Machine-Specific Predicates
--------------------------------------------
-
-Many machines have requirements for their operands that cannot be
-expressed precisely using the generic predicates. You can define
-additional predicates using `define_predicate' and
-`define_special_predicate' expressions. These expressions have three
-operands:
-
- * The name of the predicate, as it will be referred to in
- `match_operand' or `match_operator' expressions.
-
- * An RTL expression which evaluates to true if the predicate allows
- the operand OP, false if it does not. This expression can only use
- the following RTL codes:
-
- `MATCH_OPERAND'
- When written inside a predicate expression, a `MATCH_OPERAND'
- expression evaluates to true if the predicate it names would
- allow OP. The operand number and constraint are ignored.
- Due to limitations in `genrecog', you can only refer to
- generic predicates and predicates that have already been
- defined.
-
- `MATCH_CODE'
- This expression evaluates to true if OP or a specified
- subexpression of OP has one of a given list of RTX codes.
-
- The first operand of this expression is a string constant
- containing a comma-separated list of RTX code names (in lower
- case). These are the codes for which the `MATCH_CODE' will
- be true.
-
- The second operand is a string constant which indicates what
- subexpression of OP to examine. If it is absent or the empty
- string, OP itself is examined. Otherwise, the string constant
- must be a sequence of digits and/or lowercase letters. Each
- character indicates a subexpression to extract from the
- current expression; for the first character this is OP, for
- the second and subsequent characters it is the result of the
- previous character. A digit N extracts `XEXP (E, N)'; a
- letter L extracts `XVECEXP (E, 0, N)' where N is the
- alphabetic ordinal of L (0 for `a', 1 for 'b', and so on).
- The `MATCH_CODE' then examines the RTX code of the
- subexpression extracted by the complete string. It is not
- possible to extract components of an `rtvec' that is not at
- position 0 within its RTX object.
-
- `MATCH_TEST'
- This expression has one operand, a string constant containing
- a C expression. The predicate's arguments, OP and MODE, are
- available with those names in the C expression. The
- `MATCH_TEST' evaluates to true if the C expression evaluates
- to a nonzero value. `MATCH_TEST' expressions must not have
- side effects.
-
- `AND'
- `IOR'
- `NOT'
- `IF_THEN_ELSE'
- The basic `MATCH_' expressions can be combined using these
- logical operators, which have the semantics of the C operators
- `&&', `||', `!', and `? :' respectively. As in Common Lisp,
- you may give an `AND' or `IOR' expression an arbitrary number
- of arguments; this has exactly the same effect as writing a
- chain of two-argument `AND' or `IOR' expressions.
-
- * An optional block of C code, which should execute `return true' if
- the predicate is found to match and `return false' if it does not.
- It must not have any side effects. The predicate arguments, OP
- and MODE, are available with those names.
-
- If a code block is present in a predicate definition, then the RTL
- expression must evaluate to true _and_ the code block must execute
- `return true' for the predicate to allow the operand. The RTL
- expression is evaluated first; do not re-check anything in the
- code block that was checked in the RTL expression.
-
- The program `genrecog' scans `define_predicate' and
-`define_special_predicate' expressions to determine which RTX codes are
-possibly allowed. You should always make this explicit in the RTL
-predicate expression, using `MATCH_OPERAND' and `MATCH_CODE'.
-
- Here is an example of a simple predicate definition, from the IA64
-machine description:
-
- ;; True if OP is a `SYMBOL_REF' which refers to the sdata section.
- (define_predicate "small_addr_symbolic_operand"
- (and (match_code "symbol_ref")
- (match_test "SYMBOL_REF_SMALL_ADDR_P (op)")))
-
-And here is another, showing the use of the C block.
-
- ;; True if OP is a register operand that is (or could be) a GR reg.
- (define_predicate "gr_register_operand"
- (match_operand 0 "register_operand")
- {
- unsigned int regno;
- if (GET_CODE (op) == SUBREG)
- op = SUBREG_REG (op);
-
- regno = REGNO (op);
- return (regno >= FIRST_PSEUDO_REGISTER || GENERAL_REGNO_P (regno));
- })
-
- Predicates written with `define_predicate' automatically include a
-test that MODE is `VOIDmode', or OP has the same mode as MODE, or OP is
-a `CONST_INT' or `CONST_DOUBLE'. They do _not_ check specifically for
-integer `CONST_DOUBLE', nor do they test that the value of either kind
-of constant fits in the requested mode. This is because
-target-specific predicates that take constants usually have to do more
-stringent value checks anyway. If you need the exact same treatment of
-`CONST_INT' or `CONST_DOUBLE' that the generic predicates provide, use
-a `MATCH_OPERAND' subexpression to call `const_int_operand',
-`const_double_operand', or `immediate_operand'.
-
- Predicates written with `define_special_predicate' do not get any
-automatic mode checks, and are treated as having special mode handling
-by `genrecog'.
-
- The program `genpreds' is responsible for generating code to test
-predicates. It also writes a header file containing function
-declarations for all machine-specific predicates. It is not necessary
-to declare these predicates in `CPU-protos.h'.
-
-\1f
-File: gccint.info, Node: Constraints, Next: Standard Names, Prev: Predicates, Up: Machine Desc
-
-16.8 Operand Constraints
-========================
-
-Each `match_operand' in an instruction pattern can specify constraints
-for the operands allowed. The constraints allow you to fine-tune
-matching within the set of operands allowed by the predicate.
-
- Constraints can say whether an operand may be in a register, and which
-kinds of register; whether the operand can be a memory reference, and
-which kinds of address; whether the operand may be an immediate
-constant, and which possible values it may have. Constraints can also
-require two operands to match.
-
-* Menu:
-
-* Simple Constraints:: Basic use of constraints.
-* Multi-Alternative:: When an insn has two alternative constraint-patterns.
-* Class Preferences:: Constraints guide which hard register to put things in.
-* Modifiers:: More precise control over effects of constraints.
-* Disable Insn Alternatives:: Disable insn alternatives using the `enabled' attribute.
-* Machine Constraints:: Existing constraints for some particular machines.
-* Define Constraints:: How to define machine-specific constraints.
-* C Constraint Interface:: How to test constraints from C code.
-
-\1f
-File: gccint.info, Node: Simple Constraints, Next: Multi-Alternative, Up: Constraints
-
-16.8.1 Simple Constraints
--------------------------
-
-The simplest kind of constraint is a string full of letters, each of
-which describes one kind of operand that is permitted. Here are the
-letters that are allowed:
-
-whitespace
- Whitespace characters are ignored and can be inserted at any
- position except the first. This enables each alternative for
- different operands to be visually aligned in the machine
- description even if they have different number of constraints and
- modifiers.
-
-`m'
- A memory operand is allowed, with any kind of address that the
- machine supports in general. Note that the letter used for the
- general memory constraint can be re-defined by a back end using
- the `TARGET_MEM_CONSTRAINT' macro.
-
-`o'
- A memory operand is allowed, but only if the address is
- "offsettable". This means that adding a small integer (actually,
- the width in bytes of the operand, as determined by its machine
- mode) may be added to the address and the result is also a valid
- memory address.
-
- For example, an address which is constant is offsettable; so is an
- address that is the sum of a register and a constant (as long as a
- slightly larger constant is also within the range of
- address-offsets supported by the machine); but an autoincrement or
- autodecrement address is not offsettable. More complicated
- indirect/indexed addresses may or may not be offsettable depending
- on the other addressing modes that the machine supports.
-
- Note that in an output operand which can be matched by another
- operand, the constraint letter `o' is valid only when accompanied
- by both `<' (if the target machine has predecrement addressing)
- and `>' (if the target machine has preincrement addressing).
-
-`V'
- A memory operand that is not offsettable. In other words,
- anything that would fit the `m' constraint but not the `o'
- constraint.
-
-`<'
- A memory operand with autodecrement addressing (either
- predecrement or postdecrement) is allowed.
-
-`>'
- A memory operand with autoincrement addressing (either
- preincrement or postincrement) is allowed.
-
-`r'
- A register operand is allowed provided that it is in a general
- register.
-
-`i'
- An immediate integer operand (one with constant value) is allowed.
- This includes symbolic constants whose values will be known only at
- assembly time or later.
-
-`n'
- An immediate integer operand with a known numeric value is allowed.
- Many systems cannot support assembly-time constants for operands
- less than a word wide. Constraints for these operands should use
- `n' rather than `i'.
-
-`I', `J', `K', ... `P'
- Other letters in the range `I' through `P' may be defined in a
- machine-dependent fashion to permit immediate integer operands with
- explicit integer values in specified ranges. For example, on the
- 68000, `I' is defined to stand for the range of values 1 to 8.
- This is the range permitted as a shift count in the shift
- instructions.
-
-`E'
- An immediate floating operand (expression code `const_double') is
- allowed, but only if the target floating point format is the same
- as that of the host machine (on which the compiler is running).
-
-`F'
- An immediate floating operand (expression code `const_double' or
- `const_vector') is allowed.
-
-`G', `H'
- `G' and `H' may be defined in a machine-dependent fashion to
- permit immediate floating operands in particular ranges of values.
-
-`s'
- An immediate integer operand whose value is not an explicit
- integer is allowed.
-
- This might appear strange; if an insn allows a constant operand
- with a value not known at compile time, it certainly must allow
- any known value. So why use `s' instead of `i'? Sometimes it
- allows better code to be generated.
-
- For example, on the 68000 in a fullword instruction it is possible
- to use an immediate operand; but if the immediate value is between
- -128 and 127, better code results from loading the value into a
- register and using the register. This is because the load into
- the register can be done with a `moveq' instruction. We arrange
- for this to happen by defining the letter `K' to mean "any integer
- outside the range -128 to 127", and then specifying `Ks' in the
- operand constraints.
-
-`g'
- Any register, memory or immediate integer operand is allowed,
- except for registers that are not general registers.
-
-`X'
- Any operand whatsoever is allowed, even if it does not satisfy
- `general_operand'. This is normally used in the constraint of a
- `match_scratch' when certain alternatives will not actually
- require a scratch register.
-
-`0', `1', `2', ... `9'
- An operand that matches the specified operand number is allowed.
- If a digit is used together with letters within the same
- alternative, the digit should come last.
-
- This number is allowed to be more than a single digit. If multiple
- digits are encountered consecutively, they are interpreted as a
- single decimal integer. There is scant chance for ambiguity,
- since to-date it has never been desirable that `10' be interpreted
- as matching either operand 1 _or_ operand 0. Should this be
- desired, one can use multiple alternatives instead.
-
- This is called a "matching constraint" and what it really means is
- that the assembler has only a single operand that fills two roles
- considered separate in the RTL insn. For example, an add insn has
- two input operands and one output operand in the RTL, but on most
- CISC machines an add instruction really has only two operands, one
- of them an input-output operand:
-
- addl #35,r12
-
- Matching constraints are used in these circumstances. More
- precisely, the two operands that match must include one input-only
- operand and one output-only operand. Moreover, the digit must be a
- smaller number than the number of the operand that uses it in the
- constraint.
-
- For operands to match in a particular case usually means that they
- are identical-looking RTL expressions. But in a few special cases
- specific kinds of dissimilarity are allowed. For example, `*x' as
- an input operand will match `*x++' as an output operand. For
- proper results in such cases, the output template should always
- use the output-operand's number when printing the operand.
-
-`p'
- An operand that is a valid memory address is allowed. This is for
- "load address" and "push address" instructions.
-
- `p' in the constraint must be accompanied by `address_operand' as
- the predicate in the `match_operand'. This predicate interprets
- the mode specified in the `match_operand' as the mode of the memory
- reference for which the address would be valid.
-
-OTHER-LETTERS
- Other letters can be defined in machine-dependent fashion to stand
- for particular classes of registers or other arbitrary operand
- types. `d', `a' and `f' are defined on the 68000/68020 to stand
- for data, address and floating point registers.
-
- In order to have valid assembler code, each operand must satisfy its
-constraint. But a failure to do so does not prevent the pattern from
-applying to an insn. Instead, it directs the compiler to modify the
-code so that the constraint will be satisfied. Usually this is done by
-copying an operand into a register.
-
- Contrast, therefore, the two instruction patterns that follow:
-
- (define_insn ""
- [(set (match_operand:SI 0 "general_operand" "=r")
- (plus:SI (match_dup 0)
- (match_operand:SI 1 "general_operand" "r")))]
- ""
- "...")
-
-which has two operands, one of which must appear in two places, and
-
- (define_insn ""
- [(set (match_operand:SI 0 "general_operand" "=r")
- (plus:SI (match_operand:SI 1 "general_operand" "0")
- (match_operand:SI 2 "general_operand" "r")))]
- ""
- "...")
-
-which has three operands, two of which are required by a constraint to
-be identical. If we are considering an insn of the form
-
- (insn N PREV NEXT
- (set (reg:SI 3)
- (plus:SI (reg:SI 6) (reg:SI 109)))
- ...)
-
-the first pattern would not apply at all, because this insn does not
-contain two identical subexpressions in the right place. The pattern
-would say, "That does not look like an add instruction; try other
-patterns". The second pattern would say, "Yes, that's an add
-instruction, but there is something wrong with it". It would direct
-the reload pass of the compiler to generate additional insns to make
-the constraint true. The results might look like this:
-
- (insn N2 PREV N
- (set (reg:SI 3) (reg:SI 6))
- ...)
-
- (insn N N2 NEXT
- (set (reg:SI 3)
- (plus:SI (reg:SI 3) (reg:SI 109)))
- ...)
-
- It is up to you to make sure that each operand, in each pattern, has
-constraints that can handle any RTL expression that could be present for
-that operand. (When multiple alternatives are in use, each pattern
-must, for each possible combination of operand expressions, have at
-least one alternative which can handle that combination of operands.)
-The constraints don't need to _allow_ any possible operand--when this is
-the case, they do not constrain--but they must at least point the way to
-reloading any possible operand so that it will fit.
-
- * If the constraint accepts whatever operands the predicate permits,
- there is no problem: reloading is never necessary for this operand.
-
- For example, an operand whose constraints permit everything except
- registers is safe provided its predicate rejects registers.
-
- An operand whose predicate accepts only constant values is safe
- provided its constraints include the letter `i'. If any possible
- constant value is accepted, then nothing less than `i' will do; if
- the predicate is more selective, then the constraints may also be
- more selective.
-
- * Any operand expression can be reloaded by copying it into a
- register. So if an operand's constraints allow some kind of
- register, it is certain to be safe. It need not permit all
- classes of registers; the compiler knows how to copy a register
- into another register of the proper class in order to make an
- instruction valid.
-
- * A nonoffsettable memory reference can be reloaded by copying the
- address into a register. So if the constraint uses the letter
- `o', all memory references are taken care of.
-
- * A constant operand can be reloaded by allocating space in memory to
- hold it as preinitialized data. Then the memory reference can be
- used in place of the constant. So if the constraint uses the
- letters `o' or `m', constant operands are not a problem.
-
- * If the constraint permits a constant and a pseudo register used in
- an insn was not allocated to a hard register and is equivalent to
- a constant, the register will be replaced with the constant. If
- the predicate does not permit a constant and the insn is
- re-recognized for some reason, the compiler will crash. Thus the
- predicate must always recognize any objects allowed by the
- constraint.
-
- If the operand's predicate can recognize registers, but the constraint
-does not permit them, it can make the compiler crash. When this
-operand happens to be a register, the reload pass will be stymied,
-because it does not know how to copy a register temporarily into memory.
-
- If the predicate accepts a unary operator, the constraint applies to
-the operand. For example, the MIPS processor at ISA level 3 supports an
-instruction which adds two registers in `SImode' to produce a `DImode'
-result, but only if the registers are correctly sign extended. This
-predicate for the input operands accepts a `sign_extend' of an `SImode'
-register. Write the constraint to indicate the type of register that
-is required for the operand of the `sign_extend'.
-
-\1f
-File: gccint.info, Node: Multi-Alternative, Next: Class Preferences, Prev: Simple Constraints, Up: Constraints
-
-16.8.2 Multiple Alternative Constraints
----------------------------------------
-
-Sometimes a single instruction has multiple alternative sets of possible
-operands. For example, on the 68000, a logical-or instruction can
-combine register or an immediate value into memory, or it can combine
-any kind of operand into a register; but it cannot combine one memory
-location into another.
-
- These constraints are represented as multiple alternatives. An
-alternative can be described by a series of letters for each operand.
-The overall constraint for an operand is made from the letters for this
-operand from the first alternative, a comma, the letters for this
-operand from the second alternative, a comma, and so on until the last
-alternative. Here is how it is done for fullword logical-or on the
-68000:
-
- (define_insn "iorsi3"
- [(set (match_operand:SI 0 "general_operand" "=m,d")
- (ior:SI (match_operand:SI 1 "general_operand" "%0,0")
- (match_operand:SI 2 "general_operand" "dKs,dmKs")))]
- ...)
-
- The first alternative has `m' (memory) for operand 0, `0' for operand
-1 (meaning it must match operand 0), and `dKs' for operand 2. The
-second alternative has `d' (data register) for operand 0, `0' for
-operand 1, and `dmKs' for operand 2. The `=' and `%' in the
-constraints apply to all the alternatives; their meaning is explained
-in the next section (*note Class Preferences::).
-
- If all the operands fit any one alternative, the instruction is valid.
-Otherwise, for each alternative, the compiler counts how many
-instructions must be added to copy the operands so that that
-alternative applies. The alternative requiring the least copying is
-chosen. If two alternatives need the same amount of copying, the one
-that comes first is chosen. These choices can be altered with the `?'
-and `!' characters:
-
-`?'
- Disparage slightly the alternative that the `?' appears in, as a
- choice when no alternative applies exactly. The compiler regards
- this alternative as one unit more costly for each `?' that appears
- in it.
-
-`!'
- Disparage severely the alternative that the `!' appears in. This
- alternative can still be used if it fits without reloading, but if
- reloading is needed, some other alternative will be used.
-
- When an insn pattern has multiple alternatives in its constraints,
-often the appearance of the assembler code is determined mostly by which
-alternative was matched. When this is so, the C code for writing the
-assembler code can use the variable `which_alternative', which is the
-ordinal number of the alternative that was actually satisfied (0 for
-the first, 1 for the second alternative, etc.). *Note Output
-Statement::.
-
-\1f
-File: gccint.info, Node: Class Preferences, Next: Modifiers, Prev: Multi-Alternative, Up: Constraints
-
-16.8.3 Register Class Preferences
----------------------------------
-
-The operand constraints have another function: they enable the compiler
-to decide which kind of hardware register a pseudo register is best
-allocated to. The compiler examines the constraints that apply to the
-insns that use the pseudo register, looking for the machine-dependent
-letters such as `d' and `a' that specify classes of registers. The
-pseudo register is put in whichever class gets the most "votes". The
-constraint letters `g' and `r' also vote: they vote in favor of a
-general register. The machine description says which registers are
-considered general.
-
- Of course, on some machines all registers are equivalent, and no
-register classes are defined. Then none of this complexity is relevant.
-
-\1f
-File: gccint.info, Node: Modifiers, Next: Disable Insn Alternatives, Prev: Class Preferences, Up: Constraints
-
-16.8.4 Constraint Modifier Characters
--------------------------------------
-
-Here are constraint modifier characters.
-
-`='
- Means that this operand is write-only for this instruction: the
- previous value is discarded and replaced by output data.
-
-`+'
- Means that this operand is both read and written by the
- instruction.
-
- When the compiler fixes up the operands to satisfy the constraints,
- it needs to know which operands are inputs to the instruction and
- which are outputs from it. `=' identifies an output; `+'
- identifies an operand that is both input and output; all other
- operands are assumed to be input only.
-
- If you specify `=' or `+' in a constraint, you put it in the first
- character of the constraint string.
-
-`&'
- Means (in a particular alternative) that this operand is an
- "earlyclobber" operand, which is modified before the instruction is
- finished using the input operands. Therefore, this operand may
- not lie in a register that is used as an input operand or as part
- of any memory address.
-
- `&' applies only to the alternative in which it is written. In
- constraints with multiple alternatives, sometimes one alternative
- requires `&' while others do not. See, for example, the `movdf'
- insn of the 68000.
-
- An input operand can be tied to an earlyclobber operand if its only
- use as an input occurs before the early result is written. Adding
- alternatives of this form often allows GCC to produce better code
- when only some of the inputs can be affected by the earlyclobber.
- See, for example, the `mulsi3' insn of the ARM.
-
- `&' does not obviate the need to write `='.
-
-`%'
- Declares the instruction to be commutative for this operand and the
- following operand. This means that the compiler may interchange
- the two operands if that is the cheapest way to make all operands
- fit the constraints. This is often used in patterns for addition
- instructions that really have only two operands: the result must
- go in one of the arguments. Here for example, is how the 68000
- halfword-add instruction is defined:
-
- (define_insn "addhi3"
- [(set (match_operand:HI 0 "general_operand" "=m,r")
- (plus:HI (match_operand:HI 1 "general_operand" "%0,0")
- (match_operand:HI 2 "general_operand" "di,g")))]
- ...)
- GCC can only handle one commutative pair in an asm; if you use
- more, the compiler may fail. Note that you need not use the
- modifier if the two alternatives are strictly identical; this
- would only waste time in the reload pass. The modifier is not
- operational after register allocation, so the result of
- `define_peephole2' and `define_split's performed after reload
- cannot rely on `%' to make the intended insn match.
-
-`#'
- Says that all following characters, up to the next comma, are to be
- ignored as a constraint. They are significant only for choosing
- register preferences.
-
-`*'
- Says that the following character should be ignored when choosing
- register preferences. `*' has no effect on the meaning of the
- constraint as a constraint, and no effect on reloading.
-
- Here is an example: the 68000 has an instruction to sign-extend a
- halfword in a data register, and can also sign-extend a value by
- copying it into an address register. While either kind of
- register is acceptable, the constraints on an address-register
- destination are less strict, so it is best if register allocation
- makes an address register its goal. Therefore, `*' is used so
- that the `d' constraint letter (for data register) is ignored when
- computing register preferences.
-
- (define_insn "extendhisi2"
- [(set (match_operand:SI 0 "general_operand" "=*d,a")
- (sign_extend:SI
- (match_operand:HI 1 "general_operand" "0,g")))]
- ...)
-
-\1f
-File: gccint.info, Node: Machine Constraints, Next: Define Constraints, Prev: Disable Insn Alternatives, Up: Constraints
-
-16.8.5 Constraints for Particular Machines
-------------------------------------------
-
-Whenever possible, you should use the general-purpose constraint letters
-in `asm' arguments, since they will convey meaning more readily to
-people reading your code. Failing that, use the constraint letters
-that usually have very similar meanings across architectures. The most
-commonly used constraints are `m' and `r' (for memory and
-general-purpose registers respectively; *note Simple Constraints::), and
-`I', usually the letter indicating the most common immediate-constant
-format.
-
- Each architecture defines additional constraints. These constraints
-are used by the compiler itself for instruction generation, as well as
-for `asm' statements; therefore, some of the constraints are not
-particularly useful for `asm'. Here is a summary of some of the
-machine-dependent constraints available on some particular machines; it
-includes both constraints that are useful for `asm' and constraints
-that aren't. The compiler source file mentioned in the table heading
-for each architecture is the definitive reference for the meanings of
-that architecture's constraints.
-
-_ARM family--`config/arm/arm.h'_
-
- `f'
- Floating-point register
-
- `w'
- VFP floating-point register
-
- `F'
- One of the floating-point constants 0.0, 0.5, 1.0, 2.0, 3.0,
- 4.0, 5.0 or 10.0
-
- `G'
- Floating-point constant that would satisfy the constraint `F'
- if it were negated
-
- `I'
- Integer that is valid as an immediate operand in a data
- processing instruction. That is, an integer in the range 0
- to 255 rotated by a multiple of 2
-
- `J'
- Integer in the range -4095 to 4095
-
- `K'
- Integer that satisfies constraint `I' when inverted (ones
- complement)
-
- `L'
- Integer that satisfies constraint `I' when negated (twos
- complement)
-
- `M'
- Integer in the range 0 to 32
-
- `Q'
- A memory reference where the exact address is in a single
- register (``m'' is preferable for `asm' statements)
-
- `R'
- An item in the constant pool
-
- `S'
- A symbol in the text segment of the current file
-
- `Uv'
- A memory reference suitable for VFP load/store insns
- (reg+constant offset)
-
- `Uy'
- A memory reference suitable for iWMMXt load/store
- instructions.
-
- `Uq'
- A memory reference suitable for the ARMv4 ldrsb instruction.
-
-_AVR family--`config/avr/constraints.md'_
-
- `l'
- Registers from r0 to r15
-
- `a'
- Registers from r16 to r23
-
- `d'
- Registers from r16 to r31
-
- `w'
- Registers from r24 to r31. These registers can be used in
- `adiw' command
-
- `e'
- Pointer register (r26-r31)
-
- `b'
- Base pointer register (r28-r31)
-
- `q'
- Stack pointer register (SPH:SPL)
-
- `t'
- Temporary register r0
-
- `x'
- Register pair X (r27:r26)
-
- `y'
- Register pair Y (r29:r28)
-
- `z'
- Register pair Z (r31:r30)
-
- `I'
- Constant greater than -1, less than 64
-
- `J'
- Constant greater than -64, less than 1
-
- `K'
- Constant integer 2
-
- `L'
- Constant integer 0
-
- `M'
- Constant that fits in 8 bits
-
- `N'
- Constant integer -1
-
- `O'
- Constant integer 8, 16, or 24
-
- `P'
- Constant integer 1
-
- `G'
- A floating point constant 0.0
-
- `R'
- Integer constant in the range -6 ... 5.
-
- `Q'
- A memory address based on Y or Z pointer with displacement.
-
-_CRX Architecture--`config/crx/crx.h'_
-
- `b'
- Registers from r0 to r14 (registers without stack pointer)
-
- `l'
- Register r16 (64-bit accumulator lo register)
-
- `h'
- Register r17 (64-bit accumulator hi register)
-
- `k'
- Register pair r16-r17. (64-bit accumulator lo-hi pair)
-
- `I'
- Constant that fits in 3 bits
-
- `J'
- Constant that fits in 4 bits
-
- `K'
- Constant that fits in 5 bits
-
- `L'
- Constant that is one of -1, 4, -4, 7, 8, 12, 16, 20, 32, 48
-
- `G'
- Floating point constant that is legal for store immediate
-
-_Hewlett-Packard PA-RISC--`config/pa/pa.h'_
-
- `a'
- General register 1
-
- `f'
- Floating point register
-
- `q'
- Shift amount register
-
- `x'
- Floating point register (deprecated)
-
- `y'
- Upper floating point register (32-bit), floating point
- register (64-bit)
-
- `Z'
- Any register
-
- `I'
- Signed 11-bit integer constant
-
- `J'
- Signed 14-bit integer constant
-
- `K'
- Integer constant that can be deposited with a `zdepi'
- instruction
-
- `L'
- Signed 5-bit integer constant
-
- `M'
- Integer constant 0
-
- `N'
- Integer constant that can be loaded with a `ldil' instruction
-
- `O'
- Integer constant whose value plus one is a power of 2
-
- `P'
- Integer constant that can be used for `and' operations in
- `depi' and `extru' instructions
-
- `S'
- Integer constant 31
-
- `U'
- Integer constant 63
-
- `G'
- Floating-point constant 0.0
-
- `A'
- A `lo_sum' data-linkage-table memory operand
-
- `Q'
- A memory operand that can be used as the destination operand
- of an integer store instruction
-
- `R'
- A scaled or unscaled indexed memory operand
-
- `T'
- A memory operand for floating-point loads and stores
-
- `W'
- A register indirect memory operand
-
-_picoChip family--`picochip.h'_
-
- `k'
- Stack register.
-
- `f'
- Pointer register. A register which can be used to access
- memory without supplying an offset. Any other register can
- be used to access memory, but will need a constant offset.
- In the case of the offset being zero, it is more efficient to
- use a pointer register, since this reduces code size.
-
- `t'
- A twin register. A register which may be paired with an
- adjacent register to create a 32-bit register.
-
- `a'
- Any absolute memory address (e.g., symbolic constant, symbolic
- constant + offset).
-
- `I'
- 4-bit signed integer.
-
- `J'
- 4-bit unsigned integer.
-
- `K'
- 8-bit signed integer.
-
- `M'
- Any constant whose absolute value is no greater than 4-bits.
-
- `N'
- 10-bit signed integer
-
- `O'
- 16-bit signed integer.
-
-
-_PowerPC and IBM RS6000--`config/rs6000/rs6000.h'_
-
- `b'
- Address base register
-
- `f'
- Floating point register
-
- `v'
- Vector register
-
- `h'
- `MQ', `CTR', or `LINK' register
-
- `q'
- `MQ' register
-
- `c'
- `CTR' register
-
- `l'
- `LINK' register
-
- `x'
- `CR' register (condition register) number 0
-
- `y'
- `CR' register (condition register)
-
- `z'
- `FPMEM' stack memory for FPR-GPR transfers
-
- `I'
- Signed 16-bit constant
-
- `J'
- Unsigned 16-bit constant shifted left 16 bits (use `L'
- instead for `SImode' constants)
-
- `K'
- Unsigned 16-bit constant
-
- `L'
- Signed 16-bit constant shifted left 16 bits
-
- `M'
- Constant larger than 31
-
- `N'
- Exact power of 2
-
- `O'
- Zero
-
- `P'
- Constant whose negation is a signed 16-bit constant
-
- `G'
- Floating point constant that can be loaded into a register
- with one instruction per word
-
- `H'
- Integer/Floating point constant that can be loaded into a
- register using three instructions
-
- `Q'
- Memory operand that is an offset from a register (`m' is
- preferable for `asm' statements)
-
- `Z'
- Memory operand that is an indexed or indirect from a register
- (`m' is preferable for `asm' statements)
-
- `R'
- AIX TOC entry
-
- `a'
- Address operand that is an indexed or indirect from a
- register (`p' is preferable for `asm' statements)
-
- `S'
- Constant suitable as a 64-bit mask operand
-
- `T'
- Constant suitable as a 32-bit mask operand
-
- `U'
- System V Release 4 small data area reference
-
- `t'
- AND masks that can be performed by two rldic{l, r}
- instructions
-
- `W'
- Vector constant that does not require memory
-
-
-_Intel 386--`config/i386/constraints.md'_
-
- `R'
- Legacy register--the eight integer registers available on all
- i386 processors (`a', `b', `c', `d', `si', `di', `bp', `sp').
-
- `q'
- Any register accessible as `Rl'. In 32-bit mode, `a', `b',
- `c', and `d'; in 64-bit mode, any integer register.
-
- `Q'
- Any register accessible as `Rh': `a', `b', `c', and `d'.
-
- `l'
- Any register that can be used as the index in a base+index
- memory access: that is, any general register except the stack
- pointer.
-
- `a'
- The `a' register.
-
- `b'
- The `b' register.
-
- `c'
- The `c' register.
-
- `d'
- The `d' register.
-
- `S'
- The `si' register.
-
- `D'
- The `di' register.
-
- `A'
- The `a' and `d' registers, as a pair (for instructions that
- return half the result in one and half in the other).
-
- `f'
- Any 80387 floating-point (stack) register.
-
- `t'
- Top of 80387 floating-point stack (`%st(0)').
-
- `u'
- Second from top of 80387 floating-point stack (`%st(1)').
-
- `y'
- Any MMX register.
-
- `x'
- Any SSE register.
-
- `Yz'
- First SSE register (`%xmm0').
-
- `Y2'
- Any SSE register, when SSE2 is enabled.
-
- `Yi'
- Any SSE register, when SSE2 and inter-unit moves are enabled.
-
- `Ym'
- Any MMX register, when inter-unit moves are enabled.
-
- `I'
- Integer constant in the range 0 ... 31, for 32-bit shifts.
-
- `J'
- Integer constant in the range 0 ... 63, for 64-bit shifts.
-
- `K'
- Signed 8-bit integer constant.
-
- `L'
- `0xFF' or `0xFFFF', for andsi as a zero-extending move.
-
- `M'
- 0, 1, 2, or 3 (shifts for the `lea' instruction).
-
- `N'
- Unsigned 8-bit integer constant (for `in' and `out'
- instructions).
-
- `O'
- Integer constant in the range 0 ... 127, for 128-bit shifts.
-
- `G'
- Standard 80387 floating point constant.
-
- `C'
- Standard SSE floating point constant.
-
- `e'
- 32-bit signed integer constant, or a symbolic reference known
- to fit that range (for immediate operands in sign-extending
- x86-64 instructions).
-
- `Z'
- 32-bit unsigned integer constant, or a symbolic reference
- known to fit that range (for immediate operands in
- zero-extending x86-64 instructions).
-
-
-_Intel IA-64--`config/ia64/ia64.h'_
-
- `a'
- General register `r0' to `r3' for `addl' instruction
-
- `b'
- Branch register
-
- `c'
- Predicate register (`c' as in "conditional")
-
- `d'
- Application register residing in M-unit
-
- `e'
- Application register residing in I-unit
-
- `f'
- Floating-point register
-
- `m'
- Memory operand. Remember that `m' allows postincrement and
- postdecrement which require printing with `%Pn' on IA-64.
- Use `S' to disallow postincrement and postdecrement.
-
- `G'
- Floating-point constant 0.0 or 1.0
-
- `I'
- 14-bit signed integer constant
-
- `J'
- 22-bit signed integer constant
-
- `K'
- 8-bit signed integer constant for logical instructions
-
- `L'
- 8-bit adjusted signed integer constant for compare pseudo-ops
-
- `M'
- 6-bit unsigned integer constant for shift counts
-
- `N'
- 9-bit signed integer constant for load and store
- postincrements
-
- `O'
- The constant zero
-
- `P'
- 0 or -1 for `dep' instruction
-
- `Q'
- Non-volatile memory for floating-point loads and stores
-
- `R'
- Integer constant in the range 1 to 4 for `shladd' instruction
-
- `S'
- Memory operand except postincrement and postdecrement
-
-_FRV--`config/frv/frv.h'_
-
- `a'
- Register in the class `ACC_REGS' (`acc0' to `acc7').
-
- `b'
- Register in the class `EVEN_ACC_REGS' (`acc0' to `acc7').
-
- `c'
- Register in the class `CC_REGS' (`fcc0' to `fcc3' and `icc0'
- to `icc3').
-
- `d'
- Register in the class `GPR_REGS' (`gr0' to `gr63').
-
- `e'
- Register in the class `EVEN_REGS' (`gr0' to `gr63'). Odd
- registers are excluded not in the class but through the use
- of a machine mode larger than 4 bytes.
-
- `f'
- Register in the class `FPR_REGS' (`fr0' to `fr63').
-
- `h'
- Register in the class `FEVEN_REGS' (`fr0' to `fr63'). Odd
- registers are excluded not in the class but through the use
- of a machine mode larger than 4 bytes.
-
- `l'
- Register in the class `LR_REG' (the `lr' register).
-
- `q'
- Register in the class `QUAD_REGS' (`gr2' to `gr63').
- Register numbers not divisible by 4 are excluded not in the
- class but through the use of a machine mode larger than 8
- bytes.
-
- `t'
- Register in the class `ICC_REGS' (`icc0' to `icc3').
-
- `u'
- Register in the class `FCC_REGS' (`fcc0' to `fcc3').
-
- `v'
- Register in the class `ICR_REGS' (`cc4' to `cc7').
-
- `w'
- Register in the class `FCR_REGS' (`cc0' to `cc3').
-
- `x'
- Register in the class `QUAD_FPR_REGS' (`fr0' to `fr63').
- Register numbers not divisible by 4 are excluded not in the
- class but through the use of a machine mode larger than 8
- bytes.
-
- `z'
- Register in the class `SPR_REGS' (`lcr' and `lr').
-
- `A'
- Register in the class `QUAD_ACC_REGS' (`acc0' to `acc7').
-
- `B'
- Register in the class `ACCG_REGS' (`accg0' to `accg7').
-
- `C'
- Register in the class `CR_REGS' (`cc0' to `cc7').
-
- `G'
- Floating point constant zero
-
- `I'
- 6-bit signed integer constant
-
- `J'
- 10-bit signed integer constant
-
- `L'
- 16-bit signed integer constant
-
- `M'
- 16-bit unsigned integer constant
-
- `N'
- 12-bit signed integer constant that is negative--i.e. in the
- range of -2048 to -1
-
- `O'
- Constant zero
-
- `P'
- 12-bit signed integer constant that is greater than
- zero--i.e. in the range of 1 to 2047.
-
-
-_Blackfin family--`config/bfin/constraints.md'_
-
- `a'
- P register
-
- `d'
- D register
-
- `z'
- A call clobbered P register.
-
- `qN'
- A single register. If N is in the range 0 to 7, the
- corresponding D register. If it is `A', then the register P0.
-
- `D'
- Even-numbered D register
-
- `W'
- Odd-numbered D register
-
- `e'
- Accumulator register.
-
- `A'
- Even-numbered accumulator register.
-
- `B'
- Odd-numbered accumulator register.
-
- `b'
- I register
-
- `v'
- B register
-
- `f'
- M register
-
- `c'
- Registers used for circular buffering, i.e. I, B, or L
- registers.
-
- `C'
- The CC register.
-
- `t'
- LT0 or LT1.
-
- `k'
- LC0 or LC1.
-
- `u'
- LB0 or LB1.
-
- `x'
- Any D, P, B, M, I or L register.
-
- `y'
- Additional registers typically used only in prologues and
- epilogues: RETS, RETN, RETI, RETX, RETE, ASTAT, SEQSTAT and
- USP.
-
- `w'
- Any register except accumulators or CC.
-
- `Ksh'
- Signed 16 bit integer (in the range -32768 to 32767)
-
- `Kuh'
- Unsigned 16 bit integer (in the range 0 to 65535)
-
- `Ks7'
- Signed 7 bit integer (in the range -64 to 63)
-
- `Ku7'
- Unsigned 7 bit integer (in the range 0 to 127)
-
- `Ku5'
- Unsigned 5 bit integer (in the range 0 to 31)
-
- `Ks4'
- Signed 4 bit integer (in the range -8 to 7)
-
- `Ks3'
- Signed 3 bit integer (in the range -3 to 4)
-
- `Ku3'
- Unsigned 3 bit integer (in the range 0 to 7)
-
- `PN'
- Constant N, where N is a single-digit constant in the range 0
- to 4.
-
- `PA'
- An integer equal to one of the MACFLAG_XXX constants that is
- suitable for use with either accumulator.
-
- `PB'
- An integer equal to one of the MACFLAG_XXX constants that is
- suitable for use only with accumulator A1.
-
- `M1'
- Constant 255.
-
- `M2'
- Constant 65535.
-
- `J'
- An integer constant with exactly a single bit set.
-
- `L'
- An integer constant with all bits set except exactly one.
-
- `H'
-
- `Q'
- Any SYMBOL_REF.
-
-_M32C--`config/m32c/m32c.c'_
-
- `Rsp'
- `Rfb'
- `Rsb'
- `$sp', `$fb', `$sb'.
-
- `Rcr'
- Any control register, when they're 16 bits wide (nothing if
- control registers are 24 bits wide)
-
- `Rcl'
- Any control register, when they're 24 bits wide.
-
- `R0w'
- `R1w'
- `R2w'
- `R3w'
- $r0, $r1, $r2, $r3.
-
- `R02'
- $r0 or $r2, or $r2r0 for 32 bit values.
-
- `R13'
- $r1 or $r3, or $r3r1 for 32 bit values.
-
- `Rdi'
- A register that can hold a 64 bit value.
-
- `Rhl'
- $r0 or $r1 (registers with addressable high/low bytes)
-
- `R23'
- $r2 or $r3
-
- `Raa'
- Address registers
-
- `Raw'
- Address registers when they're 16 bits wide.
-
- `Ral'
- Address registers when they're 24 bits wide.
-
- `Rqi'
- Registers that can hold QI values.
-
- `Rad'
- Registers that can be used with displacements ($a0, $a1, $sb).
-
- `Rsi'
- Registers that can hold 32 bit values.
-
- `Rhi'
- Registers that can hold 16 bit values.
-
- `Rhc'
- Registers chat can hold 16 bit values, including all control
- registers.
-
- `Rra'
- $r0 through R1, plus $a0 and $a1.
-
- `Rfl'
- The flags register.
-
- `Rmm'
- The memory-based pseudo-registers $mem0 through $mem15.
-
- `Rpi'
- Registers that can hold pointers (16 bit registers for r8c,
- m16c; 24 bit registers for m32cm, m32c).
-
- `Rpa'
- Matches multiple registers in a PARALLEL to form a larger
- register. Used to match function return values.
-
- `Is3'
- -8 ... 7
-
- `IS1'
- -128 ... 127
-
- `IS2'
- -32768 ... 32767
-
- `IU2'
- 0 ... 65535
-
- `In4'
- -8 ... -1 or 1 ... 8
-
- `In5'
- -16 ... -1 or 1 ... 16
-
- `In6'
- -32 ... -1 or 1 ... 32
-
- `IM2'
- -65536 ... -1
-
- `Ilb'
- An 8 bit value with exactly one bit set.
-
- `Ilw'
- A 16 bit value with exactly one bit set.
-
- `Sd'
- The common src/dest memory addressing modes.
-
- `Sa'
- Memory addressed using $a0 or $a1.
-
- `Si'
- Memory addressed with immediate addresses.
-
- `Ss'
- Memory addressed using the stack pointer ($sp).
-
- `Sf'
- Memory addressed using the frame base register ($fb).
-
- `Ss'
- Memory addressed using the small base register ($sb).
-
- `S1'
- $r1h
-
-_MIPS--`config/mips/constraints.md'_
-
- `d'
- An address register. This is equivalent to `r' unless
- generating MIPS16 code.
-
- `f'
- A floating-point register (if available).
-
- `h'
- Formerly the `hi' register. This constraint is no longer
- supported.
-
- `l'
- The `lo' register. Use this register to store values that are
- no bigger than a word.
-
- `x'
- The concatenated `hi' and `lo' registers. Use this register
- to store doubleword values.
-
- `c'
- A register suitable for use in an indirect jump. This will
- always be `$25' for `-mabicalls'.
-
- `v'
- Register `$3'. Do not use this constraint in new code; it is
- retained only for compatibility with glibc.
-
- `y'
- Equivalent to `r'; retained for backwards compatibility.
-
- `z'
- A floating-point condition code register.
-
- `I'
- A signed 16-bit constant (for arithmetic instructions).
-
- `J'
- Integer zero.
-
- `K'
- An unsigned 16-bit constant (for logic instructions).
-
- `L'
- A signed 32-bit constant in which the lower 16 bits are zero.
- Such constants can be loaded using `lui'.
-
- `M'
- A constant that cannot be loaded using `lui', `addiu' or
- `ori'.
-
- `N'
- A constant in the range -65535 to -1 (inclusive).
-
- `O'
- A signed 15-bit constant.
-
- `P'
- A constant in the range 1 to 65535 (inclusive).
-
- `G'
- Floating-point zero.
-
- `R'
- An address that can be used in a non-macro load or store.
-
-_Motorola 680x0--`config/m68k/constraints.md'_
-
- `a'
- Address register
-
- `d'
- Data register
-
- `f'
- 68881 floating-point register, if available
-
- `I'
- Integer in the range 1 to 8
-
- `J'
- 16-bit signed number
-
- `K'
- Signed number whose magnitude is greater than 0x80
-
- `L'
- Integer in the range -8 to -1
-
- `M'
- Signed number whose magnitude is greater than 0x100
-
- `N'
- Range 24 to 31, rotatert:SI 8 to 1 expressed as rotate
-
- `O'
- 16 (for rotate using swap)
-
- `P'
- Range 8 to 15, rotatert:HI 8 to 1 expressed as rotate
-
- `R'
- Numbers that mov3q can handle
-
- `G'
- Floating point constant that is not a 68881 constant
-
- `S'
- Operands that satisfy 'm' when -mpcrel is in effect
-
- `T'
- Operands that satisfy 's' when -mpcrel is not in effect
-
- `Q'
- Address register indirect addressing mode
-
- `U'
- Register offset addressing
-
- `W'
- const_call_operand
-
- `Cs'
- symbol_ref or const
-
- `Ci'
- const_int
-
- `C0'
- const_int 0
-
- `Cj'
- Range of signed numbers that don't fit in 16 bits
-
- `Cmvq'
- Integers valid for mvq
-
- `Capsw'
- Integers valid for a moveq followed by a swap
-
- `Cmvz'
- Integers valid for mvz
-
- `Cmvs'
- Integers valid for mvs
-
- `Ap'
- push_operand
-
- `Ac'
- Non-register operands allowed in clr
-
-
-_Motorola 68HC11 & 68HC12 families--`config/m68hc11/m68hc11.h'_
-
- `a'
- Register `a'
-
- `b'
- Register `b'
-
- `d'
- Register `d'
-
- `q'
- An 8-bit register
-
- `t'
- Temporary soft register _.tmp
-
- `u'
- A soft register _.d1 to _.d31
-
- `w'
- Stack pointer register
-
- `x'
- Register `x'
-
- `y'
- Register `y'
-
- `z'
- Pseudo register `z' (replaced by `x' or `y' at the end)
-
- `A'
- An address register: x, y or z
-
- `B'
- An address register: x or y
-
- `D'
- Register pair (x:d) to form a 32-bit value
-
- `L'
- Constants in the range -65536 to 65535
-
- `M'
- Constants whose 16-bit low part is zero
-
- `N'
- Constant integer 1 or -1
-
- `O'
- Constant integer 16
-
- `P'
- Constants in the range -8 to 2
-
-
-_SPARC--`config/sparc/sparc.h'_
-
- `f'
- Floating-point register on the SPARC-V8 architecture and
- lower floating-point register on the SPARC-V9 architecture.
-
- `e'
- Floating-point register. It is equivalent to `f' on the
- SPARC-V8 architecture and contains both lower and upper
- floating-point registers on the SPARC-V9 architecture.
-
- `c'
- Floating-point condition code register.
-
- `d'
- Lower floating-point register. It is only valid on the
- SPARC-V9 architecture when the Visual Instruction Set is
- available.
-
- `b'
- Floating-point register. It is only valid on the SPARC-V9
- architecture when the Visual Instruction Set is available.
-
- `h'
- 64-bit global or out register for the SPARC-V8+ architecture.
-
- `D'
- A vector constant
-
- `I'
- Signed 13-bit constant
-
- `J'
- Zero
-
- `K'
- 32-bit constant with the low 12 bits clear (a constant that
- can be loaded with the `sethi' instruction)
-
- `L'
- A constant in the range supported by `movcc' instructions
-
- `M'
- A constant in the range supported by `movrcc' instructions
-
- `N'
- Same as `K', except that it verifies that bits that are not
- in the lower 32-bit range are all zero. Must be used instead
- of `K' for modes wider than `SImode'
-
- `O'
- The constant 4096
-
- `G'
- Floating-point zero
-
- `H'
- Signed 13-bit constant, sign-extended to 32 or 64 bits
-
- `Q'
- Floating-point constant whose integral representation can be
- moved into an integer register using a single sethi
- instruction
-
- `R'
- Floating-point constant whose integral representation can be
- moved into an integer register using a single mov instruction
-
- `S'
- Floating-point constant whose integral representation can be
- moved into an integer register using a high/lo_sum
- instruction sequence
-
- `T'
- Memory address aligned to an 8-byte boundary
-
- `U'
- Even register
-
- `W'
- Memory address for `e' constraint registers
-
- `Y'
- Vector zero
-
-
-_SPU--`config/spu/spu.h'_
-
- `a'
- An immediate which can be loaded with the il/ila/ilh/ilhu
- instructions. const_int is treated as a 64 bit value.
-
- `c'
- An immediate for and/xor/or instructions. const_int is
- treated as a 64 bit value.
-
- `d'
- An immediate for the `iohl' instruction. const_int is
- treated as a 64 bit value.
-
- `f'
- An immediate which can be loaded with `fsmbi'.
-
- `A'
- An immediate which can be loaded with the il/ila/ilh/ilhu
- instructions. const_int is treated as a 32 bit value.
-
- `B'
- An immediate for most arithmetic instructions. const_int is
- treated as a 32 bit value.
-
- `C'
- An immediate for and/xor/or instructions. const_int is
- treated as a 32 bit value.
-
- `D'
- An immediate for the `iohl' instruction. const_int is
- treated as a 32 bit value.
-
- `I'
- A constant in the range [-64, 63] for shift/rotate
- instructions.
-
- `J'
- An unsigned 7-bit constant for conversion/nop/channel
- instructions.
-
- `K'
- A signed 10-bit constant for most arithmetic instructions.
-
- `M'
- A signed 16 bit immediate for `stop'.
-
- `N'
- An unsigned 16-bit constant for `iohl' and `fsmbi'.
-
- `O'
- An unsigned 7-bit constant whose 3 least significant bits are
- 0.
-
- `P'
- An unsigned 3-bit constant for 16-byte rotates and shifts
-
- `R'
- Call operand, reg, for indirect calls
-
- `S'
- Call operand, symbol, for relative calls.
-
- `T'
- Call operand, const_int, for absolute calls.
-
- `U'
- An immediate which can be loaded with the il/ila/ilh/ilhu
- instructions. const_int is sign extended to 128 bit.
-
- `W'
- An immediate for shift and rotate instructions. const_int is
- treated as a 32 bit value.
-
- `Y'
- An immediate for and/xor/or instructions. const_int is sign
- extended as a 128 bit.
-
- `Z'
- An immediate for the `iohl' instruction. const_int is sign
- extended to 128 bit.
-
-
-_S/390 and zSeries--`config/s390/s390.h'_
-
- `a'
- Address register (general purpose register except r0)
-
- `c'
- Condition code register
-
- `d'
- Data register (arbitrary general purpose register)
-
- `f'
- Floating-point register
-
- `I'
- Unsigned 8-bit constant (0-255)
-
- `J'
- Unsigned 12-bit constant (0-4095)
-
- `K'
- Signed 16-bit constant (-32768-32767)
-
- `L'
- Value appropriate as displacement.
- `(0..4095)'
- for short displacement
-
- `(-524288..524287)'
- for long displacement
-
- `M'
- Constant integer with a value of 0x7fffffff.
-
- `N'
- Multiple letter constraint followed by 4 parameter letters.
- `0..9:'
- number of the part counting from most to least
- significant
-
- `H,Q:'
- mode of the part
-
- `D,S,H:'
- mode of the containing operand
-
- `0,F:'
- value of the other parts (F--all bits set)
- The constraint matches if the specified part of a constant
- has a value different from its other parts.
-
- `Q'
- Memory reference without index register and with short
- displacement.
-
- `R'
- Memory reference with index register and short displacement.
-
- `S'
- Memory reference without index register but with long
- displacement.
-
- `T'
- Memory reference with index register and long displacement.
-
- `U'
- Pointer with short displacement.
-
- `W'
- Pointer with long displacement.
-
- `Y'
- Shift count operand.
-
-
-_Score family--`config/score/score.h'_
-
- `d'
- Registers from r0 to r32.
-
- `e'
- Registers from r0 to r16.
-
- `t'
- r8--r11 or r22--r27 registers.
-
- `h'
- hi register.
-
- `l'
- lo register.
-
- `x'
- hi + lo register.
-
- `q'
- cnt register.
-
- `y'
- lcb register.
-
- `z'
- scb register.
-
- `a'
- cnt + lcb + scb register.
-
- `c'
- cr0--cr15 register.
-
- `b'
- cp1 registers.
-
- `f'
- cp2 registers.
-
- `i'
- cp3 registers.
-
- `j'
- cp1 + cp2 + cp3 registers.
-
- `I'
- High 16-bit constant (32-bit constant with 16 LSBs zero).
-
- `J'
- Unsigned 5 bit integer (in the range 0 to 31).
-
- `K'
- Unsigned 16 bit integer (in the range 0 to 65535).
-
- `L'
- Signed 16 bit integer (in the range -32768 to 32767).
-
- `M'
- Unsigned 14 bit integer (in the range 0 to 16383).
-
- `N'
- Signed 14 bit integer (in the range -8192 to 8191).
-
- `Z'
- Any SYMBOL_REF.
-
-_Xstormy16--`config/stormy16/stormy16.h'_
-
- `a'
- Register r0.
-
- `b'
- Register r1.
-
- `c'
- Register r2.
-
- `d'
- Register r8.
-
- `e'
- Registers r0 through r7.
-
- `t'
- Registers r0 and r1.
-
- `y'
- The carry register.
-
- `z'
- Registers r8 and r9.
-
- `I'
- A constant between 0 and 3 inclusive.
-
- `J'
- A constant that has exactly one bit set.
-
- `K'
- A constant that has exactly one bit clear.
-
- `L'
- A constant between 0 and 255 inclusive.
-
- `M'
- A constant between -255 and 0 inclusive.
-
- `N'
- A constant between -3 and 0 inclusive.
-
- `O'
- A constant between 1 and 4 inclusive.
-
- `P'
- A constant between -4 and -1 inclusive.
-
- `Q'
- A memory reference that is a stack push.
-
- `R'
- A memory reference that is a stack pop.
-
- `S'
- A memory reference that refers to a constant address of known
- value.
-
- `T'
- The register indicated by Rx (not implemented yet).
-
- `U'
- A constant that is not between 2 and 15 inclusive.
-
- `Z'
- The constant 0.
-
-
-_Xtensa--`config/xtensa/constraints.md'_
-
- `a'
- General-purpose 32-bit register
-
- `b'
- One-bit boolean register
-
- `A'
- MAC16 40-bit accumulator register
-
- `I'
- Signed 12-bit integer constant, for use in MOVI instructions
-
- `J'
- Signed 8-bit integer constant, for use in ADDI instructions
-
- `K'
- Integer constant valid for BccI instructions
-
- `L'
- Unsigned constant valid for BccUI instructions
-
-
-
-\1f
-File: gccint.info, Node: Disable Insn Alternatives, Next: Machine Constraints, Prev: Modifiers, Up: Constraints
-
-16.8.6 Disable insn alternatives using the `enabled' attribute
---------------------------------------------------------------
-
-The `enabled' insn attribute may be used to disable certain insn
-alternatives for machine-specific reasons. This is useful when adding
-new instructions to an existing pattern which are only available for
-certain cpu architecture levels as specified with the `-march=' option.
-
- If an insn alternative is disabled, then it will never be used. The
-compiler treats the constraints for the disabled alternative as
-unsatisfiable.
-
- In order to make use of the `enabled' attribute a back end has to add
-in the machine description files:
-
- 1. A definition of the `enabled' insn attribute. The attribute is
- defined as usual using the `define_attr' command. This definition
- should be based on other insn attributes and/or target flags. The
- `enabled' attribute is a numeric attribute and should evaluate to
- `(const_int 1)' for an enabled alternative and to `(const_int 0)'
- otherwise.
-
- 2. A definition of another insn attribute used to describe for what
- reason an insn alternative might be available or not. E.g.
- `cpu_facility' as in the example below.
-
- 3. An assignment for the second attribute to each insn definition
- combining instructions which are not all available under the same
- circumstances. (Note: It obviously only makes sense for
- definitions with more than one alternative. Otherwise the insn
- pattern should be disabled or enabled using the insn condition.)
-
- E.g. the following two patterns could easily be merged using the
-`enabled' attribute:
-
-
- (define_insn "*movdi_old"
- [(set (match_operand:DI 0 "register_operand" "=d")
- (match_operand:DI 1 "register_operand" " d"))]
- "!TARGET_NEW"
- "lgr %0,%1")
-
- (define_insn "*movdi_new"
- [(set (match_operand:DI 0 "register_operand" "=d,f,d")
- (match_operand:DI 1 "register_operand" " d,d,f"))]
- "TARGET_NEW"
- "@
- lgr %0,%1
- ldgr %0,%1
- lgdr %0,%1")
-
- to:
-
-
- (define_insn "*movdi_combined"
- [(set (match_operand:DI 0 "register_operand" "=d,f,d")
- (match_operand:DI 1 "register_operand" " d,d,f"))]
- ""
- "@
- lgr %0,%1
- ldgr %0,%1
- lgdr %0,%1"
- [(set_attr "cpu_facility" "*,new,new")])
-
- with the `enabled' attribute defined like this:
-
-
- (define_attr "cpu_facility" "standard,new" (const_string "standard"))
-
- (define_attr "enabled" ""
- (cond [(eq_attr "cpu_facility" "standard") (const_int 1)
- (and (eq_attr "cpu_facility" "new")
- (ne (symbol_ref "TARGET_NEW") (const_int 0)))
- (const_int 1)]
- (const_int 0)))
-
-\1f
-File: gccint.info, Node: Define Constraints, Next: C Constraint Interface, Prev: Machine Constraints, Up: Constraints
-
-16.8.7 Defining Machine-Specific Constraints
---------------------------------------------
-
-Machine-specific constraints fall into two categories: register and
-non-register constraints. Within the latter category, constraints
-which allow subsets of all possible memory or address operands should
-be specially marked, to give `reload' more information.
-
- Machine-specific constraints can be given names of arbitrary length,
-but they must be entirely composed of letters, digits, underscores
-(`_'), and angle brackets (`< >'). Like C identifiers, they must begin
-with a letter or underscore.
-
- In order to avoid ambiguity in operand constraint strings, no
-constraint can have a name that begins with any other constraint's
-name. For example, if `x' is defined as a constraint name, `xy' may
-not be, and vice versa. As a consequence of this rule, no constraint
-may begin with one of the generic constraint letters: `E F V X g i m n
-o p r s'.
-
- Register constraints correspond directly to register classes. *Note
-Register Classes::. There is thus not much flexibility in their
-definitions.
-
- -- MD Expression: define_register_constraint name regclass docstring
- All three arguments are string constants. NAME is the name of the
- constraint, as it will appear in `match_operand' expressions. If
- NAME is a multi-letter constraint its length shall be the same for
- all constraints starting with the same letter. REGCLASS can be
- either the name of the corresponding register class (*note
- Register Classes::), or a C expression which evaluates to the
- appropriate register class. If it is an expression, it must have
- no side effects, and it cannot look at the operand. The usual use
- of expressions is to map some register constraints to `NO_REGS'
- when the register class is not available on a given
- subarchitecture.
-
- DOCSTRING is a sentence documenting the meaning of the constraint.
- Docstrings are explained further below.
-
- Non-register constraints are more like predicates: the constraint
-definition gives a Boolean expression which indicates whether the
-constraint matches.
-
- -- MD Expression: define_constraint name docstring exp
- The NAME and DOCSTRING arguments are the same as for
- `define_register_constraint', but note that the docstring comes
- immediately after the name for these expressions. EXP is an RTL
- expression, obeying the same rules as the RTL expressions in
- predicate definitions. *Note Defining Predicates::, for details.
- If it evaluates true, the constraint matches; if it evaluates
- false, it doesn't. Constraint expressions should indicate which
- RTL codes they might match, just like predicate expressions.
-
- `match_test' C expressions have access to the following variables:
-
- OP
- The RTL object defining the operand.
-
- MODE
- The machine mode of OP.
-
- IVAL
- `INTVAL (OP)', if OP is a `const_int'.
-
- HVAL
- `CONST_DOUBLE_HIGH (OP)', if OP is an integer `const_double'.
-
- LVAL
- `CONST_DOUBLE_LOW (OP)', if OP is an integer `const_double'.
-
- RVAL
- `CONST_DOUBLE_REAL_VALUE (OP)', if OP is a floating-point
- `const_double'.
-
- The *VAL variables should only be used once another piece of the
- expression has verified that OP is the appropriate kind of RTL
- object.
-
- Most non-register constraints should be defined with
-`define_constraint'. The remaining two definition expressions are only
-appropriate for constraints that should be handled specially by
-`reload' if they fail to match.
-
- -- MD Expression: define_memory_constraint name docstring exp
- Use this expression for constraints that match a subset of all
- memory operands: that is, `reload' can make them match by
- converting the operand to the form `(mem (reg X))', where X is a
- base register (from the register class specified by
- `BASE_REG_CLASS', *note Register Classes::).
-
- For example, on the S/390, some instructions do not accept
- arbitrary memory references, but only those that do not make use
- of an index register. The constraint letter `Q' is defined to
- represent a memory address of this type. If `Q' is defined with
- `define_memory_constraint', a `Q' constraint can handle any memory
- operand, because `reload' knows it can simply copy the memory
- address into a base register if required. This is analogous to
- the way a `o' constraint can handle any memory operand.
-
- The syntax and semantics are otherwise identical to
- `define_constraint'.
-
- -- MD Expression: define_address_constraint name docstring exp
- Use this expression for constraints that match a subset of all
- address operands: that is, `reload' can make the constraint match
- by converting the operand to the form `(reg X)', again with X a
- base register.
-
- Constraints defined with `define_address_constraint' can only be
- used with the `address_operand' predicate, or machine-specific
- predicates that work the same way. They are treated analogously to
- the generic `p' constraint.
-
- The syntax and semantics are otherwise identical to
- `define_constraint'.
-
- For historical reasons, names beginning with the letters `G H' are
-reserved for constraints that match only `const_double's, and names
-beginning with the letters `I J K L M N O P' are reserved for
-constraints that match only `const_int's. This may change in the
-future. For the time being, constraints with these names must be
-written in a stylized form, so that `genpreds' can tell you did it
-correctly:
-
- (define_constraint "[GHIJKLMNOP]..."
- "DOC..."
- (and (match_code "const_int") ; `const_double' for G/H
- CONDITION...)) ; usually a `match_test'
-
- It is fine to use names beginning with other letters for constraints
-that match `const_double's or `const_int's.
-
- Each docstring in a constraint definition should be one or more
-complete sentences, marked up in Texinfo format. _They are currently
-unused._ In the future they will be copied into the GCC manual, in
-*note Machine Constraints::, replacing the hand-maintained tables
-currently found in that section. Also, in the future the compiler may
-use this to give more helpful diagnostics when poor choice of `asm'
-constraints causes a reload failure.
-
- If you put the pseudo-Texinfo directive `@internal' at the beginning
-of a docstring, then (in the future) it will appear only in the
-internals manual's version of the machine-specific constraint tables.
-Use this for constraints that should not appear in `asm' statements.
-
-\1f
-File: gccint.info, Node: C Constraint Interface, Prev: Define Constraints, Up: Constraints
-
-16.8.8 Testing constraints from C
----------------------------------
-
-It is occasionally useful to test a constraint from C code rather than
-implicitly via the constraint string in a `match_operand'. The
-generated file `tm_p.h' declares a few interfaces for working with
-machine-specific constraints. None of these interfaces work with the
-generic constraints described in *note Simple Constraints::. This may
-change in the future.
-
- *Warning:* `tm_p.h' may declare other functions that operate on
-constraints, besides the ones documented here. Do not use those
-functions from machine-dependent code. They exist to implement the old
-constraint interface that machine-independent components of the
-compiler still expect. They will change or disappear in the future.
-
- Some valid constraint names are not valid C identifiers, so there is a
-mangling scheme for referring to them from C. Constraint names that do
-not contain angle brackets or underscores are left unchanged.
-Underscores are doubled, each `<' is replaced with `_l', and each `>'
-with `_g'. Here are some examples:
-
- *Original* *Mangled*
- `x' `x'
- `P42x' `P42x'
- `P4_x' `P4__x'
- `P4>x' `P4_gx'
- `P4>>' `P4_g_g'
- `P4_g>' `P4__g_g'
-
- Throughout this section, the variable C is either a constraint in the
-abstract sense, or a constant from `enum constraint_num'; the variable
-M is a mangled constraint name (usually as part of a larger identifier).
-
- -- Enum: constraint_num
- For each machine-specific constraint, there is a corresponding
- enumeration constant: `CONSTRAINT_' plus the mangled name of the
- constraint. Functions that take an `enum constraint_num' as an
- argument expect one of these constants.
-
- Machine-independent constraints do not have associated constants.
- This may change in the future.
-
- -- Function: inline bool satisfies_constraint_M (rtx EXP)
- For each machine-specific, non-register constraint M, there is one
- of these functions; it returns `true' if EXP satisfies the
- constraint. These functions are only visible if `rtl.h' was
- included before `tm_p.h'.
-
- -- Function: bool constraint_satisfied_p (rtx EXP, enum constraint_num
- C)
- Like the `satisfies_constraint_M' functions, but the constraint to
- test is given as an argument, C. If C specifies a register
- constraint, this function will always return `false'.
-
- -- Function: enum reg_class regclass_for_constraint (enum
- constraint_num C)
- Returns the register class associated with C. If C is not a
- register constraint, or those registers are not available for the
- currently selected subtarget, returns `NO_REGS'.
-
- Here is an example use of `satisfies_constraint_M'. In peephole
-optimizations (*note Peephole Definitions::), operand constraint
-strings are ignored, so if there are relevant constraints, they must be
-tested in the C condition. In the example, the optimization is applied
-if operand 2 does _not_ satisfy the `K' constraint. (This is a
-simplified version of a peephole definition from the i386 machine
-description.)
-
- (define_peephole2
- [(match_scratch:SI 3 "r")
- (set (match_operand:SI 0 "register_operand" "")
- (mult:SI (match_operand:SI 1 "memory_operand" "")
- (match_operand:SI 2 "immediate_operand" "")))]
-
- "!satisfies_constraint_K (operands[2])"
-
- [(set (match_dup 3) (match_dup 1))
- (set (match_dup 0) (mult:SI (match_dup 3) (match_dup 2)))]
-
- "")
-
-\1f
-File: gccint.info, Node: Standard Names, Next: Pattern Ordering, Prev: Constraints, Up: Machine Desc
-
-16.9 Standard Pattern Names For Generation
-==========================================
-
-Here is a table of the instruction names that are meaningful in the RTL
-generation pass of the compiler. Giving one of these names to an
-instruction pattern tells the RTL generation pass that it can use the
-pattern to accomplish a certain task.
-
-`movM'
- Here M stands for a two-letter machine mode name, in lowercase.
- This instruction pattern moves data with that machine mode from
- operand 1 to operand 0. For example, `movsi' moves full-word data.
-
- If operand 0 is a `subreg' with mode M of a register whose own
- mode is wider than M, the effect of this instruction is to store
- the specified value in the part of the register that corresponds
- to mode M. Bits outside of M, but which are within the same
- target word as the `subreg' are undefined. Bits which are outside
- the target word are left unchanged.
-
- This class of patterns is special in several ways. First of all,
- each of these names up to and including full word size _must_ be
- defined, because there is no other way to copy a datum from one
- place to another. If there are patterns accepting operands in
- larger modes, `movM' must be defined for integer modes of those
- sizes.
-
- Second, these patterns are not used solely in the RTL generation
- pass. Even the reload pass can generate move insns to copy values
- from stack slots into temporary registers. When it does so, one
- of the operands is a hard register and the other is an operand
- that can need to be reloaded into a register.
-
- Therefore, when given such a pair of operands, the pattern must
- generate RTL which needs no reloading and needs no temporary
- registers--no registers other than the operands. For example, if
- you support the pattern with a `define_expand', then in such a
- case the `define_expand' mustn't call `force_reg' or any other such
- function which might generate new pseudo registers.
-
- This requirement exists even for subword modes on a RISC machine
- where fetching those modes from memory normally requires several
- insns and some temporary registers.
-
- During reload a memory reference with an invalid address may be
- passed as an operand. Such an address will be replaced with a
- valid address later in the reload pass. In this case, nothing may
- be done with the address except to use it as it stands. If it is
- copied, it will not be replaced with a valid address. No attempt
- should be made to make such an address into a valid address and no
- routine (such as `change_address') that will do so may be called.
- Note that `general_operand' will fail when applied to such an
- address.
-
- The global variable `reload_in_progress' (which must be explicitly
- declared if required) can be used to determine whether such special
- handling is required.
-
- The variety of operands that have reloads depends on the rest of
- the machine description, but typically on a RISC machine these can
- only be pseudo registers that did not get hard registers, while on
- other machines explicit memory references will get optional
- reloads.
-
- If a scratch register is required to move an object to or from
- memory, it can be allocated using `gen_reg_rtx' prior to life
- analysis.
-
- If there are cases which need scratch registers during or after
- reload, you must provide an appropriate secondary_reload target
- hook.
-
- The macro `can_create_pseudo_p' can be used to determine if it is
- unsafe to create new pseudo registers. If this variable is
- nonzero, then it is unsafe to call `gen_reg_rtx' to allocate a new
- pseudo.
-
- The constraints on a `movM' must permit moving any hard register
- to any other hard register provided that `HARD_REGNO_MODE_OK'
- permits mode M in both registers and `REGISTER_MOVE_COST' applied
- to their classes returns a value of 2.
-
- It is obligatory to support floating point `movM' instructions
- into and out of any registers that can hold fixed point values,
- because unions and structures (which have modes `SImode' or
- `DImode') can be in those registers and they may have floating
- point members.
-
- There may also be a need to support fixed point `movM'
- instructions in and out of floating point registers.
- Unfortunately, I have forgotten why this was so, and I don't know
- whether it is still true. If `HARD_REGNO_MODE_OK' rejects fixed
- point values in floating point registers, then the constraints of
- the fixed point `movM' instructions must be designed to avoid ever
- trying to reload into a floating point register.
-
-`reload_inM'
-`reload_outM'
- These named patterns have been obsoleted by the target hook
- `secondary_reload'.
-
- Like `movM', but used when a scratch register is required to move
- between operand 0 and operand 1. Operand 2 describes the scratch
- register. See the discussion of the `SECONDARY_RELOAD_CLASS'
- macro in *note Register Classes::.
-
- There are special restrictions on the form of the `match_operand's
- used in these patterns. First, only the predicate for the reload
- operand is examined, i.e., `reload_in' examines operand 1, but not
- the predicates for operand 0 or 2. Second, there may be only one
- alternative in the constraints. Third, only a single register
- class letter may be used for the constraint; subsequent constraint
- letters are ignored. As a special exception, an empty constraint
- string matches the `ALL_REGS' register class. This may relieve
- ports of the burden of defining an `ALL_REGS' constraint letter
- just for these patterns.
-
-`movstrictM'
- Like `movM' except that if operand 0 is a `subreg' with mode M of
- a register whose natural mode is wider, the `movstrictM'
- instruction is guaranteed not to alter any of the register except
- the part which belongs to mode M.
-
-`movmisalignM'
- This variant of a move pattern is designed to load or store a value
- from a memory address that is not naturally aligned for its mode.
- For a store, the memory will be in operand 0; for a load, the
- memory will be in operand 1. The other operand is guaranteed not
- to be a memory, so that it's easy to tell whether this is a load
- or store.
-
- This pattern is used by the autovectorizer, and when expanding a
- `MISALIGNED_INDIRECT_REF' expression.
-
-`load_multiple'
- Load several consecutive memory locations into consecutive
- registers. Operand 0 is the first of the consecutive registers,
- operand 1 is the first memory location, and operand 2 is a
- constant: the number of consecutive registers.
-
- Define this only if the target machine really has such an
- instruction; do not define this if the most efficient way of
- loading consecutive registers from memory is to do them one at a
- time.
-
- On some machines, there are restrictions as to which consecutive
- registers can be stored into memory, such as particular starting or
- ending register numbers or only a range of valid counts. For those
- machines, use a `define_expand' (*note Expander Definitions::) and
- make the pattern fail if the restrictions are not met.
-
- Write the generated insn as a `parallel' with elements being a
- `set' of one register from the appropriate memory location (you may
- also need `use' or `clobber' elements). Use a `match_parallel'
- (*note RTL Template::) to recognize the insn. See `rs6000.md' for
- examples of the use of this insn pattern.
-
-`store_multiple'
- Similar to `load_multiple', but store several consecutive registers
- into consecutive memory locations. Operand 0 is the first of the
- consecutive memory locations, operand 1 is the first register, and
- operand 2 is a constant: the number of consecutive registers.
-
-`vec_setM'
- Set given field in the vector value. Operand 0 is the vector to
- modify, operand 1 is new value of field and operand 2 specify the
- field index.
-
-`vec_extractM'
- Extract given field from the vector value. Operand 1 is the
- vector, operand 2 specify field index and operand 0 place to store
- value into.
-
-`vec_extract_evenM'
- Extract even elements from the input vectors (operand 1 and
- operand 2). The even elements of operand 2 are concatenated to
- the even elements of operand 1 in their original order. The result
- is stored in operand 0. The output and input vectors should have
- the same modes.
-
-`vec_extract_oddM'
- Extract odd elements from the input vectors (operand 1 and operand
- 2). The odd elements of operand 2 are concatenated to the odd
- elements of operand 1 in their original order. The result is
- stored in operand 0. The output and input vectors should have the
- same modes.
-
-`vec_interleave_highM'
- Merge high elements of the two input vectors into the output
- vector. The output and input vectors should have the same modes
- (`N' elements). The high `N/2' elements of the first input vector
- are interleaved with the high `N/2' elements of the second input
- vector.
-
-`vec_interleave_lowM'
- Merge low elements of the two input vectors into the output
- vector. The output and input vectors should have the same modes
- (`N' elements). The low `N/2' elements of the first input vector
- are interleaved with the low `N/2' elements of the second input
- vector.
-
-`vec_initM'
- Initialize the vector to given values. Operand 0 is the vector to
- initialize and operand 1 is parallel containing values for
- individual fields.
-
-`pushM1'
- Output a push instruction. Operand 0 is value to push. Used only
- when `PUSH_ROUNDING' is defined. For historical reason, this
- pattern may be missing and in such case an `mov' expander is used
- instead, with a `MEM' expression forming the push operation. The
- `mov' expander method is deprecated.
-
-`addM3'
- Add operand 2 and operand 1, storing the result in operand 0. All
- operands must have mode M. This can be used even on two-address
- machines, by means of constraints requiring operands 1 and 0 to be
- the same location.
-
-`ssaddM3', `usaddM3'
-
-`subM3', `sssubM3', `ussubM3'
-
-`mulM3', `ssmulM3', `usmulM3'
-`divM3', `ssdivM3'
-`udivM3', `usdivM3'
-`modM3', `umodM3'
-`uminM3', `umaxM3'
-`andM3', `iorM3', `xorM3'
- Similar, for other arithmetic operations.
-
-`sminM3', `smaxM3'
- Signed minimum and maximum operations. When used with floating
- point, if both operands are zeros, or if either operand is `NaN',
- then it is unspecified which of the two operands is returned as
- the result.
-
-`reduc_smin_M', `reduc_smax_M'
- Find the signed minimum/maximum of the elements of a vector. The
- vector is operand 1, and the scalar result is stored in the least
- significant bits of operand 0 (also a vector). The output and
- input vector should have the same modes.
-
-`reduc_umin_M', `reduc_umax_M'
- Find the unsigned minimum/maximum of the elements of a vector. The
- vector is operand 1, and the scalar result is stored in the least
- significant bits of operand 0 (also a vector). The output and
- input vector should have the same modes.
-
-`reduc_splus_M'
- Compute the sum of the signed elements of a vector. The vector is
- operand 1, and the scalar result is stored in the least
- significant bits of operand 0 (also a vector). The output and
- input vector should have the same modes.
-
-`reduc_uplus_M'
- Compute the sum of the unsigned elements of a vector. The vector
- is operand 1, and the scalar result is stored in the least
- significant bits of operand 0 (also a vector). The output and
- input vector should have the same modes.
-
-`sdot_prodM'
-
-`udot_prodM'
- Compute the sum of the products of two signed/unsigned elements.
- Operand 1 and operand 2 are of the same mode. Their product, which
- is of a wider mode, is computed and added to operand 3. Operand 3
- is of a mode equal or wider than the mode of the product. The
- result is placed in operand 0, which is of the same mode as
- operand 3.
-
-`ssum_widenM3'
-
-`usum_widenM3'
- Operands 0 and 2 are of the same mode, which is wider than the
- mode of operand 1. Add operand 1 to operand 2 and place the
- widened result in operand 0. (This is used express accumulation of
- elements into an accumulator of a wider mode.)
-
-`vec_shl_M', `vec_shr_M'
- Whole vector left/right shift in bits. Operand 1 is a vector to
- be shifted. Operand 2 is an integer shift amount in bits.
- Operand 0 is where the resulting shifted vector is stored. The
- output and input vectors should have the same modes.
-
-`vec_pack_trunc_M'
- Narrow (demote) and merge the elements of two vectors. Operands 1
- and 2 are vectors of the same mode having N integral or floating
- point elements of size S. Operand 0 is the resulting vector in
- which 2*N elements of size N/2 are concatenated after narrowing
- them down using truncation.
-
-`vec_pack_ssat_M', `vec_pack_usat_M'
- Narrow (demote) and merge the elements of two vectors. Operands 1
- and 2 are vectors of the same mode having N integral elements of
- size S. Operand 0 is the resulting vector in which the elements
- of the two input vectors are concatenated after narrowing them
- down using signed/unsigned saturating arithmetic.
-
-`vec_pack_sfix_trunc_M', `vec_pack_ufix_trunc_M'
- Narrow, convert to signed/unsigned integral type and merge the
- elements of two vectors. Operands 1 and 2 are vectors of the same
- mode having N floating point elements of size S. Operand 0 is the
- resulting vector in which 2*N elements of size N/2 are
- concatenated.
-
-`vec_unpacks_hi_M', `vec_unpacks_lo_M'
- Extract and widen (promote) the high/low part of a vector of signed
- integral or floating point elements. The input vector (operand 1)
- has N elements of size S. Widen (promote) the high/low elements
- of the vector using signed or floating point extension and place
- the resulting N/2 values of size 2*S in the output vector (operand
- 0).
-
-`vec_unpacku_hi_M', `vec_unpacku_lo_M'
- Extract and widen (promote) the high/low part of a vector of
- unsigned integral elements. The input vector (operand 1) has N
- elements of size S. Widen (promote) the high/low elements of the
- vector using zero extension and place the resulting N/2 values of
- size 2*S in the output vector (operand 0).
-
-`vec_unpacks_float_hi_M', `vec_unpacks_float_lo_M'
-`vec_unpacku_float_hi_M', `vec_unpacku_float_lo_M'
- Extract, convert to floating point type and widen the high/low
- part of a vector of signed/unsigned integral elements. The input
- vector (operand 1) has N elements of size S. Convert the high/low
- elements of the vector using floating point conversion and place
- the resulting N/2 values of size 2*S in the output vector (operand
- 0).
-
-`vec_widen_umult_hi_M', `vec_widen_umult_lo_M'
-`vec_widen_smult_hi_M', `vec_widen_smult_lo_M'
- Signed/Unsigned widening multiplication. The two inputs (operands
- 1 and 2) are vectors with N signed/unsigned elements of size S.
- Multiply the high/low elements of the two vectors, and put the N/2
- products of size 2*S in the output vector (operand 0).
-
-`mulhisi3'
- Multiply operands 1 and 2, which have mode `HImode', and store a
- `SImode' product in operand 0.
-
-`mulqihi3', `mulsidi3'
- Similar widening-multiplication instructions of other widths.
-
-`umulqihi3', `umulhisi3', `umulsidi3'
- Similar widening-multiplication instructions that do unsigned
- multiplication.
-
-`usmulqihi3', `usmulhisi3', `usmulsidi3'
- Similar widening-multiplication instructions that interpret the
- first operand as unsigned and the second operand as signed, then
- do a signed multiplication.
-
-`smulM3_highpart'
- Perform a signed multiplication of operands 1 and 2, which have
- mode M, and store the most significant half of the product in
- operand 0. The least significant half of the product is discarded.
-
-`umulM3_highpart'
- Similar, but the multiplication is unsigned.
-
-`maddMN4'
- Multiply operands 1 and 2, sign-extend them to mode N, add operand
- 3, and store the result in operand 0. Operands 1 and 2 have mode
- M and operands 0 and 3 have mode N. Both modes must be integer or
- fixed-point modes and N must be twice the size of M.
-
- In other words, `maddMN4' is like `mulMN3' except that it also
- adds operand 3.
-
- These instructions are not allowed to `FAIL'.
-
-`umaddMN4'
- Like `maddMN4', but zero-extend the multiplication operands
- instead of sign-extending them.
-
-`ssmaddMN4'
- Like `maddMN4', but all involved operations must be
- signed-saturating.
-
-`usmaddMN4'
- Like `umaddMN4', but all involved operations must be
- unsigned-saturating.
-
-`msubMN4'
- Multiply operands 1 and 2, sign-extend them to mode N, subtract the
- result from operand 3, and store the result in operand 0.
- Operands 1 and 2 have mode M and operands 0 and 3 have mode N.
- Both modes must be integer or fixed-point modes and N must be twice
- the size of M.
-
- In other words, `msubMN4' is like `mulMN3' except that it also
- subtracts the result from operand 3.
-
- These instructions are not allowed to `FAIL'.
-
-`umsubMN4'
- Like `msubMN4', but zero-extend the multiplication operands
- instead of sign-extending them.
-
-`ssmsubMN4'
- Like `msubMN4', but all involved operations must be
- signed-saturating.
-
-`usmsubMN4'
- Like `umsubMN4', but all involved operations must be
- unsigned-saturating.
-
-`divmodM4'
- Signed division that produces both a quotient and a remainder.
- Operand 1 is divided by operand 2 to produce a quotient stored in
- operand 0 and a remainder stored in operand 3.
-
- For machines with an instruction that produces both a quotient and
- a remainder, provide a pattern for `divmodM4' but do not provide
- patterns for `divM3' and `modM3'. This allows optimization in the
- relatively common case when both the quotient and remainder are
- computed.
-
- If an instruction that just produces a quotient or just a remainder
- exists and is more efficient than the instruction that produces
- both, write the output routine of `divmodM4' to call
- `find_reg_note' and look for a `REG_UNUSED' note on the quotient
- or remainder and generate the appropriate instruction.
-
-`udivmodM4'
- Similar, but does unsigned division.
-
-`ashlM3', `ssashlM3', `usashlM3'
- Arithmetic-shift operand 1 left by a number of bits specified by
- operand 2, and store the result in operand 0. Here M is the mode
- of operand 0 and operand 1; operand 2's mode is specified by the
- instruction pattern, and the compiler will convert the operand to
- that mode before generating the instruction. The meaning of
- out-of-range shift counts can optionally be specified by
- `TARGET_SHIFT_TRUNCATION_MASK'. *Note
- TARGET_SHIFT_TRUNCATION_MASK::. Operand 2 is always a scalar type.
-
-`ashrM3', `lshrM3', `rotlM3', `rotrM3'
- Other shift and rotate instructions, analogous to the `ashlM3'
- instructions. Operand 2 is always a scalar type.
-
-`vashlM3', `vashrM3', `vlshrM3', `vrotlM3', `vrotrM3'
- Vector shift and rotate instructions that take vectors as operand 2
- instead of a scalar type.
-
-`negM2', `ssnegM2', `usnegM2'
- Negate operand 1 and store the result in operand 0.
-
-`absM2'
- Store the absolute value of operand 1 into operand 0.
-
-`sqrtM2'
- Store the square root of operand 1 into operand 0.
-
- The `sqrt' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `sqrtf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`fmodM3'
- Store the remainder of dividing operand 1 by operand 2 into
- operand 0, rounded towards zero to an integer.
-
- The `fmod' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `fmodf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`remainderM3'
- Store the remainder of dividing operand 1 by operand 2 into
- operand 0, rounded to the nearest integer.
-
- The `remainder' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `remainderf'
- built-in function uses the mode which corresponds to the C data
- type `float'.
-
-`cosM2'
- Store the cosine of operand 1 into operand 0.
-
- The `cos' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `cosf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`sinM2'
- Store the sine of operand 1 into operand 0.
-
- The `sin' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `sinf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`expM2'
- Store the exponential of operand 1 into operand 0.
-
- The `exp' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `expf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`logM2'
- Store the natural logarithm of operand 1 into operand 0.
-
- The `log' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `logf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`powM3'
- Store the value of operand 1 raised to the exponent operand 2 into
- operand 0.
-
- The `pow' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `powf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`atan2M3'
- Store the arc tangent (inverse tangent) of operand 1 divided by
- operand 2 into operand 0, using the signs of both arguments to
- determine the quadrant of the result.
-
- The `atan2' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `atan2f' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`floorM2'
- Store the largest integral value not greater than argument.
-
- The `floor' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `floorf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`btruncM2'
- Store the argument rounded to integer towards zero.
-
- The `trunc' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `truncf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`roundM2'
- Store the argument rounded to integer away from zero.
-
- The `round' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `roundf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`ceilM2'
- Store the argument rounded to integer away from zero.
-
- The `ceil' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `ceilf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`nearbyintM2'
- Store the argument rounded according to the default rounding mode
-
- The `nearbyint' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `nearbyintf'
- built-in function uses the mode which corresponds to the C data
- type `float'.
-
-`rintM2'
- Store the argument rounded according to the default rounding mode
- and raise the inexact exception when the result differs in value
- from the argument
-
- The `rint' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `rintf' built-in
- function uses the mode which corresponds to the C data type
- `float'.
-
-`lrintMN2'
- Convert operand 1 (valid for floating point mode M) to fixed point
- mode N as a signed number according to the current rounding mode
- and store in operand 0 (which has mode N).
-
-`lroundM2'
- Convert operand 1 (valid for floating point mode M) to fixed point
- mode N as a signed number rounding to nearest and away from zero
- and store in operand 0 (which has mode N).
-
-`lfloorM2'
- Convert operand 1 (valid for floating point mode M) to fixed point
- mode N as a signed number rounding down and store in operand 0
- (which has mode N).
-
-`lceilM2'
- Convert operand 1 (valid for floating point mode M) to fixed point
- mode N as a signed number rounding up and store in operand 0
- (which has mode N).
-
-`copysignM3'
- Store a value with the magnitude of operand 1 and the sign of
- operand 2 into operand 0.
-
- The `copysign' built-in function of C always uses the mode which
- corresponds to the C data type `double' and the `copysignf'
- built-in function uses the mode which corresponds to the C data
- type `float'.
-
-`ffsM2'
- Store into operand 0 one plus the index of the least significant
- 1-bit of operand 1. If operand 1 is zero, store zero. M is the
- mode of operand 0; operand 1's mode is specified by the instruction
- pattern, and the compiler will convert the operand to that mode
- before generating the instruction.
-
- The `ffs' built-in function of C always uses the mode which
- corresponds to the C data type `int'.
-
-`clzM2'
- Store into operand 0 the number of leading 0-bits in X, starting
- at the most significant bit position. If X is 0, the
- `CLZ_DEFINED_VALUE_AT_ZERO' (*note Misc::) macro defines if the
- result is undefined or has a useful value. M is the mode of
- operand 0; operand 1's mode is specified by the instruction
- pattern, and the compiler will convert the operand to that mode
- before generating the instruction.
-
-`ctzM2'
- Store into operand 0 the number of trailing 0-bits in X, starting
- at the least significant bit position. If X is 0, the
- `CTZ_DEFINED_VALUE_AT_ZERO' (*note Misc::) macro defines if the
- result is undefined or has a useful value. M is the mode of
- operand 0; operand 1's mode is specified by the instruction
- pattern, and the compiler will convert the operand to that mode
- before generating the instruction.
-
-`popcountM2'
- Store into operand 0 the number of 1-bits in X. M is the mode of
- operand 0; operand 1's mode is specified by the instruction
- pattern, and the compiler will convert the operand to that mode
- before generating the instruction.
-
-`parityM2'
- Store into operand 0 the parity of X, i.e. the number of 1-bits in
- X modulo 2. M is the mode of operand 0; operand 1's mode is
- specified by the instruction pattern, and the compiler will convert
- the operand to that mode before generating the instruction.
-
-`one_cmplM2'
- Store the bitwise-complement of operand 1 into operand 0.
-
-`cmpM'
- Compare operand 0 and operand 1, and set the condition codes. The
- RTL pattern should look like this:
-
- (set (cc0) (compare (match_operand:M 0 ...)
- (match_operand:M 1 ...)))
-
-`tstM'
- Compare operand 0 against zero, and set the condition codes. The
- RTL pattern should look like this:
-
- (set (cc0) (match_operand:M 0 ...))
-
- `tstM' patterns should not be defined for machines that do not use
- `(cc0)'. Doing so would confuse the optimizer since it would no
- longer be clear which `set' operations were comparisons. The
- `cmpM' patterns should be used instead.
-
-`movmemM'
- Block move instruction. The destination and source blocks of
- memory are the first two operands, and both are `mem:BLK's with an
- address in mode `Pmode'.
-
- The number of bytes to move is the third operand, in mode M.
- Usually, you specify `word_mode' for M. However, if you can
- generate better code knowing the range of valid lengths is smaller
- than those representable in a full word, you should provide a
- pattern with a mode corresponding to the range of values you can
- handle efficiently (e.g., `QImode' for values in the range 0-127;
- note we avoid numbers that appear negative) and also a pattern
- with `word_mode'.
-
- The fourth operand is the known shared alignment of the source and
- destination, in the form of a `const_int' rtx. Thus, if the
- compiler knows that both source and destination are word-aligned,
- it may provide the value 4 for this operand.
-
- Optional operands 5 and 6 specify expected alignment and size of
- block respectively. The expected alignment differs from alignment
- in operand 4 in a way that the blocks are not required to be
- aligned according to it in all cases. This expected alignment is
- also in bytes, just like operand 4. Expected size, when unknown,
- is set to `(const_int -1)'.
-
- Descriptions of multiple `movmemM' patterns can only be beneficial
- if the patterns for smaller modes have fewer restrictions on their
- first, second and fourth operands. Note that the mode M in
- `movmemM' does not impose any restriction on the mode of
- individually moved data units in the block.
-
- These patterns need not give special consideration to the
- possibility that the source and destination strings might overlap.
-
-`movstr'
- String copy instruction, with `stpcpy' semantics. Operand 0 is an
- output operand in mode `Pmode'. The addresses of the destination
- and source strings are operands 1 and 2, and both are `mem:BLK's
- with addresses in mode `Pmode'. The execution of the expansion of
- this pattern should store in operand 0 the address in which the
- `NUL' terminator was stored in the destination string.
-
-`setmemM'
- Block set instruction. The destination string is the first
- operand, given as a `mem:BLK' whose address is in mode `Pmode'.
- The number of bytes to set is the second operand, in mode M. The
- value to initialize the memory with is the third operand. Targets
- that only support the clearing of memory should reject any value
- that is not the constant 0. See `movmemM' for a discussion of the
- choice of mode.
-
- The fourth operand is the known alignment of the destination, in
- the form of a `const_int' rtx. Thus, if the compiler knows that
- the destination is word-aligned, it may provide the value 4 for
- this operand.
-
- Optional operands 5 and 6 specify expected alignment and size of
- block respectively. The expected alignment differs from alignment
- in operand 4 in a way that the blocks are not required to be
- aligned according to it in all cases. This expected alignment is
- also in bytes, just like operand 4. Expected size, when unknown,
- is set to `(const_int -1)'.
-
- The use for multiple `setmemM' is as for `movmemM'.
-
-`cmpstrnM'
- String compare instruction, with five operands. Operand 0 is the
- output; it has mode M. The remaining four operands are like the
- operands of `movmemM'. The two memory blocks specified are
- compared byte by byte in lexicographic order starting at the
- beginning of each string. The instruction is not allowed to
- prefetch more than one byte at a time since either string may end
- in the first byte and reading past that may access an invalid page
- or segment and cause a fault. The effect of the instruction is to
- store a value in operand 0 whose sign indicates the result of the
- comparison.
-
-`cmpstrM'
- String compare instruction, without known maximum length. Operand
- 0 is the output; it has mode M. The second and third operand are
- the blocks of memory to be compared; both are `mem:BLK' with an
- address in mode `Pmode'.
-
- The fourth operand is the known shared alignment of the source and
- destination, in the form of a `const_int' rtx. Thus, if the
- compiler knows that both source and destination are word-aligned,
- it may provide the value 4 for this operand.
-
- The two memory blocks specified are compared byte by byte in
- lexicographic order starting at the beginning of each string. The
- instruction is not allowed to prefetch more than one byte at a
- time since either string may end in the first byte and reading
- past that may access an invalid page or segment and cause a fault.
- The effect of the instruction is to store a value in operand 0
- whose sign indicates the result of the comparison.
-
-`cmpmemM'
- Block compare instruction, with five operands like the operands of
- `cmpstrM'. The two memory blocks specified are compared byte by
- byte in lexicographic order starting at the beginning of each
- block. Unlike `cmpstrM' the instruction can prefetch any bytes in
- the two memory blocks. The effect of the instruction is to store
- a value in operand 0 whose sign indicates the result of the
- comparison.
-
-`strlenM'
- Compute the length of a string, with three operands. Operand 0 is
- the result (of mode M), operand 1 is a `mem' referring to the
- first character of the string, operand 2 is the character to
- search for (normally zero), and operand 3 is a constant describing
- the known alignment of the beginning of the string.
-
-`floatMN2'
- Convert signed integer operand 1 (valid for fixed point mode M) to
- floating point mode N and store in operand 0 (which has mode N).
-
-`floatunsMN2'
- Convert unsigned integer operand 1 (valid for fixed point mode M)
- to floating point mode N and store in operand 0 (which has mode N).
-
-`fixMN2'
- Convert operand 1 (valid for floating point mode M) to fixed point
- mode N as a signed number and store in operand 0 (which has mode
- N). This instruction's result is defined only when the value of
- operand 1 is an integer.
-
- If the machine description defines this pattern, it also needs to
- define the `ftrunc' pattern.
-
-`fixunsMN2'
- Convert operand 1 (valid for floating point mode M) to fixed point
- mode N as an unsigned number and store in operand 0 (which has
- mode N). This instruction's result is defined only when the value
- of operand 1 is an integer.
-
-`ftruncM2'
- Convert operand 1 (valid for floating point mode M) to an integer
- value, still represented in floating point mode M, and store it in
- operand 0 (valid for floating point mode M).
-
-`fix_truncMN2'
- Like `fixMN2' but works for any floating point value of mode M by
- converting the value to an integer.
-
-`fixuns_truncMN2'
- Like `fixunsMN2' but works for any floating point value of mode M
- by converting the value to an integer.
-
-`truncMN2'
- Truncate operand 1 (valid for mode M) to mode N and store in
- operand 0 (which has mode N). Both modes must be fixed point or
- both floating point.
-
-`extendMN2'
- Sign-extend operand 1 (valid for mode M) to mode N and store in
- operand 0 (which has mode N). Both modes must be fixed point or
- both floating point.
-
-`zero_extendMN2'
- Zero-extend operand 1 (valid for mode M) to mode N and store in
- operand 0 (which has mode N). Both modes must be fixed point.
-
-`fractMN2'
- Convert operand 1 of mode M to mode N and store in operand 0
- (which has mode N). Mode M and mode N could be fixed-point to
- fixed-point, signed integer to fixed-point, fixed-point to signed
- integer, floating-point to fixed-point, or fixed-point to
- floating-point. When overflows or underflows happen, the results
- are undefined.
-
-`satfractMN2'
- Convert operand 1 of mode M to mode N and store in operand 0
- (which has mode N). Mode M and mode N could be fixed-point to
- fixed-point, signed integer to fixed-point, or floating-point to
- fixed-point. When overflows or underflows happen, the instruction
- saturates the results to the maximum or the minimum.
-
-`fractunsMN2'
- Convert operand 1 of mode M to mode N and store in operand 0
- (which has mode N). Mode M and mode N could be unsigned integer
- to fixed-point, or fixed-point to unsigned integer. When
- overflows or underflows happen, the results are undefined.
-
-`satfractunsMN2'
- Convert unsigned integer operand 1 of mode M to fixed-point mode N
- and store in operand 0 (which has mode N). When overflows or
- underflows happen, the instruction saturates the results to the
- maximum or the minimum.
-
-`extv'
- Extract a bit-field from operand 1 (a register or memory operand),
- where operand 2 specifies the width in bits and operand 3 the
- starting bit, and store it in operand 0. Operand 0 must have mode
- `word_mode'. Operand 1 may have mode `byte_mode' or `word_mode';
- often `word_mode' is allowed only for registers. Operands 2 and 3
- must be valid for `word_mode'.
-
- The RTL generation pass generates this instruction only with
- constants for operands 2 and 3 and the constant is never zero for
- operand 2.
-
- The bit-field value is sign-extended to a full word integer before
- it is stored in operand 0.
-
-`extzv'
- Like `extv' except that the bit-field value is zero-extended.
-
-`insv'
- Store operand 3 (which must be valid for `word_mode') into a
- bit-field in operand 0, where operand 1 specifies the width in
- bits and operand 2 the starting bit. Operand 0 may have mode
- `byte_mode' or `word_mode'; often `word_mode' is allowed only for
- registers. Operands 1 and 2 must be valid for `word_mode'.
-
- The RTL generation pass generates this instruction only with
- constants for operands 1 and 2 and the constant is never zero for
- operand 1.
-
-`movMODEcc'
- Conditionally move operand 2 or operand 3 into operand 0 according
- to the comparison in operand 1. If the comparison is true,
- operand 2 is moved into operand 0, otherwise operand 3 is moved.
-
- The mode of the operands being compared need not be the same as
- the operands being moved. Some machines, sparc64 for example,
- have instructions that conditionally move an integer value based
- on the floating point condition codes and vice versa.
-
- If the machine does not have conditional move instructions, do not
- define these patterns.
-
-`addMODEcc'
- Similar to `movMODEcc' but for conditional addition. Conditionally
- move operand 2 or (operands 2 + operand 3) into operand 0
- according to the comparison in operand 1. If the comparison is
- true, operand 2 is moved into operand 0, otherwise (operand 2 +
- operand 3) is moved.
-
-`sCOND'
- Store zero or nonzero in the operand according to the condition
- codes. Value stored is nonzero iff the condition COND is true.
- COND is the name of a comparison operation expression code, such
- as `eq', `lt' or `leu'.
-
- You specify the mode that the operand must have when you write the
- `match_operand' expression. The compiler automatically sees which
- mode you have used and supplies an operand of that mode.
-
- The value stored for a true condition must have 1 as its low bit,
- or else must be negative. Otherwise the instruction is not
- suitable and you should omit it from the machine description. You
- describe to the compiler exactly which value is stored by defining
- the macro `STORE_FLAG_VALUE' (*note Misc::). If a description
- cannot be found that can be used for all the `sCOND' patterns, you
- should omit those operations from the machine description.
-
- These operations may fail, but should do so only in relatively
- uncommon cases; if they would fail for common cases involving
- integer comparisons, it is best to omit these patterns.
-
- If these operations are omitted, the compiler will usually
- generate code that copies the constant one to the target and
- branches around an assignment of zero to the target. If this code
- is more efficient than the potential instructions used for the
- `sCOND' pattern followed by those required to convert the result
- into a 1 or a zero in `SImode', you should omit the `sCOND'
- operations from the machine description.
-
-`bCOND'
- Conditional branch instruction. Operand 0 is a `label_ref' that
- refers to the label to jump to. Jump if the condition codes meet
- condition COND.
-
- Some machines do not follow the model assumed here where a
- comparison instruction is followed by a conditional branch
- instruction. In that case, the `cmpM' (and `tstM') patterns should
- simply store the operands away and generate all the required insns
- in a `define_expand' (*note Expander Definitions::) for the
- conditional branch operations. All calls to expand `bCOND'
- patterns are immediately preceded by calls to expand either a
- `cmpM' pattern or a `tstM' pattern.
-
- Machines that use a pseudo register for the condition code value,
- or where the mode used for the comparison depends on the condition
- being tested, should also use the above mechanism. *Note Jump
- Patterns::.
-
- The above discussion also applies to the `movMODEcc' and `sCOND'
- patterns.
-
-`cbranchMODE4'
- Conditional branch instruction combined with a compare instruction.
- Operand 0 is a comparison operator. Operand 1 and operand 2 are
- the first and second operands of the comparison, respectively.
- Operand 3 is a `label_ref' that refers to the label to jump to.
-
-`jump'
- A jump inside a function; an unconditional branch. Operand 0 is
- the `label_ref' of the label to jump to. This pattern name is
- mandatory on all machines.
-
-`call'
- Subroutine call instruction returning no value. Operand 0 is the
- function to call; operand 1 is the number of bytes of arguments
- pushed as a `const_int'; operand 2 is the number of registers used
- as operands.
-
- On most machines, operand 2 is not actually stored into the RTL
- pattern. It is supplied for the sake of some RISC machines which
- need to put this information into the assembler code; they can put
- it in the RTL instead of operand 1.
-
- Operand 0 should be a `mem' RTX whose address is the address of the
- function. Note, however, that this address can be a `symbol_ref'
- expression even if it would not be a legitimate memory address on
- the target machine. If it is also not a valid argument for a call
- instruction, the pattern for this operation should be a
- `define_expand' (*note Expander Definitions::) that places the
- address into a register and uses that register in the call
- instruction.
-
-`call_value'
- Subroutine call instruction returning a value. Operand 0 is the
- hard register in which the value is returned. There are three more
- operands, the same as the three operands of the `call' instruction
- (but with numbers increased by one).
-
- Subroutines that return `BLKmode' objects use the `call' insn.
-
-`call_pop', `call_value_pop'
- Similar to `call' and `call_value', except used if defined and if
- `RETURN_POPS_ARGS' is nonzero. They should emit a `parallel' that
- contains both the function call and a `set' to indicate the
- adjustment made to the frame pointer.
-
- For machines where `RETURN_POPS_ARGS' can be nonzero, the use of
- these patterns increases the number of functions for which the
- frame pointer can be eliminated, if desired.
-
-`untyped_call'
- Subroutine call instruction returning a value of any type.
- Operand 0 is the function to call; operand 1 is a memory location
- where the result of calling the function is to be stored; operand
- 2 is a `parallel' expression where each element is a `set'
- expression that indicates the saving of a function return value
- into the result block.
-
- This instruction pattern should be defined to support
- `__builtin_apply' on machines where special instructions are needed
- to call a subroutine with arbitrary arguments or to save the value
- returned. This instruction pattern is required on machines that
- have multiple registers that can hold a return value (i.e.
- `FUNCTION_VALUE_REGNO_P' is true for more than one register).
-
-`return'
- Subroutine return instruction. This instruction pattern name
- should be defined only if a single instruction can do all the work
- of returning from a function.
-
- Like the `movM' patterns, this pattern is also used after the RTL
- generation phase. In this case it is to support machines where
- multiple instructions are usually needed to return from a
- function, but some class of functions only requires one
- instruction to implement a return. Normally, the applicable
- functions are those which do not need to save any registers or
- allocate stack space.
-
- For such machines, the condition specified in this pattern should
- only be true when `reload_completed' is nonzero and the function's
- epilogue would only be a single instruction. For machines with
- register windows, the routine `leaf_function_p' may be used to
- determine if a register window push is required.
-
- Machines that have conditional return instructions should define
- patterns such as
-
- (define_insn ""
- [(set (pc)
- (if_then_else (match_operator
- 0 "comparison_operator"
- [(cc0) (const_int 0)])
- (return)
- (pc)))]
- "CONDITION"
- "...")
-
- where CONDITION would normally be the same condition specified on
- the named `return' pattern.
-
-`untyped_return'
- Untyped subroutine return instruction. This instruction pattern
- should be defined to support `__builtin_return' on machines where
- special instructions are needed to return a value of any type.
-
- Operand 0 is a memory location where the result of calling a
- function with `__builtin_apply' is stored; operand 1 is a
- `parallel' expression where each element is a `set' expression
- that indicates the restoring of a function return value from the
- result block.
-
-`nop'
- No-op instruction. This instruction pattern name should always be
- defined to output a no-op in assembler code. `(const_int 0)' will
- do as an RTL pattern.
-
-`indirect_jump'
- An instruction to jump to an address which is operand zero. This
- pattern name is mandatory on all machines.
-
-`casesi'
- Instruction to jump through a dispatch table, including bounds
- checking. This instruction takes five operands:
-
- 1. The index to dispatch on, which has mode `SImode'.
-
- 2. The lower bound for indices in the table, an integer constant.
-
- 3. The total range of indices in the table--the largest index
- minus the smallest one (both inclusive).
-
- 4. A label that precedes the table itself.
-
- 5. A label to jump to if the index has a value outside the
- bounds.
-
- The table is a `addr_vec' or `addr_diff_vec' inside of a
- `jump_insn'. The number of elements in the table is one plus the
- difference between the upper bound and the lower bound.
-
-`tablejump'
- Instruction to jump to a variable address. This is a low-level
- capability which can be used to implement a dispatch table when
- there is no `casesi' pattern.
-
- This pattern requires two operands: the address or offset, and a
- label which should immediately precede the jump table. If the
- macro `CASE_VECTOR_PC_RELATIVE' evaluates to a nonzero value then
- the first operand is an offset which counts from the address of
- the table; otherwise, it is an absolute address to jump to. In
- either case, the first operand has mode `Pmode'.
-
- The `tablejump' insn is always the last insn before the jump table
- it uses. Its assembler code normally has no need to use the
- second operand, but you should incorporate it in the RTL pattern so
- that the jump optimizer will not delete the table as unreachable
- code.
-
-`decrement_and_branch_until_zero'
- Conditional branch instruction that decrements a register and
- jumps if the register is nonzero. Operand 0 is the register to
- decrement and test; operand 1 is the label to jump to if the
- register is nonzero. *Note Looping Patterns::.
-
- This optional instruction pattern is only used by the combiner,
- typically for loops reversed by the loop optimizer when strength
- reduction is enabled.
-
-`doloop_end'
- Conditional branch instruction that decrements a register and
- jumps if the register is nonzero. This instruction takes five
- operands: Operand 0 is the register to decrement and test; operand
- 1 is the number of loop iterations as a `const_int' or
- `const0_rtx' if this cannot be determined until run-time; operand
- 2 is the actual or estimated maximum number of iterations as a
- `const_int'; operand 3 is the number of enclosed loops as a
- `const_int' (an innermost loop has a value of 1); operand 4 is the
- label to jump to if the register is nonzero. *Note Looping
- Patterns::.
-
- This optional instruction pattern should be defined for machines
- with low-overhead looping instructions as the loop optimizer will
- try to modify suitable loops to utilize it. If nested
- low-overhead looping is not supported, use a `define_expand'
- (*note Expander Definitions::) and make the pattern fail if
- operand 3 is not `const1_rtx'. Similarly, if the actual or
- estimated maximum number of iterations is too large for this
- instruction, make it fail.
-
-`doloop_begin'
- Companion instruction to `doloop_end' required for machines that
- need to perform some initialization, such as loading special
- registers used by a low-overhead looping instruction. If
- initialization insns do not always need to be emitted, use a
- `define_expand' (*note Expander Definitions::) and make it fail.
-
-`canonicalize_funcptr_for_compare'
- Canonicalize the function pointer in operand 1 and store the result
- into operand 0.
-
- Operand 0 is always a `reg' and has mode `Pmode'; operand 1 may be
- a `reg', `mem', `symbol_ref', `const_int', etc and also has mode
- `Pmode'.
-
- Canonicalization of a function pointer usually involves computing
- the address of the function which would be called if the function
- pointer were used in an indirect call.
-
- Only define this pattern if function pointers on the target machine
- can have different values but still call the same function when
- used in an indirect call.
-
-`save_stack_block'
-`save_stack_function'
-`save_stack_nonlocal'
-`restore_stack_block'
-`restore_stack_function'
-`restore_stack_nonlocal'
- Most machines save and restore the stack pointer by copying it to
- or from an object of mode `Pmode'. Do not define these patterns on
- such machines.
-
- Some machines require special handling for stack pointer saves and
- restores. On those machines, define the patterns corresponding to
- the non-standard cases by using a `define_expand' (*note Expander
- Definitions::) that produces the required insns. The three types
- of saves and restores are:
-
- 1. `save_stack_block' saves the stack pointer at the start of a
- block that allocates a variable-sized object, and
- `restore_stack_block' restores the stack pointer when the
- block is exited.
-
- 2. `save_stack_function' and `restore_stack_function' do a
- similar job for the outermost block of a function and are
- used when the function allocates variable-sized objects or
- calls `alloca'. Only the epilogue uses the restored stack
- pointer, allowing a simpler save or restore sequence on some
- machines.
-
- 3. `save_stack_nonlocal' is used in functions that contain labels
- branched to by nested functions. It saves the stack pointer
- in such a way that the inner function can use
- `restore_stack_nonlocal' to restore the stack pointer. The
- compiler generates code to restore the frame and argument
- pointer registers, but some machines require saving and
- restoring additional data such as register window information
- or stack backchains. Place insns in these patterns to save
- and restore any such required data.
-
- When saving the stack pointer, operand 0 is the save area and
- operand 1 is the stack pointer. The mode used to allocate the
- save area defaults to `Pmode' but you can override that choice by
- defining the `STACK_SAVEAREA_MODE' macro (*note Storage Layout::).
- You must specify an integral mode, or `VOIDmode' if no save area
- is needed for a particular type of save (either because no save is
- needed or because a machine-specific save area can be used).
- Operand 0 is the stack pointer and operand 1 is the save area for
- restore operations. If `save_stack_block' is defined, operand 0
- must not be `VOIDmode' since these saves can be arbitrarily nested.
-
- A save area is a `mem' that is at a constant offset from
- `virtual_stack_vars_rtx' when the stack pointer is saved for use by
- nonlocal gotos and a `reg' in the other two cases.
-
-`allocate_stack'
- Subtract (or add if `STACK_GROWS_DOWNWARD' is undefined) operand 1
- from the stack pointer to create space for dynamically allocated
- data.
-
- Store the resultant pointer to this space into operand 0. If you
- are allocating space from the main stack, do this by emitting a
- move insn to copy `virtual_stack_dynamic_rtx' to operand 0. If
- you are allocating the space elsewhere, generate code to copy the
- location of the space to operand 0. In the latter case, you must
- ensure this space gets freed when the corresponding space on the
- main stack is free.
-
- Do not define this pattern if all that must be done is the
- subtraction. Some machines require other operations such as stack
- probes or maintaining the back chain. Define this pattern to emit
- those operations in addition to updating the stack pointer.
-
-`check_stack'
- If stack checking cannot be done on your system by probing the
- stack with a load or store instruction (*note Stack Checking::),
- define this pattern to perform the needed check and signaling an
- error if the stack has overflowed. The single operand is the
- location in the stack furthest from the current stack pointer that
- you need to validate. Normally, on machines where this pattern is
- needed, you would obtain the stack limit from a global or
- thread-specific variable or register.
-
-`nonlocal_goto'
- Emit code to generate a non-local goto, e.g., a jump from one
- function to a label in an outer function. This pattern has four
- arguments, each representing a value to be used in the jump. The
- first argument is to be loaded into the frame pointer, the second
- is the address to branch to (code to dispatch to the actual label),
- the third is the address of a location where the stack is saved,
- and the last is the address of the label, to be placed in the
- location for the incoming static chain.
-
- On most machines you need not define this pattern, since GCC will
- already generate the correct code, which is to load the frame
- pointer and static chain, restore the stack (using the
- `restore_stack_nonlocal' pattern, if defined), and jump indirectly
- to the dispatcher. You need only define this pattern if this code
- will not work on your machine.
-
-`nonlocal_goto_receiver'
- This pattern, if defined, contains code needed at the target of a
- nonlocal goto after the code already generated by GCC. You will
- not normally need to define this pattern. A typical reason why
- you might need this pattern is if some value, such as a pointer to
- a global table, must be restored when the frame pointer is
- restored. Note that a nonlocal goto only occurs within a
- unit-of-translation, so a global table pointer that is shared by
- all functions of a given module need not be restored. There are
- no arguments.
-
-`exception_receiver'
- This pattern, if defined, contains code needed at the site of an
- exception handler that isn't needed at the site of a nonlocal
- goto. You will not normally need to define this pattern. A
- typical reason why you might need this pattern is if some value,
- such as a pointer to a global table, must be restored after
- control flow is branched to the handler of an exception. There
- are no arguments.
-
-`builtin_setjmp_setup'
- This pattern, if defined, contains additional code needed to
- initialize the `jmp_buf'. You will not normally need to define
- this pattern. A typical reason why you might need this pattern is
- if some value, such as a pointer to a global table, must be
- restored. Though it is preferred that the pointer value be
- recalculated if possible (given the address of a label for
- instance). The single argument is a pointer to the `jmp_buf'.
- Note that the buffer is five words long and that the first three
- are normally used by the generic mechanism.
-
-`builtin_setjmp_receiver'
- This pattern, if defined, contains code needed at the site of an
- built-in setjmp that isn't needed at the site of a nonlocal goto.
- You will not normally need to define this pattern. A typical
- reason why you might need this pattern is if some value, such as a
- pointer to a global table, must be restored. It takes one
- argument, which is the label to which builtin_longjmp transfered
- control; this pattern may be emitted at a small offset from that
- label.
-
-`builtin_longjmp'
- This pattern, if defined, performs the entire action of the
- longjmp. You will not normally need to define this pattern unless
- you also define `builtin_setjmp_setup'. The single argument is a
- pointer to the `jmp_buf'.
-
-`eh_return'
- This pattern, if defined, affects the way `__builtin_eh_return',
- and thence the call frame exception handling library routines, are
- built. It is intended to handle non-trivial actions needed along
- the abnormal return path.
-
- The address of the exception handler to which the function should
- return is passed as operand to this pattern. It will normally
- need to copied by the pattern to some special register or memory
- location. If the pattern needs to determine the location of the
- target call frame in order to do so, it may use
- `EH_RETURN_STACKADJ_RTX', if defined; it will have already been
- assigned.
-
- If this pattern is not defined, the default action will be to
- simply copy the return address to `EH_RETURN_HANDLER_RTX'. Either
- that macro or this pattern needs to be defined if call frame
- exception handling is to be used.
-
-`prologue'
- This pattern, if defined, emits RTL for entry to a function. The
- function entry is responsible for setting up the stack frame,
- initializing the frame pointer register, saving callee saved
- registers, etc.
-
- Using a prologue pattern is generally preferred over defining
- `TARGET_ASM_FUNCTION_PROLOGUE' to emit assembly code for the
- prologue.
-
- The `prologue' pattern is particularly useful for targets which
- perform instruction scheduling.
-
-`epilogue'
- This pattern emits RTL for exit from a function. The function
- exit is responsible for deallocating the stack frame, restoring
- callee saved registers and emitting the return instruction.
-
- Using an epilogue pattern is generally preferred over defining
- `TARGET_ASM_FUNCTION_EPILOGUE' to emit assembly code for the
- epilogue.
-
- The `epilogue' pattern is particularly useful for targets which
- perform instruction scheduling or which have delay slots for their
- return instruction.
-
-`sibcall_epilogue'
- This pattern, if defined, emits RTL for exit from a function
- without the final branch back to the calling function. This
- pattern will be emitted before any sibling call (aka tail call)
- sites.
-
- The `sibcall_epilogue' pattern must not clobber any arguments used
- for parameter passing or any stack slots for arguments passed to
- the current function.
-
-`trap'
- This pattern, if defined, signals an error, typically by causing
- some kind of signal to be raised. Among other places, it is used
- by the Java front end to signal `invalid array index' exceptions.
-
-`conditional_trap'
- Conditional trap instruction. Operand 0 is a piece of RTL which
- performs a comparison. Operand 1 is the trap code, an integer.
-
- A typical `conditional_trap' pattern looks like
-
- (define_insn "conditional_trap"
- [(trap_if (match_operator 0 "trap_operator"
- [(cc0) (const_int 0)])
- (match_operand 1 "const_int_operand" "i"))]
- ""
- "...")
-
-`prefetch'
- This pattern, if defined, emits code for a non-faulting data
- prefetch instruction. Operand 0 is the address of the memory to
- prefetch. Operand 1 is a constant 1 if the prefetch is preparing
- for a write to the memory address, or a constant 0 otherwise.
- Operand 2 is the expected degree of temporal locality of the data
- and is a value between 0 and 3, inclusive; 0 means that the data
- has no temporal locality, so it need not be left in the cache
- after the access; 3 means that the data has a high degree of
- temporal locality and should be left in all levels of cache
- possible; 1 and 2 mean, respectively, a low or moderate degree of
- temporal locality.
-
- Targets that do not support write prefetches or locality hints can
- ignore the values of operands 1 and 2.
-
-`blockage'
- This pattern defines a pseudo insn that prevents the instruction
- scheduler from moving instructions across the boundary defined by
- the blockage insn. Normally an UNSPEC_VOLATILE pattern.
-
-`memory_barrier'
- If the target memory model is not fully synchronous, then this
- pattern should be defined to an instruction that orders both loads
- and stores before the instruction with respect to loads and stores
- after the instruction. This pattern has no operands.
-
-`sync_compare_and_swapMODE'
- This pattern, if defined, emits code for an atomic compare-and-swap
- operation. Operand 1 is the memory on which the atomic operation
- is performed. Operand 2 is the "old" value to be compared against
- the current contents of the memory location. Operand 3 is the
- "new" value to store in the memory if the compare succeeds.
- Operand 0 is the result of the operation; it should contain the
- contents of the memory before the operation. If the compare
- succeeds, this should obviously be a copy of operand 2.
-
- This pattern must show that both operand 0 and operand 1 are
- modified.
-
- This pattern must issue any memory barrier instructions such that
- all memory operations before the atomic operation occur before the
- atomic operation and all memory operations after the atomic
- operation occur after the atomic operation.
-
-`sync_compare_and_swap_ccMODE'
- This pattern is just like `sync_compare_and_swapMODE', except it
- should act as if compare part of the compare-and-swap were issued
- via `cmpM'. This comparison will only be used with `EQ' and `NE'
- branches and `setcc' operations.
-
- Some targets do expose the success or failure of the
- compare-and-swap operation via the status flags. Ideally we
- wouldn't need a separate named pattern in order to take advantage
- of this, but the combine pass does not handle patterns with
- multiple sets, which is required by definition for
- `sync_compare_and_swapMODE'.
-
-`sync_addMODE', `sync_subMODE'
-`sync_iorMODE', `sync_andMODE'
-`sync_xorMODE', `sync_nandMODE'
- These patterns emit code for an atomic operation on memory.
- Operand 0 is the memory on which the atomic operation is performed.
- Operand 1 is the second operand to the binary operator.
-
- This pattern must issue any memory barrier instructions such that
- all memory operations before the atomic operation occur before the
- atomic operation and all memory operations after the atomic
- operation occur after the atomic operation.
-
- If these patterns are not defined, the operation will be
- constructed from a compare-and-swap operation, if defined.
-
-`sync_old_addMODE', `sync_old_subMODE'
-`sync_old_iorMODE', `sync_old_andMODE'
-`sync_old_xorMODE', `sync_old_nandMODE'
- These patterns are emit code for an atomic operation on memory,
- and return the value that the memory contained before the
- operation. Operand 0 is the result value, operand 1 is the memory
- on which the atomic operation is performed, and operand 2 is the
- second operand to the binary operator.
-
- This pattern must issue any memory barrier instructions such that
- all memory operations before the atomic operation occur before the
- atomic operation and all memory operations after the atomic
- operation occur after the atomic operation.
-
- If these patterns are not defined, the operation will be
- constructed from a compare-and-swap operation, if defined.
-
-`sync_new_addMODE', `sync_new_subMODE'
-`sync_new_iorMODE', `sync_new_andMODE'
-`sync_new_xorMODE', `sync_new_nandMODE'
- These patterns are like their `sync_old_OP' counterparts, except
- that they return the value that exists in the memory location
- after the operation, rather than before the operation.
-
-`sync_lock_test_and_setMODE'
- This pattern takes two forms, based on the capabilities of the
- target. In either case, operand 0 is the result of the operand,
- operand 1 is the memory on which the atomic operation is
- performed, and operand 2 is the value to set in the lock.
-
- In the ideal case, this operation is an atomic exchange operation,
- in which the previous value in memory operand is copied into the
- result operand, and the value operand is stored in the memory
- operand.
-
- For less capable targets, any value operand that is not the
- constant 1 should be rejected with `FAIL'. In this case the
- target may use an atomic test-and-set bit operation. The result
- operand should contain 1 if the bit was previously set and 0 if
- the bit was previously clear. The true contents of the memory
- operand are implementation defined.
-
- This pattern must issue any memory barrier instructions such that
- the pattern as a whole acts as an acquire barrier, that is all
- memory operations after the pattern do not occur until the lock is
- acquired.
-
- If this pattern is not defined, the operation will be constructed
- from a compare-and-swap operation, if defined.
-
-`sync_lock_releaseMODE'
- This pattern, if defined, releases a lock set by
- `sync_lock_test_and_setMODE'. Operand 0 is the memory that
- contains the lock; operand 1 is the value to store in the lock.
-
- If the target doesn't implement full semantics for
- `sync_lock_test_and_setMODE', any value operand which is not the
- constant 0 should be rejected with `FAIL', and the true contents
- of the memory operand are implementation defined.
-
- This pattern must issue any memory barrier instructions such that
- the pattern as a whole acts as a release barrier, that is the lock
- is released only after all previous memory operations have
- completed.
-
- If this pattern is not defined, then a `memory_barrier' pattern
- will be emitted, followed by a store of the value to the memory
- operand.
-
-`stack_protect_set'
- This pattern, if defined, moves a `Pmode' value from the memory in
- operand 1 to the memory in operand 0 without leaving the value in
- a register afterward. This is to avoid leaking the value some
- place that an attacker might use to rewrite the stack guard slot
- after having clobbered it.
-
- If this pattern is not defined, then a plain move pattern is
- generated.
-
-`stack_protect_test'
- This pattern, if defined, compares a `Pmode' value from the memory
- in operand 1 with the memory in operand 0 without leaving the
- value in a register afterward and branches to operand 2 if the
- values weren't equal.
-
- If this pattern is not defined, then a plain compare pattern and
- conditional branch pattern is used.
-
-`clear_cache'
- This pattern, if defined, flushes the instruction cache for a
- region of memory. The region is bounded to by the Pmode pointers
- in operand 0 inclusive and operand 1 exclusive.
-
- If this pattern is not defined, a call to the library function
- `__clear_cache' is used.
-
-
-\1f
-File: gccint.info, Node: Pattern Ordering, Next: Dependent Patterns, Prev: Standard Names, Up: Machine Desc
-
-16.10 When the Order of Patterns Matters
-========================================
-
-Sometimes an insn can match more than one instruction pattern. Then the
-pattern that appears first in the machine description is the one used.
-Therefore, more specific patterns (patterns that will match fewer
-things) and faster instructions (those that will produce better code
-when they do match) should usually go first in the description.
-
- In some cases the effect of ordering the patterns can be used to hide
-a pattern when it is not valid. For example, the 68000 has an
-instruction for converting a fullword to floating point and another for
-converting a byte to floating point. An instruction converting an
-integer to floating point could match either one. We put the pattern
-to convert the fullword first to make sure that one will be used rather
-than the other. (Otherwise a large integer might be generated as a
-single-byte immediate quantity, which would not work.) Instead of
-using this pattern ordering it would be possible to make the pattern
-for convert-a-byte smart enough to deal properly with any constant
-value.
-
-\1f
-File: gccint.info, Node: Dependent Patterns, Next: Jump Patterns, Prev: Pattern Ordering, Up: Machine Desc
-
-16.11 Interdependence of Patterns
-=================================
-
-Every machine description must have a named pattern for each of the
-conditional branch names `bCOND'. The recognition template must always
-have the form
-
- (set (pc)
- (if_then_else (COND (cc0) (const_int 0))
- (label_ref (match_operand 0 "" ""))
- (pc)))
-
-In addition, every machine description must have an anonymous pattern
-for each of the possible reverse-conditional branches. Their templates
-look like
-
- (set (pc)
- (if_then_else (COND (cc0) (const_int 0))
- (pc)
- (label_ref (match_operand 0 "" ""))))
-
-They are necessary because jump optimization can turn direct-conditional
-branches into reverse-conditional branches.
-
- It is often convenient to use the `match_operator' construct to reduce
-the number of patterns that must be specified for branches. For
-example,
-
- (define_insn ""
- [(set (pc)
- (if_then_else (match_operator 0 "comparison_operator"
- [(cc0) (const_int 0)])
- (pc)
- (label_ref (match_operand 1 "" ""))))]
- "CONDITION"
- "...")
-
- In some cases machines support instructions identical except for the
-machine mode of one or more operands. For example, there may be
-"sign-extend halfword" and "sign-extend byte" instructions whose
-patterns are
-
- (set (match_operand:SI 0 ...)
- (extend:SI (match_operand:HI 1 ...)))
-
- (set (match_operand:SI 0 ...)
- (extend:SI (match_operand:QI 1 ...)))
-
-Constant integers do not specify a machine mode, so an instruction to
-extend a constant value could match either pattern. The pattern it
-actually will match is the one that appears first in the file. For
-correct results, this must be the one for the widest possible mode
-(`HImode', here). If the pattern matches the `QImode' instruction, the
-results will be incorrect if the constant value does not actually fit
-that mode.
-
- Such instructions to extend constants are rarely generated because
-they are optimized away, but they do occasionally happen in nonoptimized
-compilations.
-
- If a constraint in a pattern allows a constant, the reload pass may
-replace a register with a constant permitted by the constraint in some
-cases. Similarly for memory references. Because of this substitution,
-you should not provide separate patterns for increment and decrement
-instructions. Instead, they should be generated from the same pattern
-that supports register-register add insns by examining the operands and
-generating the appropriate machine instruction.
-
-\1f
-File: gccint.info, Node: Jump Patterns, Next: Looping Patterns, Prev: Dependent Patterns, Up: Machine Desc
-
-16.12 Defining Jump Instruction Patterns
-========================================
-
-For most machines, GCC assumes that the machine has a condition code.
-A comparison insn sets the condition code, recording the results of both
-signed and unsigned comparison of the given operands. A separate branch
-insn tests the condition code and branches or not according its value.
-The branch insns come in distinct signed and unsigned flavors. Many
-common machines, such as the VAX, the 68000 and the 32000, work this
-way.
-
- Some machines have distinct signed and unsigned compare instructions,
-and only one set of conditional branch instructions. The easiest way
-to handle these machines is to treat them just like the others until
-the final stage where assembly code is written. At this time, when
-outputting code for the compare instruction, peek ahead at the
-following branch using `next_cc0_user (insn)'. (The variable `insn'
-refers to the insn being output, in the output-writing code in an
-instruction pattern.) If the RTL says that is an unsigned branch,
-output an unsigned compare; otherwise output a signed compare. When
-the branch itself is output, you can treat signed and unsigned branches
-identically.
-
- The reason you can do this is that GCC always generates a pair of
-consecutive RTL insns, possibly separated by `note' insns, one to set
-the condition code and one to test it, and keeps the pair inviolate
-until the end.
-
- To go with this technique, you must define the machine-description
-macro `NOTICE_UPDATE_CC' to do `CC_STATUS_INIT'; in other words, no
-compare instruction is superfluous.
-
- Some machines have compare-and-branch instructions and no condition
-code. A similar technique works for them. When it is time to "output"
-a compare instruction, record its operands in two static variables.
-When outputting the branch-on-condition-code instruction that follows,
-actually output a compare-and-branch instruction that uses the
-remembered operands.
-
- It also works to define patterns for compare-and-branch instructions.
-In optimizing compilation, the pair of compare and branch instructions
-will be combined according to these patterns. But this does not happen
-if optimization is not requested. So you must use one of the solutions
-above in addition to any special patterns you define.
-
- In many RISC machines, most instructions do not affect the condition
-code and there may not even be a separate condition code register. On
-these machines, the restriction that the definition and use of the
-condition code be adjacent insns is not necessary and can prevent
-important optimizations. For example, on the IBM RS/6000, there is a
-delay for taken branches unless the condition code register is set three
-instructions earlier than the conditional branch. The instruction
-scheduler cannot perform this optimization if it is not permitted to
-separate the definition and use of the condition code register.
-
- On these machines, do not use `(cc0)', but instead use a register to
-represent the condition code. If there is a specific condition code
-register in the machine, use a hard register. If the condition code or
-comparison result can be placed in any general register, or if there are
-multiple condition registers, use a pseudo register.
-
- On some machines, the type of branch instruction generated may depend
-on the way the condition code was produced; for example, on the 68k and
-SPARC, setting the condition code directly from an add or subtract
-instruction does not clear the overflow bit the way that a test
-instruction does, so a different branch instruction must be used for
-some conditional branches. For machines that use `(cc0)', the set and
-use of the condition code must be adjacent (separated only by `note'
-insns) allowing flags in `cc_status' to be used. (*Note Condition
-Code::.) Also, the comparison and branch insns can be located from
-each other by using the functions `prev_cc0_setter' and `next_cc0_user'.
-
- However, this is not true on machines that do not use `(cc0)'. On
-those machines, no assumptions can be made about the adjacency of the
-compare and branch insns and the above methods cannot be used. Instead,
-we use the machine mode of the condition code register to record
-different formats of the condition code register.
-
- Registers used to store the condition code value should have a mode
-that is in class `MODE_CC'. Normally, it will be `CCmode'. If
-additional modes are required (as for the add example mentioned above in
-the SPARC), define them in `MACHINE-modes.def' (*note Condition
-Code::). Also define `SELECT_CC_MODE' to choose a mode given an
-operand of a compare.
-
- If it is known during RTL generation that a different mode will be
-required (for example, if the machine has separate compare instructions
-for signed and unsigned quantities, like most IBM processors), they can
-be specified at that time.
-
- If the cases that require different modes would be made by instruction
-combination, the macro `SELECT_CC_MODE' determines which machine mode
-should be used for the comparison result. The patterns should be
-written using that mode. To support the case of the add on the SPARC
-discussed above, we have the pattern
-
- (define_insn ""
- [(set (reg:CC_NOOV 0)
- (compare:CC_NOOV
- (plus:SI (match_operand:SI 0 "register_operand" "%r")
- (match_operand:SI 1 "arith_operand" "rI"))
- (const_int 0)))]
- ""
- "...")
-
- The `SELECT_CC_MODE' macro on the SPARC returns `CC_NOOVmode' for
-comparisons whose argument is a `plus'.
-
-\1f
-File: gccint.info, Node: Looping Patterns, Next: Insn Canonicalizations, Prev: Jump Patterns, Up: Machine Desc
-
-16.13 Defining Looping Instruction Patterns
-===========================================
-
-Some machines have special jump instructions that can be utilized to
-make loops more efficient. A common example is the 68000 `dbra'
-instruction which performs a decrement of a register and a branch if the
-result was greater than zero. Other machines, in particular digital
-signal processors (DSPs), have special block repeat instructions to
-provide low-overhead loop support. For example, the TI TMS320C3x/C4x
-DSPs have a block repeat instruction that loads special registers to
-mark the top and end of a loop and to count the number of loop
-iterations. This avoids the need for fetching and executing a
-`dbra'-like instruction and avoids pipeline stalls associated with the
-jump.
-
- GCC has three special named patterns to support low overhead looping.
-They are `decrement_and_branch_until_zero', `doloop_begin', and
-`doloop_end'. The first pattern, `decrement_and_branch_until_zero', is
-not emitted during RTL generation but may be emitted during the
-instruction combination phase. This requires the assistance of the
-loop optimizer, using information collected during strength reduction,
-to reverse a loop to count down to zero. Some targets also require the
-loop optimizer to add a `REG_NONNEG' note to indicate that the
-iteration count is always positive. This is needed if the target
-performs a signed loop termination test. For example, the 68000 uses a
-pattern similar to the following for its `dbra' instruction:
-
- (define_insn "decrement_and_branch_until_zero"
- [(set (pc)
- (if_then_else
- (ge (plus:SI (match_operand:SI 0 "general_operand" "+d*am")
- (const_int -1))
- (const_int 0))
- (label_ref (match_operand 1 "" ""))
- (pc)))
- (set (match_dup 0)
- (plus:SI (match_dup 0)
- (const_int -1)))]
- "find_reg_note (insn, REG_NONNEG, 0)"
- "...")
-
- Note that since the insn is both a jump insn and has an output, it must
-deal with its own reloads, hence the `m' constraints. Also note that
-since this insn is generated by the instruction combination phase
-combining two sequential insns together into an implicit parallel insn,
-the iteration counter needs to be biased by the same amount as the
-decrement operation, in this case -1. Note that the following similar
-pattern will not be matched by the combiner.
-
- (define_insn "decrement_and_branch_until_zero"
- [(set (pc)
- (if_then_else
- (ge (match_operand:SI 0 "general_operand" "+d*am")
- (const_int 1))
- (label_ref (match_operand 1 "" ""))
- (pc)))
- (set (match_dup 0)
- (plus:SI (match_dup 0)
- (const_int -1)))]
- "find_reg_note (insn, REG_NONNEG, 0)"
- "...")
-
- The other two special looping patterns, `doloop_begin' and
-`doloop_end', are emitted by the loop optimizer for certain
-well-behaved loops with a finite number of loop iterations using
-information collected during strength reduction.
-
- The `doloop_end' pattern describes the actual looping instruction (or
-the implicit looping operation) and the `doloop_begin' pattern is an
-optional companion pattern that can be used for initialization needed
-for some low-overhead looping instructions.
-
- Note that some machines require the actual looping instruction to be
-emitted at the top of the loop (e.g., the TMS320C3x/C4x DSPs). Emitting
-the true RTL for a looping instruction at the top of the loop can cause
-problems with flow analysis. So instead, a dummy `doloop' insn is
-emitted at the end of the loop. The machine dependent reorg pass checks
-for the presence of this `doloop' insn and then searches back to the
-top of the loop, where it inserts the true looping insn (provided there
-are no instructions in the loop which would cause problems). Any
-additional labels can be emitted at this point. In addition, if the
-desired special iteration counter register was not allocated, this
-machine dependent reorg pass could emit a traditional compare and jump
-instruction pair.
-
- The essential difference between the `decrement_and_branch_until_zero'
-and the `doloop_end' patterns is that the loop optimizer allocates an
-additional pseudo register for the latter as an iteration counter.
-This pseudo register cannot be used within the loop (i.e., general
-induction variables cannot be derived from it), however, in many cases
-the loop induction variable may become redundant and removed by the
-flow pass.
-
-\1f
-File: gccint.info, Node: Insn Canonicalizations, Next: Expander Definitions, Prev: Looping Patterns, Up: Machine Desc
-
-16.14 Canonicalization of Instructions
-======================================
-
-There are often cases where multiple RTL expressions could represent an
-operation performed by a single machine instruction. This situation is
-most commonly encountered with logical, branch, and multiply-accumulate
-instructions. In such cases, the compiler attempts to convert these
-multiple RTL expressions into a single canonical form to reduce the
-number of insn patterns required.
-
- In addition to algebraic simplifications, following canonicalizations
-are performed:
-
- * For commutative and comparison operators, a constant is always
- made the second operand. If a machine only supports a constant as
- the second operand, only patterns that match a constant in the
- second operand need be supplied.
-
- * For associative operators, a sequence of operators will always
- chain to the left; for instance, only the left operand of an
- integer `plus' can itself be a `plus'. `and', `ior', `xor',
- `plus', `mult', `smin', `smax', `umin', and `umax' are associative
- when applied to integers, and sometimes to floating-point.
-
- * For these operators, if only one operand is a `neg', `not',
- `mult', `plus', or `minus' expression, it will be the first
- operand.
-
- * In combinations of `neg', `mult', `plus', and `minus', the `neg'
- operations (if any) will be moved inside the operations as far as
- possible. For instance, `(neg (mult A B))' is canonicalized as
- `(mult (neg A) B)', but `(plus (mult (neg A) B) C)' is
- canonicalized as `(minus A (mult B C))'.
-
- * For the `compare' operator, a constant is always the second operand
- on machines where `cc0' is used (*note Jump Patterns::). On other
- machines, there are rare cases where the compiler might want to
- construct a `compare' with a constant as the first operand.
- However, these cases are not common enough for it to be worthwhile
- to provide a pattern matching a constant as the first operand
- unless the machine actually has such an instruction.
-
- An operand of `neg', `not', `mult', `plus', or `minus' is made the
- first operand under the same conditions as above.
-
- * `(ltu (plus A B) B)' is converted to `(ltu (plus A B) A)'.
- Likewise with `geu' instead of `ltu'.
-
- * `(minus X (const_int N))' is converted to `(plus X (const_int
- -N))'.
-
- * Within address computations (i.e., inside `mem'), a left shift is
- converted into the appropriate multiplication by a power of two.
-
- * De Morgan's Law is used to move bitwise negation inside a bitwise
- logical-and or logical-or operation. If this results in only one
- operand being a `not' expression, it will be the first one.
-
- A machine that has an instruction that performs a bitwise
- logical-and of one operand with the bitwise negation of the other
- should specify the pattern for that instruction as
-
- (define_insn ""
- [(set (match_operand:M 0 ...)
- (and:M (not:M (match_operand:M 1 ...))
- (match_operand:M 2 ...)))]
- "..."
- "...")
-
- Similarly, a pattern for a "NAND" instruction should be written
-
- (define_insn ""
- [(set (match_operand:M 0 ...)
- (ior:M (not:M (match_operand:M 1 ...))
- (not:M (match_operand:M 2 ...))))]
- "..."
- "...")
-
- In both cases, it is not necessary to include patterns for the many
- logically equivalent RTL expressions.
-
- * The only possible RTL expressions involving both bitwise
- exclusive-or and bitwise negation are `(xor:M X Y)' and `(not:M
- (xor:M X Y))'.
-
- * The sum of three items, one of which is a constant, will only
- appear in the form
-
- (plus:M (plus:M X Y) CONSTANT)
-
- * On machines that do not use `cc0', `(compare X (const_int 0))'
- will be converted to X.
-
- * Equality comparisons of a group of bits (usually a single bit)
- with zero will be written using `zero_extract' rather than the
- equivalent `and' or `sign_extract' operations.
-
-
- Further canonicalization rules are defined in the function
-`commutative_operand_precedence' in `gcc/rtlanal.c'.
-
-\1f
-File: gccint.info, Node: Expander Definitions, Next: Insn Splitting, Prev: Insn Canonicalizations, Up: Machine Desc
-
-16.15 Defining RTL Sequences for Code Generation
-================================================
-
-On some target machines, some standard pattern names for RTL generation
-cannot be handled with single insn, but a sequence of RTL insns can
-represent them. For these target machines, you can write a
-`define_expand' to specify how to generate the sequence of RTL.
-
- A `define_expand' is an RTL expression that looks almost like a
-`define_insn'; but, unlike the latter, a `define_expand' is used only
-for RTL generation and it can produce more than one RTL insn.
-
- A `define_expand' RTX has four operands:
-
- * The name. Each `define_expand' must have a name, since the only
- use for it is to refer to it by name.
-
- * The RTL template. This is a vector of RTL expressions representing
- a sequence of separate instructions. Unlike `define_insn', there
- is no implicit surrounding `PARALLEL'.
-
- * The condition, a string containing a C expression. This
- expression is used to express how the availability of this pattern
- depends on subclasses of target machine, selected by command-line
- options when GCC is run. This is just like the condition of a
- `define_insn' that has a standard name. Therefore, the condition
- (if present) may not depend on the data in the insn being matched,
- but only the target-machine-type flags. The compiler needs to
- test these conditions during initialization in order to learn
- exactly which named instructions are available in a particular run.
-
- * The preparation statements, a string containing zero or more C
- statements which are to be executed before RTL code is generated
- from the RTL template.
-
- Usually these statements prepare temporary registers for use as
- internal operands in the RTL template, but they can also generate
- RTL insns directly by calling routines such as `emit_insn', etc.
- Any such insns precede the ones that come from the RTL template.
-
- Every RTL insn emitted by a `define_expand' must match some
-`define_insn' in the machine description. Otherwise, the compiler will
-crash when trying to generate code for the insn or trying to optimize
-it.
-
- The RTL template, in addition to controlling generation of RTL insns,
-also describes the operands that need to be specified when this pattern
-is used. In particular, it gives a predicate for each operand.
-
- A true operand, which needs to be specified in order to generate RTL
-from the pattern, should be described with a `match_operand' in its
-first occurrence in the RTL template. This enters information on the
-operand's predicate into the tables that record such things. GCC uses
-the information to preload the operand into a register if that is
-required for valid RTL code. If the operand is referred to more than
-once, subsequent references should use `match_dup'.
-
- The RTL template may also refer to internal "operands" which are
-temporary registers or labels used only within the sequence made by the
-`define_expand'. Internal operands are substituted into the RTL
-template with `match_dup', never with `match_operand'. The values of
-the internal operands are not passed in as arguments by the compiler
-when it requests use of this pattern. Instead, they are computed
-within the pattern, in the preparation statements. These statements
-compute the values and store them into the appropriate elements of
-`operands' so that `match_dup' can find them.
-
- There are two special macros defined for use in the preparation
-statements: `DONE' and `FAIL'. Use them with a following semicolon, as
-a statement.
-
-`DONE'
- Use the `DONE' macro to end RTL generation for the pattern. The
- only RTL insns resulting from the pattern on this occasion will be
- those already emitted by explicit calls to `emit_insn' within the
- preparation statements; the RTL template will not be generated.
-
-`FAIL'
- Make the pattern fail on this occasion. When a pattern fails, it
- means that the pattern was not truly available. The calling
- routines in the compiler will try other strategies for code
- generation using other patterns.
-
- Failure is currently supported only for binary (addition,
- multiplication, shifting, etc.) and bit-field (`extv', `extzv',
- and `insv') operations.
-
- If the preparation falls through (invokes neither `DONE' nor `FAIL'),
-then the `define_expand' acts like a `define_insn' in that the RTL
-template is used to generate the insn.
-
- The RTL template is not used for matching, only for generating the
-initial insn list. If the preparation statement always invokes `DONE'
-or `FAIL', the RTL template may be reduced to a simple list of
-operands, such as this example:
-
- (define_expand "addsi3"
- [(match_operand:SI 0 "register_operand" "")
- (match_operand:SI 1 "register_operand" "")
- (match_operand:SI 2 "register_operand" "")]
- ""
- "
- {
- handle_add (operands[0], operands[1], operands[2]);
- DONE;
- }")
-
- Here is an example, the definition of left-shift for the SPUR chip:
-
- (define_expand "ashlsi3"
- [(set (match_operand:SI 0 "register_operand" "")
- (ashift:SI
- (match_operand:SI 1 "register_operand" "")
- (match_operand:SI 2 "nonmemory_operand" "")))]
- ""
- "
-
- {
- if (GET_CODE (operands[2]) != CONST_INT
- || (unsigned) INTVAL (operands[2]) > 3)
- FAIL;
- }")
-
-This example uses `define_expand' so that it can generate an RTL insn
-for shifting when the shift-count is in the supported range of 0 to 3
-but fail in other cases where machine insns aren't available. When it
-fails, the compiler tries another strategy using different patterns
-(such as, a library call).
-
- If the compiler were able to handle nontrivial condition-strings in
-patterns with names, then it would be possible to use a `define_insn'
-in that case. Here is another case (zero-extension on the 68000) which
-makes more use of the power of `define_expand':
-
- (define_expand "zero_extendhisi2"
- [(set (match_operand:SI 0 "general_operand" "")
- (const_int 0))
- (set (strict_low_part
- (subreg:HI
- (match_dup 0)
- 0))
- (match_operand:HI 1 "general_operand" ""))]
- ""
- "operands[1] = make_safe_from (operands[1], operands[0]);")
-
-Here two RTL insns are generated, one to clear the entire output operand
-and the other to copy the input operand into its low half. This
-sequence is incorrect if the input operand refers to [the old value of]
-the output operand, so the preparation statement makes sure this isn't
-so. The function `make_safe_from' copies the `operands[1]' into a
-temporary register if it refers to `operands[0]'. It does this by
-emitting another RTL insn.
-
- Finally, a third example shows the use of an internal operand.
-Zero-extension on the SPUR chip is done by `and'-ing the result against
-a halfword mask. But this mask cannot be represented by a `const_int'
-because the constant value is too large to be legitimate on this
-machine. So it must be copied into a register with `force_reg' and
-then the register used in the `and'.
-
- (define_expand "zero_extendhisi2"
- [(set (match_operand:SI 0 "register_operand" "")
- (and:SI (subreg:SI
- (match_operand:HI 1 "register_operand" "")
- 0)
- (match_dup 2)))]
- ""
- "operands[2]
- = force_reg (SImode, GEN_INT (65535)); ")
-
- _Note:_ If the `define_expand' is used to serve a standard binary or
-unary arithmetic operation or a bit-field operation, then the last insn
-it generates must not be a `code_label', `barrier' or `note'. It must
-be an `insn', `jump_insn' or `call_insn'. If you don't need a real insn
-at the end, emit an insn to copy the result of the operation into
-itself. Such an insn will generate no code, but it can avoid problems
-in the compiler.
-
-\1f
-File: gccint.info, Node: Insn Splitting, Next: Including Patterns, Prev: Expander Definitions, Up: Machine Desc
-
-16.16 Defining How to Split Instructions
-========================================
-
-There are two cases where you should specify how to split a pattern
-into multiple insns. On machines that have instructions requiring
-delay slots (*note Delay Slots::) or that have instructions whose
-output is not available for multiple cycles (*note Processor pipeline
-description::), the compiler phases that optimize these cases need to
-be able to move insns into one-instruction delay slots. However, some
-insns may generate more than one machine instruction. These insns
-cannot be placed into a delay slot.
-
- Often you can rewrite the single insn as a list of individual insns,
-each corresponding to one machine instruction. The disadvantage of
-doing so is that it will cause the compilation to be slower and require
-more space. If the resulting insns are too complex, it may also
-suppress some optimizations. The compiler splits the insn if there is a
-reason to believe that it might improve instruction or delay slot
-scheduling.
-
- The insn combiner phase also splits putative insns. If three insns are
-merged into one insn with a complex expression that cannot be matched by
-some `define_insn' pattern, the combiner phase attempts to split the
-complex pattern into two insns that are recognized. Usually it can
-break the complex pattern into two patterns by splitting out some
-subexpression. However, in some other cases, such as performing an
-addition of a large constant in two insns on a RISC machine, the way to
-split the addition into two insns is machine-dependent.
-
- The `define_split' definition tells the compiler how to split a
-complex insn into several simpler insns. It looks like this:
-
- (define_split
- [INSN-PATTERN]
- "CONDITION"
- [NEW-INSN-PATTERN-1
- NEW-INSN-PATTERN-2
- ...]
- "PREPARATION-STATEMENTS")
-
- INSN-PATTERN is a pattern that needs to be split and CONDITION is the
-final condition to be tested, as in a `define_insn'. When an insn
-matching INSN-PATTERN and satisfying CONDITION is found, it is replaced
-in the insn list with the insns given by NEW-INSN-PATTERN-1,
-NEW-INSN-PATTERN-2, etc.
-
- The PREPARATION-STATEMENTS are similar to those statements that are
-specified for `define_expand' (*note Expander Definitions::) and are
-executed before the new RTL is generated to prepare for the generated
-code or emit some insns whose pattern is not fixed. Unlike those in
-`define_expand', however, these statements must not generate any new
-pseudo-registers. Once reload has completed, they also must not
-allocate any space in the stack frame.
-
- Patterns are matched against INSN-PATTERN in two different
-circumstances. If an insn needs to be split for delay slot scheduling
-or insn scheduling, the insn is already known to be valid, which means
-that it must have been matched by some `define_insn' and, if
-`reload_completed' is nonzero, is known to satisfy the constraints of
-that `define_insn'. In that case, the new insn patterns must also be
-insns that are matched by some `define_insn' and, if `reload_completed'
-is nonzero, must also satisfy the constraints of those definitions.
-
- As an example of this usage of `define_split', consider the following
-example from `a29k.md', which splits a `sign_extend' from `HImode' to
-`SImode' into a pair of shift insns:
-
- (define_split
- [(set (match_operand:SI 0 "gen_reg_operand" "")
- (sign_extend:SI (match_operand:HI 1 "gen_reg_operand" "")))]
- ""
- [(set (match_dup 0)
- (ashift:SI (match_dup 1)
- (const_int 16)))
- (set (match_dup 0)
- (ashiftrt:SI (match_dup 0)
- (const_int 16)))]
- "
- { operands[1] = gen_lowpart (SImode, operands[1]); }")
-
- When the combiner phase tries to split an insn pattern, it is always
-the case that the pattern is _not_ matched by any `define_insn'. The
-combiner pass first tries to split a single `set' expression and then
-the same `set' expression inside a `parallel', but followed by a
-`clobber' of a pseudo-reg to use as a scratch register. In these
-cases, the combiner expects exactly two new insn patterns to be
-generated. It will verify that these patterns match some `define_insn'
-definitions, so you need not do this test in the `define_split' (of
-course, there is no point in writing a `define_split' that will never
-produce insns that match).
-
- Here is an example of this use of `define_split', taken from
-`rs6000.md':
-
- (define_split
- [(set (match_operand:SI 0 "gen_reg_operand" "")
- (plus:SI (match_operand:SI 1 "gen_reg_operand" "")
- (match_operand:SI 2 "non_add_cint_operand" "")))]
- ""
- [(set (match_dup 0) (plus:SI (match_dup 1) (match_dup 3)))
- (set (match_dup 0) (plus:SI (match_dup 0) (match_dup 4)))]
- "
- {
- int low = INTVAL (operands[2]) & 0xffff;
- int high = (unsigned) INTVAL (operands[2]) >> 16;
-
- if (low & 0x8000)
- high++, low |= 0xffff0000;
-
- operands[3] = GEN_INT (high << 16);
- operands[4] = GEN_INT (low);
- }")
-
- Here the predicate `non_add_cint_operand' matches any `const_int' that
-is _not_ a valid operand of a single add insn. The add with the
-smaller displacement is written so that it can be substituted into the
-address of a subsequent operation.
-
- An example that uses a scratch register, from the same file, generates
-an equality comparison of a register and a large constant:
-
- (define_split
- [(set (match_operand:CC 0 "cc_reg_operand" "")
- (compare:CC (match_operand:SI 1 "gen_reg_operand" "")
- (match_operand:SI 2 "non_short_cint_operand" "")))
- (clobber (match_operand:SI 3 "gen_reg_operand" ""))]
- "find_single_use (operands[0], insn, 0)
- && (GET_CODE (*find_single_use (operands[0], insn, 0)) == EQ
- || GET_CODE (*find_single_use (operands[0], insn, 0)) == NE)"
- [(set (match_dup 3) (xor:SI (match_dup 1) (match_dup 4)))
- (set (match_dup 0) (compare:CC (match_dup 3) (match_dup 5)))]
- "
- {
- /* Get the constant we are comparing against, C, and see what it
- looks like sign-extended to 16 bits. Then see what constant
- could be XOR'ed with C to get the sign-extended value. */
-
- int c = INTVAL (operands[2]);
- int sextc = (c << 16) >> 16;
- int xorv = c ^ sextc;
-
- operands[4] = GEN_INT (xorv);
- operands[5] = GEN_INT (sextc);
- }")
-
- To avoid confusion, don't write a single `define_split' that accepts
-some insns that match some `define_insn' as well as some insns that
-don't. Instead, write two separate `define_split' definitions, one for
-the insns that are valid and one for the insns that are not valid.
-
- The splitter is allowed to split jump instructions into sequence of
-jumps or create new jumps in while splitting non-jump instructions. As
-the central flowgraph and branch prediction information needs to be
-updated, several restriction apply.
-
- Splitting of jump instruction into sequence that over by another jump
-instruction is always valid, as compiler expect identical behavior of
-new jump. When new sequence contains multiple jump instructions or new
-labels, more assistance is needed. Splitter is required to create only
-unconditional jumps, or simple conditional jump instructions.
-Additionally it must attach a `REG_BR_PROB' note to each conditional
-jump. A global variable `split_branch_probability' holds the
-probability of the original branch in case it was an simple conditional
-jump, -1 otherwise. To simplify recomputing of edge frequencies, the
-new sequence is required to have only forward jumps to the newly
-created labels.
-
- For the common case where the pattern of a define_split exactly
-matches the pattern of a define_insn, use `define_insn_and_split'. It
-looks like this:
-
- (define_insn_and_split
- [INSN-PATTERN]
- "CONDITION"
- "OUTPUT-TEMPLATE"
- "SPLIT-CONDITION"
- [NEW-INSN-PATTERN-1
- NEW-INSN-PATTERN-2
- ...]
- "PREPARATION-STATEMENTS"
- [INSN-ATTRIBUTES])
-
- INSN-PATTERN, CONDITION, OUTPUT-TEMPLATE, and INSN-ATTRIBUTES are used
-as in `define_insn'. The NEW-INSN-PATTERN vector and the
-PREPARATION-STATEMENTS are used as in a `define_split'. The
-SPLIT-CONDITION is also used as in `define_split', with the additional
-behavior that if the condition starts with `&&', the condition used for
-the split will be the constructed as a logical "and" of the split
-condition with the insn condition. For example, from i386.md:
-
- (define_insn_and_split "zero_extendhisi2_and"
- [(set (match_operand:SI 0 "register_operand" "=r")
- (zero_extend:SI (match_operand:HI 1 "register_operand" "0")))
- (clobber (reg:CC 17))]
- "TARGET_ZERO_EXTEND_WITH_AND && !optimize_size"
- "#"
- "&& reload_completed"
- [(parallel [(set (match_dup 0)
- (and:SI (match_dup 0) (const_int 65535)))
- (clobber (reg:CC 17))])]
- ""
- [(set_attr "type" "alu1")])
-
- In this case, the actual split condition will be
-`TARGET_ZERO_EXTEND_WITH_AND && !optimize_size && reload_completed'.
-
- The `define_insn_and_split' construction provides exactly the same
-functionality as two separate `define_insn' and `define_split'
-patterns. It exists for compactness, and as a maintenance tool to
-prevent having to ensure the two patterns' templates match.
-
-\1f
-File: gccint.info, Node: Including Patterns, Next: Peephole Definitions, Prev: Insn Splitting, Up: Machine Desc
-
-16.17 Including Patterns in Machine Descriptions.
-=================================================
-
-The `include' pattern tells the compiler tools where to look for
-patterns that are in files other than in the file `.md'. This is used
-only at build time and there is no preprocessing allowed.
-
- It looks like:
-
-
- (include
- PATHNAME)
-
- For example:
-
-
- (include "filestuff")
-
- Where PATHNAME is a string that specifies the location of the file,
-specifies the include file to be in `gcc/config/target/filestuff'. The
-directory `gcc/config/target' is regarded as the default directory.
-
- Machine descriptions may be split up into smaller more manageable
-subsections and placed into subdirectories.
-
- By specifying:
-
-
- (include "BOGUS/filestuff")
-
- the include file is specified to be in
-`gcc/config/TARGET/BOGUS/filestuff'.
-
- Specifying an absolute path for the include file such as;
-
- (include "/u2/BOGUS/filestuff")
- is permitted but is not encouraged.
-
-16.17.1 RTL Generation Tool Options for Directory Search
---------------------------------------------------------
-
-The `-IDIR' option specifies directories to search for machine
-descriptions. For example:
-
-
- genrecog -I/p1/abc/proc1 -I/p2/abcd/pro2 target.md
-
- Add the directory DIR to the head of the list of directories to be
-searched for header files. This can be used to override a system
-machine definition file, substituting your own version, since these
-directories are searched before the default machine description file
-directories. If you use more than one `-I' option, the directories are
-scanned in left-to-right order; the standard default directory come
-after.
-
-\1f
-File: gccint.info, Node: Peephole Definitions, Next: Insn Attributes, Prev: Including Patterns, Up: Machine Desc
-
-16.18 Machine-Specific Peephole Optimizers
-==========================================
-
-In addition to instruction patterns the `md' file may contain
-definitions of machine-specific peephole optimizations.
-
- The combiner does not notice certain peephole optimizations when the
-data flow in the program does not suggest that it should try them. For
-example, sometimes two consecutive insns related in purpose can be
-combined even though the second one does not appear to use a register
-computed in the first one. A machine-specific peephole optimizer can
-detect such opportunities.
-
- There are two forms of peephole definitions that may be used. The
-original `define_peephole' is run at assembly output time to match
-insns and substitute assembly text. Use of `define_peephole' is
-deprecated.
-
- A newer `define_peephole2' matches insns and substitutes new insns.
-The `peephole2' pass is run after register allocation but before
-scheduling, which may result in much better code for targets that do
-scheduling.
-
-* Menu:
-
-* define_peephole:: RTL to Text Peephole Optimizers
-* define_peephole2:: RTL to RTL Peephole Optimizers
-
-\1f
-File: gccint.info, Node: define_peephole, Next: define_peephole2, Up: Peephole Definitions
-
-16.18.1 RTL to Text Peephole Optimizers
----------------------------------------
-
-A definition looks like this:
-
- (define_peephole
- [INSN-PATTERN-1
- INSN-PATTERN-2
- ...]
- "CONDITION"
- "TEMPLATE"
- "OPTIONAL-INSN-ATTRIBUTES")
-
-The last string operand may be omitted if you are not using any
-machine-specific information in this machine description. If present,
-it must obey the same rules as in a `define_insn'.
-
- In this skeleton, INSN-PATTERN-1 and so on are patterns to match
-consecutive insns. The optimization applies to a sequence of insns when
-INSN-PATTERN-1 matches the first one, INSN-PATTERN-2 matches the next,
-and so on.
-
- Each of the insns matched by a peephole must also match a
-`define_insn'. Peepholes are checked only at the last stage just
-before code generation, and only optionally. Therefore, any insn which
-would match a peephole but no `define_insn' will cause a crash in code
-generation in an unoptimized compilation, or at various optimization
-stages.
-
- The operands of the insns are matched with `match_operands',
-`match_operator', and `match_dup', as usual. What is not usual is that
-the operand numbers apply to all the insn patterns in the definition.
-So, you can check for identical operands in two insns by using
-`match_operand' in one insn and `match_dup' in the other.
-
- The operand constraints used in `match_operand' patterns do not have
-any direct effect on the applicability of the peephole, but they will
-be validated afterward, so make sure your constraints are general enough
-to apply whenever the peephole matches. If the peephole matches but
-the constraints are not satisfied, the compiler will crash.
-
- It is safe to omit constraints in all the operands of the peephole; or
-you can write constraints which serve as a double-check on the criteria
-previously tested.
-
- Once a sequence of insns matches the patterns, the CONDITION is
-checked. This is a C expression which makes the final decision whether
-to perform the optimization (we do so if the expression is nonzero). If
-CONDITION is omitted (in other words, the string is empty) then the
-optimization is applied to every sequence of insns that matches the
-patterns.
-
- The defined peephole optimizations are applied after register
-allocation is complete. Therefore, the peephole definition can check
-which operands have ended up in which kinds of registers, just by
-looking at the operands.
-
- The way to refer to the operands in CONDITION is to write
-`operands[I]' for operand number I (as matched by `(match_operand I
-...)'). Use the variable `insn' to refer to the last of the insns
-being matched; use `prev_active_insn' to find the preceding insns.
-
- When optimizing computations with intermediate results, you can use
-CONDITION to match only when the intermediate results are not used
-elsewhere. Use the C expression `dead_or_set_p (INSN, OP)', where INSN
-is the insn in which you expect the value to be used for the last time
-(from the value of `insn', together with use of `prev_nonnote_insn'),
-and OP is the intermediate value (from `operands[I]').
-
- Applying the optimization means replacing the sequence of insns with
-one new insn. The TEMPLATE controls ultimate output of assembler code
-for this combined insn. It works exactly like the template of a
-`define_insn'. Operand numbers in this template are the same ones used
-in matching the original sequence of insns.
-
- The result of a defined peephole optimizer does not need to match any
-of the insn patterns in the machine description; it does not even have
-an opportunity to match them. The peephole optimizer definition itself
-serves as the insn pattern to control how the insn is output.
-
- Defined peephole optimizers are run as assembler code is being output,
-so the insns they produce are never combined or rearranged in any way.
-
- Here is an example, taken from the 68000 machine description:
-
- (define_peephole
- [(set (reg:SI 15) (plus:SI (reg:SI 15) (const_int 4)))
- (set (match_operand:DF 0 "register_operand" "=f")
- (match_operand:DF 1 "register_operand" "ad"))]
- "FP_REG_P (operands[0]) && ! FP_REG_P (operands[1])"
- {
- rtx xoperands[2];
- xoperands[1] = gen_rtx_REG (SImode, REGNO (operands[1]) + 1);
- #ifdef MOTOROLA
- output_asm_insn ("move.l %1,(sp)", xoperands);
- output_asm_insn ("move.l %1,-(sp)", operands);
- return "fmove.d (sp)+,%0";
- #else
- output_asm_insn ("movel %1,sp@", xoperands);
- output_asm_insn ("movel %1,sp@-", operands);
- return "fmoved sp@+,%0";
- #endif
- })
-
- The effect of this optimization is to change
-
- jbsr _foobar
- addql #4,sp
- movel d1,sp@-
- movel d0,sp@-
- fmoved sp@+,fp0
-
-into
-
- jbsr _foobar
- movel d1,sp@
- movel d0,sp@-
- fmoved sp@+,fp0
-
- INSN-PATTERN-1 and so on look _almost_ like the second operand of
-`define_insn'. There is one important difference: the second operand
-of `define_insn' consists of one or more RTX's enclosed in square
-brackets. Usually, there is only one: then the same action can be
-written as an element of a `define_peephole'. But when there are
-multiple actions in a `define_insn', they are implicitly enclosed in a
-`parallel'. Then you must explicitly write the `parallel', and the
-square brackets within it, in the `define_peephole'. Thus, if an insn
-pattern looks like this,
-
- (define_insn "divmodsi4"
- [(set (match_operand:SI 0 "general_operand" "=d")
- (div:SI (match_operand:SI 1 "general_operand" "0")
- (match_operand:SI 2 "general_operand" "dmsK")))
- (set (match_operand:SI 3 "general_operand" "=d")
- (mod:SI (match_dup 1) (match_dup 2)))]
- "TARGET_68020"
- "divsl%.l %2,%3:%0")
-
-then the way to mention this insn in a peephole is as follows:
-
- (define_peephole
- [...
- (parallel
- [(set (match_operand:SI 0 "general_operand" "=d")
- (div:SI (match_operand:SI 1 "general_operand" "0")
- (match_operand:SI 2 "general_operand" "dmsK")))
- (set (match_operand:SI 3 "general_operand" "=d")
- (mod:SI (match_dup 1) (match_dup 2)))])
- ...]
- ...)
-
-\1f
-File: gccint.info, Node: define_peephole2, Prev: define_peephole, Up: Peephole Definitions
-
-16.18.2 RTL to RTL Peephole Optimizers
---------------------------------------
-
-The `define_peephole2' definition tells the compiler how to substitute
-one sequence of instructions for another sequence, what additional
-scratch registers may be needed and what their lifetimes must be.
-
- (define_peephole2
- [INSN-PATTERN-1
- INSN-PATTERN-2
- ...]
- "CONDITION"
- [NEW-INSN-PATTERN-1
- NEW-INSN-PATTERN-2
- ...]
- "PREPARATION-STATEMENTS")
-
- The definition is almost identical to `define_split' (*note Insn
-Splitting::) except that the pattern to match is not a single
-instruction, but a sequence of instructions.
-
- It is possible to request additional scratch registers for use in the
-output template. If appropriate registers are not free, the pattern
-will simply not match.
-
- Scratch registers are requested with a `match_scratch' pattern at the
-top level of the input pattern. The allocated register (initially) will
-be dead at the point requested within the original sequence. If the
-scratch is used at more than a single point, a `match_dup' pattern at
-the top level of the input pattern marks the last position in the input
-sequence at which the register must be available.
-
- Here is an example from the IA-32 machine description:
-
- (define_peephole2
- [(match_scratch:SI 2 "r")
- (parallel [(set (match_operand:SI 0 "register_operand" "")
- (match_operator:SI 3 "arith_or_logical_operator"
- [(match_dup 0)
- (match_operand:SI 1 "memory_operand" "")]))
- (clobber (reg:CC 17))])]
- "! optimize_size && ! TARGET_READ_MODIFY"
- [(set (match_dup 2) (match_dup 1))
- (parallel [(set (match_dup 0)
- (match_op_dup 3 [(match_dup 0) (match_dup 2)]))
- (clobber (reg:CC 17))])]
- "")
-
-This pattern tries to split a load from its use in the hopes that we'll
-be able to schedule around the memory load latency. It allocates a
-single `SImode' register of class `GENERAL_REGS' (`"r"') that needs to
-be live only at the point just before the arithmetic.
-
- A real example requiring extended scratch lifetimes is harder to come
-by, so here's a silly made-up example:
-
- (define_peephole2
- [(match_scratch:SI 4 "r")
- (set (match_operand:SI 0 "" "") (match_operand:SI 1 "" ""))
- (set (match_operand:SI 2 "" "") (match_dup 1))
- (match_dup 4)
- (set (match_operand:SI 3 "" "") (match_dup 1))]
- "/* determine 1 does not overlap 0 and 2 */"
- [(set (match_dup 4) (match_dup 1))
- (set (match_dup 0) (match_dup 4))
- (set (match_dup 2) (match_dup 4))]
- (set (match_dup 3) (match_dup 4))]
- "")
-
-If we had not added the `(match_dup 4)' in the middle of the input
-sequence, it might have been the case that the register we chose at the
-beginning of the sequence is killed by the first or second `set'.
-
-\1f
-File: gccint.info, Node: Insn Attributes, Next: Conditional Execution, Prev: Peephole Definitions, Up: Machine Desc
-
-16.19 Instruction Attributes
-============================
-
-In addition to describing the instruction supported by the target
-machine, the `md' file also defines a group of "attributes" and a set of
-values for each. Every generated insn is assigned a value for each
-attribute. One possible attribute would be the effect that the insn
-has on the machine's condition code. This attribute can then be used
-by `NOTICE_UPDATE_CC' to track the condition codes.
-
-* Menu:
-
-* Defining Attributes:: Specifying attributes and their values.
-* Expressions:: Valid expressions for attribute values.
-* Tagging Insns:: Assigning attribute values to insns.
-* Attr Example:: An example of assigning attributes.
-* Insn Lengths:: Computing the length of insns.
-* Constant Attributes:: Defining attributes that are constant.
-* Delay Slots:: Defining delay slots required for a machine.
-* Processor pipeline description:: Specifying information for insn scheduling.
-
-\1f
-File: gccint.info, Node: Defining Attributes, Next: Expressions, Up: Insn Attributes
-
-16.19.1 Defining Attributes and their Values
---------------------------------------------
-
-The `define_attr' expression is used to define each attribute required
-by the target machine. It looks like:
-
- (define_attr NAME LIST-OF-VALUES DEFAULT)
-
- NAME is a string specifying the name of the attribute being defined.
-
- LIST-OF-VALUES is either a string that specifies a comma-separated
-list of values that can be assigned to the attribute, or a null string
-to indicate that the attribute takes numeric values.
-
- DEFAULT is an attribute expression that gives the value of this
-attribute for insns that match patterns whose definition does not
-include an explicit value for this attribute. *Note Attr Example::,
-for more information on the handling of defaults. *Note Constant
-Attributes::, for information on attributes that do not depend on any
-particular insn.
-
- For each defined attribute, a number of definitions are written to the
-`insn-attr.h' file. For cases where an explicit set of values is
-specified for an attribute, the following are defined:
-
- * A `#define' is written for the symbol `HAVE_ATTR_NAME'.
-
- * An enumerated class is defined for `attr_NAME' with elements of
- the form `UPPER-NAME_UPPER-VALUE' where the attribute name and
- value are first converted to uppercase.
-
- * A function `get_attr_NAME' is defined that is passed an insn and
- returns the attribute value for that insn.
-
- For example, if the following is present in the `md' file:
-
- (define_attr "type" "branch,fp,load,store,arith" ...)
-
-the following lines will be written to the file `insn-attr.h'.
-
- #define HAVE_ATTR_type
- enum attr_type {TYPE_BRANCH, TYPE_FP, TYPE_LOAD,
- TYPE_STORE, TYPE_ARITH};
- extern enum attr_type get_attr_type ();
-
- If the attribute takes numeric values, no `enum' type will be defined
-and the function to obtain the attribute's value will return `int'.
-
- There are attributes which are tied to a specific meaning. These
-attributes are not free to use for other purposes:
-
-`length'
- The `length' attribute is used to calculate the length of emitted
- code chunks. This is especially important when verifying branch
- distances. *Note Insn Lengths::.
-
-`enabled'
- The `enabled' attribute can be defined to prevent certain
- alternatives of an insn definition from being used during code
- generation. *Note Disable Insn Alternatives::.
-
-
-\1f
-File: gccint.info, Node: Expressions, Next: Tagging Insns, Prev: Defining Attributes, Up: Insn Attributes
-
-16.19.2 Attribute Expressions
------------------------------
-
-RTL expressions used to define attributes use the codes described above
-plus a few specific to attribute definitions, to be discussed below.
-Attribute value expressions must have one of the following forms:
-
-`(const_int I)'
- The integer I specifies the value of a numeric attribute. I must
- be non-negative.
-
- The value of a numeric attribute can be specified either with a
- `const_int', or as an integer represented as a string in
- `const_string', `eq_attr' (see below), `attr', `symbol_ref',
- simple arithmetic expressions, and `set_attr' overrides on
- specific instructions (*note Tagging Insns::).
-
-`(const_string VALUE)'
- The string VALUE specifies a constant attribute value. If VALUE
- is specified as `"*"', it means that the default value of the
- attribute is to be used for the insn containing this expression.
- `"*"' obviously cannot be used in the DEFAULT expression of a
- `define_attr'.
-
- If the attribute whose value is being specified is numeric, VALUE
- must be a string containing a non-negative integer (normally
- `const_int' would be used in this case). Otherwise, it must
- contain one of the valid values for the attribute.
-
-`(if_then_else TEST TRUE-VALUE FALSE-VALUE)'
- TEST specifies an attribute test, whose format is defined below.
- The value of this expression is TRUE-VALUE if TEST is true,
- otherwise it is FALSE-VALUE.
-
-`(cond [TEST1 VALUE1 ...] DEFAULT)'
- The first operand of this expression is a vector containing an even
- number of expressions and consisting of pairs of TEST and VALUE
- expressions. The value of the `cond' expression is that of the
- VALUE corresponding to the first true TEST expression. If none of
- the TEST expressions are true, the value of the `cond' expression
- is that of the DEFAULT expression.
-
- TEST expressions can have one of the following forms:
-
-`(const_int I)'
- This test is true if I is nonzero and false otherwise.
-
-`(not TEST)'
-`(ior TEST1 TEST2)'
-`(and TEST1 TEST2)'
- These tests are true if the indicated logical function is true.
-
-`(match_operand:M N PRED CONSTRAINTS)'
- This test is true if operand N of the insn whose attribute value
- is being determined has mode M (this part of the test is ignored
- if M is `VOIDmode') and the function specified by the string PRED
- returns a nonzero value when passed operand N and mode M (this
- part of the test is ignored if PRED is the null string).
-
- The CONSTRAINTS operand is ignored and should be the null string.
-
-`(le ARITH1 ARITH2)'
-`(leu ARITH1 ARITH2)'
-`(lt ARITH1 ARITH2)'
-`(ltu ARITH1 ARITH2)'
-`(gt ARITH1 ARITH2)'
-`(gtu ARITH1 ARITH2)'
-`(ge ARITH1 ARITH2)'
-`(geu ARITH1 ARITH2)'
-`(ne ARITH1 ARITH2)'
-`(eq ARITH1 ARITH2)'
- These tests are true if the indicated comparison of the two
- arithmetic expressions is true. Arithmetic expressions are formed
- with `plus', `minus', `mult', `div', `mod', `abs', `neg', `and',
- `ior', `xor', `not', `ashift', `lshiftrt', and `ashiftrt'
- expressions.
-
- `const_int' and `symbol_ref' are always valid terms (*note Insn
- Lengths::,for additional forms). `symbol_ref' is a string
- denoting a C expression that yields an `int' when evaluated by the
- `get_attr_...' routine. It should normally be a global variable.
-
-`(eq_attr NAME VALUE)'
- NAME is a string specifying the name of an attribute.
-
- VALUE is a string that is either a valid value for attribute NAME,
- a comma-separated list of values, or `!' followed by a value or
- list. If VALUE does not begin with a `!', this test is true if
- the value of the NAME attribute of the current insn is in the list
- specified by VALUE. If VALUE begins with a `!', this test is true
- if the attribute's value is _not_ in the specified list.
-
- For example,
-
- (eq_attr "type" "load,store")
-
- is equivalent to
-
- (ior (eq_attr "type" "load") (eq_attr "type" "store"))
-
- If NAME specifies an attribute of `alternative', it refers to the
- value of the compiler variable `which_alternative' (*note Output
- Statement::) and the values must be small integers. For example,
-
- (eq_attr "alternative" "2,3")
-
- is equivalent to
-
- (ior (eq (symbol_ref "which_alternative") (const_int 2))
- (eq (symbol_ref "which_alternative") (const_int 3)))
-
- Note that, for most attributes, an `eq_attr' test is simplified in
- cases where the value of the attribute being tested is known for
- all insns matching a particular pattern. This is by far the most
- common case.
-
-`(attr_flag NAME)'
- The value of an `attr_flag' expression is true if the flag
- specified by NAME is true for the `insn' currently being scheduled.
-
- NAME is a string specifying one of a fixed set of flags to test.
- Test the flags `forward' and `backward' to determine the direction
- of a conditional branch. Test the flags `very_likely', `likely',
- `very_unlikely', and `unlikely' to determine if a conditional
- branch is expected to be taken.
-
- If the `very_likely' flag is true, then the `likely' flag is also
- true. Likewise for the `very_unlikely' and `unlikely' flags.
-
- This example describes a conditional branch delay slot which can
- be nullified for forward branches that are taken (annul-true) or
- for backward branches which are not taken (annul-false).
-
- (define_delay (eq_attr "type" "cbranch")
- [(eq_attr "in_branch_delay" "true")
- (and (eq_attr "in_branch_delay" "true")
- (attr_flag "forward"))
- (and (eq_attr "in_branch_delay" "true")
- (attr_flag "backward"))])
-
- The `forward' and `backward' flags are false if the current `insn'
- being scheduled is not a conditional branch.
-
- The `very_likely' and `likely' flags are true if the `insn' being
- scheduled is not a conditional branch. The `very_unlikely' and
- `unlikely' flags are false if the `insn' being scheduled is not a
- conditional branch.
-
- `attr_flag' is only used during delay slot scheduling and has no
- meaning to other passes of the compiler.
-
-`(attr NAME)'
- The value of another attribute is returned. This is most useful
- for numeric attributes, as `eq_attr' and `attr_flag' produce more
- efficient code for non-numeric attributes.
-
-\1f
-File: gccint.info, Node: Tagging Insns, Next: Attr Example, Prev: Expressions, Up: Insn Attributes
-
-16.19.3 Assigning Attribute Values to Insns
--------------------------------------------
-
-The value assigned to an attribute of an insn is primarily determined by
-which pattern is matched by that insn (or which `define_peephole'
-generated it). Every `define_insn' and `define_peephole' can have an
-optional last argument to specify the values of attributes for matching
-insns. The value of any attribute not specified in a particular insn
-is set to the default value for that attribute, as specified in its
-`define_attr'. Extensive use of default values for attributes permits
-the specification of the values for only one or two attributes in the
-definition of most insn patterns, as seen in the example in the next
-section.
-
- The optional last argument of `define_insn' and `define_peephole' is a
-vector of expressions, each of which defines the value for a single
-attribute. The most general way of assigning an attribute's value is
-to use a `set' expression whose first operand is an `attr' expression
-giving the name of the attribute being set. The second operand of the
-`set' is an attribute expression (*note Expressions::) giving the value
-of the attribute.
-
- When the attribute value depends on the `alternative' attribute (i.e.,
-which is the applicable alternative in the constraint of the insn), the
-`set_attr_alternative' expression can be used. It allows the
-specification of a vector of attribute expressions, one for each
-alternative.
-
- When the generality of arbitrary attribute expressions is not required,
-the simpler `set_attr' expression can be used, which allows specifying
-a string giving either a single attribute value or a list of attribute
-values, one for each alternative.
-
- The form of each of the above specifications is shown below. In each
-case, NAME is a string specifying the attribute to be set.
-
-`(set_attr NAME VALUE-STRING)'
- VALUE-STRING is either a string giving the desired attribute value,
- or a string containing a comma-separated list giving the values for
- succeeding alternatives. The number of elements must match the
- number of alternatives in the constraint of the insn pattern.
-
- Note that it may be useful to specify `*' for some alternative, in
- which case the attribute will assume its default value for insns
- matching that alternative.
-
-`(set_attr_alternative NAME [VALUE1 VALUE2 ...])'
- Depending on the alternative of the insn, the value will be one of
- the specified values. This is a shorthand for using a `cond' with
- tests on the `alternative' attribute.
-
-`(set (attr NAME) VALUE)'
- The first operand of this `set' must be the special RTL expression
- `attr', whose sole operand is a string giving the name of the
- attribute being set. VALUE is the value of the attribute.
-
- The following shows three different ways of representing the same
-attribute value specification:
-
- (set_attr "type" "load,store,arith")
-
- (set_attr_alternative "type"
- [(const_string "load") (const_string "store")
- (const_string "arith")])
-
- (set (attr "type")
- (cond [(eq_attr "alternative" "1") (const_string "load")
- (eq_attr "alternative" "2") (const_string "store")]
- (const_string "arith")))
-
- The `define_asm_attributes' expression provides a mechanism to specify
-the attributes assigned to insns produced from an `asm' statement. It
-has the form:
-
- (define_asm_attributes [ATTR-SETS])
-
-where ATTR-SETS is specified the same as for both the `define_insn' and
-the `define_peephole' expressions.
-
- These values will typically be the "worst case" attribute values. For
-example, they might indicate that the condition code will be clobbered.
-
- A specification for a `length' attribute is handled specially. The
-way to compute the length of an `asm' insn is to multiply the length
-specified in the expression `define_asm_attributes' by the number of
-machine instructions specified in the `asm' statement, determined by
-counting the number of semicolons and newlines in the string.
-Therefore, the value of the `length' attribute specified in a
-`define_asm_attributes' should be the maximum possible length of a
-single machine instruction.
-
-\1f
-File: gccint.info, Node: Attr Example, Next: Insn Lengths, Prev: Tagging Insns, Up: Insn Attributes
-
-16.19.4 Example of Attribute Specifications
--------------------------------------------
-
-The judicious use of defaulting is important in the efficient use of
-insn attributes. Typically, insns are divided into "types" and an
-attribute, customarily called `type', is used to represent this value.
-This attribute is normally used only to define the default value for
-other attributes. An example will clarify this usage.
-
- Assume we have a RISC machine with a condition code and in which only
-full-word operations are performed in registers. Let us assume that we
-can divide all insns into loads, stores, (integer) arithmetic
-operations, floating point operations, and branches.
-
- Here we will concern ourselves with determining the effect of an insn
-on the condition code and will limit ourselves to the following possible
-effects: The condition code can be set unpredictably (clobbered), not
-be changed, be set to agree with the results of the operation, or only
-changed if the item previously set into the condition code has been
-modified.
-
- Here is part of a sample `md' file for such a machine:
-
- (define_attr "type" "load,store,arith,fp,branch" (const_string "arith"))
-
- (define_attr "cc" "clobber,unchanged,set,change0"
- (cond [(eq_attr "type" "load")
- (const_string "change0")
- (eq_attr "type" "store,branch")
- (const_string "unchanged")
- (eq_attr "type" "arith")
- (if_then_else (match_operand:SI 0 "" "")
- (const_string "set")
- (const_string "clobber"))]
- (const_string "clobber")))
-
- (define_insn ""
- [(set (match_operand:SI 0 "general_operand" "=r,r,m")
- (match_operand:SI 1 "general_operand" "r,m,r"))]
- ""
- "@
- move %0,%1
- load %0,%1
- store %0,%1"
- [(set_attr "type" "arith,load,store")])
-
- Note that we assume in the above example that arithmetic operations
-performed on quantities smaller than a machine word clobber the
-condition code since they will set the condition code to a value
-corresponding to the full-word result.
-
-\1f
-File: gccint.info, Node: Insn Lengths, Next: Constant Attributes, Prev: Attr Example, Up: Insn Attributes
-
-16.19.5 Computing the Length of an Insn
----------------------------------------
-
-For many machines, multiple types of branch instructions are provided,
-each for different length branch displacements. In most cases, the
-assembler will choose the correct instruction to use. However, when
-the assembler cannot do so, GCC can when a special attribute, the
-`length' attribute, is defined. This attribute must be defined to have
-numeric values by specifying a null string in its `define_attr'.
-
- In the case of the `length' attribute, two additional forms of
-arithmetic terms are allowed in test expressions:
-
-`(match_dup N)'
- This refers to the address of operand N of the current insn, which
- must be a `label_ref'.
-
-`(pc)'
- This refers to the address of the _current_ insn. It might have
- been more consistent with other usage to make this the address of
- the _next_ insn but this would be confusing because the length of
- the current insn is to be computed.
-
- For normal insns, the length will be determined by value of the
-`length' attribute. In the case of `addr_vec' and `addr_diff_vec' insn
-patterns, the length is computed as the number of vectors multiplied by
-the size of each vector.
-
- Lengths are measured in addressable storage units (bytes).
-
- The following macros can be used to refine the length computation:
-
-`ADJUST_INSN_LENGTH (INSN, LENGTH)'
- If defined, modifies the length assigned to instruction INSN as a
- function of the context in which it is used. LENGTH is an lvalue
- that contains the initially computed length of the insn and should
- be updated with the correct length of the insn.
-
- This macro will normally not be required. A case in which it is
- required is the ROMP. On this machine, the size of an `addr_vec'
- insn must be increased by two to compensate for the fact that
- alignment may be required.
-
- The routine that returns `get_attr_length' (the value of the `length'
-attribute) can be used by the output routine to determine the form of
-the branch instruction to be written, as the example below illustrates.
-
- As an example of the specification of variable-length branches,
-consider the IBM 360. If we adopt the convention that a register will
-be set to the starting address of a function, we can jump to labels
-within 4k of the start using a four-byte instruction. Otherwise, we
-need a six-byte sequence to load the address from memory and then
-branch to it.
-
- On such a machine, a pattern for a branch instruction might be
-specified as follows:
-
- (define_insn "jump"
- [(set (pc)
- (label_ref (match_operand 0 "" "")))]
- ""
- {
- return (get_attr_length (insn) == 4
- ? "b %l0" : "l r15,=a(%l0); br r15");
- }
- [(set (attr "length")
- (if_then_else (lt (match_dup 0) (const_int 4096))
- (const_int 4)
- (const_int 6)))])
-
-\1f
-File: gccint.info, Node: Constant Attributes, Next: Delay Slots, Prev: Insn Lengths, Up: Insn Attributes
-
-16.19.6 Constant Attributes
----------------------------
-
-A special form of `define_attr', where the expression for the default
-value is a `const' expression, indicates an attribute that is constant
-for a given run of the compiler. Constant attributes may be used to
-specify which variety of processor is used. For example,
-
- (define_attr "cpu" "m88100,m88110,m88000"
- (const
- (cond [(symbol_ref "TARGET_88100") (const_string "m88100")
- (symbol_ref "TARGET_88110") (const_string "m88110")]
- (const_string "m88000"))))
-
- (define_attr "memory" "fast,slow"
- (const
- (if_then_else (symbol_ref "TARGET_FAST_MEM")
- (const_string "fast")
- (const_string "slow"))))
-
- The routine generated for constant attributes has no parameters as it
-does not depend on any particular insn. RTL expressions used to define
-the value of a constant attribute may use the `symbol_ref' form, but
-may not use either the `match_operand' form or `eq_attr' forms
-involving insn attributes.
-
-\1f
-File: gccint.info, Node: Delay Slots, Next: Processor pipeline description, Prev: Constant Attributes, Up: Insn Attributes
-
-16.19.7 Delay Slot Scheduling
------------------------------
-
-The insn attribute mechanism can be used to specify the requirements for
-delay slots, if any, on a target machine. An instruction is said to
-require a "delay slot" if some instructions that are physically after
-the instruction are executed as if they were located before it.
-Classic examples are branch and call instructions, which often execute
-the following instruction before the branch or call is performed.
-
- On some machines, conditional branch instructions can optionally
-"annul" instructions in the delay slot. This means that the
-instruction will not be executed for certain branch outcomes. Both
-instructions that annul if the branch is true and instructions that
-annul if the branch is false are supported.
-
- Delay slot scheduling differs from instruction scheduling in that
-determining whether an instruction needs a delay slot is dependent only
-on the type of instruction being generated, not on data flow between the
-instructions. See the next section for a discussion of data-dependent
-instruction scheduling.
-
- The requirement of an insn needing one or more delay slots is indicated
-via the `define_delay' expression. It has the following form:
-
- (define_delay TEST
- [DELAY-1 ANNUL-TRUE-1 ANNUL-FALSE-1
- DELAY-2 ANNUL-TRUE-2 ANNUL-FALSE-2
- ...])
-
- TEST is an attribute test that indicates whether this `define_delay'
-applies to a particular insn. If so, the number of required delay
-slots is determined by the length of the vector specified as the second
-argument. An insn placed in delay slot N must satisfy attribute test
-DELAY-N. ANNUL-TRUE-N is an attribute test that specifies which insns
-may be annulled if the branch is true. Similarly, ANNUL-FALSE-N
-specifies which insns in the delay slot may be annulled if the branch
-is false. If annulling is not supported for that delay slot, `(nil)'
-should be coded.
-
- For example, in the common case where branch and call insns require a
-single delay slot, which may contain any insn other than a branch or
-call, the following would be placed in the `md' file:
-
- (define_delay (eq_attr "type" "branch,call")
- [(eq_attr "type" "!branch,call") (nil) (nil)])
-
- Multiple `define_delay' expressions may be specified. In this case,
-each such expression specifies different delay slot requirements and
-there must be no insn for which tests in two `define_delay' expressions
-are both true.
-
- For example, if we have a machine that requires one delay slot for
-branches but two for calls, no delay slot can contain a branch or call
-insn, and any valid insn in the delay slot for the branch can be
-annulled if the branch is true, we might represent this as follows:
-
- (define_delay (eq_attr "type" "branch")
- [(eq_attr "type" "!branch,call")
- (eq_attr "type" "!branch,call")
- (nil)])
-
- (define_delay (eq_attr "type" "call")
- [(eq_attr "type" "!branch,call") (nil) (nil)
- (eq_attr "type" "!branch,call") (nil) (nil)])
-
-\1f
-File: gccint.info, Node: Processor pipeline description, Prev: Delay Slots, Up: Insn Attributes
-
-16.19.8 Specifying processor pipeline description
--------------------------------------------------
-
-To achieve better performance, most modern processors (super-pipelined,
-superscalar RISC, and VLIW processors) have many "functional units" on
-which several instructions can be executed simultaneously. An
-instruction starts execution if its issue conditions are satisfied. If
-not, the instruction is stalled until its conditions are satisfied.
-Such "interlock (pipeline) delay" causes interruption of the fetching
-of successor instructions (or demands nop instructions, e.g. for some
-MIPS processors).
-
- There are two major kinds of interlock delays in modern processors.
-The first one is a data dependence delay determining "instruction
-latency time". The instruction execution is not started until all
-source data have been evaluated by prior instructions (there are more
-complex cases when the instruction execution starts even when the data
-are not available but will be ready in given time after the instruction
-execution start). Taking the data dependence delays into account is
-simple. The data dependence (true, output, and anti-dependence) delay
-between two instructions is given by a constant. In most cases this
-approach is adequate. The second kind of interlock delays is a
-reservation delay. The reservation delay means that two instructions
-under execution will be in need of shared processors resources, i.e.
-buses, internal registers, and/or functional units, which are reserved
-for some time. Taking this kind of delay into account is complex
-especially for modern RISC processors.
-
- The task of exploiting more processor parallelism is solved by an
-instruction scheduler. For a better solution to this problem, the
-instruction scheduler has to have an adequate description of the
-processor parallelism (or "pipeline description"). GCC machine
-descriptions describe processor parallelism and functional unit
-reservations for groups of instructions with the aid of "regular
-expressions".
-
- The GCC instruction scheduler uses a "pipeline hazard recognizer" to
-figure out the possibility of the instruction issue by the processor on
-a given simulated processor cycle. The pipeline hazard recognizer is
-automatically generated from the processor pipeline description. The
-pipeline hazard recognizer generated from the machine description is
-based on a deterministic finite state automaton (DFA): the instruction
-issue is possible if there is a transition from one automaton state to
-another one. This algorithm is very fast, and furthermore, its speed
-is not dependent on processor complexity(1).
-
- The rest of this section describes the directives that constitute an
-automaton-based processor pipeline description. The order of these
-constructions within the machine description file is not important.
-
- The following optional construction describes names of automata
-generated and used for the pipeline hazards recognition. Sometimes the
-generated finite state automaton used by the pipeline hazard recognizer
-is large. If we use more than one automaton and bind functional units
-to the automata, the total size of the automata is usually less than
-the size of the single automaton. If there is no one such
-construction, only one finite state automaton is generated.
-
- (define_automaton AUTOMATA-NAMES)
-
- AUTOMATA-NAMES is a string giving names of the automata. The names
-are separated by commas. All the automata should have unique names.
-The automaton name is used in the constructions `define_cpu_unit' and
-`define_query_cpu_unit'.
-
- Each processor functional unit used in the description of instruction
-reservations should be described by the following construction.
-
- (define_cpu_unit UNIT-NAMES [AUTOMATON-NAME])
-
- UNIT-NAMES is a string giving the names of the functional units
-separated by commas. Don't use name `nothing', it is reserved for
-other goals.
-
- AUTOMATON-NAME is a string giving the name of the automaton with which
-the unit is bound. The automaton should be described in construction
-`define_automaton'. You should give "automaton-name", if there is a
-defined automaton.
-
- The assignment of units to automata are constrained by the uses of the
-units in insn reservations. The most important constraint is: if a
-unit reservation is present on a particular cycle of an alternative for
-an insn reservation, then some unit from the same automaton must be
-present on the same cycle for the other alternatives of the insn
-reservation. The rest of the constraints are mentioned in the
-description of the subsequent constructions.
-
- The following construction describes CPU functional units analogously
-to `define_cpu_unit'. The reservation of such units can be queried for
-an automaton state. The instruction scheduler never queries
-reservation of functional units for given automaton state. So as a
-rule, you don't need this construction. This construction could be
-used for future code generation goals (e.g. to generate VLIW insn
-templates).
-
- (define_query_cpu_unit UNIT-NAMES [AUTOMATON-NAME])
-
- UNIT-NAMES is a string giving names of the functional units separated
-by commas.
-
- AUTOMATON-NAME is a string giving the name of the automaton with which
-the unit is bound.
-
- The following construction is the major one to describe pipeline
-characteristics of an instruction.
-
- (define_insn_reservation INSN-NAME DEFAULT_LATENCY
- CONDITION REGEXP)
-
- DEFAULT_LATENCY is a number giving latency time of the instruction.
-There is an important difference between the old description and the
-automaton based pipeline description. The latency time is used for all
-dependencies when we use the old description. In the automaton based
-pipeline description, the given latency time is only used for true
-dependencies. The cost of anti-dependencies is always zero and the
-cost of output dependencies is the difference between latency times of
-the producing and consuming insns (if the difference is negative, the
-cost is considered to be zero). You can always change the default
-costs for any description by using the target hook
-`TARGET_SCHED_ADJUST_COST' (*note Scheduling::).
-
- INSN-NAME is a string giving the internal name of the insn. The
-internal names are used in constructions `define_bypass' and in the
-automaton description file generated for debugging. The internal name
-has nothing in common with the names in `define_insn'. It is a good
-practice to use insn classes described in the processor manual.
-
- CONDITION defines what RTL insns are described by this construction.
-You should remember that you will be in trouble if CONDITION for two or
-more different `define_insn_reservation' constructions is TRUE for an
-insn. In this case what reservation will be used for the insn is not
-defined. Such cases are not checked during generation of the pipeline
-hazards recognizer because in general recognizing that two conditions
-may have the same value is quite difficult (especially if the conditions
-contain `symbol_ref'). It is also not checked during the pipeline
-hazard recognizer work because it would slow down the recognizer
-considerably.
-
- REGEXP is a string describing the reservation of the cpu's functional
-units by the instruction. The reservations are described by a regular
-expression according to the following syntax:
-
- regexp = regexp "," oneof
- | oneof
-
- oneof = oneof "|" allof
- | allof
-
- allof = allof "+" repeat
- | repeat
-
- repeat = element "*" number
- | element
-
- element = cpu_function_unit_name
- | reservation_name
- | result_name
- | "nothing"
- | "(" regexp ")"
-
- * `,' is used for describing the start of the next cycle in the
- reservation.
-
- * `|' is used for describing a reservation described by the first
- regular expression *or* a reservation described by the second
- regular expression *or* etc.
-
- * `+' is used for describing a reservation described by the first
- regular expression *and* a reservation described by the second
- regular expression *and* etc.
-
- * `*' is used for convenience and simply means a sequence in which
- the regular expression are repeated NUMBER times with cycle
- advancing (see `,').
-
- * `cpu_function_unit_name' denotes reservation of the named
- functional unit.
-
- * `reservation_name' -- see description of construction
- `define_reservation'.
-
- * `nothing' denotes no unit reservations.
-
- Sometimes unit reservations for different insns contain common parts.
-In such case, you can simplify the pipeline description by describing
-the common part by the following construction
-
- (define_reservation RESERVATION-NAME REGEXP)
-
- RESERVATION-NAME is a string giving name of REGEXP. Functional unit
-names and reservation names are in the same name space. So the
-reservation names should be different from the functional unit names
-and can not be the reserved name `nothing'.
-
- The following construction is used to describe exceptions in the
-latency time for given instruction pair. This is so called bypasses.
-
- (define_bypass NUMBER OUT_INSN_NAMES IN_INSN_NAMES
- [GUARD])
-
- NUMBER defines when the result generated by the instructions given in
-string OUT_INSN_NAMES will be ready for the instructions given in
-string IN_INSN_NAMES. The instructions in the string are separated by
-commas.
-
- GUARD is an optional string giving the name of a C function which
-defines an additional guard for the bypass. The function will get the
-two insns as parameters. If the function returns zero the bypass will
-be ignored for this case. The additional guard is necessary to
-recognize complicated bypasses, e.g. when the consumer is only an
-address of insn `store' (not a stored value).
-
- The following five constructions are usually used to describe VLIW
-processors, or more precisely, to describe a placement of small
-instructions into VLIW instruction slots. They can be used for RISC
-processors, too.
-
- (exclusion_set UNIT-NAMES UNIT-NAMES)
- (presence_set UNIT-NAMES PATTERNS)
- (final_presence_set UNIT-NAMES PATTERNS)
- (absence_set UNIT-NAMES PATTERNS)
- (final_absence_set UNIT-NAMES PATTERNS)
-
- UNIT-NAMES is a string giving names of functional units separated by
-commas.
-
- PATTERNS is a string giving patterns of functional units separated by
-comma. Currently pattern is one unit or units separated by
-white-spaces.
-
- The first construction (`exclusion_set') means that each functional
-unit in the first string can not be reserved simultaneously with a unit
-whose name is in the second string and vice versa. For example, the
-construction is useful for describing processors (e.g. some SPARC
-processors) with a fully pipelined floating point functional unit which
-can execute simultaneously only single floating point insns or only
-double floating point insns.
-
- The second construction (`presence_set') means that each functional
-unit in the first string can not be reserved unless at least one of
-pattern of units whose names are in the second string is reserved.
-This is an asymmetric relation. For example, it is useful for
-description that VLIW `slot1' is reserved after `slot0' reservation.
-We could describe it by the following construction
-
- (presence_set "slot1" "slot0")
-
- Or `slot1' is reserved only after `slot0' and unit `b0' reservation.
-In this case we could write
-
- (presence_set "slot1" "slot0 b0")
-
- The third construction (`final_presence_set') is analogous to
-`presence_set'. The difference between them is when checking is done.
-When an instruction is issued in given automaton state reflecting all
-current and planned unit reservations, the automaton state is changed.
-The first state is a source state, the second one is a result state.
-Checking for `presence_set' is done on the source state reservation,
-checking for `final_presence_set' is done on the result reservation.
-This construction is useful to describe a reservation which is actually
-two subsequent reservations. For example, if we use
-
- (presence_set "slot1" "slot0")
-
- the following insn will be never issued (because `slot1' requires
-`slot0' which is absent in the source state).
-
- (define_reservation "insn_and_nop" "slot0 + slot1")
-
- but it can be issued if we use analogous `final_presence_set'.
-
- The forth construction (`absence_set') means that each functional unit
-in the first string can be reserved only if each pattern of units whose
-names are in the second string is not reserved. This is an asymmetric
-relation (actually `exclusion_set' is analogous to this one but it is
-symmetric). For example it might be useful in a VLIW description to
-say that `slot0' cannot be reserved after either `slot1' or `slot2'
-have been reserved. This can be described as:
-
- (absence_set "slot0" "slot1, slot2")
-
- Or `slot2' can not be reserved if `slot0' and unit `b0' are reserved
-or `slot1' and unit `b1' are reserved. In this case we could write
-
- (absence_set "slot2" "slot0 b0, slot1 b1")
-
- All functional units mentioned in a set should belong to the same
-automaton.
-
- The last construction (`final_absence_set') is analogous to
-`absence_set' but checking is done on the result (state) reservation.
-See comments for `final_presence_set'.
-
- You can control the generator of the pipeline hazard recognizer with
-the following construction.
-
- (automata_option OPTIONS)
-
- OPTIONS is a string giving options which affect the generated code.
-Currently there are the following options:
-
- * "no-minimization" makes no minimization of the automaton. This is
- only worth to do when we are debugging the description and need to
- look more accurately at reservations of states.
-
- * "time" means printing time statistics about the generation of
- automata.
-
- * "stats" means printing statistics about the generated automata
- such as the number of DFA states, NDFA states and arcs.
-
- * "v" means a generation of the file describing the result automata.
- The file has suffix `.dfa' and can be used for the description
- verification and debugging.
-
- * "w" means a generation of warning instead of error for
- non-critical errors.
-
- * "ndfa" makes nondeterministic finite state automata. This affects
- the treatment of operator `|' in the regular expressions. The
- usual treatment of the operator is to try the first alternative
- and, if the reservation is not possible, the second alternative.
- The nondeterministic treatment means trying all alternatives, some
- of them may be rejected by reservations in the subsequent insns.
-
- * "progress" means output of a progress bar showing how many states
- were generated so far for automaton being processed. This is
- useful during debugging a DFA description. If you see too many
- generated states, you could interrupt the generator of the pipeline
- hazard recognizer and try to figure out a reason for generation of
- the huge automaton.
-
- As an example, consider a superscalar RISC machine which can issue
-three insns (two integer insns and one floating point insn) on the
-cycle but can finish only two insns. To describe this, we define the
-following functional units.
-
- (define_cpu_unit "i0_pipeline, i1_pipeline, f_pipeline")
- (define_cpu_unit "port0, port1")
-
- All simple integer insns can be executed in any integer pipeline and
-their result is ready in two cycles. The simple integer insns are
-issued into the first pipeline unless it is reserved, otherwise they
-are issued into the second pipeline. Integer division and
-multiplication insns can be executed only in the second integer
-pipeline and their results are ready correspondingly in 8 and 4 cycles.
-The integer division is not pipelined, i.e. the subsequent integer
-division insn can not be issued until the current division insn
-finished. Floating point insns are fully pipelined and their results
-are ready in 3 cycles. Where the result of a floating point insn is
-used by an integer insn, an additional delay of one cycle is incurred.
-To describe all of this we could specify
-
- (define_cpu_unit "div")
-
- (define_insn_reservation "simple" 2 (eq_attr "type" "int")
- "(i0_pipeline | i1_pipeline), (port0 | port1)")
-
- (define_insn_reservation "mult" 4 (eq_attr "type" "mult")
- "i1_pipeline, nothing*2, (port0 | port1)")
-
- (define_insn_reservation "div" 8 (eq_attr "type" "div")
- "i1_pipeline, div*7, div + (port0 | port1)")
-
- (define_insn_reservation "float" 3 (eq_attr "type" "float")
- "f_pipeline, nothing, (port0 | port1))
-
- (define_bypass 4 "float" "simple,mult,div")
-
- To simplify the description we could describe the following reservation
-
- (define_reservation "finish" "port0|port1")
-
- and use it in all `define_insn_reservation' as in the following
-construction
-
- (define_insn_reservation "simple" 2 (eq_attr "type" "int")
- "(i0_pipeline | i1_pipeline), finish")
-
- ---------- Footnotes ----------
-
- (1) However, the size of the automaton depends on processor
-complexity. To limit this effect, machine descriptions can split
-orthogonal parts of the machine description among several automata: but
-then, since each of these must be stepped independently, this does
-cause a small decrease in the algorithm's performance.
-
-\1f
-File: gccint.info, Node: Conditional Execution, Next: Constant Definitions, Prev: Insn Attributes, Up: Machine Desc
-
-16.20 Conditional Execution
-===========================
-
-A number of architectures provide for some form of conditional
-execution, or predication. The hallmark of this feature is the ability
-to nullify most of the instructions in the instruction set. When the
-instruction set is large and not entirely symmetric, it can be quite
-tedious to describe these forms directly in the `.md' file. An
-alternative is the `define_cond_exec' template.
-
- (define_cond_exec
- [PREDICATE-PATTERN]
- "CONDITION"
- "OUTPUT-TEMPLATE")
-
- PREDICATE-PATTERN is the condition that must be true for the insn to
-be executed at runtime and should match a relational operator. One can
-use `match_operator' to match several relational operators at once.
-Any `match_operand' operands must have no more than one alternative.
-
- CONDITION is a C expression that must be true for the generated
-pattern to match.
-
- OUTPUT-TEMPLATE is a string similar to the `define_insn' output
-template (*note Output Template::), except that the `*' and `@' special
-cases do not apply. This is only useful if the assembly text for the
-predicate is a simple prefix to the main insn. In order to handle the
-general case, there is a global variable `current_insn_predicate' that
-will contain the entire predicate if the current insn is predicated,
-and will otherwise be `NULL'.
-
- When `define_cond_exec' is used, an implicit reference to the
-`predicable' instruction attribute is made. *Note Insn Attributes::.
-This attribute must be boolean (i.e. have exactly two elements in its
-LIST-OF-VALUES). Further, it must not be used with complex
-expressions. That is, the default and all uses in the insns must be a
-simple constant, not dependent on the alternative or anything else.
-
- For each `define_insn' for which the `predicable' attribute is true, a
-new `define_insn' pattern will be generated that matches a predicated
-version of the instruction. For example,
-
- (define_insn "addsi"
- [(set (match_operand:SI 0 "register_operand" "r")
- (plus:SI (match_operand:SI 1 "register_operand" "r")
- (match_operand:SI 2 "register_operand" "r")))]
- "TEST1"
- "add %2,%1,%0")
-
- (define_cond_exec
- [(ne (match_operand:CC 0 "register_operand" "c")
- (const_int 0))]
- "TEST2"
- "(%0)")
-
-generates a new pattern
-
- (define_insn ""
- [(cond_exec
- (ne (match_operand:CC 3 "register_operand" "c") (const_int 0))
- (set (match_operand:SI 0 "register_operand" "r")
- (plus:SI (match_operand:SI 1 "register_operand" "r")
- (match_operand:SI 2 "register_operand" "r"))))]
- "(TEST2) && (TEST1)"
- "(%3) add %2,%1,%0")
-
-\1f
-File: gccint.info, Node: Constant Definitions, Next: Iterators, Prev: Conditional Execution, Up: Machine Desc
-
-16.21 Constant Definitions
-==========================
-
-Using literal constants inside instruction patterns reduces legibility
-and can be a maintenance problem.
-
- To overcome this problem, you may use the `define_constants'
-expression. It contains a vector of name-value pairs. From that point
-on, wherever any of the names appears in the MD file, it is as if the
-corresponding value had been written instead. You may use
-`define_constants' multiple times; each appearance adds more constants
-to the table. It is an error to redefine a constant with a different
-value.
-
- To come back to the a29k load multiple example, instead of
-
- (define_insn ""
- [(match_parallel 0 "load_multiple_operation"
- [(set (match_operand:SI 1 "gpc_reg_operand" "=r")
- (match_operand:SI 2 "memory_operand" "m"))
- (use (reg:SI 179))
- (clobber (reg:SI 179))])]
- ""
- "loadm 0,0,%1,%2")
-
- You could write:
-
- (define_constants [
- (R_BP 177)
- (R_FC 178)
- (R_CR 179)
- (R_Q 180)
- ])
-
- (define_insn ""
- [(match_parallel 0 "load_multiple_operation"
- [(set (match_operand:SI 1 "gpc_reg_operand" "=r")
- (match_operand:SI 2 "memory_operand" "m"))
- (use (reg:SI R_CR))
- (clobber (reg:SI R_CR))])]
- ""
- "loadm 0,0,%1,%2")
-
- The constants that are defined with a define_constant are also output
-in the insn-codes.h header file as #defines.
-
-\1f
-File: gccint.info, Node: Iterators, Prev: Constant Definitions, Up: Machine Desc
-
-16.22 Iterators
-===============
-
-Ports often need to define similar patterns for more than one machine
-mode or for more than one rtx code. GCC provides some simple iterator
-facilities to make this process easier.
-
-* Menu:
-
-* Mode Iterators:: Generating variations of patterns for different modes.
-* Code Iterators:: Doing the same for codes.
-
-\1f
-File: gccint.info, Node: Mode Iterators, Next: Code Iterators, Up: Iterators
-
-16.22.1 Mode Iterators
-----------------------
-
-Ports often need to define similar patterns for two or more different
-modes. For example:
-
- * If a processor has hardware support for both single and double
- floating-point arithmetic, the `SFmode' patterns tend to be very
- similar to the `DFmode' ones.
-
- * If a port uses `SImode' pointers in one configuration and `DImode'
- pointers in another, it will usually have very similar `SImode'
- and `DImode' patterns for manipulating pointers.
-
- Mode iterators allow several patterns to be instantiated from one
-`.md' file template. They can be used with any type of rtx-based
-construct, such as a `define_insn', `define_split', or
-`define_peephole2'.
-
-* Menu:
-
-* Defining Mode Iterators:: Defining a new mode iterator.
-* Substitutions:: Combining mode iterators with substitutions
-* Examples:: Examples
-
-\1f
-File: gccint.info, Node: Defining Mode Iterators, Next: Substitutions, Up: Mode Iterators
-
-16.22.1.1 Defining Mode Iterators
-.................................
-
-The syntax for defining a mode iterator is:
-
- (define_mode_iterator NAME [(MODE1 "COND1") ... (MODEN "CONDN")])
-
- This allows subsequent `.md' file constructs to use the mode suffix
-`:NAME'. Every construct that does so will be expanded N times, once
-with every use of `:NAME' replaced by `:MODE1', once with every use
-replaced by `:MODE2', and so on. In the expansion for a particular
-MODEI, every C condition will also require that CONDI be true.
-
- For example:
-
- (define_mode_iterator P [(SI "Pmode == SImode") (DI "Pmode == DImode")])
-
- defines a new mode suffix `:P'. Every construct that uses `:P' will
-be expanded twice, once with every `:P' replaced by `:SI' and once with
-every `:P' replaced by `:DI'. The `:SI' version will only apply if
-`Pmode == SImode' and the `:DI' version will only apply if `Pmode ==
-DImode'.
-
- As with other `.md' conditions, an empty string is treated as "always
-true". `(MODE "")' can also be abbreviated to `MODE'. For example:
-
- (define_mode_iterator GPR [SI (DI "TARGET_64BIT")])
-
- means that the `:DI' expansion only applies if `TARGET_64BIT' but that
-the `:SI' expansion has no such constraint.
-
- Iterators are applied in the order they are defined. This can be
-significant if two iterators are used in a construct that requires
-substitutions. *Note Substitutions::.
-
-\1f
-File: gccint.info, Node: Substitutions, Next: Examples, Prev: Defining Mode Iterators, Up: Mode Iterators
-
-16.22.1.2 Substitution in Mode Iterators
-........................................
-
-If an `.md' file construct uses mode iterators, each version of the
-construct will often need slightly different strings or modes. For
-example:
-
- * When a `define_expand' defines several `addM3' patterns (*note
- Standard Names::), each expander will need to use the appropriate
- mode name for M.
-
- * When a `define_insn' defines several instruction patterns, each
- instruction will often use a different assembler mnemonic.
-
- * When a `define_insn' requires operands with different modes, using
- an iterator for one of the operand modes usually requires a
- specific mode for the other operand(s).
-
- GCC supports such variations through a system of "mode attributes".
-There are two standard attributes: `mode', which is the name of the
-mode in lower case, and `MODE', which is the same thing in upper case.
-You can define other attributes using:
-
- (define_mode_attr NAME [(MODE1 "VALUE1") ... (MODEN "VALUEN")])
-
- where NAME is the name of the attribute and VALUEI is the value
-associated with MODEI.
-
- When GCC replaces some :ITERATOR with :MODE, it will scan each string
-and mode in the pattern for sequences of the form `<ITERATOR:ATTR>',
-where ATTR is the name of a mode attribute. If the attribute is
-defined for MODE, the whole `<...>' sequence will be replaced by the
-appropriate attribute value.
-
- For example, suppose an `.md' file has:
-
- (define_mode_iterator P [(SI "Pmode == SImode") (DI "Pmode == DImode")])
- (define_mode_attr load [(SI "lw") (DI "ld")])
-
- If one of the patterns that uses `:P' contains the string
-`"<P:load>\t%0,%1"', the `SI' version of that pattern will use
-`"lw\t%0,%1"' and the `DI' version will use `"ld\t%0,%1"'.
-
- Here is an example of using an attribute for a mode:
-
- (define_mode_iterator LONG [SI DI])
- (define_mode_attr SHORT [(SI "HI") (DI "SI")])
- (define_insn ...
- (sign_extend:LONG (match_operand:<LONG:SHORT> ...)) ...)
-
- The `ITERATOR:' prefix may be omitted, in which case the substitution
-will be attempted for every iterator expansion.
-
-\1f
-File: gccint.info, Node: Examples, Prev: Substitutions, Up: Mode Iterators
-
-16.22.1.3 Mode Iterator Examples
-................................
-
-Here is an example from the MIPS port. It defines the following modes
-and attributes (among others):
-
- (define_mode_iterator GPR [SI (DI "TARGET_64BIT")])
- (define_mode_attr d [(SI "") (DI "d")])
-
- and uses the following template to define both `subsi3' and `subdi3':
-
- (define_insn "sub<mode>3"
- [(set (match_operand:GPR 0 "register_operand" "=d")
- (minus:GPR (match_operand:GPR 1 "register_operand" "d")
- (match_operand:GPR 2 "register_operand" "d")))]
- ""
- "<d>subu\t%0,%1,%2"
- [(set_attr "type" "arith")
- (set_attr "mode" "<MODE>")])
-
- This is exactly equivalent to:
-
- (define_insn "subsi3"
- [(set (match_operand:SI 0 "register_operand" "=d")
- (minus:SI (match_operand:SI 1 "register_operand" "d")
- (match_operand:SI 2 "register_operand" "d")))]
- ""
- "subu\t%0,%1,%2"
- [(set_attr "type" "arith")
- (set_attr "mode" "SI")])
-
- (define_insn "subdi3"
- [(set (match_operand:DI 0 "register_operand" "=d")
- (minus:DI (match_operand:DI 1 "register_operand" "d")
- (match_operand:DI 2 "register_operand" "d")))]
- ""
- "dsubu\t%0,%1,%2"
- [(set_attr "type" "arith")
- (set_attr "mode" "DI")])
-
-\1f
-File: gccint.info, Node: Code Iterators, Prev: Mode Iterators, Up: Iterators
-
-16.22.2 Code Iterators
-----------------------
-
-Code iterators operate in a similar way to mode iterators. *Note Mode
-Iterators::.
-
- The construct:
-
- (define_code_iterator NAME [(CODE1 "COND1") ... (CODEN "CONDN")])
-
- defines a pseudo rtx code NAME that can be instantiated as CODEI if
-condition CONDI is true. Each CODEI must have the same rtx format.
-*Note RTL Classes::.
-
- As with mode iterators, each pattern that uses NAME will be expanded N
-times, once with all uses of NAME replaced by CODE1, once with all uses
-replaced by CODE2, and so on. *Note Defining Mode Iterators::.
-
- It is possible to define attributes for codes as well as for modes.
-There are two standard code attributes: `code', the name of the code in
-lower case, and `CODE', the name of the code in upper case. Other
-attributes are defined using:
-
- (define_code_attr NAME [(CODE1 "VALUE1") ... (CODEN "VALUEN")])
-
- Here's an example of code iterators in action, taken from the MIPS
-port:
-
- (define_code_iterator any_cond [unordered ordered unlt unge uneq ltgt unle ungt
- eq ne gt ge lt le gtu geu ltu leu])
-
- (define_expand "b<code>"
- [(set (pc)
- (if_then_else (any_cond:CC (cc0)
- (const_int 0))
- (label_ref (match_operand 0 ""))
- (pc)))]
- ""
- {
- gen_conditional_branch (operands, <CODE>);
- DONE;
- })
-
- This is equivalent to:
-
- (define_expand "bunordered"
- [(set (pc)
- (if_then_else (unordered:CC (cc0)
- (const_int 0))
- (label_ref (match_operand 0 ""))
- (pc)))]
- ""
- {
- gen_conditional_branch (operands, UNORDERED);
- DONE;
- })
-
- (define_expand "bordered"
- [(set (pc)
- (if_then_else (ordered:CC (cc0)
- (const_int 0))
- (label_ref (match_operand 0 ""))
- (pc)))]
- ""
- {
- gen_conditional_branch (operands, ORDERED);
- DONE;
- })
-
- ...
-
-\1f
-File: gccint.info, Node: Target Macros, Next: Host Config, Prev: Machine Desc, Up: Top
-
-17 Target Description Macros and Functions
-******************************************
-
-In addition to the file `MACHINE.md', a machine description includes a
-C header file conventionally given the name `MACHINE.h' and a C source
-file named `MACHINE.c'. The header file defines numerous macros that
-convey the information about the target machine that does not fit into
-the scheme of the `.md' file. The file `tm.h' should be a link to
-`MACHINE.h'. The header file `config.h' includes `tm.h' and most
-compiler source files include `config.h'. The source file defines a
-variable `targetm', which is a structure containing pointers to
-functions and data relating to the target machine. `MACHINE.c' should
-also contain their definitions, if they are not defined elsewhere in
-GCC, and other functions called through the macros defined in the `.h'
-file.
-
-* Menu:
-
-* Target Structure:: The `targetm' variable.
-* Driver:: Controlling how the driver runs the compilation passes.
-* Run-time Target:: Defining `-m' options like `-m68000' and `-m68020'.
-* Per-Function Data:: Defining data structures for per-function information.
-* Storage Layout:: Defining sizes and alignments of data.
-* Type Layout:: Defining sizes and properties of basic user data types.
-* Registers:: Naming and describing the hardware registers.
-* Register Classes:: Defining the classes of hardware registers.
-* Old Constraints:: The old way to define machine-specific constraints.
-* Stack and Calling:: Defining which way the stack grows and by how much.
-* Varargs:: Defining the varargs macros.
-* Trampolines:: Code set up at run time to enter a nested function.
-* Library Calls:: Controlling how library routines are implicitly called.
-* Addressing Modes:: Defining addressing modes valid for memory operands.
-* Anchored Addresses:: Defining how `-fsection-anchors' should work.
-* Condition Code:: Defining how insns update the condition code.
-* Costs:: Defining relative costs of different operations.
-* Scheduling:: Adjusting the behavior of the instruction scheduler.
-* Sections:: Dividing storage into text, data, and other sections.
-* PIC:: Macros for position independent code.
-* Assembler Format:: Defining how to write insns and pseudo-ops to output.
-* Debugging Info:: Defining the format of debugging output.
-* Floating Point:: Handling floating point for cross-compilers.
-* Mode Switching:: Insertion of mode-switching instructions.
-* Target Attributes:: Defining target-specific uses of `__attribute__'.
-* Emulated TLS:: Emulated TLS support.
-* MIPS Coprocessors:: MIPS coprocessor support and how to customize it.
-* PCH Target:: Validity checking for precompiled headers.
-* C++ ABI:: Controlling C++ ABI changes.
-* Misc:: Everything else.
-
-\1f
-File: gccint.info, Node: Target Structure, Next: Driver, Up: Target Macros
-
-17.1 The Global `targetm' Variable
-==================================
-
- -- Variable: struct gcc_target targetm
- The target `.c' file must define the global `targetm' variable
- which contains pointers to functions and data relating to the
- target machine. The variable is declared in `target.h';
- `target-def.h' defines the macro `TARGET_INITIALIZER' which is
- used to initialize the variable, and macros for the default
- initializers for elements of the structure. The `.c' file should
- override those macros for which the default definition is
- inappropriate. For example:
- #include "target.h"
- #include "target-def.h"
-
- /* Initialize the GCC target structure. */
-
- #undef TARGET_COMP_TYPE_ATTRIBUTES
- #define TARGET_COMP_TYPE_ATTRIBUTES MACHINE_comp_type_attributes
-
- struct gcc_target targetm = TARGET_INITIALIZER;
-
-Where a macro should be defined in the `.c' file in this manner to form
-part of the `targetm' structure, it is documented below as a "Target
-Hook" with a prototype. Many macros will change in future from being
-defined in the `.h' file to being part of the `targetm' structure.
-
-\1f
-File: gccint.info, Node: Driver, Next: Run-time Target, Prev: Target Structure, Up: Target Macros
-
-17.2 Controlling the Compilation Driver, `gcc'
-==============================================
-
-You can control the compilation driver.
-
- -- Macro: SWITCH_TAKES_ARG (CHAR)
- A C expression which determines whether the option `-CHAR' takes
- arguments. The value should be the number of arguments that
- option takes-zero, for many options.
-
- By default, this macro is defined as `DEFAULT_SWITCH_TAKES_ARG',
- which handles the standard options properly. You need not define
- `SWITCH_TAKES_ARG' unless you wish to add additional options which
- take arguments. Any redefinition should call
- `DEFAULT_SWITCH_TAKES_ARG' and then check for additional options.
-
- -- Macro: WORD_SWITCH_TAKES_ARG (NAME)
- A C expression which determines whether the option `-NAME' takes
- arguments. The value should be the number of arguments that
- option takes-zero, for many options. This macro rather than
- `SWITCH_TAKES_ARG' is used for multi-character option names.
-
- By default, this macro is defined as
- `DEFAULT_WORD_SWITCH_TAKES_ARG', which handles the standard options
- properly. You need not define `WORD_SWITCH_TAKES_ARG' unless you
- wish to add additional options which take arguments. Any
- redefinition should call `DEFAULT_WORD_SWITCH_TAKES_ARG' and then
- check for additional options.
-
- -- Macro: SWITCH_CURTAILS_COMPILATION (CHAR)
- A C expression which determines whether the option `-CHAR' stops
- compilation before the generation of an executable. The value is
- boolean, nonzero if the option does stop an executable from being
- generated, zero otherwise.
-
- By default, this macro is defined as
- `DEFAULT_SWITCH_CURTAILS_COMPILATION', which handles the standard
- options properly. You need not define
- `SWITCH_CURTAILS_COMPILATION' unless you wish to add additional
- options which affect the generation of an executable. Any
- redefinition should call `DEFAULT_SWITCH_CURTAILS_COMPILATION' and
- then check for additional options.
-
- -- Macro: SWITCHES_NEED_SPACES
- A string-valued C expression which enumerates the options for which
- the linker needs a space between the option and its argument.
-
- If this macro is not defined, the default value is `""'.
-
- -- Macro: TARGET_OPTION_TRANSLATE_TABLE
- If defined, a list of pairs of strings, the first of which is a
- potential command line target to the `gcc' driver program, and the
- second of which is a space-separated (tabs and other whitespace
- are not supported) list of options with which to replace the first
- option. The target defining this list is responsible for assuring
- that the results are valid. Replacement options may not be the
- `--opt' style, they must be the `-opt' style. It is the intention
- of this macro to provide a mechanism for substitution that affects
- the multilibs chosen, such as one option that enables many
- options, some of which select multilibs. Example nonsensical
- definition, where `-malt-abi', `-EB', and `-mspoo' cause different
- multilibs to be chosen:
-
- #define TARGET_OPTION_TRANSLATE_TABLE \
- { "-fast", "-march=fast-foo -malt-abi -I/usr/fast-foo" }, \
- { "-compat", "-EB -malign=4 -mspoo" }
-
- -- Macro: DRIVER_SELF_SPECS
- A list of specs for the driver itself. It should be a suitable
- initializer for an array of strings, with no surrounding braces.
-
- The driver applies these specs to its own command line between
- loading default `specs' files (but not command-line specified
- ones) and choosing the multilib directory or running any
- subcommands. It applies them in the order given, so each spec can
- depend on the options added by earlier ones. It is also possible
- to remove options using `%<OPTION' in the usual way.
-
- This macro can be useful when a port has several interdependent
- target options. It provides a way of standardizing the command
- line so that the other specs are easier to write.
-
- Do not define this macro if it does not need to do anything.
-
- -- Macro: OPTION_DEFAULT_SPECS
- A list of specs used to support configure-time default options
- (i.e. `--with' options) in the driver. It should be a suitable
- initializer for an array of structures, each containing two
- strings, without the outermost pair of surrounding braces.
-
- The first item in the pair is the name of the default. This must
- match the code in `config.gcc' for the target. The second item is
- a spec to apply if a default with this name was specified. The
- string `%(VALUE)' in the spec will be replaced by the value of the
- default everywhere it occurs.
-
- The driver will apply these specs to its own command line between
- loading default `specs' files and processing `DRIVER_SELF_SPECS',
- using the same mechanism as `DRIVER_SELF_SPECS'.
-
- Do not define this macro if it does not need to do anything.
-
- -- Macro: CPP_SPEC
- A C string constant that tells the GCC driver program options to
- pass to CPP. It can also specify how to translate options you
- give to GCC into options for GCC to pass to the CPP.
-
- Do not define this macro if it does not need to do anything.
-
- -- Macro: CPLUSPLUS_CPP_SPEC
- This macro is just like `CPP_SPEC', but is used for C++, rather
- than C. If you do not define this macro, then the value of
- `CPP_SPEC' (if any) will be used instead.
-
- -- Macro: CC1_SPEC
- A C string constant that tells the GCC driver program options to
- pass to `cc1', `cc1plus', `f771', and the other language front
- ends. It can also specify how to translate options you give to
- GCC into options for GCC to pass to front ends.
-
- Do not define this macro if it does not need to do anything.
-
- -- Macro: CC1PLUS_SPEC
- A C string constant that tells the GCC driver program options to
- pass to `cc1plus'. It can also specify how to translate options
- you give to GCC into options for GCC to pass to the `cc1plus'.
-
- Do not define this macro if it does not need to do anything. Note
- that everything defined in CC1_SPEC is already passed to `cc1plus'
- so there is no need to duplicate the contents of CC1_SPEC in
- CC1PLUS_SPEC.
-
- -- Macro: ASM_SPEC
- A C string constant that tells the GCC driver program options to
- pass to the assembler. It can also specify how to translate
- options you give to GCC into options for GCC to pass to the
- assembler. See the file `sun3.h' for an example of this.
-
- Do not define this macro if it does not need to do anything.
-
- -- Macro: ASM_FINAL_SPEC
- A C string constant that tells the GCC driver program how to run
- any programs which cleanup after the normal assembler. Normally,
- this is not needed. See the file `mips.h' for an example of this.
-
- Do not define this macro if it does not need to do anything.
-
- -- Macro: AS_NEEDS_DASH_FOR_PIPED_INPUT
- Define this macro, with no value, if the driver should give the
- assembler an argument consisting of a single dash, `-', to
- instruct it to read from its standard input (which will be a pipe
- connected to the output of the compiler proper). This argument is
- given after any `-o' option specifying the name of the output file.
-
- If you do not define this macro, the assembler is assumed to read
- its standard input if given no non-option arguments. If your
- assembler cannot read standard input at all, use a `%{pipe:%e}'
- construct; see `mips.h' for instance.
-
- -- Macro: LINK_SPEC
- A C string constant that tells the GCC driver program options to
- pass to the linker. It can also specify how to translate options
- you give to GCC into options for GCC to pass to the linker.
-
- Do not define this macro if it does not need to do anything.
-
- -- Macro: LIB_SPEC
- Another C string constant used much like `LINK_SPEC'. The
- difference between the two is that `LIB_SPEC' is used at the end
- of the command given to the linker.
-
- If this macro is not defined, a default is provided that loads the
- standard C library from the usual place. See `gcc.c'.
-
- -- Macro: LIBGCC_SPEC
- Another C string constant that tells the GCC driver program how
- and when to place a reference to `libgcc.a' into the linker
- command line. This constant is placed both before and after the
- value of `LIB_SPEC'.
-
- If this macro is not defined, the GCC driver provides a default
- that passes the string `-lgcc' to the linker.
-
- -- Macro: REAL_LIBGCC_SPEC
- By default, if `ENABLE_SHARED_LIBGCC' is defined, the
- `LIBGCC_SPEC' is not directly used by the driver program but is
- instead modified to refer to different versions of `libgcc.a'
- depending on the values of the command line flags `-static',
- `-shared', `-static-libgcc', and `-shared-libgcc'. On targets
- where these modifications are inappropriate, define
- `REAL_LIBGCC_SPEC' instead. `REAL_LIBGCC_SPEC' tells the driver
- how to place a reference to `libgcc' on the link command line,
- but, unlike `LIBGCC_SPEC', it is used unmodified.
-
- -- Macro: USE_LD_AS_NEEDED
- A macro that controls the modifications to `LIBGCC_SPEC' mentioned
- in `REAL_LIBGCC_SPEC'. If nonzero, a spec will be generated that
- uses -as-needed and the shared libgcc in place of the static
- exception handler library, when linking without any of `-static',
- `-static-libgcc', or `-shared-libgcc'.
-
- -- Macro: LINK_EH_SPEC
- If defined, this C string constant is added to `LINK_SPEC'. When
- `USE_LD_AS_NEEDED' is zero or undefined, it also affects the
- modifications to `LIBGCC_SPEC' mentioned in `REAL_LIBGCC_SPEC'.
-
- -- Macro: STARTFILE_SPEC
- Another C string constant used much like `LINK_SPEC'. The
- difference between the two is that `STARTFILE_SPEC' is used at the
- very beginning of the command given to the linker.
-
- If this macro is not defined, a default is provided that loads the
- standard C startup file from the usual place. See `gcc.c'.
-
- -- Macro: ENDFILE_SPEC
- Another C string constant used much like `LINK_SPEC'. The
- difference between the two is that `ENDFILE_SPEC' is used at the
- very end of the command given to the linker.
-
- Do not define this macro if it does not need to do anything.
-
- -- Macro: THREAD_MODEL_SPEC
- GCC `-v' will print the thread model GCC was configured to use.
- However, this doesn't work on platforms that are multilibbed on
- thread models, such as AIX 4.3. On such platforms, define
- `THREAD_MODEL_SPEC' such that it evaluates to a string without
- blanks that names one of the recognized thread models. `%*', the
- default value of this macro, will expand to the value of
- `thread_file' set in `config.gcc'.
-
- -- Macro: SYSROOT_SUFFIX_SPEC
- Define this macro to add a suffix to the target sysroot when GCC is
- configured with a sysroot. This will cause GCC to search for
- usr/lib, et al, within sysroot+suffix.
-
- -- Macro: SYSROOT_HEADERS_SUFFIX_SPEC
- Define this macro to add a headers_suffix to the target sysroot
- when GCC is configured with a sysroot. This will cause GCC to
- pass the updated sysroot+headers_suffix to CPP, causing it to
- search for usr/include, et al, within sysroot+headers_suffix.
-
- -- Macro: EXTRA_SPECS
- Define this macro to provide additional specifications to put in
- the `specs' file that can be used in various specifications like
- `CC1_SPEC'.
-
- The definition should be an initializer for an array of structures,
- containing a string constant, that defines the specification name,
- and a string constant that provides the specification.
-
- Do not define this macro if it does not need to do anything.
-
- `EXTRA_SPECS' is useful when an architecture contains several
- related targets, which have various `..._SPECS' which are similar
- to each other, and the maintainer would like one central place to
- keep these definitions.
-
- For example, the PowerPC System V.4 targets use `EXTRA_SPECS' to
- define either `_CALL_SYSV' when the System V calling sequence is
- used or `_CALL_AIX' when the older AIX-based calling sequence is
- used.
-
- The `config/rs6000/rs6000.h' target file defines:
-
- #define EXTRA_SPECS \
- { "cpp_sysv_default", CPP_SYSV_DEFAULT },
-
- #define CPP_SYS_DEFAULT ""
-
- The `config/rs6000/sysv.h' target file defines:
- #undef CPP_SPEC
- #define CPP_SPEC \
- "%{posix: -D_POSIX_SOURCE } \
- %{mcall-sysv: -D_CALL_SYSV } \
- %{!mcall-sysv: %(cpp_sysv_default) } \
- %{msoft-float: -D_SOFT_FLOAT} %{mcpu=403: -D_SOFT_FLOAT}"
-
- #undef CPP_SYSV_DEFAULT
- #define CPP_SYSV_DEFAULT "-D_CALL_SYSV"
-
- while the `config/rs6000/eabiaix.h' target file defines
- `CPP_SYSV_DEFAULT' as:
-
- #undef CPP_SYSV_DEFAULT
- #define CPP_SYSV_DEFAULT "-D_CALL_AIX"
-
- -- Macro: LINK_LIBGCC_SPECIAL_1
- Define this macro if the driver program should find the library
- `libgcc.a'. If you do not define this macro, the driver program
- will pass the argument `-lgcc' to tell the linker to do the search.
-
- -- Macro: LINK_GCC_C_SEQUENCE_SPEC
- The sequence in which libgcc and libc are specified to the linker.
- By default this is `%G %L %G'.
-
- -- Macro: LINK_COMMAND_SPEC
- A C string constant giving the complete command line need to
- execute the linker. When you do this, you will need to update
- your port each time a change is made to the link command line
- within `gcc.c'. Therefore, define this macro only if you need to
- completely redefine the command line for invoking the linker and
- there is no other way to accomplish the effect you need.
- Overriding this macro may be avoidable by overriding
- `LINK_GCC_C_SEQUENCE_SPEC' instead.
-
- -- Macro: LINK_ELIMINATE_DUPLICATE_LDIRECTORIES
- A nonzero value causes `collect2' to remove duplicate
- `-LDIRECTORY' search directories from linking commands. Do not
- give it a nonzero value if removing duplicate search directories
- changes the linker's semantics.
-
- -- Macro: MULTILIB_DEFAULTS
- Define this macro as a C expression for the initializer of an
- array of string to tell the driver program which options are
- defaults for this target and thus do not need to be handled
- specially when using `MULTILIB_OPTIONS'.
-
- Do not define this macro if `MULTILIB_OPTIONS' is not defined in
- the target makefile fragment or if none of the options listed in
- `MULTILIB_OPTIONS' are set by default. *Note Target Fragment::.
-
- -- Macro: RELATIVE_PREFIX_NOT_LINKDIR
- Define this macro to tell `gcc' that it should only translate a
- `-B' prefix into a `-L' linker option if the prefix indicates an
- absolute file name.
-
- -- Macro: MD_EXEC_PREFIX
- If defined, this macro is an additional prefix to try after
- `STANDARD_EXEC_PREFIX'. `MD_EXEC_PREFIX' is not searched when the
- `-b' option is used, or the compiler is built as a cross compiler.
- If you define `MD_EXEC_PREFIX', then be sure to add it to the list
- of directories used to find the assembler in `configure.in'.
-
- -- Macro: STANDARD_STARTFILE_PREFIX
- Define this macro as a C string constant if you wish to override
- the standard choice of `libdir' as the default prefix to try when
- searching for startup files such as `crt0.o'.
- `STANDARD_STARTFILE_PREFIX' is not searched when the compiler is
- built as a cross compiler.
-
- -- Macro: STANDARD_STARTFILE_PREFIX_1
- Define this macro as a C string constant if you wish to override
- the standard choice of `/lib' as a prefix to try after the default
- prefix when searching for startup files such as `crt0.o'.
- `STANDARD_STARTFILE_PREFIX_1' is not searched when the compiler is
- built as a cross compiler.
-
- -- Macro: STANDARD_STARTFILE_PREFIX_2
- Define this macro as a C string constant if you wish to override
- the standard choice of `/lib' as yet another prefix to try after
- the default prefix when searching for startup files such as
- `crt0.o'. `STANDARD_STARTFILE_PREFIX_2' is not searched when the
- compiler is built as a cross compiler.
-
- -- Macro: MD_STARTFILE_PREFIX
- If defined, this macro supplies an additional prefix to try after
- the standard prefixes. `MD_EXEC_PREFIX' is not searched when the
- `-b' option is used, or when the compiler is built as a cross
- compiler.
-
- -- Macro: MD_STARTFILE_PREFIX_1
- If defined, this macro supplies yet another prefix to try after the
- standard prefixes. It is not searched when the `-b' option is
- used, or when the compiler is built as a cross compiler.
-
- -- Macro: INIT_ENVIRONMENT
- Define this macro as a C string constant if you wish to set
- environment variables for programs called by the driver, such as
- the assembler and loader. The driver passes the value of this
- macro to `putenv' to initialize the necessary environment
- variables.
-
- -- Macro: LOCAL_INCLUDE_DIR
- Define this macro as a C string constant if you wish to override
- the standard choice of `/usr/local/include' as the default prefix
- to try when searching for local header files. `LOCAL_INCLUDE_DIR'
- comes before `SYSTEM_INCLUDE_DIR' in the search order.
-
- Cross compilers do not search either `/usr/local/include' or its
- replacement.
-
- -- Macro: MODIFY_TARGET_NAME
- Define this macro if you wish to define command-line switches that
- modify the default target name.
-
- For each switch, you can include a string to be appended to the
- first part of the configuration name or a string to be deleted
- from the configuration name, if present. The definition should be
- an initializer for an array of structures. Each array element
- should have three elements: the switch name (a string constant,
- including the initial dash), one of the enumeration codes `ADD' or
- `DELETE' to indicate whether the string should be inserted or
- deleted, and the string to be inserted or deleted (a string
- constant).
-
- For example, on a machine where `64' at the end of the
- configuration name denotes a 64-bit target and you want the `-32'
- and `-64' switches to select between 32- and 64-bit targets, you
- would code
-
- #define MODIFY_TARGET_NAME \
- { { "-32", DELETE, "64"}, \
- {"-64", ADD, "64"}}
-
- -- Macro: SYSTEM_INCLUDE_DIR
- Define this macro as a C string constant if you wish to specify a
- system-specific directory to search for header files before the
- standard directory. `SYSTEM_INCLUDE_DIR' comes before
- `STANDARD_INCLUDE_DIR' in the search order.
-
- Cross compilers do not use this macro and do not search the
- directory specified.
-
- -- Macro: STANDARD_INCLUDE_DIR
- Define this macro as a C string constant if you wish to override
- the standard choice of `/usr/include' as the default prefix to try
- when searching for header files.
-
- Cross compilers ignore this macro and do not search either
- `/usr/include' or its replacement.
-
- -- Macro: STANDARD_INCLUDE_COMPONENT
- The "component" corresponding to `STANDARD_INCLUDE_DIR'. See
- `INCLUDE_DEFAULTS', below, for the description of components. If
- you do not define this macro, no component is used.
-
- -- Macro: INCLUDE_DEFAULTS
- Define this macro if you wish to override the entire default
- search path for include files. For a native compiler, the default
- search path usually consists of `GCC_INCLUDE_DIR',
- `LOCAL_INCLUDE_DIR', `SYSTEM_INCLUDE_DIR',
- `GPLUSPLUS_INCLUDE_DIR', and `STANDARD_INCLUDE_DIR'. In addition,
- `GPLUSPLUS_INCLUDE_DIR' and `GCC_INCLUDE_DIR' are defined
- automatically by `Makefile', and specify private search areas for
- GCC. The directory `GPLUSPLUS_INCLUDE_DIR' is used only for C++
- programs.
-
- The definition should be an initializer for an array of structures.
- Each array element should have four elements: the directory name (a
- string constant), the component name (also a string constant), a
- flag for C++-only directories, and a flag showing that the
- includes in the directory don't need to be wrapped in `extern `C''
- when compiling C++. Mark the end of the array with a null element.
-
- The component name denotes what GNU package the include file is
- part of, if any, in all uppercase letters. For example, it might
- be `GCC' or `BINUTILS'. If the package is part of a
- vendor-supplied operating system, code the component name as `0'.
-
- For example, here is the definition used for VAX/VMS:
-
- #define INCLUDE_DEFAULTS \
- { \
- { "GNU_GXX_INCLUDE:", "G++", 1, 1}, \
- { "GNU_CC_INCLUDE:", "GCC", 0, 0}, \
- { "SYS$SYSROOT:[SYSLIB.]", 0, 0, 0}, \
- { ".", 0, 0, 0}, \
- { 0, 0, 0, 0} \
- }
-
- Here is the order of prefixes tried for exec files:
-
- 1. Any prefixes specified by the user with `-B'.
-
- 2. The environment variable `GCC_EXEC_PREFIX' or, if `GCC_EXEC_PREFIX'
- is not set and the compiler has not been installed in the
- configure-time PREFIX, the location in which the compiler has
- actually been installed.
-
- 3. The directories specified by the environment variable
- `COMPILER_PATH'.
-
- 4. The macro `STANDARD_EXEC_PREFIX', if the compiler has been
- installed in the configured-time PREFIX.
-
- 5. The location `/usr/libexec/gcc/', but only if this is a native
- compiler.
-
- 6. The location `/usr/lib/gcc/', but only if this is a native
- compiler.
-
- 7. The macro `MD_EXEC_PREFIX', if defined, but only if this is a
- native compiler.
-
- Here is the order of prefixes tried for startfiles:
-
- 1. Any prefixes specified by the user with `-B'.
-
- 2. The environment variable `GCC_EXEC_PREFIX' or its automatically
- determined value based on the installed toolchain location.
-
- 3. The directories specified by the environment variable
- `LIBRARY_PATH' (or port-specific name; native only, cross
- compilers do not use this).
-
- 4. The macro `STANDARD_EXEC_PREFIX', but only if the toolchain is
- installed in the configured PREFIX or this is a native compiler.
-
- 5. The location `/usr/lib/gcc/', but only if this is a native
- compiler.
-
- 6. The macro `MD_EXEC_PREFIX', if defined, but only if this is a
- native compiler.
-
- 7. The macro `MD_STARTFILE_PREFIX', if defined, but only if this is a
- native compiler, or we have a target system root.
-
- 8. The macro `MD_STARTFILE_PREFIX_1', if defined, but only if this is
- a native compiler, or we have a target system root.
-
- 9. The macro `STANDARD_STARTFILE_PREFIX', with any sysroot
- modifications. If this path is relative it will be prefixed by
- `GCC_EXEC_PREFIX' and the machine suffix or `STANDARD_EXEC_PREFIX'
- and the machine suffix.
-
- 10. The macro `STANDARD_STARTFILE_PREFIX_1', but only if this is a
- native compiler, or we have a target system root. The default for
- this macro is `/lib/'.
-
- 11. The macro `STANDARD_STARTFILE_PREFIX_2', but only if this is a
- native compiler, or we have a target system root. The default for
- this macro is `/usr/lib/'.
-
-\1f
-File: gccint.info, Node: Run-time Target, Next: Per-Function Data, Prev: Driver, Up: Target Macros
-
-17.3 Run-time Target Specification
-==================================
-
-Here are run-time target specifications.
-
- -- Macro: TARGET_CPU_CPP_BUILTINS ()
- This function-like macro expands to a block of code that defines
- built-in preprocessor macros and assertions for the target CPU,
- using the functions `builtin_define', `builtin_define_std' and
- `builtin_assert'. When the front end calls this macro it provides
- a trailing semicolon, and since it has finished command line
- option processing your code can use those results freely.
-
- `builtin_assert' takes a string in the form you pass to the
- command-line option `-A', such as `cpu=mips', and creates the
- assertion. `builtin_define' takes a string in the form accepted
- by option `-D' and unconditionally defines the macro.
-
- `builtin_define_std' takes a string representing the name of an
- object-like macro. If it doesn't lie in the user's namespace,
- `builtin_define_std' defines it unconditionally. Otherwise, it
- defines a version with two leading underscores, and another version
- with two leading and trailing underscores, and defines the original
- only if an ISO standard was not requested on the command line. For
- example, passing `unix' defines `__unix', `__unix__' and possibly
- `unix'; passing `_mips' defines `__mips', `__mips__' and possibly
- `_mips', and passing `_ABI64' defines only `_ABI64'.
-
- You can also test for the C dialect being compiled. The variable
- `c_language' is set to one of `clk_c', `clk_cplusplus' or
- `clk_objective_c'. Note that if we are preprocessing assembler,
- this variable will be `clk_c' but the function-like macro
- `preprocessing_asm_p()' will return true, so you might want to
- check for that first. If you need to check for strict ANSI, the
- variable `flag_iso' can be used. The function-like macro
- `preprocessing_trad_p()' can be used to check for traditional
- preprocessing.
-
- -- Macro: TARGET_OS_CPP_BUILTINS ()
- Similarly to `TARGET_CPU_CPP_BUILTINS' but this macro is optional
- and is used for the target operating system instead.
-
- -- Macro: TARGET_OBJFMT_CPP_BUILTINS ()
- Similarly to `TARGET_CPU_CPP_BUILTINS' but this macro is optional
- and is used for the target object format. `elfos.h' uses this
- macro to define `__ELF__', so you probably do not need to define
- it yourself.
-
- -- Variable: extern int target_flags
- This variable is declared in `options.h', which is included before
- any target-specific headers.
-
- -- Variable: Target Hook int TARGET_DEFAULT_TARGET_FLAGS
- This variable specifies the initial value of `target_flags'. Its
- default setting is 0.
-
- -- Target Hook: bool TARGET_HANDLE_OPTION (size_t CODE, const char
- *ARG, int VALUE)
- This hook is called whenever the user specifies one of the
- target-specific options described by the `.opt' definition files
- (*note Options::). It has the opportunity to do some
- option-specific processing and should return true if the option is
- valid. The default definition does nothing but return true.
-
- CODE specifies the `OPT_NAME' enumeration value associated with
- the selected option; NAME is just a rendering of the option name
- in which non-alphanumeric characters are replaced by underscores.
- ARG specifies the string argument and is null if no argument was
- given. If the option is flagged as a `UInteger' (*note Option
- properties::), VALUE is the numeric value of the argument.
- Otherwise VALUE is 1 if the positive form of the option was used
- and 0 if the "no-" form was.
-
- -- Target Hook: bool TARGET_HANDLE_C_OPTION (size_t CODE, const char
- *ARG, int VALUE)
- This target hook is called whenever the user specifies one of the
- target-specific C language family options described by the `.opt'
- definition files(*note Options::). It has the opportunity to do
- some option-specific processing and should return true if the
- option is valid. The default definition does nothing but return
- false.
-
- In general, you should use `TARGET_HANDLE_OPTION' to handle
- options. However, if processing an option requires routines that
- are only available in the C (and related language) front ends,
- then you should use `TARGET_HANDLE_C_OPTION' instead.
-
- -- Macro: TARGET_VERSION
- This macro is a C statement to print on `stderr' a string
- describing the particular machine description choice. Every
- machine description should define `TARGET_VERSION'. For example:
-
- #ifdef MOTOROLA
- #define TARGET_VERSION \
- fprintf (stderr, " (68k, Motorola syntax)");
- #else
- #define TARGET_VERSION \
- fprintf (stderr, " (68k, MIT syntax)");
- #endif
-
- -- Macro: OVERRIDE_OPTIONS
- Sometimes certain combinations of command options do not make
- sense on a particular target machine. You can define a macro
- `OVERRIDE_OPTIONS' to take account of this. This macro, if
- defined, is executed once just after all the command options have
- been parsed.
-
- Don't use this macro to turn on various extra optimizations for
- `-O'. That is what `OPTIMIZATION_OPTIONS' is for.
-
- -- Macro: C_COMMON_OVERRIDE_OPTIONS
- This is similar to `OVERRIDE_OPTIONS' but is only used in the C
- language frontends (C, Objective-C, C++, Objective-C++) and so can
- be used to alter option flag variables which only exist in those
- frontends.
-
- -- Macro: OPTIMIZATION_OPTIONS (LEVEL, SIZE)
- Some machines may desire to change what optimizations are
- performed for various optimization levels. This macro, if
- defined, is executed once just after the optimization level is
- determined and before the remainder of the command options have
- been parsed. Values set in this macro are used as the default
- values for the other command line options.
-
- LEVEL is the optimization level specified; 2 if `-O2' is
- specified, 1 if `-O' is specified, and 0 if neither is specified.
-
- SIZE is nonzero if `-Os' is specified and zero otherwise.
-
- This macro is run once at program startup and when the optimization
- options are changed via `#pragma GCC optimize' or by using the
- `optimize' attribute.
-
- *Do not examine `write_symbols' in this macro!* The debugging
- options are not supposed to alter the generated code.
-
- -- Target Hook: bool TARGET_HELP (void)
- This hook is called in response to the user invoking
- `--target-help' on the command line. It gives the target a chance
- to display extra information on the target specific command line
- options found in its `.opt' file.
-
- -- Macro: CAN_DEBUG_WITHOUT_FP
- Define this macro if debugging can be performed even without a
- frame pointer. If this macro is defined, GCC will turn on the
- `-fomit-frame-pointer' option whenever `-O' is specified.
-
-\1f
-File: gccint.info, Node: Per-Function Data, Next: Storage Layout, Prev: Run-time Target, Up: Target Macros
-
-17.4 Defining data structures for per-function information.
-===========================================================
-
-If the target needs to store information on a per-function basis, GCC
-provides a macro and a couple of variables to allow this. Note, just
-using statics to store the information is a bad idea, since GCC supports
-nested functions, so you can be halfway through encoding one function
-when another one comes along.
-
- GCC defines a data structure called `struct function' which contains
-all of the data specific to an individual function. This structure
-contains a field called `machine' whose type is `struct
-machine_function *', which can be used by targets to point to their own
-specific data.
-
- If a target needs per-function specific data it should define the type
-`struct machine_function' and also the macro `INIT_EXPANDERS'. This
-macro should be used to initialize the function pointer
-`init_machine_status'. This pointer is explained below.
-
- One typical use of per-function, target specific data is to create an
-RTX to hold the register containing the function's return address. This
-RTX can then be used to implement the `__builtin_return_address'
-function, for level 0.
-
- Note--earlier implementations of GCC used a single data area to hold
-all of the per-function information. Thus when processing of a nested
-function began the old per-function data had to be pushed onto a stack,
-and when the processing was finished, it had to be popped off the
-stack. GCC used to provide function pointers called
-`save_machine_status' and `restore_machine_status' to handle the saving
-and restoring of the target specific information. Since the single
-data area approach is no longer used, these pointers are no longer
-supported.
-
- -- Macro: INIT_EXPANDERS
- Macro called to initialize any target specific information. This
- macro is called once per function, before generation of any RTL
- has begun. The intention of this macro is to allow the
- initialization of the function pointer `init_machine_status'.
-
- -- Variable: void (*)(struct function *) init_machine_status
- If this function pointer is non-`NULL' it will be called once per
- function, before function compilation starts, in order to allow the
- target to perform any target specific initialization of the
- `struct function' structure. It is intended that this would be
- used to initialize the `machine' of that structure.
-
- `struct machine_function' structures are expected to be freed by
- GC. Generally, any memory that they reference must be allocated
- by using `ggc_alloc', including the structure itself.
-
-\1f
-File: gccint.info, Node: Storage Layout, Next: Type Layout, Prev: Per-Function Data, Up: Target Macros
-
-17.5 Storage Layout
-===================
-
-Note that the definitions of the macros in this table which are sizes or
-alignments measured in bits do not need to be constant. They can be C
-expressions that refer to static variables, such as the `target_flags'.
-*Note Run-time Target::.
-
- -- Macro: BITS_BIG_ENDIAN
- Define this macro to have the value 1 if the most significant bit
- in a byte has the lowest number; otherwise define it to have the
- value zero. This means that bit-field instructions count from the
- most significant bit. If the machine has no bit-field
- instructions, then this must still be defined, but it doesn't
- matter which value it is defined to. This macro need not be a
- constant.
-
- This macro does not affect the way structure fields are packed into
- bytes or words; that is controlled by `BYTES_BIG_ENDIAN'.
-
- -- Macro: BYTES_BIG_ENDIAN
- Define this macro to have the value 1 if the most significant byte
- in a word has the lowest number. This macro need not be a
- constant.
-
- -- Macro: WORDS_BIG_ENDIAN
- Define this macro to have the value 1 if, in a multiword object,
- the most significant word has the lowest number. This applies to
- both memory locations and registers; GCC fundamentally assumes
- that the order of words in memory is the same as the order in
- registers. This macro need not be a constant.
-
- -- Macro: LIBGCC2_WORDS_BIG_ENDIAN
- Define this macro if `WORDS_BIG_ENDIAN' is not constant. This
- must be a constant value with the same meaning as
- `WORDS_BIG_ENDIAN', which will be used only when compiling
- `libgcc2.c'. Typically the value will be set based on
- preprocessor defines.
-
- -- Macro: FLOAT_WORDS_BIG_ENDIAN
- Define this macro to have the value 1 if `DFmode', `XFmode' or
- `TFmode' floating point numbers are stored in memory with the word
- containing the sign bit at the lowest address; otherwise define it
- to have the value 0. This macro need not be a constant.
-
- You need not define this macro if the ordering is the same as for
- multi-word integers.
-
- -- Macro: BITS_PER_UNIT
- Define this macro to be the number of bits in an addressable
- storage unit (byte). If you do not define this macro the default
- is 8.
-
- -- Macro: BITS_PER_WORD
- Number of bits in a word. If you do not define this macro, the
- default is `BITS_PER_UNIT * UNITS_PER_WORD'.
-
- -- Macro: MAX_BITS_PER_WORD
- Maximum number of bits in a word. If this is undefined, the
- default is `BITS_PER_WORD'. Otherwise, it is the constant value
- that is the largest value that `BITS_PER_WORD' can have at
- run-time.
-
- -- Macro: UNITS_PER_WORD
- Number of storage units in a word; normally the size of a
- general-purpose register, a power of two from 1 or 8.
-
- -- Macro: MIN_UNITS_PER_WORD
- Minimum number of units in a word. If this is undefined, the
- default is `UNITS_PER_WORD'. Otherwise, it is the constant value
- that is the smallest value that `UNITS_PER_WORD' can have at
- run-time.
-
- -- Macro: UNITS_PER_SIMD_WORD (MODE)
- Number of units in the vectors that the vectorizer can produce for
- scalar mode MODE. The default is equal to `UNITS_PER_WORD',
- because the vectorizer can do some transformations even in absence
- of specialized SIMD hardware.
-
- -- Macro: POINTER_SIZE
- Width of a pointer, in bits. You must specify a value no wider
- than the width of `Pmode'. If it is not equal to the width of
- `Pmode', you must define `POINTERS_EXTEND_UNSIGNED'. If you do
- not specify a value the default is `BITS_PER_WORD'.
-
- -- Macro: POINTERS_EXTEND_UNSIGNED
- A C expression that determines how pointers should be extended from
- `ptr_mode' to either `Pmode' or `word_mode'. It is greater than
- zero if pointers should be zero-extended, zero if they should be
- sign-extended, and negative if some other sort of conversion is
- needed. In the last case, the extension is done by the target's
- `ptr_extend' instruction.
-
- You need not define this macro if the `ptr_mode', `Pmode' and
- `word_mode' are all the same width.
-
- -- Macro: PROMOTE_MODE (M, UNSIGNEDP, TYPE)
- A macro to update M and UNSIGNEDP when an object whose type is
- TYPE and which has the specified mode and signedness is to be
- stored in a register. This macro is only called when TYPE is a
- scalar type.
-
- On most RISC machines, which only have operations that operate on
- a full register, define this macro to set M to `word_mode' if M is
- an integer mode narrower than `BITS_PER_WORD'. In most cases,
- only integer modes should be widened because wider-precision
- floating-point operations are usually more expensive than their
- narrower counterparts.
-
- For most machines, the macro definition does not change UNSIGNEDP.
- However, some machines, have instructions that preferentially
- handle either signed or unsigned quantities of certain modes. For
- example, on the DEC Alpha, 32-bit loads from memory and 32-bit add
- instructions sign-extend the result to 64 bits. On such machines,
- set UNSIGNEDP according to which kind of extension is more
- efficient.
-
- Do not define this macro if it would never modify M.
-
- -- Macro: PROMOTE_FUNCTION_MODE
- Like `PROMOTE_MODE', but is applied to outgoing function arguments
- or function return values, as specified by
- `TARGET_PROMOTE_FUNCTION_ARGS' and
- `TARGET_PROMOTE_FUNCTION_RETURN', respectively.
-
- The default is `PROMOTE_MODE'.
-
- -- Target Hook: bool TARGET_PROMOTE_FUNCTION_ARGS (tree FNTYPE)
- This target hook should return `true' if the promotion described by
- `PROMOTE_FUNCTION_MODE' should be done for outgoing function
- arguments.
-
- -- Target Hook: bool TARGET_PROMOTE_FUNCTION_RETURN (tree FNTYPE)
- This target hook should return `true' if the promotion described by
- `PROMOTE_FUNCTION_MODE' should be done for the return value of
- functions.
-
- If this target hook returns `true', `TARGET_FUNCTION_VALUE' must
- perform the same promotions done by `PROMOTE_FUNCTION_MODE'.
-
- -- Macro: PARM_BOUNDARY
- Normal alignment required for function parameters on the stack, in
- bits. All stack parameters receive at least this much alignment
- regardless of data type. On most machines, this is the same as the
- size of an integer.
-
- -- Macro: STACK_BOUNDARY
- Define this macro to the minimum alignment enforced by hardware
- for the stack pointer on this machine. The definition is a C
- expression for the desired alignment (measured in bits). This
- value is used as a default if `PREFERRED_STACK_BOUNDARY' is not
- defined. On most machines, this should be the same as
- `PARM_BOUNDARY'.
-
- -- Macro: PREFERRED_STACK_BOUNDARY
- Define this macro if you wish to preserve a certain alignment for
- the stack pointer, greater than what the hardware enforces. The
- definition is a C expression for the desired alignment (measured
- in bits). This macro must evaluate to a value equal to or larger
- than `STACK_BOUNDARY'.
-
- -- Macro: INCOMING_STACK_BOUNDARY
- Define this macro if the incoming stack boundary may be different
- from `PREFERRED_STACK_BOUNDARY'. This macro must evaluate to a
- value equal to or larger than `STACK_BOUNDARY'.
-
- -- Macro: FUNCTION_BOUNDARY
- Alignment required for a function entry point, in bits.
-
- -- Macro: BIGGEST_ALIGNMENT
- Biggest alignment that any data type can require on this machine,
- in bits. Note that this is not the biggest alignment that is
- supported, just the biggest alignment that, when violated, may
- cause a fault.
-
- -- Macro: MALLOC_ABI_ALIGNMENT
- Alignment, in bits, a C conformant malloc implementation has to
- provide. If not defined, the default value is `BITS_PER_WORD'.
-
- -- Macro: ATTRIBUTE_ALIGNED_VALUE
- Alignment used by the `__attribute__ ((aligned))' construct. If
- not defined, the default value is `BIGGEST_ALIGNMENT'.
-
- -- Macro: MINIMUM_ATOMIC_ALIGNMENT
- If defined, the smallest alignment, in bits, that can be given to
- an object that can be referenced in one operation, without
- disturbing any nearby object. Normally, this is `BITS_PER_UNIT',
- but may be larger on machines that don't have byte or half-word
- store operations.
-
- -- Macro: BIGGEST_FIELD_ALIGNMENT
- Biggest alignment that any structure or union field can require on
- this machine, in bits. If defined, this overrides
- `BIGGEST_ALIGNMENT' for structure and union fields only, unless
- the field alignment has been set by the `__attribute__ ((aligned
- (N)))' construct.
-
- -- Macro: ADJUST_FIELD_ALIGN (FIELD, COMPUTED)
- An expression for the alignment of a structure field FIELD if the
- alignment computed in the usual way (including applying of
- `BIGGEST_ALIGNMENT' and `BIGGEST_FIELD_ALIGNMENT' to the
- alignment) is COMPUTED. It overrides alignment only if the field
- alignment has not been set by the `__attribute__ ((aligned (N)))'
- construct.
-
- -- Macro: MAX_STACK_ALIGNMENT
- Biggest stack alignment guaranteed by the backend. Use this macro
- to specify the maximum alignment of a variable on stack.
-
- If not defined, the default value is `STACK_BOUNDARY'.
-
-
- -- Macro: MAX_OFILE_ALIGNMENT
- Biggest alignment supported by the object file format of this
- machine. Use this macro to limit the alignment which can be
- specified using the `__attribute__ ((aligned (N)))' construct. If
- not defined, the default value is `BIGGEST_ALIGNMENT'.
-
- On systems that use ELF, the default (in `config/elfos.h') is the
- largest supported 32-bit ELF section alignment representable on a
- 32-bit host e.g. `(((unsigned HOST_WIDEST_INT) 1 << 28) * 8)'. On
- 32-bit ELF the largest supported section alignment in bits is
- `(0x80000000 * 8)', but this is not representable on 32-bit hosts.
-
- -- Macro: DATA_ALIGNMENT (TYPE, BASIC-ALIGN)
- If defined, a C expression to compute the alignment for a variable
- in the static store. TYPE is the data type, and BASIC-ALIGN is
- the alignment that the object would ordinarily have. The value of
- this macro is used instead of that alignment to align the object.
-
- If this macro is not defined, then BASIC-ALIGN is used.
-
- One use of this macro is to increase alignment of medium-size data
- to make it all fit in fewer cache lines. Another is to cause
- character arrays to be word-aligned so that `strcpy' calls that
- copy constants to character arrays can be done inline.
-
- -- Macro: CONSTANT_ALIGNMENT (CONSTANT, BASIC-ALIGN)
- If defined, a C expression to compute the alignment given to a
- constant that is being placed in memory. CONSTANT is the constant
- and BASIC-ALIGN is the alignment that the object would ordinarily
- have. The value of this macro is used instead of that alignment to
- align the object.
-
- If this macro is not defined, then BASIC-ALIGN is used.
-
- The typical use of this macro is to increase alignment for string
- constants to be word aligned so that `strcpy' calls that copy
- constants can be done inline.
-
- -- Macro: LOCAL_ALIGNMENT (TYPE, BASIC-ALIGN)
- If defined, a C expression to compute the alignment for a variable
- in the local store. TYPE is the data type, and BASIC-ALIGN is the
- alignment that the object would ordinarily have. The value of this
- macro is used instead of that alignment to align the object.
-
- If this macro is not defined, then BASIC-ALIGN is used.
-
- One use of this macro is to increase alignment of medium-size data
- to make it all fit in fewer cache lines.
-
- -- Macro: STACK_SLOT_ALIGNMENT (TYPE, MODE, BASIC-ALIGN)
- If defined, a C expression to compute the alignment for stack slot.
- TYPE is the data type, MODE is the widest mode available, and
- BASIC-ALIGN is the alignment that the slot would ordinarily have.
- The value of this macro is used instead of that alignment to align
- the slot.
-
- If this macro is not defined, then BASIC-ALIGN is used when TYPE
- is `NULL'. Otherwise, `LOCAL_ALIGNMENT' will be used.
-
- This macro is to set alignment of stack slot to the maximum
- alignment of all possible modes which the slot may have.
-
- -- Macro: LOCAL_DECL_ALIGNMENT (DECL)
- If defined, a C expression to compute the alignment for a local
- variable DECL.
-
- If this macro is not defined, then `LOCAL_ALIGNMENT (TREE_TYPE
- (DECL), DECL_ALIGN (DECL))' is used.
-
- One use of this macro is to increase alignment of medium-size data
- to make it all fit in fewer cache lines.
-
- -- Macro: MINIMUM_ALIGNMENT (EXP, MODE, ALIGN)
- If defined, a C expression to compute the minimum required
- alignment for dynamic stack realignment purposes for EXP (a type
- or decl), MODE, assuming normal alignment ALIGN.
-
- If this macro is not defined, then ALIGN will be used.
-
- -- Macro: EMPTY_FIELD_BOUNDARY
- Alignment in bits to be given to a structure bit-field that
- follows an empty field such as `int : 0;'.
-
- If `PCC_BITFIELD_TYPE_MATTERS' is true, it overrides this macro.
-
- -- Macro: STRUCTURE_SIZE_BOUNDARY
- Number of bits which any structure or union's size must be a
- multiple of. Each structure or union's size is rounded up to a
- multiple of this.
-
- If you do not define this macro, the default is the same as
- `BITS_PER_UNIT'.
-
- -- Macro: STRICT_ALIGNMENT
- Define this macro to be the value 1 if instructions will fail to
- work if given data not on the nominal alignment. If instructions
- will merely go slower in that case, define this macro as 0.
-
- -- Macro: PCC_BITFIELD_TYPE_MATTERS
- Define this if you wish to imitate the way many other C compilers
- handle alignment of bit-fields and the structures that contain
- them.
-
- The behavior is that the type written for a named bit-field (`int',
- `short', or other integer type) imposes an alignment for the entire
- structure, as if the structure really did contain an ordinary
- field of that type. In addition, the bit-field is placed within
- the structure so that it would fit within such a field, not
- crossing a boundary for it.
-
- Thus, on most machines, a named bit-field whose type is written as
- `int' would not cross a four-byte boundary, and would force
- four-byte alignment for the whole structure. (The alignment used
- may not be four bytes; it is controlled by the other alignment
- parameters.)
-
- An unnamed bit-field will not affect the alignment of the
- containing structure.
-
- If the macro is defined, its definition should be a C expression;
- a nonzero value for the expression enables this behavior.
-
- Note that if this macro is not defined, or its value is zero, some
- bit-fields may cross more than one alignment boundary. The
- compiler can support such references if there are `insv', `extv',
- and `extzv' insns that can directly reference memory.
-
- The other known way of making bit-fields work is to define
- `STRUCTURE_SIZE_BOUNDARY' as large as `BIGGEST_ALIGNMENT'. Then
- every structure can be accessed with fullwords.
-
- Unless the machine has bit-field instructions or you define
- `STRUCTURE_SIZE_BOUNDARY' that way, you must define
- `PCC_BITFIELD_TYPE_MATTERS' to have a nonzero value.
-
- If your aim is to make GCC use the same conventions for laying out
- bit-fields as are used by another compiler, here is how to
- investigate what the other compiler does. Compile and run this
- program:
-
- struct foo1
- {
- char x;
- char :0;
- char y;
- };
-
- struct foo2
- {
- char x;
- int :0;
- char y;
- };
-
- main ()
- {
- printf ("Size of foo1 is %d\n",
- sizeof (struct foo1));
- printf ("Size of foo2 is %d\n",
- sizeof (struct foo2));
- exit (0);
- }
-
- If this prints 2 and 5, then the compiler's behavior is what you
- would get from `PCC_BITFIELD_TYPE_MATTERS'.
-
- -- Macro: BITFIELD_NBYTES_LIMITED
- Like `PCC_BITFIELD_TYPE_MATTERS' except that its effect is limited
- to aligning a bit-field within the structure.
-
- -- Target Hook: bool TARGET_ALIGN_ANON_BITFIELD (void)
- When `PCC_BITFIELD_TYPE_MATTERS' is true this hook will determine
- whether unnamed bitfields affect the alignment of the containing
- structure. The hook should return true if the structure should
- inherit the alignment requirements of an unnamed bitfield's type.
-
- -- Target Hook: bool TARGET_NARROW_VOLATILE_BITFIELD (void)
- This target hook should return `true' if accesses to volatile
- bitfields should use the narrowest mode possible. It should
- return `false' if these accesses should use the bitfield container
- type.
-
- The default is `!TARGET_STRICT_ALIGN'.
-
- -- Macro: MEMBER_TYPE_FORCES_BLK (FIELD, MODE)
- Return 1 if a structure or array containing FIELD should be
- accessed using `BLKMODE'.
-
- If FIELD is the only field in the structure, MODE is its mode,
- otherwise MODE is VOIDmode. MODE is provided in the case where
- structures of one field would require the structure's mode to
- retain the field's mode.
-
- Normally, this is not needed.
-
- -- Macro: ROUND_TYPE_ALIGN (TYPE, COMPUTED, SPECIFIED)
- Define this macro as an expression for the alignment of a type
- (given by TYPE as a tree node) if the alignment computed in the
- usual way is COMPUTED and the alignment explicitly specified was
- SPECIFIED.
-
- The default is to use SPECIFIED if it is larger; otherwise, use
- the smaller of COMPUTED and `BIGGEST_ALIGNMENT'
-
- -- Macro: MAX_FIXED_MODE_SIZE
- An integer expression for the size in bits of the largest integer
- machine mode that should actually be used. All integer machine
- modes of this size or smaller can be used for structures and
- unions with the appropriate sizes. If this macro is undefined,
- `GET_MODE_BITSIZE (DImode)' is assumed.
-
- -- Macro: STACK_SAVEAREA_MODE (SAVE_LEVEL)
- If defined, an expression of type `enum machine_mode' that
- specifies the mode of the save area operand of a
- `save_stack_LEVEL' named pattern (*note Standard Names::).
- SAVE_LEVEL is one of `SAVE_BLOCK', `SAVE_FUNCTION', or
- `SAVE_NONLOCAL' and selects which of the three named patterns is
- having its mode specified.
-
- You need not define this macro if it always returns `Pmode'. You
- would most commonly define this macro if the `save_stack_LEVEL'
- patterns need to support both a 32- and a 64-bit mode.
-
- -- Macro: STACK_SIZE_MODE
- If defined, an expression of type `enum machine_mode' that
- specifies the mode of the size increment operand of an
- `allocate_stack' named pattern (*note Standard Names::).
-
- You need not define this macro if it always returns `word_mode'.
- You would most commonly define this macro if the `allocate_stack'
- pattern needs to support both a 32- and a 64-bit mode.
-
- -- Target Hook: enum machine_mode TARGET_LIBGCC_CMP_RETURN_MODE ()
- This target hook should return the mode to be used for the return
- value of compare instructions expanded to libgcc calls. If not
- defined `word_mode' is returned which is the right choice for a
- majority of targets.
-
- -- Target Hook: enum machine_mode TARGET_LIBGCC_SHIFT_COUNT_MODE ()
- This target hook should return the mode to be used for the shift
- count operand of shift instructions expanded to libgcc calls. If
- not defined `word_mode' is returned which is the right choice for
- a majority of targets.
-
- -- Macro: ROUND_TOWARDS_ZERO
- If defined, this macro should be true if the prevailing rounding
- mode is towards zero.
-
- Defining this macro only affects the way `libgcc.a' emulates
- floating-point arithmetic.
-
- Not defining this macro is equivalent to returning zero.
-
- -- Macro: LARGEST_EXPONENT_IS_NORMAL (SIZE)
- This macro should return true if floats with SIZE bits do not have
- a NaN or infinity representation, but use the largest exponent for
- normal numbers instead.
-
- Defining this macro only affects the way `libgcc.a' emulates
- floating-point arithmetic.
-
- The default definition of this macro returns false for all sizes.
-
- -- Target Hook: bool TARGET_VECTOR_OPAQUE_P (tree TYPE)
- This target hook should return `true' a vector is opaque. That
- is, if no cast is needed when copying a vector value of type TYPE
- into another vector lvalue of the same size. Vector opaque types
- cannot be initialized. The default is that there are no such
- types.
-
- -- Target Hook: bool TARGET_MS_BITFIELD_LAYOUT_P (tree RECORD_TYPE)
- This target hook returns `true' if bit-fields in the given
- RECORD_TYPE are to be laid out following the rules of Microsoft
- Visual C/C++, namely: (i) a bit-field won't share the same storage
- unit with the previous bit-field if their underlying types have
- different sizes, and the bit-field will be aligned to the highest
- alignment of the underlying types of itself and of the previous
- bit-field; (ii) a zero-sized bit-field will affect the alignment of
- the whole enclosing structure, even if it is unnamed; except that
- (iii) a zero-sized bit-field will be disregarded unless it follows
- another bit-field of nonzero size. If this hook returns `true',
- other macros that control bit-field layout are ignored.
-
- When a bit-field is inserted into a packed record, the whole size
- of the underlying type is used by one or more same-size adjacent
- bit-fields (that is, if its long:3, 32 bits is used in the record,
- and any additional adjacent long bit-fields are packed into the
- same chunk of 32 bits. However, if the size changes, a new field
- of that size is allocated). In an unpacked record, this is the
- same as using alignment, but not equivalent when packing.
-
- If both MS bit-fields and `__attribute__((packed))' are used, the
- latter will take precedence. If `__attribute__((packed))' is used
- on a single field when MS bit-fields are in use, it will take
- precedence for that field, but the alignment of the rest of the
- structure may affect its placement.
-
- -- Target Hook: bool TARGET_DECIMAL_FLOAT_SUPPORTED_P (void)
- Returns true if the target supports decimal floating point.
-
- -- Target Hook: bool TARGET_FIXED_POINT_SUPPORTED_P (void)
- Returns true if the target supports fixed-point arithmetic.
-
- -- Target Hook: void TARGET_EXPAND_TO_RTL_HOOK (void)
- This hook is called just before expansion into rtl, allowing the
- target to perform additional initializations or analysis before
- the expansion. For example, the rs6000 port uses it to allocate a
- scratch stack slot for use in copying SDmode values between memory
- and floating point registers whenever the function being expanded
- has any SDmode usage.
-
- -- Target Hook: void TARGET_INSTANTIATE_DECLS (void)
- This hook allows the backend to perform additional instantiations
- on rtl that are not actually in any insns yet, but will be later.
-
- -- Target Hook: const char * TARGET_MANGLE_TYPE (tree TYPE)
- If your target defines any fundamental types, or any types your
- target uses should be mangled differently from the default, define
- this hook to return the appropriate encoding for these types as
- part of a C++ mangled name. The TYPE argument is the tree
- structure representing the type to be mangled. The hook may be
- applied to trees which are not target-specific fundamental types;
- it should return `NULL' for all such types, as well as arguments
- it does not recognize. If the return value is not `NULL', it must
- point to a statically-allocated string constant.
-
- Target-specific fundamental types might be new fundamental types or
- qualified versions of ordinary fundamental types. Encode new
- fundamental types as `u N NAME', where NAME is the name used for
- the type in source code, and N is the length of NAME in decimal.
- Encode qualified versions of ordinary types as `U N NAME CODE',
- where NAME is the name used for the type qualifier in source code,
- N is the length of NAME as above, and CODE is the code used to
- represent the unqualified version of this type. (See
- `write_builtin_type' in `cp/mangle.c' for the list of codes.) In
- both cases the spaces are for clarity; do not include any spaces
- in your string.
-
- This hook is applied to types prior to typedef resolution. If the
- mangled name for a particular type depends only on that type's
- main variant, you can perform typedef resolution yourself using
- `TYPE_MAIN_VARIANT' before mangling.
-
- The default version of this hook always returns `NULL', which is
- appropriate for a target that does not define any new fundamental
- types.
-
-\1f
-File: gccint.info, Node: Type Layout, Next: Registers, Prev: Storage Layout, Up: Target Macros
-
-17.6 Layout of Source Language Data Types
-=========================================
-
-These macros define the sizes and other characteristics of the standard
-basic data types used in programs being compiled. Unlike the macros in
-the previous section, these apply to specific features of C and related
-languages, rather than to fundamental aspects of storage layout.
-
- -- Macro: INT_TYPE_SIZE
- A C expression for the size in bits of the type `int' on the
- target machine. If you don't define this, the default is one word.
-
- -- Macro: SHORT_TYPE_SIZE
- A C expression for the size in bits of the type `short' on the
- target machine. If you don't define this, the default is half a
- word. (If this would be less than one storage unit, it is rounded
- up to one unit.)
-
- -- Macro: LONG_TYPE_SIZE
- A C expression for the size in bits of the type `long' on the
- target machine. If you don't define this, the default is one word.
-
- -- Macro: ADA_LONG_TYPE_SIZE
- On some machines, the size used for the Ada equivalent of the type
- `long' by a native Ada compiler differs from that used by C. In
- that situation, define this macro to be a C expression to be used
- for the size of that type. If you don't define this, the default
- is the value of `LONG_TYPE_SIZE'.
-
- -- Macro: LONG_LONG_TYPE_SIZE
- A C expression for the size in bits of the type `long long' on the
- target machine. If you don't define this, the default is two
- words. If you want to support GNU Ada on your machine, the value
- of this macro must be at least 64.
-
- -- Macro: CHAR_TYPE_SIZE
- A C expression for the size in bits of the type `char' on the
- target machine. If you don't define this, the default is
- `BITS_PER_UNIT'.
-
- -- Macro: BOOL_TYPE_SIZE
- A C expression for the size in bits of the C++ type `bool' and C99
- type `_Bool' on the target machine. If you don't define this, and
- you probably shouldn't, the default is `CHAR_TYPE_SIZE'.
-
- -- Macro: FLOAT_TYPE_SIZE
- A C expression for the size in bits of the type `float' on the
- target machine. If you don't define this, the default is one word.
-
- -- Macro: DOUBLE_TYPE_SIZE
- A C expression for the size in bits of the type `double' on the
- target machine. If you don't define this, the default is two
- words.
-
- -- Macro: LONG_DOUBLE_TYPE_SIZE
- A C expression for the size in bits of the type `long double' on
- the target machine. If you don't define this, the default is two
- words.
-
- -- Macro: SHORT_FRACT_TYPE_SIZE
- A C expression for the size in bits of the type `short _Fract' on
- the target machine. If you don't define this, the default is
- `BITS_PER_UNIT'.
-
- -- Macro: FRACT_TYPE_SIZE
- A C expression for the size in bits of the type `_Fract' on the
- target machine. If you don't define this, the default is
- `BITS_PER_UNIT * 2'.
-
- -- Macro: LONG_FRACT_TYPE_SIZE
- A C expression for the size in bits of the type `long _Fract' on
- the target machine. If you don't define this, the default is
- `BITS_PER_UNIT * 4'.
-
- -- Macro: LONG_LONG_FRACT_TYPE_SIZE
- A C expression for the size in bits of the type `long long _Fract'
- on the target machine. If you don't define this, the default is
- `BITS_PER_UNIT * 8'.
-
- -- Macro: SHORT_ACCUM_TYPE_SIZE
- A C expression for the size in bits of the type `short _Accum' on
- the target machine. If you don't define this, the default is
- `BITS_PER_UNIT * 2'.
-
- -- Macro: ACCUM_TYPE_SIZE
- A C expression for the size in bits of the type `_Accum' on the
- target machine. If you don't define this, the default is
- `BITS_PER_UNIT * 4'.
-
- -- Macro: LONG_ACCUM_TYPE_SIZE
- A C expression for the size in bits of the type `long _Accum' on
- the target machine. If you don't define this, the default is
- `BITS_PER_UNIT * 8'.
-
- -- Macro: LONG_LONG_ACCUM_TYPE_SIZE
- A C expression for the size in bits of the type `long long _Accum'
- on the target machine. If you don't define this, the default is
- `BITS_PER_UNIT * 16'.
-
- -- Macro: LIBGCC2_LONG_DOUBLE_TYPE_SIZE
- Define this macro if `LONG_DOUBLE_TYPE_SIZE' is not constant or if
- you want routines in `libgcc2.a' for a size other than
- `LONG_DOUBLE_TYPE_SIZE'. If you don't define this, the default is
- `LONG_DOUBLE_TYPE_SIZE'.
-
- -- Macro: LIBGCC2_HAS_DF_MODE
- Define this macro if neither `LIBGCC2_DOUBLE_TYPE_SIZE' nor
- `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is `DFmode' but you want `DFmode'
- routines in `libgcc2.a' anyway. If you don't define this and
- either `LIBGCC2_DOUBLE_TYPE_SIZE' or
- `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is 64 then the default is 1,
- otherwise it is 0.
-
- -- Macro: LIBGCC2_HAS_XF_MODE
- Define this macro if `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is not
- `XFmode' but you want `XFmode' routines in `libgcc2.a' anyway. If
- you don't define this and `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is 80
- then the default is 1, otherwise it is 0.
-
- -- Macro: LIBGCC2_HAS_TF_MODE
- Define this macro if `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is not
- `TFmode' but you want `TFmode' routines in `libgcc2.a' anyway. If
- you don't define this and `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is 128
- then the default is 1, otherwise it is 0.
-
- -- Macro: SF_SIZE
- -- Macro: DF_SIZE
- -- Macro: XF_SIZE
- -- Macro: TF_SIZE
- Define these macros to be the size in bits of the mantissa of
- `SFmode', `DFmode', `XFmode' and `TFmode' values, if the defaults
- in `libgcc2.h' are inappropriate. By default, `FLT_MANT_DIG' is
- used for `SF_SIZE', `LDBL_MANT_DIG' for `XF_SIZE' and `TF_SIZE',
- and `DBL_MANT_DIG' or `LDBL_MANT_DIG' for `DF_SIZE' according to
- whether `LIBGCC2_DOUBLE_TYPE_SIZE' or
- `LIBGCC2_LONG_DOUBLE_TYPE_SIZE' is 64.
-
- -- Macro: TARGET_FLT_EVAL_METHOD
- A C expression for the value for `FLT_EVAL_METHOD' in `float.h',
- assuming, if applicable, that the floating-point control word is
- in its default state. If you do not define this macro the value of
- `FLT_EVAL_METHOD' will be zero.
-
- -- Macro: WIDEST_HARDWARE_FP_SIZE
- A C expression for the size in bits of the widest floating-point
- format supported by the hardware. If you define this macro, you
- must specify a value less than or equal to the value of
- `LONG_DOUBLE_TYPE_SIZE'. If you do not define this macro, the
- value of `LONG_DOUBLE_TYPE_SIZE' is the default.
-
- -- Macro: DEFAULT_SIGNED_CHAR
- An expression whose value is 1 or 0, according to whether the type
- `char' should be signed or unsigned by default. The user can
- always override this default with the options `-fsigned-char' and
- `-funsigned-char'.
-
- -- Target Hook: bool TARGET_DEFAULT_SHORT_ENUMS (void)
- This target hook should return true if the compiler should give an
- `enum' type only as many bytes as it takes to represent the range
- of possible values of that type. It should return false if all
- `enum' types should be allocated like `int'.
-
- The default is to return false.
-
- -- Macro: SIZE_TYPE
- A C expression for a string describing the name of the data type
- to use for size values. The typedef name `size_t' is defined
- using the contents of the string.
-
- The string can contain more than one keyword. If so, separate
- them with spaces, and write first any length keyword, then
- `unsigned' if appropriate, and finally `int'. The string must
- exactly match one of the data type names defined in the function
- `init_decl_processing' in the file `c-decl.c'. You may not omit
- `int' or change the order--that would cause the compiler to crash
- on startup.
-
- If you don't define this macro, the default is `"long unsigned
- int"'.
-
- -- Macro: PTRDIFF_TYPE
- A C expression for a string describing the name of the data type
- to use for the result of subtracting two pointers. The typedef
- name `ptrdiff_t' is defined using the contents of the string. See
- `SIZE_TYPE' above for more information.
-
- If you don't define this macro, the default is `"long int"'.
-
- -- Macro: WCHAR_TYPE
- A C expression for a string describing the name of the data type
- to use for wide characters. The typedef name `wchar_t' is defined
- using the contents of the string. See `SIZE_TYPE' above for more
- information.
-
- If you don't define this macro, the default is `"int"'.
-
- -- Macro: WCHAR_TYPE_SIZE
- A C expression for the size in bits of the data type for wide
- characters. This is used in `cpp', which cannot make use of
- `WCHAR_TYPE'.
-
- -- Macro: WINT_TYPE
- A C expression for a string describing the name of the data type to
- use for wide characters passed to `printf' and returned from
- `getwc'. The typedef name `wint_t' is defined using the contents
- of the string. See `SIZE_TYPE' above for more information.
-
- If you don't define this macro, the default is `"unsigned int"'.
-
- -- Macro: INTMAX_TYPE
- A C expression for a string describing the name of the data type
- that can represent any value of any standard or extended signed
- integer type. The typedef name `intmax_t' is defined using the
- contents of the string. See `SIZE_TYPE' above for more
- information.
-
- If you don't define this macro, the default is the first of
- `"int"', `"long int"', or `"long long int"' that has as much
- precision as `long long int'.
-
- -- Macro: UINTMAX_TYPE
- A C expression for a string describing the name of the data type
- that can represent any value of any standard or extended unsigned
- integer type. The typedef name `uintmax_t' is defined using the
- contents of the string. See `SIZE_TYPE' above for more
- information.
-
- If you don't define this macro, the default is the first of
- `"unsigned int"', `"long unsigned int"', or `"long long unsigned
- int"' that has as much precision as `long long unsigned int'.
-
- -- Macro: TARGET_PTRMEMFUNC_VBIT_LOCATION
- The C++ compiler represents a pointer-to-member-function with a
- struct that looks like:
-
- struct {
- union {
- void (*fn)();
- ptrdiff_t vtable_index;
- };
- ptrdiff_t delta;
- };
-
- The C++ compiler must use one bit to indicate whether the function
- that will be called through a pointer-to-member-function is
- virtual. Normally, we assume that the low-order bit of a function
- pointer must always be zero. Then, by ensuring that the
- vtable_index is odd, we can distinguish which variant of the union
- is in use. But, on some platforms function pointers can be odd,
- and so this doesn't work. In that case, we use the low-order bit
- of the `delta' field, and shift the remainder of the `delta' field
- to the left.
-
- GCC will automatically make the right selection about where to
- store this bit using the `FUNCTION_BOUNDARY' setting for your
- platform. However, some platforms such as ARM/Thumb have
- `FUNCTION_BOUNDARY' set such that functions always start at even
- addresses, but the lowest bit of pointers to functions indicate
- whether the function at that address is in ARM or Thumb mode. If
- this is the case of your architecture, you should define this
- macro to `ptrmemfunc_vbit_in_delta'.
-
- In general, you should not have to define this macro. On
- architectures in which function addresses are always even,
- according to `FUNCTION_BOUNDARY', GCC will automatically define
- this macro to `ptrmemfunc_vbit_in_pfn'.
-
- -- Macro: TARGET_VTABLE_USES_DESCRIPTORS
- Normally, the C++ compiler uses function pointers in vtables. This
- macro allows the target to change to use "function descriptors"
- instead. Function descriptors are found on targets for whom a
- function pointer is actually a small data structure. Normally the
- data structure consists of the actual code address plus a data
- pointer to which the function's data is relative.
-
- If vtables are used, the value of this macro should be the number
- of words that the function descriptor occupies.
-
- -- Macro: TARGET_VTABLE_ENTRY_ALIGN
- By default, the vtable entries are void pointers, the so the
- alignment is the same as pointer alignment. The value of this
- macro specifies the alignment of the vtable entry in bits. It
- should be defined only when special alignment is necessary. */
-
- -- Macro: TARGET_VTABLE_DATA_ENTRY_DISTANCE
- There are a few non-descriptor entries in the vtable at offsets
- below zero. If these entries must be padded (say, to preserve the
- alignment specified by `TARGET_VTABLE_ENTRY_ALIGN'), set this to
- the number of words in each data entry.
-
-\1f
-File: gccint.info, Node: Registers, Next: Register Classes, Prev: Type Layout, Up: Target Macros
-
-17.7 Register Usage
-===================
-
-This section explains how to describe what registers the target machine
-has, and how (in general) they can be used.
-
- The description of which registers a specific instruction can use is
-done with register classes; see *note Register Classes::. For
-information on using registers to access a stack frame, see *note Frame
-Registers::. For passing values in registers, see *note Register
-Arguments::. For returning values in registers, see *note Scalar
-Return::.
-
-* Menu:
-
-* Register Basics:: Number and kinds of registers.
-* Allocation Order:: Order in which registers are allocated.
-* Values in Registers:: What kinds of values each reg can hold.
-* Leaf Functions:: Renumbering registers for leaf functions.
-* Stack Registers:: Handling a register stack such as 80387.
-
-\1f
-File: gccint.info, Node: Register Basics, Next: Allocation Order, Up: Registers
-
-17.7.1 Basic Characteristics of Registers
------------------------------------------
-
-Registers have various characteristics.
-
- -- Macro: FIRST_PSEUDO_REGISTER
- Number of hardware registers known to the compiler. They receive
- numbers 0 through `FIRST_PSEUDO_REGISTER-1'; thus, the first
- pseudo register's number really is assigned the number
- `FIRST_PSEUDO_REGISTER'.
-
- -- Macro: FIXED_REGISTERS
- An initializer that says which registers are used for fixed
- purposes all throughout the compiled code and are therefore not
- available for general allocation. These would include the stack
- pointer, the frame pointer (except on machines where that can be
- used as a general register when no frame pointer is needed), the
- program counter on machines where that is considered one of the
- addressable registers, and any other numbered register with a
- standard use.
-
- This information is expressed as a sequence of numbers, separated
- by commas and surrounded by braces. The Nth number is 1 if
- register N is fixed, 0 otherwise.
-
- The table initialized from this macro, and the table initialized by
- the following one, may be overridden at run time either
- automatically, by the actions of the macro
- `CONDITIONAL_REGISTER_USAGE', or by the user with the command
- options `-ffixed-REG', `-fcall-used-REG' and `-fcall-saved-REG'.
-
- -- Macro: CALL_USED_REGISTERS
- Like `FIXED_REGISTERS' but has 1 for each register that is
- clobbered (in general) by function calls as well as for fixed
- registers. This macro therefore identifies the registers that are
- not available for general allocation of values that must live
- across function calls.
-
- If a register has 0 in `CALL_USED_REGISTERS', the compiler
- automatically saves it on function entry and restores it on
- function exit, if the register is used within the function.
-
- -- Macro: CALL_REALLY_USED_REGISTERS
- Like `CALL_USED_REGISTERS' except this macro doesn't require that
- the entire set of `FIXED_REGISTERS' be included.
- (`CALL_USED_REGISTERS' must be a superset of `FIXED_REGISTERS').
- This macro is optional. If not specified, it defaults to the value
- of `CALL_USED_REGISTERS'.
-
- -- Macro: HARD_REGNO_CALL_PART_CLOBBERED (REGNO, MODE)
- A C expression that is nonzero if it is not permissible to store a
- value of mode MODE in hard register number REGNO across a call
- without some part of it being clobbered. For most machines this
- macro need not be defined. It is only required for machines that
- do not preserve the entire contents of a register across a call.
-
- -- Macro: CONDITIONAL_REGISTER_USAGE
- Zero or more C statements that may conditionally modify five
- variables `fixed_regs', `call_used_regs', `global_regs',
- `reg_names', and `reg_class_contents', to take into account any
- dependence of these register sets on target flags. The first three
- of these are of type `char []' (interpreted as Boolean vectors).
- `global_regs' is a `const char *[]', and `reg_class_contents' is a
- `HARD_REG_SET'. Before the macro is called, `fixed_regs',
- `call_used_regs', `reg_class_contents', and `reg_names' have been
- initialized from `FIXED_REGISTERS', `CALL_USED_REGISTERS',
- `REG_CLASS_CONTENTS', and `REGISTER_NAMES', respectively.
- `global_regs' has been cleared, and any `-ffixed-REG',
- `-fcall-used-REG' and `-fcall-saved-REG' command options have been
- applied.
-
- You need not define this macro if it has no work to do.
-
- If the usage of an entire class of registers depends on the target
- flags, you may indicate this to GCC by using this macro to modify
- `fixed_regs' and `call_used_regs' to 1 for each of the registers
- in the classes which should not be used by GCC. Also define the
- macro `REG_CLASS_FROM_LETTER' / `REG_CLASS_FROM_CONSTRAINT' to
- return `NO_REGS' if it is called with a letter for a class that
- shouldn't be used.
-
- (However, if this class is not included in `GENERAL_REGS' and all
- of the insn patterns whose constraints permit this class are
- controlled by target switches, then GCC will automatically avoid
- using these registers when the target switches are opposed to
- them.)
-
- -- Macro: INCOMING_REGNO (OUT)
- Define this macro if the target machine has register windows.
- This C expression returns the register number as seen by the
- called function corresponding to the register number OUT as seen
- by the calling function. Return OUT if register number OUT is not
- an outbound register.
-
- -- Macro: OUTGOING_REGNO (IN)
- Define this macro if the target machine has register windows.
- This C expression returns the register number as seen by the
- calling function corresponding to the register number IN as seen
- by the called function. Return IN if register number IN is not an
- inbound register.
-
- -- Macro: LOCAL_REGNO (REGNO)
- Define this macro if the target machine has register windows.
- This C expression returns true if the register is call-saved but
- is in the register window. Unlike most call-saved registers, such
- registers need not be explicitly restored on function exit or
- during non-local gotos.
-
- -- Macro: PC_REGNUM
- If the program counter has a register number, define this as that
- register number. Otherwise, do not define it.
-
-\1f
-File: gccint.info, Node: Allocation Order, Next: Values in Registers, Prev: Register Basics, Up: Registers
-
-17.7.2 Order of Allocation of Registers
----------------------------------------
-
-Registers are allocated in order.
-
- -- Macro: REG_ALLOC_ORDER
- If defined, an initializer for a vector of integers, containing the
- numbers of hard registers in the order in which GCC should prefer
- to use them (from most preferred to least).
-
- If this macro is not defined, registers are used lowest numbered
- first (all else being equal).
-
- One use of this macro is on machines where the highest numbered
- registers must always be saved and the save-multiple-registers
- instruction supports only sequences of consecutive registers. On
- such machines, define `REG_ALLOC_ORDER' to be an initializer that
- lists the highest numbered allocable register first.
-
- -- Macro: ADJUST_REG_ALLOC_ORDER
- A C statement (sans semicolon) to choose the order in which to
- allocate hard registers for pseudo-registers local to a basic
- block.
-
- Store the desired register order in the array `reg_alloc_order'.
- Element 0 should be the register to allocate first; element 1, the
- next register; and so on.
-
- The macro body should not assume anything about the contents of
- `reg_alloc_order' before execution of the macro.
-
- On most machines, it is not necessary to define this macro.
-
- -- Macro: HONOR_REG_ALLOC_ORDER
- Normally, IRA tries to estimate the costs for saving a register in
- the prologue and restoring it in the epilogue. This discourages
- it from using call-saved registers. If a machine wants to ensure
- that IRA allocates registers in the order given by REG_ALLOC_ORDER
- even if some call-saved registers appear earlier than call-used
- ones, this macro should be defined.
-
- -- Macro: IRA_HARD_REGNO_ADD_COST_MULTIPLIER (REGNO)
- In some case register allocation order is not enough for the
- Integrated Register Allocator (IRA) to generate a good code. If
- this macro is defined, it should return a floating point value
- based on REGNO. The cost of using REGNO for a pseudo will be
- increased by approximately the pseudo's usage frequency times the
- value returned by this macro. Not defining this macro is
- equivalent to having it always return `0.0'.
-
- On most machines, it is not necessary to define this macro.
-
-\1f
-File: gccint.info, Node: Values in Registers, Next: Leaf Functions, Prev: Allocation Order, Up: Registers
-
-17.7.3 How Values Fit in Registers
-----------------------------------
-
-This section discusses the macros that describe which kinds of values
-(specifically, which machine modes) each register can hold, and how many
-consecutive registers are needed for a given mode.
-
- -- Macro: HARD_REGNO_NREGS (REGNO, MODE)
- A C expression for the number of consecutive hard registers,
- starting at register number REGNO, required to hold a value of mode
- MODE. This macro must never return zero, even if a register
- cannot hold the requested mode - indicate that with
- HARD_REGNO_MODE_OK and/or CANNOT_CHANGE_MODE_CLASS instead.
-
- On a machine where all registers are exactly one word, a suitable
- definition of this macro is
-
- #define HARD_REGNO_NREGS(REGNO, MODE) \
- ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) \
- / UNITS_PER_WORD)
-
- -- Macro: HARD_REGNO_NREGS_HAS_PADDING (REGNO, MODE)
- A C expression that is nonzero if a value of mode MODE, stored in
- memory, ends with padding that causes it to take up more space than
- in registers starting at register number REGNO (as determined by
- multiplying GCC's notion of the size of the register when
- containing this mode by the number of registers returned by
- `HARD_REGNO_NREGS'). By default this is zero.
-
- For example, if a floating-point value is stored in three 32-bit
- registers but takes up 128 bits in memory, then this would be
- nonzero.
-
- This macros only needs to be defined if there are cases where
- `subreg_get_info' would otherwise wrongly determine that a
- `subreg' can be represented by an offset to the register number,
- when in fact such a `subreg' would contain some of the padding not
- stored in registers and so not be representable.
-
- -- Macro: HARD_REGNO_NREGS_WITH_PADDING (REGNO, MODE)
- For values of REGNO and MODE for which
- `HARD_REGNO_NREGS_HAS_PADDING' returns nonzero, a C expression
- returning the greater number of registers required to hold the
- value including any padding. In the example above, the value
- would be four.
-
- -- Macro: REGMODE_NATURAL_SIZE (MODE)
- Define this macro if the natural size of registers that hold values
- of mode MODE is not the word size. It is a C expression that
- should give the natural size in bytes for the specified mode. It
- is used by the register allocator to try to optimize its results.
- This happens for example on SPARC 64-bit where the natural size of
- floating-point registers is still 32-bit.
-
- -- Macro: HARD_REGNO_MODE_OK (REGNO, MODE)
- A C expression that is nonzero if it is permissible to store a
- value of mode MODE in hard register number REGNO (or in several
- registers starting with that one). For a machine where all
- registers are equivalent, a suitable definition is
-
- #define HARD_REGNO_MODE_OK(REGNO, MODE) 1
-
- You need not include code to check for the numbers of fixed
- registers, because the allocation mechanism considers them to be
- always occupied.
-
- On some machines, double-precision values must be kept in even/odd
- register pairs. You can implement that by defining this macro to
- reject odd register numbers for such modes.
-
- The minimum requirement for a mode to be OK in a register is that
- the `movMODE' instruction pattern support moves between the
- register and other hard register in the same class and that moving
- a value into the register and back out not alter it.
-
- Since the same instruction used to move `word_mode' will work for
- all narrower integer modes, it is not necessary on any machine for
- `HARD_REGNO_MODE_OK' to distinguish between these modes, provided
- you define patterns `movhi', etc., to take advantage of this. This
- is useful because of the interaction between `HARD_REGNO_MODE_OK'
- and `MODES_TIEABLE_P'; it is very desirable for all integer modes
- to be tieable.
-
- Many machines have special registers for floating point arithmetic.
- Often people assume that floating point machine modes are allowed
- only in floating point registers. This is not true. Any
- registers that can hold integers can safely _hold_ a floating
- point machine mode, whether or not floating arithmetic can be done
- on it in those registers. Integer move instructions can be used
- to move the values.
-
- On some machines, though, the converse is true: fixed-point machine
- modes may not go in floating registers. This is true if the
- floating registers normalize any value stored in them, because
- storing a non-floating value there would garble it. In this case,
- `HARD_REGNO_MODE_OK' should reject fixed-point machine modes in
- floating registers. But if the floating registers do not
- automatically normalize, if you can store any bit pattern in one
- and retrieve it unchanged without a trap, then any machine mode
- may go in a floating register, so you can define this macro to say
- so.
-
- The primary significance of special floating registers is rather
- that they are the registers acceptable in floating point arithmetic
- instructions. However, this is of no concern to
- `HARD_REGNO_MODE_OK'. You handle it by writing the proper
- constraints for those instructions.
-
- On some machines, the floating registers are especially slow to
- access, so that it is better to store a value in a stack frame
- than in such a register if floating point arithmetic is not being
- done. As long as the floating registers are not in class
- `GENERAL_REGS', they will not be used unless some pattern's
- constraint asks for one.
-
- -- Macro: HARD_REGNO_RENAME_OK (FROM, TO)
- A C expression that is nonzero if it is OK to rename a hard
- register FROM to another hard register TO.
-
- One common use of this macro is to prevent renaming of a register
- to another register that is not saved by a prologue in an interrupt
- handler.
-
- The default is always nonzero.
-
- -- Macro: MODES_TIEABLE_P (MODE1, MODE2)
- A C expression that is nonzero if a value of mode MODE1 is
- accessible in mode MODE2 without copying.
-
- If `HARD_REGNO_MODE_OK (R, MODE1)' and `HARD_REGNO_MODE_OK (R,
- MODE2)' are always the same for any R, then `MODES_TIEABLE_P
- (MODE1, MODE2)' should be nonzero. If they differ for any R, you
- should define this macro to return zero unless some other
- mechanism ensures the accessibility of the value in a narrower
- mode.
-
- You should define this macro to return nonzero in as many cases as
- possible since doing so will allow GCC to perform better register
- allocation.
-
- -- Target Hook: bool TARGET_HARD_REGNO_SCRATCH_OK (unsigned int REGNO)
- This target hook should return `true' if it is OK to use a hard
- register REGNO as scratch reg in peephole2.
-
- One common use of this macro is to prevent using of a register that
- is not saved by a prologue in an interrupt handler.
-
- The default version of this hook always returns `true'.
-
- -- Macro: AVOID_CCMODE_COPIES
- Define this macro if the compiler should avoid copies to/from
- `CCmode' registers. You should only define this macro if support
- for copying to/from `CCmode' is incomplete.
-
-\1f
-File: gccint.info, Node: Leaf Functions, Next: Stack Registers, Prev: Values in Registers, Up: Registers
-
-17.7.4 Handling Leaf Functions
-------------------------------
-
-On some machines, a leaf function (i.e., one which makes no calls) can
-run more efficiently if it does not make its own register window.
-Often this means it is required to receive its arguments in the
-registers where they are passed by the caller, instead of the registers
-where they would normally arrive.
-
- The special treatment for leaf functions generally applies only when
-other conditions are met; for example, often they may use only those
-registers for its own variables and temporaries. We use the term "leaf
-function" to mean a function that is suitable for this special
-handling, so that functions with no calls are not necessarily "leaf
-functions".
-
- GCC assigns register numbers before it knows whether the function is
-suitable for leaf function treatment. So it needs to renumber the
-registers in order to output a leaf function. The following macros
-accomplish this.
-
- -- Macro: LEAF_REGISTERS
- Name of a char vector, indexed by hard register number, which
- contains 1 for a register that is allowable in a candidate for leaf
- function treatment.
-
- If leaf function treatment involves renumbering the registers,
- then the registers marked here should be the ones before
- renumbering--those that GCC would ordinarily allocate. The
- registers which will actually be used in the assembler code, after
- renumbering, should not be marked with 1 in this vector.
-
- Define this macro only if the target machine offers a way to
- optimize the treatment of leaf functions.
-
- -- Macro: LEAF_REG_REMAP (REGNO)
- A C expression whose value is the register number to which REGNO
- should be renumbered, when a function is treated as a leaf
- function.
-
- If REGNO is a register number which should not appear in a leaf
- function before renumbering, then the expression should yield -1,
- which will cause the compiler to abort.
-
- Define this macro only if the target machine offers a way to
- optimize the treatment of leaf functions, and registers need to be
- renumbered to do this.
-
- `TARGET_ASM_FUNCTION_PROLOGUE' and `TARGET_ASM_FUNCTION_EPILOGUE' must
-usually treat leaf functions specially. They can test the C variable
-`current_function_is_leaf' which is nonzero for leaf functions.
-`current_function_is_leaf' is set prior to local register allocation
-and is valid for the remaining compiler passes. They can also test the
-C variable `current_function_uses_only_leaf_regs' which is nonzero for
-leaf functions which only use leaf registers.
-`current_function_uses_only_leaf_regs' is valid after all passes that
-modify the instructions have been run and is only useful if
-`LEAF_REGISTERS' is defined.
-
-\1f
-File: gccint.info, Node: Stack Registers, Prev: Leaf Functions, Up: Registers
-
-17.7.5 Registers That Form a Stack
-----------------------------------
-
-There are special features to handle computers where some of the
-"registers" form a stack. Stack registers are normally written by
-pushing onto the stack, and are numbered relative to the top of the
-stack.
-
- Currently, GCC can only handle one group of stack-like registers, and
-they must be consecutively numbered. Furthermore, the existing support
-for stack-like registers is specific to the 80387 floating point
-coprocessor. If you have a new architecture that uses stack-like
-registers, you will need to do substantial work on `reg-stack.c' and
-write your machine description to cooperate with it, as well as
-defining these macros.
-
- -- Macro: STACK_REGS
- Define this if the machine has any stack-like registers.
-
- -- Macro: FIRST_STACK_REG
- The number of the first stack-like register. This one is the top
- of the stack.
-
- -- Macro: LAST_STACK_REG
- The number of the last stack-like register. This one is the
- bottom of the stack.
-
-\1f
-File: gccint.info, Node: Register Classes, Next: Old Constraints, Prev: Registers, Up: Target Macros
-
-17.8 Register Classes
-=====================
-
-On many machines, the numbered registers are not all equivalent. For
-example, certain registers may not be allowed for indexed addressing;
-certain registers may not be allowed in some instructions. These
-machine restrictions are described to the compiler using "register
-classes".
-
- You define a number of register classes, giving each one a name and
-saying which of the registers belong to it. Then you can specify
-register classes that are allowed as operands to particular instruction
-patterns.
-
- In general, each register will belong to several classes. In fact, one
-class must be named `ALL_REGS' and contain all the registers. Another
-class must be named `NO_REGS' and contain no registers. Often the
-union of two classes will be another class; however, this is not
-required.
-
- One of the classes must be named `GENERAL_REGS'. There is nothing
-terribly special about the name, but the operand constraint letters `r'
-and `g' specify this class. If `GENERAL_REGS' is the same as
-`ALL_REGS', just define it as a macro which expands to `ALL_REGS'.
-
- Order the classes so that if class X is contained in class Y then X
-has a lower class number than Y.
-
- The way classes other than `GENERAL_REGS' are specified in operand
-constraints is through machine-dependent operand constraint letters.
-You can define such letters to correspond to various classes, then use
-them in operand constraints.
-
- You should define a class for the union of two classes whenever some
-instruction allows both classes. For example, if an instruction allows
-either a floating point (coprocessor) register or a general register
-for a certain operand, you should define a class `FLOAT_OR_GENERAL_REGS'
-which includes both of them. Otherwise you will get suboptimal code.
-
- You must also specify certain redundant information about the register
-classes: for each class, which classes contain it and which ones are
-contained in it; for each pair of classes, the largest class contained
-in their union.
-
- When a value occupying several consecutive registers is expected in a
-certain class, all the registers used must belong to that class.
-Therefore, register classes cannot be used to enforce a requirement for
-a register pair to start with an even-numbered register. The way to
-specify this requirement is with `HARD_REGNO_MODE_OK'.
-
- Register classes used for input-operands of bitwise-and or shift
-instructions have a special requirement: each such class must have, for
-each fixed-point machine mode, a subclass whose registers can transfer
-that mode to or from memory. For example, on some machines, the
-operations for single-byte values (`QImode') are limited to certain
-registers. When this is so, each register class that is used in a
-bitwise-and or shift instruction must have a subclass consisting of
-registers from which single-byte values can be loaded or stored. This
-is so that `PREFERRED_RELOAD_CLASS' can always have a possible value to
-return.
-
- -- Data type: enum reg_class
- An enumerated type that must be defined with all the register
- class names as enumerated values. `NO_REGS' must be first.
- `ALL_REGS' must be the last register class, followed by one more
- enumerated value, `LIM_REG_CLASSES', which is not a register class
- but rather tells how many classes there are.
-
- Each register class has a number, which is the value of casting
- the class name to type `int'. The number serves as an index in
- many of the tables described below.
-
- -- Macro: N_REG_CLASSES
- The number of distinct register classes, defined as follows:
-
- #define N_REG_CLASSES (int) LIM_REG_CLASSES
-
- -- Macro: REG_CLASS_NAMES
- An initializer containing the names of the register classes as C
- string constants. These names are used in writing some of the
- debugging dumps.
-
- -- Macro: REG_CLASS_CONTENTS
- An initializer containing the contents of the register classes, as
- integers which are bit masks. The Nth integer specifies the
- contents of class N. The way the integer MASK is interpreted is
- that register R is in the class if `MASK & (1 << R)' is 1.
-
- When the machine has more than 32 registers, an integer does not
- suffice. Then the integers are replaced by sub-initializers,
- braced groupings containing several integers. Each
- sub-initializer must be suitable as an initializer for the type
- `HARD_REG_SET' which is defined in `hard-reg-set.h'. In this
- situation, the first integer in each sub-initializer corresponds to
- registers 0 through 31, the second integer to registers 32 through
- 63, and so on.
-
- -- Macro: REGNO_REG_CLASS (REGNO)
- A C expression whose value is a register class containing hard
- register REGNO. In general there is more than one such class;
- choose a class which is "minimal", meaning that no smaller class
- also contains the register.
-
- -- Macro: BASE_REG_CLASS
- A macro whose definition is the name of the class to which a valid
- base register must belong. A base register is one used in an
- address which is the register value plus a displacement.
-
- -- Macro: MODE_BASE_REG_CLASS (MODE)
- This is a variation of the `BASE_REG_CLASS' macro which allows the
- selection of a base register in a mode dependent manner. If MODE
- is VOIDmode then it should return the same value as
- `BASE_REG_CLASS'.
-
- -- Macro: MODE_BASE_REG_REG_CLASS (MODE)
- A C expression whose value is the register class to which a valid
- base register must belong in order to be used in a base plus index
- register address. You should define this macro if base plus index
- addresses have different requirements than other base register
- uses.
-
- -- Macro: MODE_CODE_BASE_REG_CLASS (MODE, OUTER_CODE, INDEX_CODE)
- A C expression whose value is the register class to which a valid
- base register must belong. OUTER_CODE and INDEX_CODE define the
- context in which the base register occurs. OUTER_CODE is the code
- of the immediately enclosing expression (`MEM' for the top level
- of an address, `ADDRESS' for something that occurs in an
- `address_operand'). INDEX_CODE is the code of the corresponding
- index expression if OUTER_CODE is `PLUS'; `SCRATCH' otherwise.
-
- -- Macro: INDEX_REG_CLASS
- A macro whose definition is the name of the class to which a valid
- index register must belong. An index register is one used in an
- address where its value is either multiplied by a scale factor or
- added to another register (as well as added to a displacement).
-
- -- Macro: REGNO_OK_FOR_BASE_P (NUM)
- A C expression which is nonzero if register number NUM is suitable
- for use as a base register in operand addresses. It may be either
- a suitable hard register or a pseudo register that has been
- allocated such a hard register.
-
- -- Macro: REGNO_MODE_OK_FOR_BASE_P (NUM, MODE)
- A C expression that is just like `REGNO_OK_FOR_BASE_P', except that
- that expression may examine the mode of the memory reference in
- MODE. You should define this macro if the mode of the memory
- reference affects whether a register may be used as a base
- register. If you define this macro, the compiler will use it
- instead of `REGNO_OK_FOR_BASE_P'. The mode may be `VOIDmode' for
- addresses that appear outside a `MEM', i.e., as an
- `address_operand'.
-
-
- -- Macro: REGNO_MODE_OK_FOR_REG_BASE_P (NUM, MODE)
- A C expression which is nonzero if register number NUM is suitable
- for use as a base register in base plus index operand addresses,
- accessing memory in mode MODE. It may be either a suitable hard
- register or a pseudo register that has been allocated such a hard
- register. You should define this macro if base plus index
- addresses have different requirements than other base register
- uses.
-
- Use of this macro is deprecated; please use the more general
- `REGNO_MODE_CODE_OK_FOR_BASE_P'.
-
- -- Macro: REGNO_MODE_CODE_OK_FOR_BASE_P (NUM, MODE, OUTER_CODE,
- INDEX_CODE)
- A C expression that is just like `REGNO_MODE_OK_FOR_BASE_P', except
- that that expression may examine the context in which the register
- appears in the memory reference. OUTER_CODE is the code of the
- immediately enclosing expression (`MEM' if at the top level of the
- address, `ADDRESS' for something that occurs in an
- `address_operand'). INDEX_CODE is the code of the corresponding
- index expression if OUTER_CODE is `PLUS'; `SCRATCH' otherwise.
- The mode may be `VOIDmode' for addresses that appear outside a
- `MEM', i.e., as an `address_operand'.
-
- -- Macro: REGNO_OK_FOR_INDEX_P (NUM)
- A C expression which is nonzero if register number NUM is suitable
- for use as an index register in operand addresses. It may be
- either a suitable hard register or a pseudo register that has been
- allocated such a hard register.
-
- The difference between an index register and a base register is
- that the index register may be scaled. If an address involves the
- sum of two registers, neither one of them scaled, then either one
- may be labeled the "base" and the other the "index"; but whichever
- labeling is used must fit the machine's constraints of which
- registers may serve in each capacity. The compiler will try both
- labelings, looking for one that is valid, and will reload one or
- both registers only if neither labeling works.
-
- -- Macro: PREFERRED_RELOAD_CLASS (X, CLASS)
- A C expression that places additional restrictions on the register
- class to use when it is necessary to copy value X into a register
- in class CLASS. The value is a register class; perhaps CLASS, or
- perhaps another, smaller class. On many machines, the following
- definition is safe:
-
- #define PREFERRED_RELOAD_CLASS(X,CLASS) CLASS
-
- Sometimes returning a more restrictive class makes better code.
- For example, on the 68000, when X is an integer constant that is
- in range for a `moveq' instruction, the value of this macro is
- always `DATA_REGS' as long as CLASS includes the data registers.
- Requiring a data register guarantees that a `moveq' will be used.
-
- One case where `PREFERRED_RELOAD_CLASS' must not return CLASS is
- if X is a legitimate constant which cannot be loaded into some
- register class. By returning `NO_REGS' you can force X into a
- memory location. For example, rs6000 can load immediate values
- into general-purpose registers, but does not have an instruction
- for loading an immediate value into a floating-point register, so
- `PREFERRED_RELOAD_CLASS' returns `NO_REGS' when X is a
- floating-point constant. If the constant can't be loaded into any
- kind of register, code generation will be better if
- `LEGITIMATE_CONSTANT_P' makes the constant illegitimate instead of
- using `PREFERRED_RELOAD_CLASS'.
-
- If an insn has pseudos in it after register allocation, reload
- will go through the alternatives and call repeatedly
- `PREFERRED_RELOAD_CLASS' to find the best one. Returning
- `NO_REGS', in this case, makes reload add a `!' in front of the
- constraint: the x86 back-end uses this feature to discourage usage
- of 387 registers when math is done in the SSE registers (and vice
- versa).
-
- -- Macro: PREFERRED_OUTPUT_RELOAD_CLASS (X, CLASS)
- Like `PREFERRED_RELOAD_CLASS', but for output reloads instead of
- input reloads. If you don't define this macro, the default is to
- use CLASS, unchanged.
-
- You can also use `PREFERRED_OUTPUT_RELOAD_CLASS' to discourage
- reload from using some alternatives, like `PREFERRED_RELOAD_CLASS'.
-
- -- Macro: LIMIT_RELOAD_CLASS (MODE, CLASS)
- A C expression that places additional restrictions on the register
- class to use when it is necessary to be able to hold a value of
- mode MODE in a reload register for which class CLASS would
- ordinarily be used.
-
- Unlike `PREFERRED_RELOAD_CLASS', this macro should be used when
- there are certain modes that simply can't go in certain reload
- classes.
-
- The value is a register class; perhaps CLASS, or perhaps another,
- smaller class.
-
- Don't define this macro unless the target machine has limitations
- which require the macro to do something nontrivial.
-
- -- Target Hook: enum reg_class TARGET_SECONDARY_RELOAD (bool IN_P, rtx
- X, enum reg_class RELOAD_CLASS, enum machine_mode
- RELOAD_MODE, secondary_reload_info *SRI)
- Many machines have some registers that cannot be copied directly
- to or from memory or even from other types of registers. An
- example is the `MQ' register, which on most machines, can only be
- copied to or from general registers, but not memory. Below, we
- shall be using the term 'intermediate register' when a move
- operation cannot be performed directly, but has to be done by
- copying the source into the intermediate register first, and then
- copying the intermediate register to the destination. An
- intermediate register always has the same mode as source and
- destination. Since it holds the actual value being copied, reload
- might apply optimizations to re-use an intermediate register and
- eliding the copy from the source when it can determine that the
- intermediate register still holds the required value.
-
- Another kind of secondary reload is required on some machines which
- allow copying all registers to and from memory, but require a
- scratch register for stores to some memory locations (e.g., those
- with symbolic address on the RT, and those with certain symbolic
- address on the SPARC when compiling PIC). Scratch registers need
- not have the same mode as the value being copied, and usually hold
- a different value that that being copied. Special patterns in the
- md file are needed to describe how the copy is performed with the
- help of the scratch register; these patterns also describe the
- number, register class(es) and mode(s) of the scratch register(s).
-
- In some cases, both an intermediate and a scratch register are
- required.
-
- For input reloads, this target hook is called with nonzero IN_P,
- and X is an rtx that needs to be copied to a register of class
- RELOAD_CLASS in RELOAD_MODE. For output reloads, this target hook
- is called with zero IN_P, and a register of class RELOAD_CLASS
- needs to be copied to rtx X in RELOAD_MODE.
-
- If copying a register of RELOAD_CLASS from/to X requires an
- intermediate register, the hook `secondary_reload' should return
- the register class required for this intermediate register. If no
- intermediate register is required, it should return NO_REGS. If
- more than one intermediate register is required, describe the one
- that is closest in the copy chain to the reload register.
-
- If scratch registers are needed, you also have to describe how to
- perform the copy from/to the reload register to/from this closest
- intermediate register. Or if no intermediate register is
- required, but still a scratch register is needed, describe the
- copy from/to the reload register to/from the reload operand X.
-
- You do this by setting `sri->icode' to the instruction code of a
- pattern in the md file which performs the move. Operands 0 and 1
- are the output and input of this copy, respectively. Operands
- from operand 2 onward are for scratch operands. These scratch
- operands must have a mode, and a single-register-class output
- constraint.
-
- When an intermediate register is used, the `secondary_reload' hook
- will be called again to determine how to copy the intermediate
- register to/from the reload operand X, so your hook must also have
- code to handle the register class of the intermediate operand.
-
- X might be a pseudo-register or a `subreg' of a pseudo-register,
- which could either be in a hard register or in memory. Use
- `true_regnum' to find out; it will return -1 if the pseudo is in
- memory and the hard register number if it is in a register.
-
- Scratch operands in memory (constraint `"=m"' / `"=&m"') are
- currently not supported. For the time being, you will have to
- continue to use `SECONDARY_MEMORY_NEEDED' for that purpose.
-
- `copy_cost' also uses this target hook to find out how values are
- copied. If you want it to include some extra cost for the need to
- allocate (a) scratch register(s), set `sri->extra_cost' to the
- additional cost. Or if two dependent moves are supposed to have a
- lower cost than the sum of the individual moves due to expected
- fortuitous scheduling and/or special forwarding logic, you can set
- `sri->extra_cost' to a negative amount.
-
- -- Macro: SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
- -- Macro: SECONDARY_INPUT_RELOAD_CLASS (CLASS, MODE, X)
- -- Macro: SECONDARY_OUTPUT_RELOAD_CLASS (CLASS, MODE, X)
- These macros are obsolete, new ports should use the target hook
- `TARGET_SECONDARY_RELOAD' instead.
-
- These are obsolete macros, replaced by the
- `TARGET_SECONDARY_RELOAD' target hook. Older ports still define
- these macros to indicate to the reload phase that it may need to
- allocate at least one register for a reload in addition to the
- register to contain the data. Specifically, if copying X to a
- register CLASS in MODE requires an intermediate register, you were
- supposed to define `SECONDARY_INPUT_RELOAD_CLASS' to return the
- largest register class all of whose registers can be used as
- intermediate registers or scratch registers.
-
- If copying a register CLASS in MODE to X requires an intermediate
- or scratch register, `SECONDARY_OUTPUT_RELOAD_CLASS' was supposed
- to be defined be defined to return the largest register class
- required. If the requirements for input and output reloads were
- the same, the macro `SECONDARY_RELOAD_CLASS' should have been used
- instead of defining both macros identically.
-
- The values returned by these macros are often `GENERAL_REGS'.
- Return `NO_REGS' if no spare register is needed; i.e., if X can be
- directly copied to or from a register of CLASS in MODE without
- requiring a scratch register. Do not define this macro if it
- would always return `NO_REGS'.
-
- If a scratch register is required (either with or without an
- intermediate register), you were supposed to define patterns for
- `reload_inM' or `reload_outM', as required (*note Standard
- Names::. These patterns, which were normally implemented with a
- `define_expand', should be similar to the `movM' patterns, except
- that operand 2 is the scratch register.
-
- These patterns need constraints for the reload register and scratch
- register that contain a single register class. If the original
- reload register (whose class is CLASS) can meet the constraint
- given in the pattern, the value returned by these macros is used
- for the class of the scratch register. Otherwise, two additional
- reload registers are required. Their classes are obtained from
- the constraints in the insn pattern.
-
- X might be a pseudo-register or a `subreg' of a pseudo-register,
- which could either be in a hard register or in memory. Use
- `true_regnum' to find out; it will return -1 if the pseudo is in
- memory and the hard register number if it is in a register.
-
- These macros should not be used in the case where a particular
- class of registers can only be copied to memory and not to another
- class of registers. In that case, secondary reload registers are
- not needed and would not be helpful. Instead, a stack location
- must be used to perform the copy and the `movM' pattern should use
- memory as an intermediate storage. This case often occurs between
- floating-point and general registers.
-
- -- Macro: SECONDARY_MEMORY_NEEDED (CLASS1, CLASS2, M)
- Certain machines have the property that some registers cannot be
- copied to some other registers without using memory. Define this
- macro on those machines to be a C expression that is nonzero if
- objects of mode M in registers of CLASS1 can only be copied to
- registers of class CLASS2 by storing a register of CLASS1 into
- memory and loading that memory location into a register of CLASS2.
-
- Do not define this macro if its value would always be zero.
-
- -- Macro: SECONDARY_MEMORY_NEEDED_RTX (MODE)
- Normally when `SECONDARY_MEMORY_NEEDED' is defined, the compiler
- allocates a stack slot for a memory location needed for register
- copies. If this macro is defined, the compiler instead uses the
- memory location defined by this macro.
-
- Do not define this macro if you do not define
- `SECONDARY_MEMORY_NEEDED'.
-
- -- Macro: SECONDARY_MEMORY_NEEDED_MODE (MODE)
- When the compiler needs a secondary memory location to copy
- between two registers of mode MODE, it normally allocates
- sufficient memory to hold a quantity of `BITS_PER_WORD' bits and
- performs the store and load operations in a mode that many bits
- wide and whose class is the same as that of MODE.
-
- This is right thing to do on most machines because it ensures that
- all bits of the register are copied and prevents accesses to the
- registers in a narrower mode, which some machines prohibit for
- floating-point registers.
-
- However, this default behavior is not correct on some machines,
- such as the DEC Alpha, that store short integers in floating-point
- registers differently than in integer registers. On those
- machines, the default widening will not work correctly and you
- must define this macro to suppress that widening in some cases.
- See the file `alpha.h' for details.
-
- Do not define this macro if you do not define
- `SECONDARY_MEMORY_NEEDED' or if widening MODE to a mode that is
- `BITS_PER_WORD' bits wide is correct for your machine.
-
- -- Macro: SMALL_REGISTER_CLASSES
- On some machines, it is risky to let hard registers live across
- arbitrary insns. Typically, these machines have instructions that
- require values to be in specific registers (like an accumulator),
- and reload will fail if the required hard register is used for
- another purpose across such an insn.
-
- Define `SMALL_REGISTER_CLASSES' to be an expression with a nonzero
- value on these machines. When this macro has a nonzero value, the
- compiler will try to minimize the lifetime of hard registers.
-
- It is always safe to define this macro with a nonzero value, but
- if you unnecessarily define it, you will reduce the amount of
- optimizations that can be performed in some cases. If you do not
- define this macro with a nonzero value when it is required, the
- compiler will run out of spill registers and print a fatal error
- message. For most machines, you should not define this macro at
- all.
-
- -- Macro: CLASS_LIKELY_SPILLED_P (CLASS)
- A C expression whose value is nonzero if pseudos that have been
- assigned to registers of class CLASS would likely be spilled
- because registers of CLASS are needed for spill registers.
-
- The default value of this macro returns 1 if CLASS has exactly one
- register and zero otherwise. On most machines, this default
- should be used. Only define this macro to some other expression
- if pseudos allocated by `local-alloc.c' end up in memory because
- their hard registers were needed for spill registers. If this
- macro returns nonzero for those classes, those pseudos will only
- be allocated by `global.c', which knows how to reallocate the
- pseudo to another register. If there would not be another
- register available for reallocation, you should not change the
- definition of this macro since the only effect of such a
- definition would be to slow down register allocation.
-
- -- Macro: CLASS_MAX_NREGS (CLASS, MODE)
- A C expression for the maximum number of consecutive registers of
- class CLASS needed to hold a value of mode MODE.
-
- This is closely related to the macro `HARD_REGNO_NREGS'. In fact,
- the value of the macro `CLASS_MAX_NREGS (CLASS, MODE)' should be
- the maximum value of `HARD_REGNO_NREGS (REGNO, MODE)' for all
- REGNO values in the class CLASS.
-
- This macro helps control the handling of multiple-word values in
- the reload pass.
-
- -- Macro: CANNOT_CHANGE_MODE_CLASS (FROM, TO, CLASS)
- If defined, a C expression that returns nonzero for a CLASS for
- which a change from mode FROM to mode TO is invalid.
-
- For the example, loading 32-bit integer or floating-point objects
- into floating-point registers on the Alpha extends them to 64 bits.
- Therefore loading a 64-bit object and then storing it as a 32-bit
- object does not store the low-order 32 bits, as would be the case
- for a normal register. Therefore, `alpha.h' defines
- `CANNOT_CHANGE_MODE_CLASS' as below:
-
- #define CANNOT_CHANGE_MODE_CLASS(FROM, TO, CLASS) \
- (GET_MODE_SIZE (FROM) != GET_MODE_SIZE (TO) \
- ? reg_classes_intersect_p (FLOAT_REGS, (CLASS)) : 0)
-
- -- Target Hook: const enum reg_class * TARGET_IRA_COVER_CLASSES ()
- Return an array of cover classes for the Integrated Register
- Allocator (IRA). Cover classes are a set of non-intersecting
- register classes covering all hard registers used for register
- allocation purposes. If a move between two registers in the same
- cover class is possible, it should be cheaper than a load or store
- of the registers. The array is terminated by a `LIM_REG_CLASSES'
- element.
-
- This hook is called once at compiler startup, after the
- command-line options have been processed. It is then re-examined
- by every call to `target_reinit'.
-
- The default implementation returns `IRA_COVER_CLASSES', if defined,
- otherwise there is no default implementation. You must define
- either this macro or `IRA_COVER_CLASSES' in order to use the
- integrated register allocator with Chaitin-Briggs coloring. If the
- macro is not defined, the only available coloring algorithm is
- Chow's priority coloring.
-
- -- Macro: IRA_COVER_CLASSES
- See the documentation for `TARGET_IRA_COVER_CLASSES'.
-
-\1f
-File: gccint.info, Node: Old Constraints, Next: Stack and Calling, Prev: Register Classes, Up: Target Macros
-
-17.9 Obsolete Macros for Defining Constraints
-=============================================
-
-Machine-specific constraints can be defined with these macros instead
-of the machine description constructs described in *note Define
-Constraints::. This mechanism is obsolete. New ports should not use
-it; old ports should convert to the new mechanism.
-
- -- Macro: CONSTRAINT_LEN (CHAR, STR)
- For the constraint at the start of STR, which starts with the
- letter C, return the length. This allows you to have register
- class / constant / extra constraints that are longer than a single
- letter; you don't need to define this macro if you can do with
- single-letter constraints only. The definition of this macro
- should use DEFAULT_CONSTRAINT_LEN for all the characters that you
- don't want to handle specially. There are some sanity checks in
- genoutput.c that check the constraint lengths for the md file, so
- you can also use this macro to help you while you are
- transitioning from a byzantine single-letter-constraint scheme:
- when you return a negative length for a constraint you want to
- re-use, genoutput will complain about every instance where it is
- used in the md file.
-
- -- Macro: REG_CLASS_FROM_LETTER (CHAR)
- A C expression which defines the machine-dependent operand
- constraint letters for register classes. If CHAR is such a
- letter, the value should be the register class corresponding to
- it. Otherwise, the value should be `NO_REGS'. The register
- letter `r', corresponding to class `GENERAL_REGS', will not be
- passed to this macro; you do not need to handle it.
-
- -- Macro: REG_CLASS_FROM_CONSTRAINT (CHAR, STR)
- Like `REG_CLASS_FROM_LETTER', but you also get the constraint
- string passed in STR, so that you can use suffixes to distinguish
- between different variants.
-
- -- Macro: CONST_OK_FOR_LETTER_P (VALUE, C)
- A C expression that defines the machine-dependent operand
- constraint letters (`I', `J', `K', ... `P') that specify
- particular ranges of integer values. If C is one of those
- letters, the expression should check that VALUE, an integer, is in
- the appropriate range and return 1 if so, 0 otherwise. If C is
- not one of those letters, the value should be 0 regardless of
- VALUE.
-
- -- Macro: CONST_OK_FOR_CONSTRAINT_P (VALUE, C, STR)
- Like `CONST_OK_FOR_LETTER_P', but you also get the constraint
- string passed in STR, so that you can use suffixes to distinguish
- between different variants.
-
- -- Macro: CONST_DOUBLE_OK_FOR_LETTER_P (VALUE, C)
- A C expression that defines the machine-dependent operand
- constraint letters that specify particular ranges of
- `const_double' values (`G' or `H').
-
- If C is one of those letters, the expression should check that
- VALUE, an RTX of code `const_double', is in the appropriate range
- and return 1 if so, 0 otherwise. If C is not one of those
- letters, the value should be 0 regardless of VALUE.
-
- `const_double' is used for all floating-point constants and for
- `DImode' fixed-point constants. A given letter can accept either
- or both kinds of values. It can use `GET_MODE' to distinguish
- between these kinds.
-
- -- Macro: CONST_DOUBLE_OK_FOR_CONSTRAINT_P (VALUE, C, STR)
- Like `CONST_DOUBLE_OK_FOR_LETTER_P', but you also get the
- constraint string passed in STR, so that you can use suffixes to
- distinguish between different variants.
-
- -- Macro: EXTRA_CONSTRAINT (VALUE, C)
- A C expression that defines the optional machine-dependent
- constraint letters that can be used to segregate specific types of
- operands, usually memory references, for the target machine. Any
- letter that is not elsewhere defined and not matched by
- `REG_CLASS_FROM_LETTER' / `REG_CLASS_FROM_CONSTRAINT' may be used.
- Normally this macro will not be defined.
-
- If it is required for a particular target machine, it should
- return 1 if VALUE corresponds to the operand type represented by
- the constraint letter C. If C is not defined as an extra
- constraint, the value returned should be 0 regardless of VALUE.
-
- For example, on the ROMP, load instructions cannot have their
- output in r0 if the memory reference contains a symbolic address.
- Constraint letter `Q' is defined as representing a memory address
- that does _not_ contain a symbolic address. An alternative is
- specified with a `Q' constraint on the input and `r' on the
- output. The next alternative specifies `m' on the input and a
- register class that does not include r0 on the output.
-
- -- Macro: EXTRA_CONSTRAINT_STR (VALUE, C, STR)
- Like `EXTRA_CONSTRAINT', but you also get the constraint string
- passed in STR, so that you can use suffixes to distinguish between
- different variants.
-
- -- Macro: EXTRA_MEMORY_CONSTRAINT (C, STR)
- A C expression that defines the optional machine-dependent
- constraint letters, amongst those accepted by `EXTRA_CONSTRAINT',
- that should be treated like memory constraints by the reload pass.
-
- It should return 1 if the operand type represented by the
- constraint at the start of STR, the first letter of which is the
- letter C, comprises a subset of all memory references including
- all those whose address is simply a base register. This allows
- the reload pass to reload an operand, if it does not directly
- correspond to the operand type of C, by copying its address into a
- base register.
-
- For example, on the S/390, some instructions do not accept
- arbitrary memory references, but only those that do not make use
- of an index register. The constraint letter `Q' is defined via
- `EXTRA_CONSTRAINT' as representing a memory address of this type.
- If the letter `Q' is marked as `EXTRA_MEMORY_CONSTRAINT', a `Q'
- constraint can handle any memory operand, because the reload pass
- knows it can be reloaded by copying the memory address into a base
- register if required. This is analogous to the way a `o'
- constraint can handle any memory operand.
-
- -- Macro: EXTRA_ADDRESS_CONSTRAINT (C, STR)
- A C expression that defines the optional machine-dependent
- constraint letters, amongst those accepted by `EXTRA_CONSTRAINT' /
- `EXTRA_CONSTRAINT_STR', that should be treated like address
- constraints by the reload pass.
-
- It should return 1 if the operand type represented by the
- constraint at the start of STR, which starts with the letter C,
- comprises a subset of all memory addresses including all those
- that consist of just a base register. This allows the reload pass
- to reload an operand, if it does not directly correspond to the
- operand type of STR, by copying it into a base register.
-
- Any constraint marked as `EXTRA_ADDRESS_CONSTRAINT' can only be
- used with the `address_operand' predicate. It is treated
- analogously to the `p' constraint.
-
-\1f
-File: gccint.info, Node: Stack and Calling, Next: Varargs, Prev: Old Constraints, Up: Target Macros
-
-17.10 Stack Layout and Calling Conventions
-==========================================
-
-This describes the stack layout and calling conventions.
-
-* Menu:
-
-* Frame Layout::
-* Exception Handling::
-* Stack Checking::
-* Frame Registers::
-* Elimination::
-* Stack Arguments::
-* Register Arguments::
-* Scalar Return::
-* Aggregate Return::
-* Caller Saves::
-* Function Entry::
-* Profiling::
-* Tail Calls::
-* Stack Smashing Protection::
-
-\1f
-File: gccint.info, Node: Frame Layout, Next: Exception Handling, Up: Stack and Calling
-
-17.10.1 Basic Stack Layout
---------------------------
-
-Here is the basic stack layout.
-
- -- Macro: STACK_GROWS_DOWNWARD
- Define this macro if pushing a word onto the stack moves the stack
- pointer to a smaller address.
-
- When we say, "define this macro if ...", it means that the
- compiler checks this macro only with `#ifdef' so the precise
- definition used does not matter.
-
- -- Macro: STACK_PUSH_CODE
- This macro defines the operation used when something is pushed on
- the stack. In RTL, a push operation will be `(set (mem
- (STACK_PUSH_CODE (reg sp))) ...)'
-
- The choices are `PRE_DEC', `POST_DEC', `PRE_INC', and `POST_INC'.
- Which of these is correct depends on the stack direction and on
- whether the stack pointer points to the last item on the stack or
- whether it points to the space for the next item on the stack.
-
- The default is `PRE_DEC' when `STACK_GROWS_DOWNWARD' is defined,
- which is almost always right, and `PRE_INC' otherwise, which is
- often wrong.
-
- -- Macro: FRAME_GROWS_DOWNWARD
- Define this macro to nonzero value if the addresses of local
- variable slots are at negative offsets from the frame pointer.
-
- -- Macro: ARGS_GROW_DOWNWARD
- Define this macro if successive arguments to a function occupy
- decreasing addresses on the stack.
-
- -- Macro: STARTING_FRAME_OFFSET
- Offset from the frame pointer to the first local variable slot to
- be allocated.
-
- If `FRAME_GROWS_DOWNWARD', find the next slot's offset by
- subtracting the first slot's length from `STARTING_FRAME_OFFSET'.
- Otherwise, it is found by adding the length of the first slot to
- the value `STARTING_FRAME_OFFSET'.
-
- -- Macro: STACK_ALIGNMENT_NEEDED
- Define to zero to disable final alignment of the stack during
- reload. The nonzero default for this macro is suitable for most
- ports.
-
- On ports where `STARTING_FRAME_OFFSET' is nonzero or where there
- is a register save block following the local block that doesn't
- require alignment to `STACK_BOUNDARY', it may be beneficial to
- disable stack alignment and do it in the backend.
-
- -- Macro: STACK_POINTER_OFFSET
- Offset from the stack pointer register to the first location at
- which outgoing arguments are placed. If not specified, the
- default value of zero is used. This is the proper value for most
- machines.
-
- If `ARGS_GROW_DOWNWARD', this is the offset to the location above
- the first location at which outgoing arguments are placed.
-
- -- Macro: FIRST_PARM_OFFSET (FUNDECL)
- Offset from the argument pointer register to the first argument's
- address. On some machines it may depend on the data type of the
- function.
-
- If `ARGS_GROW_DOWNWARD', this is the offset to the location above
- the first argument's address.
-
- -- Macro: STACK_DYNAMIC_OFFSET (FUNDECL)
- Offset from the stack pointer register to an item dynamically
- allocated on the stack, e.g., by `alloca'.
-
- The default value for this macro is `STACK_POINTER_OFFSET' plus the
- length of the outgoing arguments. The default is correct for most
- machines. See `function.c' for details.
-
- -- Macro: INITIAL_FRAME_ADDRESS_RTX
- A C expression whose value is RTL representing the address of the
- initial stack frame. This address is passed to `RETURN_ADDR_RTX'
- and `DYNAMIC_CHAIN_ADDRESS'. If you don't define this macro, a
- reasonable default value will be used. Define this macro in order
- to make frame pointer elimination work in the presence of
- `__builtin_frame_address (count)' and `__builtin_return_address
- (count)' for `count' not equal to zero.
-
- -- Macro: DYNAMIC_CHAIN_ADDRESS (FRAMEADDR)
- A C expression whose value is RTL representing the address in a
- stack frame where the pointer to the caller's frame is stored.
- Assume that FRAMEADDR is an RTL expression for the address of the
- stack frame itself.
-
- If you don't define this macro, the default is to return the value
- of FRAMEADDR--that is, the stack frame address is also the address
- of the stack word that points to the previous frame.
-
- -- Macro: SETUP_FRAME_ADDRESSES
- If defined, a C expression that produces the machine-specific code
- to setup the stack so that arbitrary frames can be accessed. For
- example, on the SPARC, we must flush all of the register windows
- to the stack before we can access arbitrary stack frames. You
- will seldom need to define this macro.
-
- -- Target Hook: bool TARGET_BUILTIN_SETJMP_FRAME_VALUE ()
- This target hook should return an rtx that is used to store the
- address of the current frame into the built in `setjmp' buffer.
- The default value, `virtual_stack_vars_rtx', is correct for most
- machines. One reason you may need to define this target hook is if
- `hard_frame_pointer_rtx' is the appropriate value on your machine.
-
- -- Macro: FRAME_ADDR_RTX (FRAMEADDR)
- A C expression whose value is RTL representing the value of the
- frame address for the current frame. FRAMEADDR is the frame
- pointer of the current frame. This is used for
- __builtin_frame_address. You need only define this macro if the
- frame address is not the same as the frame pointer. Most machines
- do not need to define it.
-
- -- Macro: RETURN_ADDR_RTX (COUNT, FRAMEADDR)
- A C expression whose value is RTL representing the value of the
- return address for the frame COUNT steps up from the current
- frame, after the prologue. FRAMEADDR is the frame pointer of the
- COUNT frame, or the frame pointer of the COUNT - 1 frame if
- `RETURN_ADDR_IN_PREVIOUS_FRAME' is defined.
-
- The value of the expression must always be the correct address when
- COUNT is zero, but may be `NULL_RTX' if there is no way to
- determine the return address of other frames.
-
- -- Macro: RETURN_ADDR_IN_PREVIOUS_FRAME
- Define this if the return address of a particular stack frame is
- accessed from the frame pointer of the previous stack frame.
-
- -- Macro: INCOMING_RETURN_ADDR_RTX
- A C expression whose value is RTL representing the location of the
- incoming return address at the beginning of any function, before
- the prologue. This RTL is either a `REG', indicating that the
- return value is saved in `REG', or a `MEM' representing a location
- in the stack.
-
- You only need to define this macro if you want to support call
- frame debugging information like that provided by DWARF 2.
-
- If this RTL is a `REG', you should also define
- `DWARF_FRAME_RETURN_COLUMN' to `DWARF_FRAME_REGNUM (REGNO)'.
-
- -- Macro: DWARF_ALT_FRAME_RETURN_COLUMN
- A C expression whose value is an integer giving a DWARF 2 column
- number that may be used as an alternative return column. The
- column must not correspond to any gcc hard register (that is, it
- must not be in the range of `DWARF_FRAME_REGNUM').
-
- This macro can be useful if `DWARF_FRAME_RETURN_COLUMN' is set to a
- general register, but an alternative column needs to be used for
- signal frames. Some targets have also used different frame return
- columns over time.
-
- -- Macro: DWARF_ZERO_REG
- A C expression whose value is an integer giving a DWARF 2 register
- number that is considered to always have the value zero. This
- should only be defined if the target has an architected zero
- register, and someone decided it was a good idea to use that
- register number to terminate the stack backtrace. New ports
- should avoid this.
-
- -- Target Hook: void TARGET_DWARF_HANDLE_FRAME_UNSPEC (const char
- *LABEL, rtx PATTERN, int INDEX)
- This target hook allows the backend to emit frame-related insns
- that contain UNSPECs or UNSPEC_VOLATILEs. The DWARF 2 call frame
- debugging info engine will invoke it on insns of the form
- (set (reg) (unspec [...] UNSPEC_INDEX))
- and
- (set (reg) (unspec_volatile [...] UNSPECV_INDEX)).
- to let the backend emit the call frame instructions. LABEL is the
- CFI label attached to the insn, PATTERN is the pattern of the insn
- and INDEX is `UNSPEC_INDEX' or `UNSPECV_INDEX'.
-
- -- Macro: INCOMING_FRAME_SP_OFFSET
- A C expression whose value is an integer giving the offset, in
- bytes, from the value of the stack pointer register to the top of
- the stack frame at the beginning of any function, before the
- prologue. The top of the frame is defined to be the value of the
- stack pointer in the previous frame, just before the call
- instruction.
-
- You only need to define this macro if you want to support call
- frame debugging information like that provided by DWARF 2.
-
- -- Macro: ARG_POINTER_CFA_OFFSET (FUNDECL)
- A C expression whose value is an integer giving the offset, in
- bytes, from the argument pointer to the canonical frame address
- (cfa). The final value should coincide with that calculated by
- `INCOMING_FRAME_SP_OFFSET'. Which is unfortunately not usable
- during virtual register instantiation.
-
- The default value for this macro is `FIRST_PARM_OFFSET (fundecl)',
- which is correct for most machines; in general, the arguments are
- found immediately before the stack frame. Note that this is not
- the case on some targets that save registers into the caller's
- frame, such as SPARC and rs6000, and so such targets need to
- define this macro.
-
- You only need to define this macro if the default is incorrect,
- and you want to support call frame debugging information like that
- provided by DWARF 2.
-
- -- Macro: FRAME_POINTER_CFA_OFFSET (FUNDECL)
- If defined, a C expression whose value is an integer giving the
- offset in bytes from the frame pointer to the canonical frame
- address (cfa). The final value should coincide with that
- calculated by `INCOMING_FRAME_SP_OFFSET'.
-
- Normally the CFA is calculated as an offset from the argument
- pointer, via `ARG_POINTER_CFA_OFFSET', but if the argument pointer
- is variable due to the ABI, this may not be possible. If this
- macro is defined, it implies that the virtual register
- instantiation should be based on the frame pointer instead of the
- argument pointer. Only one of `FRAME_POINTER_CFA_OFFSET' and
- `ARG_POINTER_CFA_OFFSET' should be defined.
-
- -- Macro: CFA_FRAME_BASE_OFFSET (FUNDECL)
- If defined, a C expression whose value is an integer giving the
- offset in bytes from the canonical frame address (cfa) to the
- frame base used in DWARF 2 debug information. The default is
- zero. A different value may reduce the size of debug information
- on some ports.
-
-\1f
-File: gccint.info, Node: Exception Handling, Next: Stack Checking, Prev: Frame Layout, Up: Stack and Calling
-
-17.10.2 Exception Handling Support
-----------------------------------
-
- -- Macro: EH_RETURN_DATA_REGNO (N)
- A C expression whose value is the Nth register number used for
- data by exception handlers, or `INVALID_REGNUM' if fewer than N
- registers are usable.
-
- The exception handling library routines communicate with the
- exception handlers via a set of agreed upon registers. Ideally
- these registers should be call-clobbered; it is possible to use
- call-saved registers, but may negatively impact code size. The
- target must support at least 2 data registers, but should define 4
- if there are enough free registers.
-
- You must define this macro if you want to support call frame
- exception handling like that provided by DWARF 2.
-
- -- Macro: EH_RETURN_STACKADJ_RTX
- A C expression whose value is RTL representing a location in which
- to store a stack adjustment to be applied before function return.
- This is used to unwind the stack to an exception handler's call
- frame. It will be assigned zero on code paths that return
- normally.
-
- Typically this is a call-clobbered hard register that is otherwise
- untouched by the epilogue, but could also be a stack slot.
-
- Do not define this macro if the stack pointer is saved and restored
- by the regular prolog and epilog code in the call frame itself; in
- this case, the exception handling library routines will update the
- stack location to be restored in place. Otherwise, you must define
- this macro if you want to support call frame exception handling
- like that provided by DWARF 2.
-
- -- Macro: EH_RETURN_HANDLER_RTX
- A C expression whose value is RTL representing a location in which
- to store the address of an exception handler to which we should
- return. It will not be assigned on code paths that return
- normally.
-
- Typically this is the location in the call frame at which the
- normal return address is stored. For targets that return by
- popping an address off the stack, this might be a memory address
- just below the _target_ call frame rather than inside the current
- call frame. If defined, `EH_RETURN_STACKADJ_RTX' will have already
- been assigned, so it may be used to calculate the location of the
- target call frame.
-
- Some targets have more complex requirements than storing to an
- address calculable during initial code generation. In that case
- the `eh_return' instruction pattern should be used instead.
-
- If you want to support call frame exception handling, you must
- define either this macro or the `eh_return' instruction pattern.
-
- -- Macro: RETURN_ADDR_OFFSET
- If defined, an integer-valued C expression for which rtl will be
- generated to add it to the exception handler address before it is
- searched in the exception handling tables, and to subtract it
- again from the address before using it to return to the exception
- handler.
-
- -- Macro: ASM_PREFERRED_EH_DATA_FORMAT (CODE, GLOBAL)
- This macro chooses the encoding of pointers embedded in the
- exception handling sections. If at all possible, this should be
- defined such that the exception handling section will not require
- dynamic relocations, and so may be read-only.
-
- CODE is 0 for data, 1 for code labels, 2 for function pointers.
- GLOBAL is true if the symbol may be affected by dynamic
- relocations. The macro should return a combination of the
- `DW_EH_PE_*' defines as found in `dwarf2.h'.
-
- If this macro is not defined, pointers will not be encoded but
- represented directly.
-
- -- Macro: ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX (FILE, ENCODING, SIZE,
- ADDR, DONE)
- This macro allows the target to emit whatever special magic is
- required to represent the encoding chosen by
- `ASM_PREFERRED_EH_DATA_FORMAT'. Generic code takes care of
- pc-relative and indirect encodings; this must be defined if the
- target uses text-relative or data-relative encodings.
-
- This is a C statement that branches to DONE if the format was
- handled. ENCODING is the format chosen, SIZE is the number of
- bytes that the format occupies, ADDR is the `SYMBOL_REF' to be
- emitted.
-
- -- Macro: MD_UNWIND_SUPPORT
- A string specifying a file to be #include'd in unwind-dw2.c. The
- file so included typically defines `MD_FALLBACK_FRAME_STATE_FOR'.
-
- -- Macro: MD_FALLBACK_FRAME_STATE_FOR (CONTEXT, FS)
- This macro allows the target to add CPU and operating system
- specific code to the call-frame unwinder for use when there is no
- unwind data available. The most common reason to implement this
- macro is to unwind through signal frames.
-
- This macro is called from `uw_frame_state_for' in `unwind-dw2.c',
- `unwind-dw2-xtensa.c' and `unwind-ia64.c'. CONTEXT is an
- `_Unwind_Context'; FS is an `_Unwind_FrameState'. Examine
- `context->ra' for the address of the code being executed and
- `context->cfa' for the stack pointer value. If the frame can be
- decoded, the register save addresses should be updated in FS and
- the macro should evaluate to `_URC_NO_REASON'. If the frame
- cannot be decoded, the macro should evaluate to
- `_URC_END_OF_STACK'.
-
- For proper signal handling in Java this macro is accompanied by
- `MAKE_THROW_FRAME', defined in `libjava/include/*-signal.h'
- headers.
-
- -- Macro: MD_HANDLE_UNWABI (CONTEXT, FS)
- This macro allows the target to add operating system specific code
- to the call-frame unwinder to handle the IA-64 `.unwabi' unwinding
- directive, usually used for signal or interrupt frames.
-
- This macro is called from `uw_update_context' in `unwind-ia64.c'.
- CONTEXT is an `_Unwind_Context'; FS is an `_Unwind_FrameState'.
- Examine `fs->unwabi' for the abi and context in the `.unwabi'
- directive. If the `.unwabi' directive can be handled, the
- register save addresses should be updated in FS.
-
- -- Macro: TARGET_USES_WEAK_UNWIND_INFO
- A C expression that evaluates to true if the target requires unwind
- info to be given comdat linkage. Define it to be `1' if comdat
- linkage is necessary. The default is `0'.
-
-\1f
-File: gccint.info, Node: Stack Checking, Next: Frame Registers, Prev: Exception Handling, Up: Stack and Calling
-
-17.10.3 Specifying How Stack Checking is Done
----------------------------------------------
-
-GCC will check that stack references are within the boundaries of the
-stack, if the option `-fstack-check' is specified, in one of three ways:
-
- 1. If the value of the `STACK_CHECK_BUILTIN' macro is nonzero, GCC
- will assume that you have arranged for full stack checking to be
- done at appropriate places in the configuration files. GCC will
- not do other special processing.
-
- 2. If `STACK_CHECK_BUILTIN' is zero and the value of the
- `STACK_CHECK_STATIC_BUILTIN' macro is nonzero, GCC will assume
- that you have arranged for static stack checking (checking of the
- static stack frame of functions) to be done at appropriate places
- in the configuration files. GCC will only emit code to do dynamic
- stack checking (checking on dynamic stack allocations) using the
- third approach below.
-
- 3. If neither of the above are true, GCC will generate code to
- periodically "probe" the stack pointer using the values of the
- macros defined below.
-
- If neither STACK_CHECK_BUILTIN nor STACK_CHECK_STATIC_BUILTIN is
-defined, GCC will change its allocation strategy for large objects if
-the option `-fstack-check' is specified: they will always be allocated
-dynamically if their size exceeds `STACK_CHECK_MAX_VAR_SIZE' bytes.
-
- -- Macro: STACK_CHECK_BUILTIN
- A nonzero value if stack checking is done by the configuration
- files in a machine-dependent manner. You should define this macro
- if stack checking is require by the ABI of your machine or if you
- would like to do stack checking in some more efficient way than
- the generic approach. The default value of this macro is zero.
-
- -- Macro: STACK_CHECK_STATIC_BUILTIN
- A nonzero value if static stack checking is done by the
- configuration files in a machine-dependent manner. You should
- define this macro if you would like to do static stack checking in
- some more efficient way than the generic approach. The default
- value of this macro is zero.
-
- -- Macro: STACK_CHECK_PROBE_INTERVAL
- An integer representing the interval at which GCC must generate
- stack probe instructions. You will normally define this macro to
- be no larger than the size of the "guard pages" at the end of a
- stack area. The default value of 4096 is suitable for most
- systems.
-
- -- Macro: STACK_CHECK_PROBE_LOAD
- An integer which is nonzero if GCC should perform the stack probe
- as a load instruction and zero if GCC should use a store
- instruction. The default is zero, which is the most efficient
- choice on most systems.
-
- -- Macro: STACK_CHECK_PROTECT
- The number of bytes of stack needed to recover from a stack
- overflow, for languages where such a recovery is supported. The
- default value of 75 words should be adequate for most machines.
-
- The following macros are relevant only if neither STACK_CHECK_BUILTIN
-nor STACK_CHECK_STATIC_BUILTIN is defined; you can omit them altogether
-in the opposite case.
-
- -- Macro: STACK_CHECK_MAX_FRAME_SIZE
- The maximum size of a stack frame, in bytes. GCC will generate
- probe instructions in non-leaf functions to ensure at least this
- many bytes of stack are available. If a stack frame is larger
- than this size, stack checking will not be reliable and GCC will
- issue a warning. The default is chosen so that GCC only generates
- one instruction on most systems. You should normally not change
- the default value of this macro.
-
- -- Macro: STACK_CHECK_FIXED_FRAME_SIZE
- GCC uses this value to generate the above warning message. It
- represents the amount of fixed frame used by a function, not
- including space for any callee-saved registers, temporaries and
- user variables. You need only specify an upper bound for this
- amount and will normally use the default of four words.
-
- -- Macro: STACK_CHECK_MAX_VAR_SIZE
- The maximum size, in bytes, of an object that GCC will place in the
- fixed area of the stack frame when the user specifies
- `-fstack-check'. GCC computed the default from the values of the
- above macros and you will normally not need to override that
- default.
-
-\1f
-File: gccint.info, Node: Frame Registers, Next: Elimination, Prev: Stack Checking, Up: Stack and Calling
-
-17.10.4 Registers That Address the Stack Frame
-----------------------------------------------
-
-This discusses registers that address the stack frame.
-
- -- Macro: STACK_POINTER_REGNUM
- The register number of the stack pointer register, which must also
- be a fixed register according to `FIXED_REGISTERS'. On most
- machines, the hardware determines which register this is.
-
- -- Macro: FRAME_POINTER_REGNUM
- The register number of the frame pointer register, which is used to
- access automatic variables in the stack frame. On some machines,
- the hardware determines which register this is. On other
- machines, you can choose any register you wish for this purpose.
-
- -- Macro: HARD_FRAME_POINTER_REGNUM
- On some machines the offset between the frame pointer and starting
- offset of the automatic variables is not known until after register
- allocation has been done (for example, because the saved registers
- are between these two locations). On those machines, define
- `FRAME_POINTER_REGNUM' the number of a special, fixed register to
- be used internally until the offset is known, and define
- `HARD_FRAME_POINTER_REGNUM' to be the actual hard register number
- used for the frame pointer.
-
- You should define this macro only in the very rare circumstances
- when it is not possible to calculate the offset between the frame
- pointer and the automatic variables until after register
- allocation has been completed. When this macro is defined, you
- must also indicate in your definition of `ELIMINABLE_REGS' how to
- eliminate `FRAME_POINTER_REGNUM' into either
- `HARD_FRAME_POINTER_REGNUM' or `STACK_POINTER_REGNUM'.
-
- Do not define this macro if it would be the same as
- `FRAME_POINTER_REGNUM'.
-
- -- Macro: ARG_POINTER_REGNUM
- The register number of the arg pointer register, which is used to
- access the function's argument list. On some machines, this is
- the same as the frame pointer register. On some machines, the
- hardware determines which register this is. On other machines,
- you can choose any register you wish for this purpose. If this is
- not the same register as the frame pointer register, then you must
- mark it as a fixed register according to `FIXED_REGISTERS', or
- arrange to be able to eliminate it (*note Elimination::).
-
- -- Macro: RETURN_ADDRESS_POINTER_REGNUM
- The register number of the return address pointer register, which
- is used to access the current function's return address from the
- stack. On some machines, the return address is not at a fixed
- offset from the frame pointer or stack pointer or argument
- pointer. This register can be defined to point to the return
- address on the stack, and then be converted by `ELIMINABLE_REGS'
- into either the frame pointer or stack pointer.
-
- Do not define this macro unless there is no other way to get the
- return address from the stack.
-
- -- Macro: STATIC_CHAIN_REGNUM
- -- Macro: STATIC_CHAIN_INCOMING_REGNUM
- Register numbers used for passing a function's static chain
- pointer. If register windows are used, the register number as
- seen by the called function is `STATIC_CHAIN_INCOMING_REGNUM',
- while the register number as seen by the calling function is
- `STATIC_CHAIN_REGNUM'. If these registers are the same,
- `STATIC_CHAIN_INCOMING_REGNUM' need not be defined.
-
- The static chain register need not be a fixed register.
-
- If the static chain is passed in memory, these macros should not be
- defined; instead, the next two macros should be defined.
-
- -- Macro: STATIC_CHAIN
- -- Macro: STATIC_CHAIN_INCOMING
- If the static chain is passed in memory, these macros provide rtx
- giving `mem' expressions that denote where they are stored.
- `STATIC_CHAIN' and `STATIC_CHAIN_INCOMING' give the locations as
- seen by the calling and called functions, respectively. Often the
- former will be at an offset from the stack pointer and the latter
- at an offset from the frame pointer.
-
- The variables `stack_pointer_rtx', `frame_pointer_rtx', and
- `arg_pointer_rtx' will have been initialized prior to the use of
- these macros and should be used to refer to those items.
-
- If the static chain is passed in a register, the two previous
- macros should be defined instead.
-
- -- Macro: DWARF_FRAME_REGISTERS
- This macro specifies the maximum number of hard registers that can
- be saved in a call frame. This is used to size data structures
- used in DWARF2 exception handling.
-
- Prior to GCC 3.0, this macro was needed in order to establish a
- stable exception handling ABI in the face of adding new hard
- registers for ISA extensions. In GCC 3.0 and later, the EH ABI is
- insulated from changes in the number of hard registers.
- Nevertheless, this macro can still be used to reduce the runtime
- memory requirements of the exception handling routines, which can
- be substantial if the ISA contains a lot of registers that are not
- call-saved.
-
- If this macro is not defined, it defaults to
- `FIRST_PSEUDO_REGISTER'.
-
- -- Macro: PRE_GCC3_DWARF_FRAME_REGISTERS
- This macro is similar to `DWARF_FRAME_REGISTERS', but is provided
- for backward compatibility in pre GCC 3.0 compiled code.
-
- If this macro is not defined, it defaults to
- `DWARF_FRAME_REGISTERS'.
-
- -- Macro: DWARF_REG_TO_UNWIND_COLUMN (REGNO)
- Define this macro if the target's representation for dwarf
- registers is different than the internal representation for unwind
- column. Given a dwarf register, this macro should return the
- internal unwind column number to use instead.
-
- See the PowerPC's SPE target for an example.
-
- -- Macro: DWARF_FRAME_REGNUM (REGNO)
- Define this macro if the target's representation for dwarf
- registers used in .eh_frame or .debug_frame is different from that
- used in other debug info sections. Given a GCC hard register
- number, this macro should return the .eh_frame register number.
- The default is `DBX_REGISTER_NUMBER (REGNO)'.
-
-
- -- Macro: DWARF2_FRAME_REG_OUT (REGNO, FOR_EH)
- Define this macro to map register numbers held in the call frame
- info that GCC has collected using `DWARF_FRAME_REGNUM' to those
- that should be output in .debug_frame (`FOR_EH' is zero) and
- .eh_frame (`FOR_EH' is nonzero). The default is to return `REGNO'.
-
-
-\1f
-File: gccint.info, Node: Elimination, Next: Stack Arguments, Prev: Frame Registers, Up: Stack and Calling
-
-17.10.5 Eliminating Frame Pointer and Arg Pointer
--------------------------------------------------
-
-This is about eliminating the frame pointer and arg pointer.
-
- -- Macro: FRAME_POINTER_REQUIRED
- A C expression which is nonzero if a function must have and use a
- frame pointer. This expression is evaluated in the reload pass.
- If its value is nonzero the function will have a frame pointer.
-
- The expression can in principle examine the current function and
- decide according to the facts, but on most machines the constant 0
- or the constant 1 suffices. Use 0 when the machine allows code to
- be generated with no frame pointer, and doing so saves some time
- or space. Use 1 when there is no possible advantage to avoiding a
- frame pointer.
-
- In certain cases, the compiler does not know how to produce valid
- code without a frame pointer. The compiler recognizes those cases
- and automatically gives the function a frame pointer regardless of
- what `FRAME_POINTER_REQUIRED' says. You don't need to worry about
- them.
-
- In a function that does not require a frame pointer, the frame
- pointer register can be allocated for ordinary usage, unless you
- mark it as a fixed register. See `FIXED_REGISTERS' for more
- information.
-
- -- Macro: INITIAL_FRAME_POINTER_OFFSET (DEPTH-VAR)
- A C statement to store in the variable DEPTH-VAR the difference
- between the frame pointer and the stack pointer values immediately
- after the function prologue. The value would be computed from
- information such as the result of `get_frame_size ()' and the
- tables of registers `regs_ever_live' and `call_used_regs'.
-
- If `ELIMINABLE_REGS' is defined, this macro will be not be used and
- need not be defined. Otherwise, it must be defined even if
- `FRAME_POINTER_REQUIRED' is defined to always be true; in that
- case, you may set DEPTH-VAR to anything.
-
- -- Macro: ELIMINABLE_REGS
- If defined, this macro specifies a table of register pairs used to
- eliminate unneeded registers that point into the stack frame. If
- it is not defined, the only elimination attempted by the compiler
- is to replace references to the frame pointer with references to
- the stack pointer.
-
- The definition of this macro is a list of structure
- initializations, each of which specifies an original and
- replacement register.
-
- On some machines, the position of the argument pointer is not
- known until the compilation is completed. In such a case, a
- separate hard register must be used for the argument pointer.
- This register can be eliminated by replacing it with either the
- frame pointer or the argument pointer, depending on whether or not
- the frame pointer has been eliminated.
-
- In this case, you might specify:
- #define ELIMINABLE_REGS \
- {{ARG_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
- {ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM}, \
- {FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}}
-
- Note that the elimination of the argument pointer with the stack
- pointer is specified first since that is the preferred elimination.
-
- -- Macro: CAN_ELIMINATE (FROM-REG, TO-REG)
- A C expression that returns nonzero if the compiler is allowed to
- try to replace register number FROM-REG with register number
- TO-REG. This macro need only be defined if `ELIMINABLE_REGS' is
- defined, and will usually be the constant 1, since most of the
- cases preventing register elimination are things that the compiler
- already knows about.
-
- -- Macro: INITIAL_ELIMINATION_OFFSET (FROM-REG, TO-REG, OFFSET-VAR)
- This macro is similar to `INITIAL_FRAME_POINTER_OFFSET'. It
- specifies the initial difference between the specified pair of
- registers. This macro must be defined if `ELIMINABLE_REGS' is
- defined.
-
-\1f
-File: gccint.info, Node: Stack Arguments, Next: Register Arguments, Prev: Elimination, Up: Stack and Calling
-
-17.10.6 Passing Function Arguments on the Stack
------------------------------------------------
-
-The macros in this section control how arguments are passed on the
-stack. See the following section for other macros that control passing
-certain arguments in registers.
-
- -- Target Hook: bool TARGET_PROMOTE_PROTOTYPES (tree FNTYPE)
- This target hook returns `true' if an argument declared in a
- prototype as an integral type smaller than `int' should actually be
- passed as an `int'. In addition to avoiding errors in certain
- cases of mismatch, it also makes for better code on certain
- machines. The default is to not promote prototypes.
-
- -- Macro: PUSH_ARGS
- A C expression. If nonzero, push insns will be used to pass
- outgoing arguments. If the target machine does not have a push
- instruction, set it to zero. That directs GCC to use an alternate
- strategy: to allocate the entire argument block and then store the
- arguments into it. When `PUSH_ARGS' is nonzero, `PUSH_ROUNDING'
- must be defined too.
-
- -- Macro: PUSH_ARGS_REVERSED
- A C expression. If nonzero, function arguments will be evaluated
- from last to first, rather than from first to last. If this macro
- is not defined, it defaults to `PUSH_ARGS' on targets where the
- stack and args grow in opposite directions, and 0 otherwise.
-
- -- Macro: PUSH_ROUNDING (NPUSHED)
- A C expression that is the number of bytes actually pushed onto the
- stack when an instruction attempts to push NPUSHED bytes.
-
- On some machines, the definition
-
- #define PUSH_ROUNDING(BYTES) (BYTES)
-
- will suffice. But on other machines, instructions that appear to
- push one byte actually push two bytes in an attempt to maintain
- alignment. Then the definition should be
-
- #define PUSH_ROUNDING(BYTES) (((BYTES) + 1) & ~1)
-
- -- Macro: ACCUMULATE_OUTGOING_ARGS
- A C expression. If nonzero, the maximum amount of space required
- for outgoing arguments will be computed and placed into the
- variable `current_function_outgoing_args_size'. No space will be
- pushed onto the stack for each call; instead, the function
- prologue should increase the stack frame size by this amount.
-
- Setting both `PUSH_ARGS' and `ACCUMULATE_OUTGOING_ARGS' is not
- proper.
-
- -- Macro: REG_PARM_STACK_SPACE (FNDECL)
- Define this macro if functions should assume that stack space has
- been allocated for arguments even when their values are passed in
- registers.
-
- The value of this macro is the size, in bytes, of the area
- reserved for arguments passed in registers for the function
- represented by FNDECL, which can be zero if GCC is calling a
- library function. The argument FNDECL can be the FUNCTION_DECL,
- or the type itself of the function.
-
- This space can be allocated by the caller, or be a part of the
- machine-dependent stack frame: `OUTGOING_REG_PARM_STACK_SPACE' says
- which.
-
- -- Macro: OUTGOING_REG_PARM_STACK_SPACE (FNTYPE)
- Define this to a nonzero value if it is the responsibility of the
- caller to allocate the area reserved for arguments passed in
- registers when calling a function of FNTYPE. FNTYPE may be NULL
- if the function called is a library function.
-
- If `ACCUMULATE_OUTGOING_ARGS' is defined, this macro controls
- whether the space for these arguments counts in the value of
- `current_function_outgoing_args_size'.
-
- -- Macro: STACK_PARMS_IN_REG_PARM_AREA
- Define this macro if `REG_PARM_STACK_SPACE' is defined, but the
- stack parameters don't skip the area specified by it.
-
- Normally, when a parameter is not passed in registers, it is
- placed on the stack beyond the `REG_PARM_STACK_SPACE' area.
- Defining this macro suppresses this behavior and causes the
- parameter to be passed on the stack in its natural location.
-
- -- Macro: RETURN_POPS_ARGS (FUNDECL, FUNTYPE, STACK-SIZE)
- A C expression that should indicate the number of bytes of its own
- arguments that a function pops on returning, or 0 if the function
- pops no arguments and the caller must therefore pop them all after
- the function returns.
-
- FUNDECL is a C variable whose value is a tree node that describes
- the function in question. Normally it is a node of type
- `FUNCTION_DECL' that describes the declaration of the function.
- From this you can obtain the `DECL_ATTRIBUTES' of the function.
-
- FUNTYPE is a C variable whose value is a tree node that describes
- the function in question. Normally it is a node of type
- `FUNCTION_TYPE' that describes the data type of the function.
- From this it is possible to obtain the data types of the value and
- arguments (if known).
-
- When a call to a library function is being considered, FUNDECL
- will contain an identifier node for the library function. Thus, if
- you need to distinguish among various library functions, you can
- do so by their names. Note that "library function" in this
- context means a function used to perform arithmetic, whose name is
- known specially in the compiler and was not mentioned in the C
- code being compiled.
-
- STACK-SIZE is the number of bytes of arguments passed on the
- stack. If a variable number of bytes is passed, it is zero, and
- argument popping will always be the responsibility of the calling
- function.
-
- On the VAX, all functions always pop their arguments, so the
- definition of this macro is STACK-SIZE. On the 68000, using the
- standard calling convention, no functions pop their arguments, so
- the value of the macro is always 0 in this case. But an
- alternative calling convention is available in which functions
- that take a fixed number of arguments pop them but other functions
- (such as `printf') pop nothing (the caller pops all). When this
- convention is in use, FUNTYPE is examined to determine whether a
- function takes a fixed number of arguments.
-
- -- Macro: CALL_POPS_ARGS (CUM)
- A C expression that should indicate the number of bytes a call
- sequence pops off the stack. It is added to the value of
- `RETURN_POPS_ARGS' when compiling a function call.
-
- CUM is the variable in which all arguments to the called function
- have been accumulated.
-
- On certain architectures, such as the SH5, a call trampoline is
- used that pops certain registers off the stack, depending on the
- arguments that have been passed to the function. Since this is a
- property of the call site, not of the called function,
- `RETURN_POPS_ARGS' is not appropriate.
-
-\1f
-File: gccint.info, Node: Register Arguments, Next: Scalar Return, Prev: Stack Arguments, Up: Stack and Calling
-
-17.10.7 Passing Arguments in Registers
---------------------------------------
-
-This section describes the macros which let you control how various
-types of arguments are passed in registers or how they are arranged in
-the stack.
-
- -- Macro: FUNCTION_ARG (CUM, MODE, TYPE, NAMED)
- A C expression that controls whether a function argument is passed
- in a register, and which register.
-
- The arguments are CUM, which summarizes all the previous
- arguments; MODE, the machine mode of the argument; TYPE, the data
- type of the argument as a tree node or 0 if that is not known
- (which happens for C support library functions); and NAMED, which
- is 1 for an ordinary argument and 0 for nameless arguments that
- correspond to `...' in the called function's prototype. TYPE can
- be an incomplete type if a syntax error has previously occurred.
-
- The value of the expression is usually either a `reg' RTX for the
- hard register in which to pass the argument, or zero to pass the
- argument on the stack.
-
- For machines like the VAX and 68000, where normally all arguments
- are pushed, zero suffices as a definition.
-
- The value of the expression can also be a `parallel' RTX. This is
- used when an argument is passed in multiple locations. The mode
- of the `parallel' should be the mode of the entire argument. The
- `parallel' holds any number of `expr_list' pairs; each one
- describes where part of the argument is passed. In each
- `expr_list' the first operand must be a `reg' RTX for the hard
- register in which to pass this part of the argument, and the mode
- of the register RTX indicates how large this part of the argument
- is. The second operand of the `expr_list' is a `const_int' which
- gives the offset in bytes into the entire argument of where this
- part starts. As a special exception the first `expr_list' in the
- `parallel' RTX may have a first operand of zero. This indicates
- that the entire argument is also stored on the stack.
-
- The last time this macro is called, it is called with `MODE ==
- VOIDmode', and its result is passed to the `call' or `call_value'
- pattern as operands 2 and 3 respectively.
-
- The usual way to make the ISO library `stdarg.h' work on a machine
- where some arguments are usually passed in registers, is to cause
- nameless arguments to be passed on the stack instead. This is done
- by making `FUNCTION_ARG' return 0 whenever NAMED is 0.
-
- You may use the hook `targetm.calls.must_pass_in_stack' in the
- definition of this macro to determine if this argument is of a
- type that must be passed in the stack. If `REG_PARM_STACK_SPACE'
- is not defined and `FUNCTION_ARG' returns nonzero for such an
- argument, the compiler will abort. If `REG_PARM_STACK_SPACE' is
- defined, the argument will be computed in the stack and then
- loaded into a register.
-
- -- Target Hook: bool TARGET_MUST_PASS_IN_STACK (enum machine_mode
- MODE, tree TYPE)
- This target hook should return `true' if we should not pass TYPE
- solely in registers. The file `expr.h' defines a definition that
- is usually appropriate, refer to `expr.h' for additional
- documentation.
-
- -- Macro: FUNCTION_INCOMING_ARG (CUM, MODE, TYPE, NAMED)
- Define this macro if the target machine has "register windows", so
- that the register in which a function sees an arguments is not
- necessarily the same as the one in which the caller passed the
- argument.
-
- For such machines, `FUNCTION_ARG' computes the register in which
- the caller passes the value, and `FUNCTION_INCOMING_ARG' should be
- defined in a similar fashion to tell the function being called
- where the arguments will arrive.
-
- If `FUNCTION_INCOMING_ARG' is not defined, `FUNCTION_ARG' serves
- both purposes.
-
- -- Target Hook: int TARGET_ARG_PARTIAL_BYTES (CUMULATIVE_ARGS *CUM,
- enum machine_mode MODE, tree TYPE, bool NAMED)
- This target hook returns the number of bytes at the beginning of an
- argument that must be put in registers. The value must be zero for
- arguments that are passed entirely in registers or that are
- entirely pushed on the stack.
-
- On some machines, certain arguments must be passed partially in
- registers and partially in memory. On these machines, typically
- the first few words of arguments are passed in registers, and the
- rest on the stack. If a multi-word argument (a `double' or a
- structure) crosses that boundary, its first few words must be
- passed in registers and the rest must be pushed. This macro tells
- the compiler when this occurs, and how many bytes should go in
- registers.
-
- `FUNCTION_ARG' for these arguments should return the first
- register to be used by the caller for this argument; likewise
- `FUNCTION_INCOMING_ARG', for the called function.
-
- -- Target Hook: bool TARGET_PASS_BY_REFERENCE (CUMULATIVE_ARGS *CUM,
- enum machine_mode MODE, tree TYPE, bool NAMED)
- This target hook should return `true' if an argument at the
- position indicated by CUM should be passed by reference. This
- predicate is queried after target independent reasons for being
- passed by reference, such as `TREE_ADDRESSABLE (type)'.
-
- If the hook returns true, a copy of that argument is made in
- memory and a pointer to the argument is passed instead of the
- argument itself. The pointer is passed in whatever way is
- appropriate for passing a pointer to that type.
-
- -- Target Hook: bool TARGET_CALLEE_COPIES (CUMULATIVE_ARGS *CUM, enum
- machine_mode MODE, tree TYPE, bool NAMED)
- The function argument described by the parameters to this hook is
- known to be passed by reference. The hook should return true if
- the function argument should be copied by the callee instead of
- copied by the caller.
-
- For any argument for which the hook returns true, if it can be
- determined that the argument is not modified, then a copy need not
- be generated.
-
- The default version of this hook always returns false.
-
- -- Macro: CUMULATIVE_ARGS
- A C type for declaring a variable that is used as the first
- argument of `FUNCTION_ARG' and other related values. For some
- target machines, the type `int' suffices and can hold the number
- of bytes of argument so far.
-
- There is no need to record in `CUMULATIVE_ARGS' anything about the
- arguments that have been passed on the stack. The compiler has
- other variables to keep track of that. For target machines on
- which all arguments are passed on the stack, there is no need to
- store anything in `CUMULATIVE_ARGS'; however, the data structure
- must exist and should not be empty, so use `int'.
-
- -- Macro: OVERRIDE_ABI_FORMAT (FNDECL)
- If defined, this macro is called before generating any code for a
- function, but after the CFUN descriptor for the function has been
- created. The back end may use this macro to update CFUN to
- reflect an ABI other than that which would normally be used by
- default. If the compiler is generating code for a
- compiler-generated function, FNDECL may be `NULL'.
-
- -- Macro: INIT_CUMULATIVE_ARGS (CUM, FNTYPE, LIBNAME, FNDECL,
- N_NAMED_ARGS)
- A C statement (sans semicolon) for initializing the variable CUM
- for the state at the beginning of the argument list. The variable
- has type `CUMULATIVE_ARGS'. The value of FNTYPE is the tree node
- for the data type of the function which will receive the args, or
- 0 if the args are to a compiler support library function. For
- direct calls that are not libcalls, FNDECL contain the declaration
- node of the function. FNDECL is also set when
- `INIT_CUMULATIVE_ARGS' is used to find arguments for the function
- being compiled. N_NAMED_ARGS is set to the number of named
- arguments, including a structure return address if it is passed as
- a parameter, when making a call. When processing incoming
- arguments, N_NAMED_ARGS is set to -1.
-
- When processing a call to a compiler support library function,
- LIBNAME identifies which one. It is a `symbol_ref' rtx which
- contains the name of the function, as a string. LIBNAME is 0 when
- an ordinary C function call is being processed. Thus, each time
- this macro is called, either LIBNAME or FNTYPE is nonzero, but
- never both of them at once.
-
- -- Macro: INIT_CUMULATIVE_LIBCALL_ARGS (CUM, MODE, LIBNAME)
- Like `INIT_CUMULATIVE_ARGS' but only used for outgoing libcalls,
- it gets a `MODE' argument instead of FNTYPE, that would be `NULL'.
- INDIRECT would always be zero, too. If this macro is not defined,
- `INIT_CUMULATIVE_ARGS (cum, NULL_RTX, libname, 0)' is used instead.
-
- -- Macro: INIT_CUMULATIVE_INCOMING_ARGS (CUM, FNTYPE, LIBNAME)
- Like `INIT_CUMULATIVE_ARGS' but overrides it for the purposes of
- finding the arguments for the function being compiled. If this
- macro is undefined, `INIT_CUMULATIVE_ARGS' is used instead.
-
- The value passed for LIBNAME is always 0, since library routines
- with special calling conventions are never compiled with GCC. The
- argument LIBNAME exists for symmetry with `INIT_CUMULATIVE_ARGS'.
-
- -- Macro: FUNCTION_ARG_ADVANCE (CUM, MODE, TYPE, NAMED)
- A C statement (sans semicolon) to update the summarizer variable
- CUM to advance past an argument in the argument list. The values
- MODE, TYPE and NAMED describe that argument. Once this is done,
- the variable CUM is suitable for analyzing the _following_
- argument with `FUNCTION_ARG', etc.
-
- This macro need not do anything if the argument in question was
- passed on the stack. The compiler knows how to track the amount
- of stack space used for arguments without any special help.
-
- -- Macro: FUNCTION_ARG_OFFSET (MODE, TYPE)
- If defined, a C expression that is the number of bytes to add to
- the offset of the argument passed in memory. This is needed for
- the SPU, which passes `char' and `short' arguments in the preferred
- slot that is in the middle of the quad word instead of starting at
- the top.
-
- -- Macro: FUNCTION_ARG_PADDING (MODE, TYPE)
- If defined, a C expression which determines whether, and in which
- direction, to pad out an argument with extra space. The value
- should be of type `enum direction': either `upward' to pad above
- the argument, `downward' to pad below, or `none' to inhibit
- padding.
-
- The _amount_ of padding is always just enough to reach the next
- multiple of `FUNCTION_ARG_BOUNDARY'; this macro does not control
- it.
-
- This macro has a default definition which is right for most
- systems. For little-endian machines, the default is to pad
- upward. For big-endian machines, the default is to pad downward
- for an argument of constant size shorter than an `int', and upward
- otherwise.
-
- -- Macro: PAD_VARARGS_DOWN
- If defined, a C expression which determines whether the default
- implementation of va_arg will attempt to pad down before reading
- the next argument, if that argument is smaller than its aligned
- space as controlled by `PARM_BOUNDARY'. If this macro is not
- defined, all such arguments are padded down if `BYTES_BIG_ENDIAN'
- is true.
-
- -- Macro: BLOCK_REG_PADDING (MODE, TYPE, FIRST)
- Specify padding for the last element of a block move between
- registers and memory. FIRST is nonzero if this is the only
- element. Defining this macro allows better control of register
- function parameters on big-endian machines, without using
- `PARALLEL' rtl. In particular, `MUST_PASS_IN_STACK' need not test
- padding and mode of types in registers, as there is no longer a
- "wrong" part of a register; For example, a three byte aggregate
- may be passed in the high part of a register if so required.
-
- -- Macro: FUNCTION_ARG_BOUNDARY (MODE, TYPE)
- If defined, a C expression that gives the alignment boundary, in
- bits, of an argument with the specified mode and type. If it is
- not defined, `PARM_BOUNDARY' is used for all arguments.
-
- -- Macro: FUNCTION_ARG_REGNO_P (REGNO)
- A C expression that is nonzero if REGNO is the number of a hard
- register in which function arguments are sometimes passed. This
- does _not_ include implicit arguments such as the static chain and
- the structure-value address. On many machines, no registers can be
- used for this purpose since all function arguments are pushed on
- the stack.
-
- -- Target Hook: bool TARGET_SPLIT_COMPLEX_ARG (tree TYPE)
- This hook should return true if parameter of type TYPE are passed
- as two scalar parameters. By default, GCC will attempt to pack
- complex arguments into the target's word size. Some ABIs require
- complex arguments to be split and treated as their individual
- components. For example, on AIX64, complex floats should be
- passed in a pair of floating point registers, even though a
- complex float would fit in one 64-bit floating point register.
-
- The default value of this hook is `NULL', which is treated as
- always false.
-
- -- Target Hook: tree TARGET_BUILD_BUILTIN_VA_LIST (void)
- This hook returns a type node for `va_list' for the target. The
- default version of the hook returns `void*'.
-
- -- Target Hook: tree TARGET_FN_ABI_VA_LIST (tree FNDECL)
- This hook returns the va_list type of the calling convention
- specified by FNDECL. The default version of this hook returns
- `va_list_type_node'.
-
- -- Target Hook: tree TARGET_CANONICAL_VA_LIST_TYPE (tree TYPE)
- This hook returns the va_list type of the calling convention
- specified by the type of TYPE. If TYPE is not a valid va_list
- type, it returns `NULL_TREE'.
-
- -- Target Hook: tree TARGET_GIMPLIFY_VA_ARG_EXPR (tree VALIST, tree
- TYPE, tree *PRE_P, tree *POST_P)
- This hook performs target-specific gimplification of
- `VA_ARG_EXPR'. The first two parameters correspond to the
- arguments to `va_arg'; the latter two are as in
- `gimplify.c:gimplify_expr'.
-
- -- Target Hook: bool TARGET_VALID_POINTER_MODE (enum machine_mode MODE)
- Define this to return nonzero if the port can handle pointers with
- machine mode MODE. The default version of this hook returns true
- for both `ptr_mode' and `Pmode'.
-
- -- Target Hook: bool TARGET_SCALAR_MODE_SUPPORTED_P (enum machine_mode
- MODE)
- Define this to return nonzero if the port is prepared to handle
- insns involving scalar mode MODE. For a scalar mode to be
- considered supported, all the basic arithmetic and comparisons
- must work.
-
- The default version of this hook returns true for any mode
- required to handle the basic C types (as defined by the port).
- Included here are the double-word arithmetic supported by the code
- in `optabs.c'.
-
- -- Target Hook: bool TARGET_VECTOR_MODE_SUPPORTED_P (enum machine_mode
- MODE)
- Define this to return nonzero if the port is prepared to handle
- insns involving vector mode MODE. At the very least, it must have
- move patterns for this mode.
-
-\1f
-File: gccint.info, Node: Scalar Return, Next: Aggregate Return, Prev: Register Arguments, Up: Stack and Calling
-
-17.10.8 How Scalar Function Values Are Returned
------------------------------------------------
-
-This section discusses the macros that control returning scalars as
-values--values that can fit in registers.
-
- -- Target Hook: rtx TARGET_FUNCTION_VALUE (tree RET_TYPE, tree
- FN_DECL_OR_TYPE, bool OUTGOING)
- Define this to return an RTX representing the place where a
- function returns or receives a value of data type RET_TYPE, a tree
- node node representing a data type. FN_DECL_OR_TYPE is a tree node
- representing `FUNCTION_DECL' or `FUNCTION_TYPE' of a function
- being called. If OUTGOING is false, the hook should compute the
- register in which the caller will see the return value.
- Otherwise, the hook should return an RTX representing the place
- where a function returns a value.
-
- On many machines, only `TYPE_MODE (RET_TYPE)' is relevant.
- (Actually, on most machines, scalar values are returned in the same
- place regardless of mode.) The value of the expression is usually
- a `reg' RTX for the hard register where the return value is stored.
- The value can also be a `parallel' RTX, if the return value is in
- multiple places. See `FUNCTION_ARG' for an explanation of the
- `parallel' form. Note that the callee will populate every
- location specified in the `parallel', but if the first element of
- the `parallel' contains the whole return value, callers will use
- that element as the canonical location and ignore the others. The
- m68k port uses this type of `parallel' to return pointers in both
- `%a0' (the canonical location) and `%d0'.
-
- If `TARGET_PROMOTE_FUNCTION_RETURN' returns true, you must apply
- the same promotion rules specified in `PROMOTE_MODE' if VALTYPE is
- a scalar type.
-
- If the precise function being called is known, FUNC is a tree node
- (`FUNCTION_DECL') for it; otherwise, FUNC is a null pointer. This
- makes it possible to use a different value-returning convention
- for specific functions when all their calls are known.
-
- Some target machines have "register windows" so that the register
- in which a function returns its value is not the same as the one
- in which the caller sees the value. For such machines, you should
- return different RTX depending on OUTGOING.
-
- `TARGET_FUNCTION_VALUE' is not used for return values with
- aggregate data types, because these are returned in another way.
- See `TARGET_STRUCT_VALUE_RTX' and related macros, below.
-
- -- Macro: FUNCTION_VALUE (VALTYPE, FUNC)
- This macro has been deprecated. Use `TARGET_FUNCTION_VALUE' for a
- new target instead.
-
- -- Macro: FUNCTION_OUTGOING_VALUE (VALTYPE, FUNC)
- This macro has been deprecated. Use `TARGET_FUNCTION_VALUE' for a
- new target instead.
-
- -- Macro: LIBCALL_VALUE (MODE)
- A C expression to create an RTX representing the place where a
- library function returns a value of mode MODE.
-
- Note that "library function" in this context means a compiler
- support routine, used to perform arithmetic, whose name is known
- specially by the compiler and was not mentioned in the C code being
- compiled.
-
- -- Macro: FUNCTION_VALUE_REGNO_P (REGNO)
- A C expression that is nonzero if REGNO is the number of a hard
- register in which the values of called function may come back.
-
- A register whose use for returning values is limited to serving as
- the second of a pair (for a value of type `double', say) need not
- be recognized by this macro. So for most machines, this definition
- suffices:
-
- #define FUNCTION_VALUE_REGNO_P(N) ((N) == 0)
-
- If the machine has register windows, so that the caller and the
- called function use different registers for the return value, this
- macro should recognize only the caller's register numbers.
-
- -- Macro: TARGET_ENUM_VA_LIST (IDX, PNAME, PTYPE)
- This target macro is used in function `c_common_nodes_and_builtins'
- to iterate through the target specific builtin types for va_list.
- The variable IDX is used as iterator. PNAME has to be a pointer to
- a `const char *' and PTYPE a pointer to a `tree' typed variable.
- The arguments PNAME and PTYPE are used to store the result of this
- macro and are set to the name of the va_list builtin type and its
- internal type. If the return value of this macro is zero, then
- there is no more element. Otherwise the IDX should be increased
- for the next call of this macro to iterate through all types.
-
- -- Macro: APPLY_RESULT_SIZE
- Define this macro if `untyped_call' and `untyped_return' need more
- space than is implied by `FUNCTION_VALUE_REGNO_P' for saving and
- restoring an arbitrary return value.
-
- -- Target Hook: bool TARGET_RETURN_IN_MSB (tree TYPE)
- This hook should return true if values of type TYPE are returned
- at the most significant end of a register (in other words, if they
- are padded at the least significant end). You can assume that TYPE
- is returned in a register; the caller is required to check this.
-
- Note that the register provided by `TARGET_FUNCTION_VALUE' must be
- able to hold the complete return value. For example, if a 1-, 2-
- or 3-byte structure is returned at the most significant end of a
- 4-byte register, `TARGET_FUNCTION_VALUE' should provide an
- `SImode' rtx.
-
-\1f
-File: gccint.info, Node: Aggregate Return, Next: Caller Saves, Prev: Scalar Return, Up: Stack and Calling
-
-17.10.9 How Large Values Are Returned
--------------------------------------
-
-When a function value's mode is `BLKmode' (and in some other cases),
-the value is not returned according to `TARGET_FUNCTION_VALUE' (*note
-Scalar Return::). Instead, the caller passes the address of a block of
-memory in which the value should be stored. This address is called the
-"structure value address".
-
- This section describes how to control returning structure values in
-memory.
-
- -- Target Hook: bool TARGET_RETURN_IN_MEMORY (tree TYPE, tree FNTYPE)
- This target hook should return a nonzero value to say to return the
- function value in memory, just as large structures are always
- returned. Here TYPE will be the data type of the value, and FNTYPE
- will be the type of the function doing the returning, or `NULL' for
- libcalls.
-
- Note that values of mode `BLKmode' must be explicitly handled by
- this function. Also, the option `-fpcc-struct-return' takes
- effect regardless of this macro. On most systems, it is possible
- to leave the hook undefined; this causes a default definition to
- be used, whose value is the constant 1 for `BLKmode' values, and 0
- otherwise.
-
- Do not use this hook to indicate that structures and unions should
- always be returned in memory. You should instead use
- `DEFAULT_PCC_STRUCT_RETURN' to indicate this.
-
- -- Macro: DEFAULT_PCC_STRUCT_RETURN
- Define this macro to be 1 if all structure and union return values
- must be in memory. Since this results in slower code, this should
- be defined only if needed for compatibility with other compilers
- or with an ABI. If you define this macro to be 0, then the
- conventions used for structure and union return values are decided
- by the `TARGET_RETURN_IN_MEMORY' target hook.
-
- If not defined, this defaults to the value 1.
-
- -- Target Hook: rtx TARGET_STRUCT_VALUE_RTX (tree FNDECL, int INCOMING)
- This target hook should return the location of the structure value
- address (normally a `mem' or `reg'), or 0 if the address is passed
- as an "invisible" first argument. Note that FNDECL may be `NULL',
- for libcalls. You do not need to define this target hook if the
- address is always passed as an "invisible" first argument.
-
- On some architectures the place where the structure value address
- is found by the called function is not the same place that the
- caller put it. This can be due to register windows, or it could
- be because the function prologue moves it to a different place.
- INCOMING is `1' or `2' when the location is needed in the context
- of the called function, and `0' in the context of the caller.
-
- If INCOMING is nonzero and the address is to be found on the
- stack, return a `mem' which refers to the frame pointer. If
- INCOMING is `2', the result is being used to fetch the structure
- value address at the beginning of a function. If you need to emit
- adjusting code, you should do it at this point.
-
- -- Macro: PCC_STATIC_STRUCT_RETURN
- Define this macro if the usual system convention on the target
- machine for returning structures and unions is for the called
- function to return the address of a static variable containing the
- value.
-
- Do not define this if the usual system convention is for the
- caller to pass an address to the subroutine.
-
- This macro has effect in `-fpcc-struct-return' mode, but it does
- nothing when you use `-freg-struct-return' mode.
-
-\1f
-File: gccint.info, Node: Caller Saves, Next: Function Entry, Prev: Aggregate Return, Up: Stack and Calling
-
-17.10.10 Caller-Saves Register Allocation
------------------------------------------
-
-If you enable it, GCC can save registers around function calls. This
-makes it possible to use call-clobbered registers to hold variables that
-must live across calls.
-
- -- Macro: CALLER_SAVE_PROFITABLE (REFS, CALLS)
- A C expression to determine whether it is worthwhile to consider
- placing a pseudo-register in a call-clobbered hard register and
- saving and restoring it around each function call. The expression
- should be 1 when this is worth doing, and 0 otherwise.
-
- If you don't define this macro, a default is used which is good on
- most machines: `4 * CALLS < REFS'.
-
- -- Macro: HARD_REGNO_CALLER_SAVE_MODE (REGNO, NREGS)
- A C expression specifying which mode is required for saving NREGS
- of a pseudo-register in call-clobbered hard register REGNO. If
- REGNO is unsuitable for caller save, `VOIDmode' should be
- returned. For most machines this macro need not be defined since
- GCC will select the smallest suitable mode.
-
-\1f
-File: gccint.info, Node: Function Entry, Next: Profiling, Prev: Caller Saves, Up: Stack and Calling
-
-17.10.11 Function Entry and Exit
---------------------------------
-
-This section describes the macros that output function entry
-("prologue") and exit ("epilogue") code.
-
- -- Target Hook: void TARGET_ASM_FUNCTION_PROLOGUE (FILE *FILE,
- HOST_WIDE_INT SIZE)
- If defined, a function that outputs the assembler code for entry
- to a function. The prologue is responsible for setting up the
- stack frame, initializing the frame pointer register, saving
- registers that must be saved, and allocating SIZE additional bytes
- of storage for the local variables. SIZE is an integer. FILE is
- a stdio stream to which the assembler code should be output.
-
- The label for the beginning of the function need not be output by
- this macro. That has already been done when the macro is run.
-
- To determine which registers to save, the macro can refer to the
- array `regs_ever_live': element R is nonzero if hard register R is
- used anywhere within the function. This implies the function
- prologue should save register R, provided it is not one of the
- call-used registers. (`TARGET_ASM_FUNCTION_EPILOGUE' must
- likewise use `regs_ever_live'.)
-
- On machines that have "register windows", the function entry code
- does not save on the stack the registers that are in the windows,
- even if they are supposed to be preserved by function calls;
- instead it takes appropriate steps to "push" the register stack,
- if any non-call-used registers are used in the function.
-
- On machines where functions may or may not have frame-pointers, the
- function entry code must vary accordingly; it must set up the frame
- pointer if one is wanted, and not otherwise. To determine whether
- a frame pointer is in wanted, the macro can refer to the variable
- `frame_pointer_needed'. The variable's value will be 1 at run
- time in a function that needs a frame pointer. *Note
- Elimination::.
-
- The function entry code is responsible for allocating any stack
- space required for the function. This stack space consists of the
- regions listed below. In most cases, these regions are allocated
- in the order listed, with the last listed region closest to the
- top of the stack (the lowest address if `STACK_GROWS_DOWNWARD' is
- defined, and the highest address if it is not defined). You can
- use a different order for a machine if doing so is more convenient
- or required for compatibility reasons. Except in cases where
- required by standard or by a debugger, there is no reason why the
- stack layout used by GCC need agree with that used by other
- compilers for a machine.
-
- -- Target Hook: void TARGET_ASM_FUNCTION_END_PROLOGUE (FILE *FILE)
- If defined, a function that outputs assembler code at the end of a
- prologue. This should be used when the function prologue is being
- emitted as RTL, and you have some extra assembler that needs to be
- emitted. *Note prologue instruction pattern::.
-
- -- Target Hook: void TARGET_ASM_FUNCTION_BEGIN_EPILOGUE (FILE *FILE)
- If defined, a function that outputs assembler code at the start of
- an epilogue. This should be used when the function epilogue is
- being emitted as RTL, and you have some extra assembler that needs
- to be emitted. *Note epilogue instruction pattern::.
-
- -- Target Hook: void TARGET_ASM_FUNCTION_EPILOGUE (FILE *FILE,
- HOST_WIDE_INT SIZE)
- If defined, a function that outputs the assembler code for exit
- from a function. The epilogue is responsible for restoring the
- saved registers and stack pointer to their values when the
- function was called, and returning control to the caller. This
- macro takes the same arguments as the macro
- `TARGET_ASM_FUNCTION_PROLOGUE', and the registers to restore are
- determined from `regs_ever_live' and `CALL_USED_REGISTERS' in the
- same way.
-
- On some machines, there is a single instruction that does all the
- work of returning from the function. On these machines, give that
- instruction the name `return' and do not define the macro
- `TARGET_ASM_FUNCTION_EPILOGUE' at all.
-
- Do not define a pattern named `return' if you want the
- `TARGET_ASM_FUNCTION_EPILOGUE' to be used. If you want the target
- switches to control whether return instructions or epilogues are
- used, define a `return' pattern with a validity condition that
- tests the target switches appropriately. If the `return'
- pattern's validity condition is false, epilogues will be used.
-
- On machines where functions may or may not have frame-pointers, the
- function exit code must vary accordingly. Sometimes the code for
- these two cases is completely different. To determine whether a
- frame pointer is wanted, the macro can refer to the variable
- `frame_pointer_needed'. The variable's value will be 1 when
- compiling a function that needs a frame pointer.
-
- Normally, `TARGET_ASM_FUNCTION_PROLOGUE' and
- `TARGET_ASM_FUNCTION_EPILOGUE' must treat leaf functions specially.
- The C variable `current_function_is_leaf' is nonzero for such a
- function. *Note Leaf Functions::.
-
- On some machines, some functions pop their arguments on exit while
- others leave that for the caller to do. For example, the 68020
- when given `-mrtd' pops arguments in functions that take a fixed
- number of arguments.
-
- Your definition of the macro `RETURN_POPS_ARGS' decides which
- functions pop their own arguments. `TARGET_ASM_FUNCTION_EPILOGUE'
- needs to know what was decided. The variable that is called
- `current_function_pops_args' is the number of bytes of its
- arguments that a function should pop. *Note Scalar Return::.
-
- * A region of `current_function_pretend_args_size' bytes of
- uninitialized space just underneath the first argument arriving on
- the stack. (This may not be at the very start of the allocated
- stack region if the calling sequence has pushed anything else
- since pushing the stack arguments. But usually, on such machines,
- nothing else has been pushed yet, because the function prologue
- itself does all the pushing.) This region is used on machines
- where an argument may be passed partly in registers and partly in
- memory, and, in some cases to support the features in `<stdarg.h>'.
-
- * An area of memory used to save certain registers used by the
- function. The size of this area, which may also include space for
- such things as the return address and pointers to previous stack
- frames, is machine-specific and usually depends on which registers
- have been used in the function. Machines with register windows
- often do not require a save area.
-
- * A region of at least SIZE bytes, possibly rounded up to an
- allocation boundary, to contain the local variables of the
- function. On some machines, this region and the save area may
- occur in the opposite order, with the save area closer to the top
- of the stack.
-
- * Optionally, when `ACCUMULATE_OUTGOING_ARGS' is defined, a region of
- `current_function_outgoing_args_size' bytes to be used for outgoing
- argument lists of the function. *Note Stack Arguments::.
-
- -- Macro: EXIT_IGNORE_STACK
- Define this macro as a C expression that is nonzero if the return
- instruction or the function epilogue ignores the value of the stack
- pointer; in other words, if it is safe to delete an instruction to
- adjust the stack pointer before a return from the function. The
- default is 0.
-
- Note that this macro's value is relevant only for functions for
- which frame pointers are maintained. It is never safe to delete a
- final stack adjustment in a function that has no frame pointer,
- and the compiler knows this regardless of `EXIT_IGNORE_STACK'.
-
- -- Macro: EPILOGUE_USES (REGNO)
- Define this macro as a C expression that is nonzero for registers
- that are used by the epilogue or the `return' pattern. The stack
- and frame pointer registers are already assumed to be used as
- needed.
-
- -- Macro: EH_USES (REGNO)
- Define this macro as a C expression that is nonzero for registers
- that are used by the exception handling mechanism, and so should
- be considered live on entry to an exception edge.
-
- -- Macro: DELAY_SLOTS_FOR_EPILOGUE
- Define this macro if the function epilogue contains delay slots to
- which instructions from the rest of the function can be "moved".
- The definition should be a C expression whose value is an integer
- representing the number of delay slots there.
-
- -- Macro: ELIGIBLE_FOR_EPILOGUE_DELAY (INSN, N)
- A C expression that returns 1 if INSN can be placed in delay slot
- number N of the epilogue.
-
- The argument N is an integer which identifies the delay slot now
- being considered (since different slots may have different rules of
- eligibility). It is never negative and is always less than the
- number of epilogue delay slots (what `DELAY_SLOTS_FOR_EPILOGUE'
- returns). If you reject a particular insn for a given delay slot,
- in principle, it may be reconsidered for a subsequent delay slot.
- Also, other insns may (at least in principle) be considered for
- the so far unfilled delay slot.
-
- The insns accepted to fill the epilogue delay slots are put in an
- RTL list made with `insn_list' objects, stored in the variable
- `current_function_epilogue_delay_list'. The insn for the first
- delay slot comes first in the list. Your definition of the macro
- `TARGET_ASM_FUNCTION_EPILOGUE' should fill the delay slots by
- outputting the insns in this list, usually by calling
- `final_scan_insn'.
-
- You need not define this macro if you did not define
- `DELAY_SLOTS_FOR_EPILOGUE'.
-
- -- Target Hook: void TARGET_ASM_OUTPUT_MI_THUNK (FILE *FILE, tree
- THUNK_FNDECL, HOST_WIDE_INT DELTA, HOST_WIDE_INT
- VCALL_OFFSET, tree FUNCTION)
- A function that outputs the assembler code for a thunk function,
- used to implement C++ virtual function calls with multiple
- inheritance. The thunk acts as a wrapper around a virtual
- function, adjusting the implicit object parameter before handing
- control off to the real function.
-
- First, emit code to add the integer DELTA to the location that
- contains the incoming first argument. Assume that this argument
- contains a pointer, and is the one used to pass the `this' pointer
- in C++. This is the incoming argument _before_ the function
- prologue, e.g. `%o0' on a sparc. The addition must preserve the
- values of all other incoming arguments.
-
- Then, if VCALL_OFFSET is nonzero, an additional adjustment should
- be made after adding `delta'. In particular, if P is the adjusted
- pointer, the following adjustment should be made:
-
- p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)]
-
- After the additions, emit code to jump to FUNCTION, which is a
- `FUNCTION_DECL'. This is a direct pure jump, not a call, and does
- not touch the return address. Hence returning from FUNCTION will
- return to whoever called the current `thunk'.
-
- The effect must be as if FUNCTION had been called directly with
- the adjusted first argument. This macro is responsible for
- emitting all of the code for a thunk function;
- `TARGET_ASM_FUNCTION_PROLOGUE' and `TARGET_ASM_FUNCTION_EPILOGUE'
- are not invoked.
-
- The THUNK_FNDECL is redundant. (DELTA and FUNCTION have already
- been extracted from it.) It might possibly be useful on some
- targets, but probably not.
-
- If you do not define this macro, the target-independent code in
- the C++ front end will generate a less efficient heavyweight thunk
- that calls FUNCTION instead of jumping to it. The generic
- approach does not support varargs.
-
- -- Target Hook: bool TARGET_ASM_CAN_OUTPUT_MI_THUNK (tree
- THUNK_FNDECL, HOST_WIDE_INT DELTA, HOST_WIDE_INT
- VCALL_OFFSET, tree FUNCTION)
- A function that returns true if TARGET_ASM_OUTPUT_MI_THUNK would
- be able to output the assembler code for the thunk function
- specified by the arguments it is passed, and false otherwise. In
- the latter case, the generic approach will be used by the C++
- front end, with the limitations previously exposed.
-
-\1f
-File: gccint.info, Node: Profiling, Next: Tail Calls, Prev: Function Entry, Up: Stack and Calling
-
-17.10.12 Generating Code for Profiling
---------------------------------------
-
-These macros will help you generate code for profiling.
-
- -- Macro: FUNCTION_PROFILER (FILE, LABELNO)
- A C statement or compound statement to output to FILE some
- assembler code to call the profiling subroutine `mcount'.
-
- The details of how `mcount' expects to be called are determined by
- your operating system environment, not by GCC. To figure them out,
- compile a small program for profiling using the system's installed
- C compiler and look at the assembler code that results.
-
- Older implementations of `mcount' expect the address of a counter
- variable to be loaded into some register. The name of this
- variable is `LP' followed by the number LABELNO, so you would
- generate the name using `LP%d' in a `fprintf'.
-
- -- Macro: PROFILE_HOOK
- A C statement or compound statement to output to FILE some assembly
- code to call the profiling subroutine `mcount' even the target does
- not support profiling.
-
- -- Macro: NO_PROFILE_COUNTERS
- Define this macro to be an expression with a nonzero value if the
- `mcount' subroutine on your system does not need a counter variable
- allocated for each function. This is true for almost all modern
- implementations. If you define this macro, you must not use the
- LABELNO argument to `FUNCTION_PROFILER'.
-
- -- Macro: PROFILE_BEFORE_PROLOGUE
- Define this macro if the code for function profiling should come
- before the function prologue. Normally, the profiling code comes
- after.
-
-\1f
-File: gccint.info, Node: Tail Calls, Next: Stack Smashing Protection, Prev: Profiling, Up: Stack and Calling
-
-17.10.13 Permitting tail calls
-------------------------------
-
- -- Target Hook: bool TARGET_FUNCTION_OK_FOR_SIBCALL (tree DECL, tree
- EXP)
- True if it is ok to do sibling call optimization for the specified
- call expression EXP. DECL will be the called function, or `NULL'
- if this is an indirect call.
-
- It is not uncommon for limitations of calling conventions to
- prevent tail calls to functions outside the current unit of
- translation, or during PIC compilation. The hook is used to
- enforce these restrictions, as the `sibcall' md pattern can not
- fail, or fall over to a "normal" call. The criteria for
- successful sibling call optimization may vary greatly between
- different architectures.
-
- -- Target Hook: void TARGET_EXTRA_LIVE_ON_ENTRY (bitmap *REGS)
- Add any hard registers to REGS that are live on entry to the
- function. This hook only needs to be defined to provide registers
- that cannot be found by examination of FUNCTION_ARG_REGNO_P, the
- callee saved registers, STATIC_CHAIN_INCOMING_REGNUM,
- STATIC_CHAIN_REGNUM, TARGET_STRUCT_VALUE_RTX,
- FRAME_POINTER_REGNUM, EH_USES, FRAME_POINTER_REGNUM,
- ARG_POINTER_REGNUM, and the PIC_OFFSET_TABLE_REGNUM.
-
-\1f
-File: gccint.info, Node: Stack Smashing Protection, Prev: Tail Calls, Up: Stack and Calling
-
-17.10.14 Stack smashing protection
-----------------------------------
-
- -- Target Hook: tree TARGET_STACK_PROTECT_GUARD (void)
- This hook returns a `DECL' node for the external variable to use
- for the stack protection guard. This variable is initialized by
- the runtime to some random value and is used to initialize the
- guard value that is placed at the top of the local stack frame.
- The type of this variable must be `ptr_type_node'.
-
- The default version of this hook creates a variable called
- `__stack_chk_guard', which is normally defined in `libgcc2.c'.
-
- -- Target Hook: tree TARGET_STACK_PROTECT_FAIL (void)
- This hook returns a tree expression that alerts the runtime that
- the stack protect guard variable has been modified. This
- expression should involve a call to a `noreturn' function.
-
- The default version of this hook invokes a function called
- `__stack_chk_fail', taking no arguments. This function is
- normally defined in `libgcc2.c'.
-
-\1f
-File: gccint.info, Node: Varargs, Next: Trampolines, Prev: Stack and Calling, Up: Target Macros
-
-17.11 Implementing the Varargs Macros
-=====================================
-
-GCC comes with an implementation of `<varargs.h>' and `<stdarg.h>' that
-work without change on machines that pass arguments on the stack.
-Other machines require their own implementations of varargs, and the
-two machine independent header files must have conditionals to include
-it.
-
- ISO `<stdarg.h>' differs from traditional `<varargs.h>' mainly in the
-calling convention for `va_start'. The traditional implementation
-takes just one argument, which is the variable in which to store the
-argument pointer. The ISO implementation of `va_start' takes an
-additional second argument. The user is supposed to write the last
-named argument of the function here.
-
- However, `va_start' should not use this argument. The way to find the
-end of the named arguments is with the built-in functions described
-below.
-
- -- Macro: __builtin_saveregs ()
- Use this built-in function to save the argument registers in
- memory so that the varargs mechanism can access them. Both ISO
- and traditional versions of `va_start' must use
- `__builtin_saveregs', unless you use
- `TARGET_SETUP_INCOMING_VARARGS' (see below) instead.
-
- On some machines, `__builtin_saveregs' is open-coded under the
- control of the target hook `TARGET_EXPAND_BUILTIN_SAVEREGS'. On
- other machines, it calls a routine written in assembler language,
- found in `libgcc2.c'.
-
- Code generated for the call to `__builtin_saveregs' appears at the
- beginning of the function, as opposed to where the call to
- `__builtin_saveregs' is written, regardless of what the code is.
- This is because the registers must be saved before the function
- starts to use them for its own purposes.
-
- -- Macro: __builtin_args_info (CATEGORY)
- Use this built-in function to find the first anonymous arguments in
- registers.
-
- In general, a machine may have several categories of registers
- used for arguments, each for a particular category of data types.
- (For example, on some machines, floating-point registers are used
- for floating-point arguments while other arguments are passed in
- the general registers.) To make non-varargs functions use the
- proper calling convention, you have defined the `CUMULATIVE_ARGS'
- data type to record how many registers in each category have been
- used so far
-
- `__builtin_args_info' accesses the same data structure of type
- `CUMULATIVE_ARGS' after the ordinary argument layout is finished
- with it, with CATEGORY specifying which word to access. Thus, the
- value indicates the first unused register in a given category.
-
- Normally, you would use `__builtin_args_info' in the implementation
- of `va_start', accessing each category just once and storing the
- value in the `va_list' object. This is because `va_list' will
- have to update the values, and there is no way to alter the values
- accessed by `__builtin_args_info'.
-
- -- Macro: __builtin_next_arg (LASTARG)
- This is the equivalent of `__builtin_args_info', for stack
- arguments. It returns the address of the first anonymous stack
- argument, as type `void *'. If `ARGS_GROW_DOWNWARD', it returns
- the address of the location above the first anonymous stack
- argument. Use it in `va_start' to initialize the pointer for
- fetching arguments from the stack. Also use it in `va_start' to
- verify that the second parameter LASTARG is the last named argument
- of the current function.
-
- -- Macro: __builtin_classify_type (OBJECT)
- Since each machine has its own conventions for which data types are
- passed in which kind of register, your implementation of `va_arg'
- has to embody these conventions. The easiest way to categorize the
- specified data type is to use `__builtin_classify_type' together
- with `sizeof' and `__alignof__'.
-
- `__builtin_classify_type' ignores the value of OBJECT, considering
- only its data type. It returns an integer describing what kind of
- type that is--integer, floating, pointer, structure, and so on.
-
- The file `typeclass.h' defines an enumeration that you can use to
- interpret the values of `__builtin_classify_type'.
-
- These machine description macros help implement varargs:
-
- -- Target Hook: rtx TARGET_EXPAND_BUILTIN_SAVEREGS (void)
- If defined, this hook produces the machine-specific code for a
- call to `__builtin_saveregs'. This code will be moved to the very
- beginning of the function, before any parameter access are made.
- The return value of this function should be an RTX that contains
- the value to use as the return of `__builtin_saveregs'.
-
- -- Target Hook: void TARGET_SETUP_INCOMING_VARARGS (CUMULATIVE_ARGS
- *ARGS_SO_FAR, enum machine_mode MODE, tree TYPE, int
- *PRETEND_ARGS_SIZE, int SECOND_TIME)
- This target hook offers an alternative to using
- `__builtin_saveregs' and defining the hook
- `TARGET_EXPAND_BUILTIN_SAVEREGS'. Use it to store the anonymous
- register arguments into the stack so that all the arguments appear
- to have been passed consecutively on the stack. Once this is
- done, you can use the standard implementation of varargs that
- works for machines that pass all their arguments on the stack.
-
- The argument ARGS_SO_FAR points to the `CUMULATIVE_ARGS' data
- structure, containing the values that are obtained after
- processing the named arguments. The arguments MODE and TYPE
- describe the last named argument--its machine mode and its data
- type as a tree node.
-
- The target hook should do two things: first, push onto the stack
- all the argument registers _not_ used for the named arguments, and
- second, store the size of the data thus pushed into the
- `int'-valued variable pointed to by PRETEND_ARGS_SIZE. The value
- that you store here will serve as additional offset for setting up
- the stack frame.
-
- Because you must generate code to push the anonymous arguments at
- compile time without knowing their data types,
- `TARGET_SETUP_INCOMING_VARARGS' is only useful on machines that
- have just a single category of argument register and use it
- uniformly for all data types.
-
- If the argument SECOND_TIME is nonzero, it means that the
- arguments of the function are being analyzed for the second time.
- This happens for an inline function, which is not actually
- compiled until the end of the source file. The hook
- `TARGET_SETUP_INCOMING_VARARGS' should not generate any
- instructions in this case.
-
- -- Target Hook: bool TARGET_STRICT_ARGUMENT_NAMING (CUMULATIVE_ARGS
- *CA)
- Define this hook to return `true' if the location where a function
- argument is passed depends on whether or not it is a named
- argument.
-
- This hook controls how the NAMED argument to `FUNCTION_ARG' is set
- for varargs and stdarg functions. If this hook returns `true',
- the NAMED argument is always true for named arguments, and false
- for unnamed arguments. If it returns `false', but
- `TARGET_PRETEND_OUTGOING_VARARGS_NAMED' returns `true', then all
- arguments are treated as named. Otherwise, all named arguments
- except the last are treated as named.
-
- You need not define this hook if it always returns zero.
-
- -- Target Hook: bool TARGET_PRETEND_OUTGOING_VARARGS_NAMED
- If you need to conditionally change ABIs so that one works with
- `TARGET_SETUP_INCOMING_VARARGS', but the other works like neither
- `TARGET_SETUP_INCOMING_VARARGS' nor
- `TARGET_STRICT_ARGUMENT_NAMING' was defined, then define this hook
- to return `true' if `TARGET_SETUP_INCOMING_VARARGS' is used,
- `false' otherwise. Otherwise, you should not define this hook.
-
-\1f
-File: gccint.info, Node: Trampolines, Next: Library Calls, Prev: Varargs, Up: Target Macros
-
-17.12 Trampolines for Nested Functions
-======================================
-
-A "trampoline" is a small piece of code that is created at run time
-when the address of a nested function is taken. It normally resides on
-the stack, in the stack frame of the containing function. These macros
-tell GCC how to generate code to allocate and initialize a trampoline.
-
- The instructions in the trampoline must do two things: load a constant
-address into the static chain register, and jump to the real address of
-the nested function. On CISC machines such as the m68k, this requires
-two instructions, a move immediate and a jump. Then the two addresses
-exist in the trampoline as word-long immediate operands. On RISC
-machines, it is often necessary to load each address into a register in
-two parts. Then pieces of each address form separate immediate
-operands.
-
- The code generated to initialize the trampoline must store the variable
-parts--the static chain value and the function address--into the
-immediate operands of the instructions. On a CISC machine, this is
-simply a matter of copying each address to a memory reference at the
-proper offset from the start of the trampoline. On a RISC machine, it
-may be necessary to take out pieces of the address and store them
-separately.
-
- -- Macro: TRAMPOLINE_TEMPLATE (FILE)
- A C statement to output, on the stream FILE, assembler code for a
- block of data that contains the constant parts of a trampoline.
- This code should not include a label--the label is taken care of
- automatically.
-
- If you do not define this macro, it means no template is needed
- for the target. Do not define this macro on systems where the
- block move code to copy the trampoline into place would be larger
- than the code to generate it on the spot.
-
- -- Macro: TRAMPOLINE_SECTION
- Return the section into which the trampoline template is to be
- placed (*note Sections::). The default value is
- `readonly_data_section'.
-
- -- Macro: TRAMPOLINE_SIZE
- A C expression for the size in bytes of the trampoline, as an
- integer.
-
- -- Macro: TRAMPOLINE_ALIGNMENT
- Alignment required for trampolines, in bits.
-
- If you don't define this macro, the value of `BIGGEST_ALIGNMENT'
- is used for aligning trampolines.
-
- -- Macro: INITIALIZE_TRAMPOLINE (ADDR, FNADDR, STATIC_CHAIN)
- A C statement to initialize the variable parts of a trampoline.
- ADDR is an RTX for the address of the trampoline; FNADDR is an RTX
- for the address of the nested function; STATIC_CHAIN is an RTX for
- the static chain value that should be passed to the function when
- it is called.
-
- -- Macro: TRAMPOLINE_ADJUST_ADDRESS (ADDR)
- A C statement that should perform any machine-specific adjustment
- in the address of the trampoline. Its argument contains the
- address that was passed to `INITIALIZE_TRAMPOLINE'. In case the
- address to be used for a function call should be different from
- the address in which the template was stored, the different
- address should be assigned to ADDR. If this macro is not defined,
- ADDR will be used for function calls.
-
- If this macro is not defined, by default the trampoline is
- allocated as a stack slot. This default is right for most
- machines. The exceptions are machines where it is impossible to
- execute instructions in the stack area. On such machines, you may
- have to implement a separate stack, using this macro in
- conjunction with `TARGET_ASM_FUNCTION_PROLOGUE' and
- `TARGET_ASM_FUNCTION_EPILOGUE'.
-
- FP points to a data structure, a `struct function', which
- describes the compilation status of the immediate containing
- function of the function which the trampoline is for. The stack
- slot for the trampoline is in the stack frame of this containing
- function. Other allocation strategies probably must do something
- analogous with this information.
-
- Implementing trampolines is difficult on many machines because they
-have separate instruction and data caches. Writing into a stack
-location fails to clear the memory in the instruction cache, so when
-the program jumps to that location, it executes the old contents.
-
- Here are two possible solutions. One is to clear the relevant parts of
-the instruction cache whenever a trampoline is set up. The other is to
-make all trampolines identical, by having them jump to a standard
-subroutine. The former technique makes trampoline execution faster; the
-latter makes initialization faster.
-
- To clear the instruction cache when a trampoline is initialized, define
-the following macro.
-
- -- Macro: CLEAR_INSN_CACHE (BEG, END)
- If defined, expands to a C expression clearing the _instruction
- cache_ in the specified interval. The definition of this macro
- would typically be a series of `asm' statements. Both BEG and END
- are both pointer expressions.
-
- The operating system may also require the stack to be made executable
-before calling the trampoline. To implement this requirement, define
-the following macro.
-
- -- Macro: ENABLE_EXECUTE_STACK
- Define this macro if certain operations must be performed before
- executing code located on the stack. The macro should expand to a
- series of C file-scope constructs (e.g. functions) and provide a
- unique entry point named `__enable_execute_stack'. The target is
- responsible for emitting calls to the entry point in the code, for
- example from the `INITIALIZE_TRAMPOLINE' macro.
-
- To use a standard subroutine, define the following macro. In addition,
-you must make sure that the instructions in a trampoline fill an entire
-cache line with identical instructions, or else ensure that the
-beginning of the trampoline code is always aligned at the same point in
-its cache line. Look in `m68k.h' as a guide.
-
- -- Macro: TRANSFER_FROM_TRAMPOLINE
- Define this macro if trampolines need a special subroutine to do
- their work. The macro should expand to a series of `asm'
- statements which will be compiled with GCC. They go in a library
- function named `__transfer_from_trampoline'.
-
- If you need to avoid executing the ordinary prologue code of a
- compiled C function when you jump to the subroutine, you can do so
- by placing a special label of your own in the assembler code. Use
- one `asm' statement to generate an assembler label, and another to
- make the label global. Then trampolines can use that label to
- jump directly to your special assembler code.
-
-\1f
-File: gccint.info, Node: Library Calls, Next: Addressing Modes, Prev: Trampolines, Up: Target Macros
-
-17.13 Implicit Calls to Library Routines
-========================================
-
-Here is an explanation of implicit calls to library routines.
-
- -- Macro: DECLARE_LIBRARY_RENAMES
- This macro, if defined, should expand to a piece of C code that
- will get expanded when compiling functions for libgcc.a. It can
- be used to provide alternate names for GCC's internal library
- functions if there are ABI-mandated names that the compiler should
- provide.
-
- -- Target Hook: void TARGET_INIT_LIBFUNCS (void)
- This hook should declare additional library routines or rename
- existing ones, using the functions `set_optab_libfunc' and
- `init_one_libfunc' defined in `optabs.c'. `init_optabs' calls
- this macro after initializing all the normal library routines.
-
- The default is to do nothing. Most ports don't need to define
- this hook.
-
- -- Macro: FLOAT_LIB_COMPARE_RETURNS_BOOL (MODE, COMPARISON)
- This macro should return `true' if the library routine that
- implements the floating point comparison operator COMPARISON in
- mode MODE will return a boolean, and FALSE if it will return a
- tristate.
-
- GCC's own floating point libraries return tristates from the
- comparison operators, so the default returns false always. Most
- ports don't need to define this macro.
-
- -- Macro: TARGET_LIB_INT_CMP_BIASED
- This macro should evaluate to `true' if the integer comparison
- functions (like `__cmpdi2') return 0 to indicate that the first
- operand is smaller than the second, 1 to indicate that they are
- equal, and 2 to indicate that the first operand is greater than
- the second. If this macro evaluates to `false' the comparison
- functions return -1, 0, and 1 instead of 0, 1, and 2. If the
- target uses the routines in `libgcc.a', you do not need to define
- this macro.
-
- -- Macro: US_SOFTWARE_GOFAST
- Define this macro if your system C library uses the US Software
- GOFAST library to provide floating point emulation.
-
- In addition to defining this macro, your architecture must set
- `TARGET_INIT_LIBFUNCS' to `gofast_maybe_init_libfuncs', or else
- call that function from its version of that hook. It is defined
- in `config/gofast.h', which must be included by your
- architecture's `CPU.c' file. See `sparc/sparc.c' for an example.
-
- If this macro is defined, the
- `TARGET_FLOAT_LIB_COMPARE_RETURNS_BOOL' target hook must return
- false for `SFmode' and `DFmode' comparisons.
-
- -- Macro: TARGET_EDOM
- The value of `EDOM' on the target machine, as a C integer constant
- expression. If you don't define this macro, GCC does not attempt
- to deposit the value of `EDOM' into `errno' directly. Look in
- `/usr/include/errno.h' to find the value of `EDOM' on your system.
-
- If you do not define `TARGET_EDOM', then compiled code reports
- domain errors by calling the library function and letting it
- report the error. If mathematical functions on your system use
- `matherr' when there is an error, then you should leave
- `TARGET_EDOM' undefined so that `matherr' is used normally.
-
- -- Macro: GEN_ERRNO_RTX
- Define this macro as a C expression to create an rtl expression
- that refers to the global "variable" `errno'. (On certain systems,
- `errno' may not actually be a variable.) If you don't define this
- macro, a reasonable default is used.
-
- -- Macro: TARGET_C99_FUNCTIONS
- When this macro is nonzero, GCC will implicitly optimize `sin'
- calls into `sinf' and similarly for other functions defined by C99
- standard. The default is zero because a number of existing
- systems lack support for these functions in their runtime so this
- macro needs to be redefined to one on systems that do support the
- C99 runtime.
-
- -- Macro: TARGET_HAS_SINCOS
- When this macro is nonzero, GCC will implicitly optimize calls to
- `sin' and `cos' with the same argument to a call to `sincos'. The
- default is zero. The target has to provide the following
- functions:
- void sincos(double x, double *sin, double *cos);
- void sincosf(float x, float *sin, float *cos);
- void sincosl(long double x, long double *sin, long double *cos);
-
- -- Macro: NEXT_OBJC_RUNTIME
- Define this macro to generate code for Objective-C message sending
- using the calling convention of the NeXT system. This calling
- convention involves passing the object, the selector and the
- method arguments all at once to the method-lookup library function.
-
- The default calling convention passes just the object and the
- selector to the lookup function, which returns a pointer to the
- method.
-
-\1f
-File: gccint.info, Node: Addressing Modes, Next: Anchored Addresses, Prev: Library Calls, Up: Target Macros
-
-17.14 Addressing Modes
-======================
-
-This is about addressing modes.
-
- -- Macro: HAVE_PRE_INCREMENT
- -- Macro: HAVE_PRE_DECREMENT
- -- Macro: HAVE_POST_INCREMENT
- -- Macro: HAVE_POST_DECREMENT
- A C expression that is nonzero if the machine supports
- pre-increment, pre-decrement, post-increment, or post-decrement
- addressing respectively.
-
- -- Macro: HAVE_PRE_MODIFY_DISP
- -- Macro: HAVE_POST_MODIFY_DISP
- A C expression that is nonzero if the machine supports pre- or
- post-address side-effect generation involving constants other than
- the size of the memory operand.
-
- -- Macro: HAVE_PRE_MODIFY_REG
- -- Macro: HAVE_POST_MODIFY_REG
- A C expression that is nonzero if the machine supports pre- or
- post-address side-effect generation involving a register
- displacement.
-
- -- Macro: CONSTANT_ADDRESS_P (X)
- A C expression that is 1 if the RTX X is a constant which is a
- valid address. On most machines, this can be defined as
- `CONSTANT_P (X)', but a few machines are more restrictive in which
- constant addresses are supported.
-
- -- Macro: CONSTANT_P (X)
- `CONSTANT_P', which is defined by target-independent code, accepts
- integer-values expressions whose values are not explicitly known,
- such as `symbol_ref', `label_ref', and `high' expressions and
- `const' arithmetic expressions, in addition to `const_int' and
- `const_double' expressions.
-
- -- Macro: MAX_REGS_PER_ADDRESS
- A number, the maximum number of registers that can appear in a
- valid memory address. Note that it is up to you to specify a
- value equal to the maximum number that `GO_IF_LEGITIMATE_ADDRESS'
- would ever accept.
-
- -- Macro: GO_IF_LEGITIMATE_ADDRESS (MODE, X, LABEL)
- A C compound statement with a conditional `goto LABEL;' executed
- if X (an RTX) is a legitimate memory address on the target machine
- for a memory operand of mode MODE.
-
- It usually pays to define several simpler macros to serve as
- subroutines for this one. Otherwise it may be too complicated to
- understand.
-
- This macro must exist in two variants: a strict variant and a
- non-strict one. The strict variant is used in the reload pass. It
- must be defined so that any pseudo-register that has not been
- allocated a hard register is considered a memory reference. In
- contexts where some kind of register is required, a pseudo-register
- with no hard register must be rejected.
-
- The non-strict variant is used in other passes. It must be
- defined to accept all pseudo-registers in every context where some
- kind of register is required.
-
- Compiler source files that want to use the strict variant of this
- macro define the macro `REG_OK_STRICT'. You should use an `#ifdef
- REG_OK_STRICT' conditional to define the strict variant in that
- case and the non-strict variant otherwise.
-
- Subroutines to check for acceptable registers for various purposes
- (one for base registers, one for index registers, and so on) are
- typically among the subroutines used to define
- `GO_IF_LEGITIMATE_ADDRESS'. Then only these subroutine macros
- need have two variants; the higher levels of macros may be the
- same whether strict or not.
-
- Normally, constant addresses which are the sum of a `symbol_ref'
- and an integer are stored inside a `const' RTX to mark them as
- constant. Therefore, there is no need to recognize such sums
- specifically as legitimate addresses. Normally you would simply
- recognize any `const' as legitimate.
-
- Usually `PRINT_OPERAND_ADDRESS' is not prepared to handle constant
- sums that are not marked with `const'. It assumes that a naked
- `plus' indicates indexing. If so, then you _must_ reject such
- naked constant sums as illegitimate addresses, so that none of
- them will be given to `PRINT_OPERAND_ADDRESS'.
-
- On some machines, whether a symbolic address is legitimate depends
- on the section that the address refers to. On these machines,
- define the target hook `TARGET_ENCODE_SECTION_INFO' to store the
- information into the `symbol_ref', and then check for it here.
- When you see a `const', you will have to look inside it to find the
- `symbol_ref' in order to determine the section. *Note Assembler
- Format::.
-
- -- Macro: TARGET_MEM_CONSTRAINT
- A single character to be used instead of the default `'m''
- character for general memory addresses. This defines the
- constraint letter which matches the memory addresses accepted by
- `GO_IF_LEGITIMATE_ADDRESS_P'. Define this macro if you want to
- support new address formats in your back end without changing the
- semantics of the `'m'' constraint. This is necessary in order to
- preserve functionality of inline assembly constructs using the
- `'m'' constraint.
-
- -- Macro: FIND_BASE_TERM (X)
- A C expression to determine the base term of address X, or to
- provide a simplified version of X from which `alias.c' can easily
- find the base term. This macro is used in only two places:
- `find_base_value' and `find_base_term' in `alias.c'.
-
- It is always safe for this macro to not be defined. It exists so
- that alias analysis can understand machine-dependent addresses.
-
- The typical use of this macro is to handle addresses containing a
- label_ref or symbol_ref within an UNSPEC.
-
- -- Macro: LEGITIMIZE_ADDRESS (X, OLDX, MODE, WIN)
- A C compound statement that attempts to replace X with a valid
- memory address for an operand of mode MODE. WIN will be a C
- statement label elsewhere in the code; the macro definition may use
-
- GO_IF_LEGITIMATE_ADDRESS (MODE, X, WIN);
-
- to avoid further processing if the address has become legitimate.
-
- X will always be the result of a call to `break_out_memory_refs',
- and OLDX will be the operand that was given to that function to
- produce X.
-
- The code generated by this macro should not alter the substructure
- of X. If it transforms X into a more legitimate form, it should
- assign X (which will always be a C variable) a new value.
-
- It is not necessary for this macro to come up with a legitimate
- address. The compiler has standard ways of doing so in all cases.
- In fact, it is safe to omit this macro. But often a
- machine-dependent strategy can generate better code.
-
- -- Macro: LEGITIMIZE_RELOAD_ADDRESS (X, MODE, OPNUM, TYPE, IND_LEVELS,
- WIN)
- A C compound statement that attempts to replace X, which is an
- address that needs reloading, with a valid memory address for an
- operand of mode MODE. WIN will be a C statement label elsewhere
- in the code. It is not necessary to define this macro, but it
- might be useful for performance reasons.
-
- For example, on the i386, it is sometimes possible to use a single
- reload register instead of two by reloading a sum of two pseudo
- registers into a register. On the other hand, for number of RISC
- processors offsets are limited so that often an intermediate
- address needs to be generated in order to address a stack slot.
- By defining `LEGITIMIZE_RELOAD_ADDRESS' appropriately, the
- intermediate addresses generated for adjacent some stack slots can
- be made identical, and thus be shared.
-
- _Note_: This macro should be used with caution. It is necessary
- to know something of how reload works in order to effectively use
- this, and it is quite easy to produce macros that build in too
- much knowledge of reload internals.
-
- _Note_: This macro must be able to reload an address created by a
- previous invocation of this macro. If it fails to handle such
- addresses then the compiler may generate incorrect code or abort.
-
- The macro definition should use `push_reload' to indicate parts
- that need reloading; OPNUM, TYPE and IND_LEVELS are usually
- suitable to be passed unaltered to `push_reload'.
-
- The code generated by this macro must not alter the substructure of
- X. If it transforms X into a more legitimate form, it should
- assign X (which will always be a C variable) a new value. This
- also applies to parts that you change indirectly by calling
- `push_reload'.
-
- The macro definition may use `strict_memory_address_p' to test if
- the address has become legitimate.
-
- If you want to change only a part of X, one standard way of doing
- this is to use `copy_rtx'. Note, however, that it unshares only a
- single level of rtl. Thus, if the part to be changed is not at the
- top level, you'll need to replace first the top level. It is not
- necessary for this macro to come up with a legitimate address;
- but often a machine-dependent strategy can generate better code.
-
- -- Macro: GO_IF_MODE_DEPENDENT_ADDRESS (ADDR, LABEL)
- A C statement or compound statement with a conditional `goto
- LABEL;' executed if memory address X (an RTX) can have different
- meanings depending on the machine mode of the memory reference it
- is used for or if the address is valid for some modes but not
- others.
-
- Autoincrement and autodecrement addresses typically have
- mode-dependent effects because the amount of the increment or
- decrement is the size of the operand being addressed. Some
- machines have other mode-dependent addresses. Many RISC machines
- have no mode-dependent addresses.
-
- You may assume that ADDR is a valid address for the machine.
-
- -- Macro: LEGITIMATE_CONSTANT_P (X)
- A C expression that is nonzero if X is a legitimate constant for
- an immediate operand on the target machine. You can assume that X
- satisfies `CONSTANT_P', so you need not check this. In fact, `1'
- is a suitable definition for this macro on machines where anything
- `CONSTANT_P' is valid.
-
- -- Target Hook: rtx TARGET_DELEGITIMIZE_ADDRESS (rtx X)
- This hook is used to undo the possibly obfuscating effects of the
- `LEGITIMIZE_ADDRESS' and `LEGITIMIZE_RELOAD_ADDRESS' target
- macros. Some backend implementations of these macros wrap symbol
- references inside an `UNSPEC' rtx to represent PIC or similar
- addressing modes. This target hook allows GCC's optimizers to
- understand the semantics of these opaque `UNSPEC's by converting
- them back into their original form.
-
- -- Target Hook: bool TARGET_CANNOT_FORCE_CONST_MEM (rtx X)
- This hook should return true if X is of a form that cannot (or
- should not) be spilled to the constant pool. The default version
- of this hook returns false.
-
- The primary reason to define this hook is to prevent reload from
- deciding that a non-legitimate constant would be better reloaded
- from the constant pool instead of spilling and reloading a register
- holding the constant. This restriction is often true of addresses
- of TLS symbols for various targets.
-
- -- Target Hook: bool TARGET_USE_BLOCKS_FOR_CONSTANT_P (enum
- machine_mode MODE, rtx X)
- This hook should return true if pool entries for constant X can be
- placed in an `object_block' structure. MODE is the mode of X.
-
- The default version returns false for all constants.
-
- -- Target Hook: tree TARGET_BUILTIN_RECIPROCAL (enum tree_code FN,
- bool TM_FN, bool SQRT)
- This hook should return the DECL of a function that implements
- reciprocal of the builtin function with builtin function code FN,
- or `NULL_TREE' if such a function is not available. TM_FN is true
- when FN is a code of a machine-dependent builtin function. When
- SQRT is true, additional optimizations that apply only to the
- reciprocal of a square root function are performed, and only
- reciprocals of `sqrt' function are valid.
-
- -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_MASK_FOR_LOAD (void)
- This hook should return the DECL of a function F that given an
- address ADDR as an argument returns a mask M that can be used to
- extract from two vectors the relevant data that resides in ADDR in
- case ADDR is not properly aligned.
-
- The autovectorizer, when vectorizing a load operation from an
- address ADDR that may be unaligned, will generate two vector loads
- from the two aligned addresses around ADDR. It then generates a
- `REALIGN_LOAD' operation to extract the relevant data from the two
- loaded vectors. The first two arguments to `REALIGN_LOAD', V1 and
- V2, are the two vectors, each of size VS, and the third argument,
- OFF, defines how the data will be extracted from these two
- vectors: if OFF is 0, then the returned vector is V2; otherwise,
- the returned vector is composed from the last VS-OFF elements of
- V1 concatenated to the first OFF elements of V2.
-
- If this hook is defined, the autovectorizer will generate a call
- to F (using the DECL tree that this hook returns) and will use the
- return value of F as the argument OFF to `REALIGN_LOAD'.
- Therefore, the mask M returned by F should comply with the
- semantics expected by `REALIGN_LOAD' described above. If this
- hook is not defined, then ADDR will be used as the argument OFF to
- `REALIGN_LOAD', in which case the low log2(VS)-1 bits of ADDR will
- be considered.
-
- -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_EVEN (tree X)
- This hook should return the DECL of a function F that implements
- widening multiplication of the even elements of two input vectors
- of type X.
-
- If this hook is defined, the autovectorizer will use it along with
- the `TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_ODD' target hook when
- vectorizing widening multiplication in cases that the order of the
- results does not have to be preserved (e.g. used only by a
- reduction computation). Otherwise, the `widen_mult_hi/lo' idioms
- will be used.
-
- -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_ODD (tree X)
- This hook should return the DECL of a function F that implements
- widening multiplication of the odd elements of two input vectors
- of type X.
-
- If this hook is defined, the autovectorizer will use it along with
- the `TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_EVEN' target hook when
- vectorizing widening multiplication in cases that the order of the
- results does not have to be preserved (e.g. used only by a
- reduction computation). Otherwise, the `widen_mult_hi/lo' idioms
- will be used.
-
- -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_CONVERSION (enum
- tree_code CODE, tree TYPE)
- This hook should return the DECL of a function that implements
- conversion of the input vector of type TYPE. If TYPE is an
- integral type, the result of the conversion is a vector of
- floating-point type of the same size. If TYPE is a floating-point
- type, the result of the conversion is a vector of integral type of
- the same size. CODE specifies how the conversion is to be applied
- (truncation, rounding, etc.).
-
- If this hook is defined, the autovectorizer will use the
- `TARGET_VECTORIZE_BUILTIN_CONVERSION' target hook when vectorizing
- conversion. Otherwise, it will return `NULL_TREE'.
-
- -- Target Hook: tree TARGET_VECTORIZE_BUILTIN_VECTORIZED_FUNCTION
- (enum built_in_function CODE, tree VEC_TYPE_OUT, tree
- VEC_TYPE_IN)
- This hook should return the decl of a function that implements the
- vectorized variant of the builtin function with builtin function
- code CODE or `NULL_TREE' if such a function is not available. The
- return type of the vectorized function shall be of vector type
- VEC_TYPE_OUT and the argument types should be VEC_TYPE_IN.
-
-\1f
-File: gccint.info, Node: Anchored Addresses, Next: Condition Code, Prev: Addressing Modes, Up: Target Macros
-
-17.15 Anchored Addresses
-========================
-
-GCC usually addresses every static object as a separate entity. For
-example, if we have:
-
- static int a, b, c;
- int foo (void) { return a + b + c; }
-
- the code for `foo' will usually calculate three separate symbolic
-addresses: those of `a', `b' and `c'. On some targets, it would be
-better to calculate just one symbolic address and access the three
-variables relative to it. The equivalent pseudocode would be something
-like:
-
- int foo (void)
- {
- register int *xr = &x;
- return xr[&a - &x] + xr[&b - &x] + xr[&c - &x];
- }
-
- (which isn't valid C). We refer to shared addresses like `x' as
-"section anchors". Their use is controlled by `-fsection-anchors'.
-
- The hooks below describe the target properties that GCC needs to know
-in order to make effective use of section anchors. It won't use
-section anchors at all unless either `TARGET_MIN_ANCHOR_OFFSET' or
-`TARGET_MAX_ANCHOR_OFFSET' is set to a nonzero value.
-
- -- Variable: Target Hook HOST_WIDE_INT TARGET_MIN_ANCHOR_OFFSET
- The minimum offset that should be applied to a section anchor. On
- most targets, it should be the smallest offset that can be applied
- to a base register while still giving a legitimate address for
- every mode. The default value is 0.
-
- -- Variable: Target Hook HOST_WIDE_INT TARGET_MAX_ANCHOR_OFFSET
- Like `TARGET_MIN_ANCHOR_OFFSET', but the maximum (inclusive)
- offset that should be applied to section anchors. The default
- value is 0.
-
- -- Target Hook: void TARGET_ASM_OUTPUT_ANCHOR (rtx X)
- Write the assembly code to define section anchor X, which is a
- `SYMBOL_REF' for which `SYMBOL_REF_ANCHOR_P (X)' is true. The
- hook is called with the assembly output position set to the
- beginning of `SYMBOL_REF_BLOCK (X)'.
-
- If `ASM_OUTPUT_DEF' is available, the hook's default definition
- uses it to define the symbol as `. + SYMBOL_REF_BLOCK_OFFSET (X)'.
- If `ASM_OUTPUT_DEF' is not available, the hook's default definition
- is `NULL', which disables the use of section anchors altogether.
-
- -- Target Hook: bool TARGET_USE_ANCHORS_FOR_SYMBOL_P (rtx X)
- Return true if GCC should attempt to use anchors to access
- `SYMBOL_REF' X. You can assume `SYMBOL_REF_HAS_BLOCK_INFO_P (X)'
- and `!SYMBOL_REF_ANCHOR_P (X)'.
-
- The default version is correct for most targets, but you might
- need to intercept this hook to handle things like target-specific
- attributes or target-specific sections.
-
-\1f
-File: gccint.info, Node: Condition Code, Next: Costs, Prev: Anchored Addresses, Up: Target Macros
-
-17.16 Condition Code Status
-===========================
-
-This describes the condition code status.
-
- The file `conditions.h' defines a variable `cc_status' to describe how
-the condition code was computed (in case the interpretation of the
-condition code depends on the instruction that it was set by). This
-variable contains the RTL expressions on which the condition code is
-currently based, and several standard flags.
-
- Sometimes additional machine-specific flags must be defined in the
-machine description header file. It can also add additional
-machine-specific information by defining `CC_STATUS_MDEP'.
-
- -- Macro: CC_STATUS_MDEP
- C code for a data type which is used for declaring the `mdep'
- component of `cc_status'. It defaults to `int'.
-
- This macro is not used on machines that do not use `cc0'.
-
- -- Macro: CC_STATUS_MDEP_INIT
- A C expression to initialize the `mdep' field to "empty". The
- default definition does nothing, since most machines don't use the
- field anyway. If you want to use the field, you should probably
- define this macro to initialize it.
-
- This macro is not used on machines that do not use `cc0'.
-
- -- Macro: NOTICE_UPDATE_CC (EXP, INSN)
- A C compound statement to set the components of `cc_status'
- appropriately for an insn INSN whose body is EXP. It is this
- macro's responsibility to recognize insns that set the condition
- code as a byproduct of other activity as well as those that
- explicitly set `(cc0)'.
-
- This macro is not used on machines that do not use `cc0'.
-
- If there are insns that do not set the condition code but do alter
- other machine registers, this macro must check to see whether they
- invalidate the expressions that the condition code is recorded as
- reflecting. For example, on the 68000, insns that store in address
- registers do not set the condition code, which means that usually
- `NOTICE_UPDATE_CC' can leave `cc_status' unaltered for such insns.
- But suppose that the previous insn set the condition code based on
- location `a4@(102)' and the current insn stores a new value in
- `a4'. Although the condition code is not changed by this, it will
- no longer be true that it reflects the contents of `a4@(102)'.
- Therefore, `NOTICE_UPDATE_CC' must alter `cc_status' in this case
- to say that nothing is known about the condition code value.
-
- The definition of `NOTICE_UPDATE_CC' must be prepared to deal with
- the results of peephole optimization: insns whose patterns are
- `parallel' RTXs containing various `reg', `mem' or constants which
- are just the operands. The RTL structure of these insns is not
- sufficient to indicate what the insns actually do. What
- `NOTICE_UPDATE_CC' should do when it sees one is just to run
- `CC_STATUS_INIT'.
-
- A possible definition of `NOTICE_UPDATE_CC' is to call a function
- that looks at an attribute (*note Insn Attributes::) named, for
- example, `cc'. This avoids having detailed information about
- patterns in two places, the `md' file and in `NOTICE_UPDATE_CC'.
-
- -- Macro: SELECT_CC_MODE (OP, X, Y)
- Returns a mode from class `MODE_CC' to be used when comparison
- operation code OP is applied to rtx X and Y. For example, on the
- SPARC, `SELECT_CC_MODE' is defined as (see *note Jump Patterns::
- for a description of the reason for this definition)
-
- #define SELECT_CC_MODE(OP,X,Y) \
- (GET_MODE_CLASS (GET_MODE (X)) == MODE_FLOAT \
- ? ((OP == EQ || OP == NE) ? CCFPmode : CCFPEmode) \
- : ((GET_CODE (X) == PLUS || GET_CODE (X) == MINUS \
- || GET_CODE (X) == NEG) \
- ? CC_NOOVmode : CCmode))
-
- You should define this macro if and only if you define extra CC
- modes in `MACHINE-modes.def'.
-
- -- Macro: CANONICALIZE_COMPARISON (CODE, OP0, OP1)
- On some machines not all possible comparisons are defined, but you
- can convert an invalid comparison into a valid one. For example,
- the Alpha does not have a `GT' comparison, but you can use an `LT'
- comparison instead and swap the order of the operands.
-
- On such machines, define this macro to be a C statement to do any
- required conversions. CODE is the initial comparison code and OP0
- and OP1 are the left and right operands of the comparison,
- respectively. You should modify CODE, OP0, and OP1 as required.
-
- GCC will not assume that the comparison resulting from this macro
- is valid but will see if the resulting insn matches a pattern in
- the `md' file.
-
- You need not define this macro if it would never change the
- comparison code or operands.
-
- -- Macro: REVERSIBLE_CC_MODE (MODE)
- A C expression whose value is one if it is always safe to reverse a
- comparison whose mode is MODE. If `SELECT_CC_MODE' can ever
- return MODE for a floating-point inequality comparison, then
- `REVERSIBLE_CC_MODE (MODE)' must be zero.
-
- You need not define this macro if it would always returns zero or
- if the floating-point format is anything other than
- `IEEE_FLOAT_FORMAT'. For example, here is the definition used on
- the SPARC, where floating-point inequality comparisons are always
- given `CCFPEmode':
-
- #define REVERSIBLE_CC_MODE(MODE) ((MODE) != CCFPEmode)
-
- -- Macro: REVERSE_CONDITION (CODE, MODE)
- A C expression whose value is reversed condition code of the CODE
- for comparison done in CC_MODE MODE. The macro is used only in
- case `REVERSIBLE_CC_MODE (MODE)' is nonzero. Define this macro in
- case machine has some non-standard way how to reverse certain
- conditionals. For instance in case all floating point conditions
- are non-trapping, compiler may freely convert unordered compares
- to ordered one. Then definition may look like:
-
- #define REVERSE_CONDITION(CODE, MODE) \
- ((MODE) != CCFPmode ? reverse_condition (CODE) \
- : reverse_condition_maybe_unordered (CODE))
-
- -- Macro: REVERSE_CONDEXEC_PREDICATES_P (OP1, OP2)
- A C expression that returns true if the conditional execution
- predicate OP1, a comparison operation, is the inverse of OP2 and
- vice versa. Define this to return 0 if the target has conditional
- execution predicates that cannot be reversed safely. There is no
- need to validate that the arguments of op1 and op2 are the same,
- this is done separately. If no expansion is specified, this macro
- is defined as follows:
-
- #define REVERSE_CONDEXEC_PREDICATES_P (x, y) \
- (GET_CODE ((x)) == reversed_comparison_code ((y), NULL))
-
- -- Target Hook: bool TARGET_FIXED_CONDITION_CODE_REGS (unsigned int *,
- unsigned int *)
- On targets which do not use `(cc0)', and which use a hard register
- rather than a pseudo-register to hold condition codes, the regular
- CSE passes are often not able to identify cases in which the hard
- register is set to a common value. Use this hook to enable a
- small pass which optimizes such cases. This hook should return
- true to enable this pass, and it should set the integers to which
- its arguments point to the hard register numbers used for
- condition codes. When there is only one such register, as is true
- on most systems, the integer pointed to by the second argument
- should be set to `INVALID_REGNUM'.
-
- The default version of this hook returns false.
-
- -- Target Hook: enum machine_mode TARGET_CC_MODES_COMPATIBLE (enum
- machine_mode, enum machine_mode)
- On targets which use multiple condition code modes in class
- `MODE_CC', it is sometimes the case that a comparison can be
- validly done in more than one mode. On such a system, define this
- target hook to take two mode arguments and to return a mode in
- which both comparisons may be validly done. If there is no such
- mode, return `VOIDmode'.
-
- The default version of this hook checks whether the modes are the
- same. If they are, it returns that mode. If they are different,
- it returns `VOIDmode'.
-
-\1f
-File: gccint.info, Node: Costs, Next: Scheduling, Prev: Condition Code, Up: Target Macros
-
-17.17 Describing Relative Costs of Operations
-=============================================
-
-These macros let you describe the relative speed of various operations
-on the target machine.
-
- -- Macro: REGISTER_MOVE_COST (MODE, FROM, TO)
- A C expression for the cost of moving data of mode MODE from a
- register in class FROM to one in class TO. The classes are
- expressed using the enumeration values such as `GENERAL_REGS'. A
- value of 2 is the default; other values are interpreted relative to
- that.
-
- It is not required that the cost always equal 2 when FROM is the
- same as TO; on some machines it is expensive to move between
- registers if they are not general registers.
-
- If reload sees an insn consisting of a single `set' between two
- hard registers, and if `REGISTER_MOVE_COST' applied to their
- classes returns a value of 2, reload does not check to ensure that
- the constraints of the insn are met. Setting a cost of other than
- 2 will allow reload to verify that the constraints are met. You
- should do this if the `movM' pattern's constraints do not allow
- such copying.
-
- -- Macro: MEMORY_MOVE_COST (MODE, CLASS, IN)
- A C expression for the cost of moving data of mode MODE between a
- register of class CLASS and memory; IN is zero if the value is to
- be written to memory, nonzero if it is to be read in. This cost
- is relative to those in `REGISTER_MOVE_COST'. If moving between
- registers and memory is more expensive than between two registers,
- you should define this macro to express the relative cost.
-
- If you do not define this macro, GCC uses a default cost of 4 plus
- the cost of copying via a secondary reload register, if one is
- needed. If your machine requires a secondary reload register to
- copy between memory and a register of CLASS but the reload
- mechanism is more complex than copying via an intermediate, define
- this macro to reflect the actual cost of the move.
-
- GCC defines the function `memory_move_secondary_cost' if secondary
- reloads are needed. It computes the costs due to copying via a
- secondary register. If your machine copies from memory using a
- secondary register in the conventional way but the default base
- value of 4 is not correct for your machine, define this macro to
- add some other value to the result of that function. The
- arguments to that function are the same as to this macro.
-
- -- Macro: BRANCH_COST (SPEED_P, PREDICTABLE_P)
- A C expression for the cost of a branch instruction. A value of 1
- is the default; other values are interpreted relative to that.
- Parameter SPEED_P is true when the branch in question should be
- optimized for speed. When it is false, `BRANCH_COST' should be
- returning value optimal for code size rather then performance
- considerations. PREDICTABLE_P is true for well predictable
- branches. On many architectures the `BRANCH_COST' can be reduced
- then.
-
- Here are additional macros which do not specify precise relative costs,
-but only that certain actions are more expensive than GCC would
-ordinarily expect.
-
- -- Macro: SLOW_BYTE_ACCESS
- Define this macro as a C expression which is nonzero if accessing
- less than a word of memory (i.e. a `char' or a `short') is no
- faster than accessing a word of memory, i.e., if such access
- require more than one instruction or if there is no difference in
- cost between byte and (aligned) word loads.
-
- When this macro is not defined, the compiler will access a field by
- finding the smallest containing object; when it is defined, a
- fullword load will be used if alignment permits. Unless bytes
- accesses are faster than word accesses, using word accesses is
- preferable since it may eliminate subsequent memory access if
- subsequent accesses occur to other fields in the same word of the
- structure, but to different bytes.
-
- -- Macro: SLOW_UNALIGNED_ACCESS (MODE, ALIGNMENT)
- Define this macro to be the value 1 if memory accesses described
- by the MODE and ALIGNMENT parameters have a cost many times greater
- than aligned accesses, for example if they are emulated in a trap
- handler.
-
- When this macro is nonzero, the compiler will act as if
- `STRICT_ALIGNMENT' were nonzero when generating code for block
- moves. This can cause significantly more instructions to be
- produced. Therefore, do not set this macro nonzero if unaligned
- accesses only add a cycle or two to the time for a memory access.
-
- If the value of this macro is always zero, it need not be defined.
- If this macro is defined, it should produce a nonzero value when
- `STRICT_ALIGNMENT' is nonzero.
-
- -- Macro: MOVE_RATIO
- The threshold of number of scalar memory-to-memory move insns,
- _below_ which a sequence of insns should be generated instead of a
- string move insn or a library call. Increasing the value will
- always make code faster, but eventually incurs high cost in
- increased code size.
-
- Note that on machines where the corresponding move insn is a
- `define_expand' that emits a sequence of insns, this macro counts
- the number of such sequences.
-
- If you don't define this, a reasonable default is used.
-
- -- Macro: MOVE_BY_PIECES_P (SIZE, ALIGNMENT)
- A C expression used to determine whether `move_by_pieces' will be
- used to copy a chunk of memory, or whether some other block move
- mechanism will be used. Defaults to 1 if `move_by_pieces_ninsns'
- returns less than `MOVE_RATIO'.
-
- -- Macro: MOVE_MAX_PIECES
- A C expression used by `move_by_pieces' to determine the largest
- unit a load or store used to copy memory is. Defaults to
- `MOVE_MAX'.
-
- -- Macro: CLEAR_RATIO
- The threshold of number of scalar move insns, _below_ which a
- sequence of insns should be generated to clear memory instead of a
- string clear insn or a library call. Increasing the value will
- always make code faster, but eventually incurs high cost in
- increased code size.
-
- If you don't define this, a reasonable default is used.
-
- -- Macro: CLEAR_BY_PIECES_P (SIZE, ALIGNMENT)
- A C expression used to determine whether `clear_by_pieces' will be
- used to clear a chunk of memory, or whether some other block clear
- mechanism will be used. Defaults to 1 if `move_by_pieces_ninsns'
- returns less than `CLEAR_RATIO'.
-
- -- Macro: SET_RATIO
- The threshold of number of scalar move insns, _below_ which a
- sequence of insns should be generated to set memory to a constant
- value, instead of a block set insn or a library call. Increasing
- the value will always make code faster, but eventually incurs high
- cost in increased code size.
-
- If you don't define this, it defaults to the value of `MOVE_RATIO'.
-
- -- Macro: SET_BY_PIECES_P (SIZE, ALIGNMENT)
- A C expression used to determine whether `store_by_pieces' will be
- used to set a chunk of memory to a constant value, or whether some
- other mechanism will be used. Used by `__builtin_memset' when
- storing values other than constant zero. Defaults to 1 if
- `move_by_pieces_ninsns' returns less than `SET_RATIO'.
-
- -- Macro: STORE_BY_PIECES_P (SIZE, ALIGNMENT)
- A C expression used to determine whether `store_by_pieces' will be
- used to set a chunk of memory to a constant string value, or
- whether some other mechanism will be used. Used by
- `__builtin_strcpy' when called with a constant source string.
- Defaults to 1 if `move_by_pieces_ninsns' returns less than
- `MOVE_RATIO'.
-
- -- Macro: USE_LOAD_POST_INCREMENT (MODE)
- A C expression used to determine whether a load postincrement is a
- good thing to use for a given mode. Defaults to the value of
- `HAVE_POST_INCREMENT'.
-
- -- Macro: USE_LOAD_POST_DECREMENT (MODE)
- A C expression used to determine whether a load postdecrement is a
- good thing to use for a given mode. Defaults to the value of
- `HAVE_POST_DECREMENT'.
-
- -- Macro: USE_LOAD_PRE_INCREMENT (MODE)
- A C expression used to determine whether a load preincrement is a
- good thing to use for a given mode. Defaults to the value of
- `HAVE_PRE_INCREMENT'.
-
- -- Macro: USE_LOAD_PRE_DECREMENT (MODE)
- A C expression used to determine whether a load predecrement is a
- good thing to use for a given mode. Defaults to the value of
- `HAVE_PRE_DECREMENT'.
-
- -- Macro: USE_STORE_POST_INCREMENT (MODE)
- A C expression used to determine whether a store postincrement is
- a good thing to use for a given mode. Defaults to the value of
- `HAVE_POST_INCREMENT'.
-
- -- Macro: USE_STORE_POST_DECREMENT (MODE)
- A C expression used to determine whether a store postdecrement is
- a good thing to use for a given mode. Defaults to the value of
- `HAVE_POST_DECREMENT'.
-
- -- Macro: USE_STORE_PRE_INCREMENT (MODE)
- This macro is used to determine whether a store preincrement is a
- good thing to use for a given mode. Defaults to the value of
- `HAVE_PRE_INCREMENT'.
-
- -- Macro: USE_STORE_PRE_DECREMENT (MODE)
- This macro is used to determine whether a store predecrement is a
- good thing to use for a given mode. Defaults to the value of
- `HAVE_PRE_DECREMENT'.
-
- -- Macro: NO_FUNCTION_CSE
- Define this macro if it is as good or better to call a constant
- function address than to call an address kept in a register.
-
- -- Macro: RANGE_TEST_NON_SHORT_CIRCUIT
- Define this macro if a non-short-circuit operation produced by
- `fold_range_test ()' is optimal. This macro defaults to true if
- `BRANCH_COST' is greater than or equal to the value 2.
-
- -- Target Hook: bool TARGET_RTX_COSTS (rtx X, int CODE, int
- OUTER_CODE, int *TOTAL)
- This target hook describes the relative costs of RTL expressions.
-
- The cost may depend on the precise form of the expression, which is
- available for examination in X, and the rtx code of the expression
- in which it is contained, found in OUTER_CODE. CODE is the
- expression code--redundant, since it can be obtained with
- `GET_CODE (X)'.
-
- In implementing this hook, you can use the construct
- `COSTS_N_INSNS (N)' to specify a cost equal to N fast instructions.
-
- On entry to the hook, `*TOTAL' contains a default estimate for the
- cost of the expression. The hook should modify this value as
- necessary. Traditionally, the default costs are `COSTS_N_INSNS
- (5)' for multiplications, `COSTS_N_INSNS (7)' for division and
- modulus operations, and `COSTS_N_INSNS (1)' for all other
- operations.
-
- When optimizing for code size, i.e. when `optimize_size' is
- nonzero, this target hook should be used to estimate the relative
- size cost of an expression, again relative to `COSTS_N_INSNS'.
-
- The hook returns true when all subexpressions of X have been
- processed, and false when `rtx_cost' should recurse.
-
- -- Target Hook: int TARGET_ADDRESS_COST (rtx ADDRESS)
- This hook computes the cost of an addressing mode that contains
- ADDRESS. If not defined, the cost is computed from the ADDRESS
- expression and the `TARGET_RTX_COST' hook.
-
- For most CISC machines, the default cost is a good approximation
- of the true cost of the addressing mode. However, on RISC
- machines, all instructions normally have the same length and
- execution time. Hence all addresses will have equal costs.
-
- In cases where more than one form of an address is known, the form
- with the lowest cost will be used. If multiple forms have the
- same, lowest, cost, the one that is the most complex will be used.
-
- For example, suppose an address that is equal to the sum of a
- register and a constant is used twice in the same basic block.
- When this macro is not defined, the address will be computed in a
- register and memory references will be indirect through that
- register. On machines where the cost of the addressing mode
- containing the sum is no higher than that of a simple indirect
- reference, this will produce an additional instruction and
- possibly require an additional register. Proper specification of
- this macro eliminates this overhead for such machines.
-
- This hook is never called with an invalid address.
-
- On machines where an address involving more than one register is as
- cheap as an address computation involving only one register,
- defining `TARGET_ADDRESS_COST' to reflect this can cause two
- registers to be live over a region of code where only one would
- have been if `TARGET_ADDRESS_COST' were not defined in that
- manner. This effect should be considered in the definition of
- this macro. Equivalent costs should probably only be given to
- addresses with different numbers of registers on machines with
- lots of registers.
-
-\1f
-File: gccint.info, Node: Scheduling, Next: Sections, Prev: Costs, Up: Target Macros
-
-17.18 Adjusting the Instruction Scheduler
-=========================================
-
-The instruction scheduler may need a fair amount of machine-specific
-adjustment in order to produce good code. GCC provides several target
-hooks for this purpose. It is usually enough to define just a few of
-them: try the first ones in this list first.
-
- -- Target Hook: int TARGET_SCHED_ISSUE_RATE (void)
- This hook returns the maximum number of instructions that can ever
- issue at the same time on the target machine. The default is one.
- Although the insn scheduler can define itself the possibility of
- issue an insn on the same cycle, the value can serve as an
- additional constraint to issue insns on the same simulated
- processor cycle (see hooks `TARGET_SCHED_REORDER' and
- `TARGET_SCHED_REORDER2'). This value must be constant over the
- entire compilation. If you need it to vary depending on what the
- instructions are, you must use `TARGET_SCHED_VARIABLE_ISSUE'.
-
- -- Target Hook: int TARGET_SCHED_VARIABLE_ISSUE (FILE *FILE, int
- VERBOSE, rtx INSN, int MORE)
- This hook is executed by the scheduler after it has scheduled an
- insn from the ready list. It should return the number of insns
- which can still be issued in the current cycle. The default is
- `MORE - 1' for insns other than `CLOBBER' and `USE', which
- normally are not counted against the issue rate. You should
- define this hook if some insns take more machine resources than
- others, so that fewer insns can follow them in the same cycle.
- FILE is either a null pointer, or a stdio stream to write any
- debug output to. VERBOSE is the verbose level provided by
- `-fsched-verbose-N'. INSN is the instruction that was scheduled.
-
- -- Target Hook: int TARGET_SCHED_ADJUST_COST (rtx INSN, rtx LINK, rtx
- DEP_INSN, int COST)
- This function corrects the value of COST based on the relationship
- between INSN and DEP_INSN through the dependence LINK. It should
- return the new value. The default is to make no adjustment to
- COST. This can be used for example to specify to the scheduler
- using the traditional pipeline description that an output- or
- anti-dependence does not incur the same cost as a data-dependence.
- If the scheduler using the automaton based pipeline description,
- the cost of anti-dependence is zero and the cost of
- output-dependence is maximum of one and the difference of latency
- times of the first and the second insns. If these values are not
- acceptable, you could use the hook to modify them too. See also
- *note Processor pipeline description::.
-
- -- Target Hook: int TARGET_SCHED_ADJUST_PRIORITY (rtx INSN, int
- PRIORITY)
- This hook adjusts the integer scheduling priority PRIORITY of
- INSN. It should return the new priority. Increase the priority to
- execute INSN earlier, reduce the priority to execute INSN later.
- Do not define this hook if you do not need to adjust the
- scheduling priorities of insns.
-
- -- Target Hook: int TARGET_SCHED_REORDER (FILE *FILE, int VERBOSE, rtx
- *READY, int *N_READYP, int CLOCK)
- This hook is executed by the scheduler after it has scheduled the
- ready list, to allow the machine description to reorder it (for
- example to combine two small instructions together on `VLIW'
- machines). FILE is either a null pointer, or a stdio stream to
- write any debug output to. VERBOSE is the verbose level provided
- by `-fsched-verbose-N'. READY is a pointer to the ready list of
- instructions that are ready to be scheduled. N_READYP is a
- pointer to the number of elements in the ready list. The scheduler
- reads the ready list in reverse order, starting with
- READY[*N_READYP-1] and going to READY[0]. CLOCK is the timer tick
- of the scheduler. You may modify the ready list and the number of
- ready insns. The return value is the number of insns that can
- issue this cycle; normally this is just `issue_rate'. See also
- `TARGET_SCHED_REORDER2'.
-
- -- Target Hook: int TARGET_SCHED_REORDER2 (FILE *FILE, int VERBOSE,
- rtx *READY, int *N_READY, CLOCK)
- Like `TARGET_SCHED_REORDER', but called at a different time. That
- function is called whenever the scheduler starts a new cycle.
- This one is called once per iteration over a cycle, immediately
- after `TARGET_SCHED_VARIABLE_ISSUE'; it can reorder the ready list
- and return the number of insns to be scheduled in the same cycle.
- Defining this hook can be useful if there are frequent situations
- where scheduling one insn causes other insns to become ready in
- the same cycle. These other insns can then be taken into account
- properly.
-
- -- Target Hook: void TARGET_SCHED_DEPENDENCIES_EVALUATION_HOOK (rtx
- HEAD, rtx TAIL)
- This hook is called after evaluation forward dependencies of insns
- in chain given by two parameter values (HEAD and TAIL
- correspondingly) but before insns scheduling of the insn chain.
- For example, it can be used for better insn classification if it
- requires analysis of dependencies. This hook can use backward and
- forward dependencies of the insn scheduler because they are already
- calculated.
-
- -- Target Hook: void TARGET_SCHED_INIT (FILE *FILE, int VERBOSE, int
- MAX_READY)
- This hook is executed by the scheduler at the beginning of each
- block of instructions that are to be scheduled. FILE is either a
- null pointer, or a stdio stream to write any debug output to.
- VERBOSE is the verbose level provided by `-fsched-verbose-N'.
- MAX_READY is the maximum number of insns in the current scheduling
- region that can be live at the same time. This can be used to
- allocate scratch space if it is needed, e.g. by
- `TARGET_SCHED_REORDER'.
-
- -- Target Hook: void TARGET_SCHED_FINISH (FILE *FILE, int VERBOSE)
- This hook is executed by the scheduler at the end of each block of
- instructions that are to be scheduled. It can be used to perform
- cleanup of any actions done by the other scheduling hooks. FILE
- is either a null pointer, or a stdio stream to write any debug
- output to. VERBOSE is the verbose level provided by
- `-fsched-verbose-N'.
-
- -- Target Hook: void TARGET_SCHED_INIT_GLOBAL (FILE *FILE, int
- VERBOSE, int OLD_MAX_UID)
- This hook is executed by the scheduler after function level
- initializations. FILE is either a null pointer, or a stdio stream
- to write any debug output to. VERBOSE is the verbose level
- provided by `-fsched-verbose-N'. OLD_MAX_UID is the maximum insn
- uid when scheduling begins.
-
- -- Target Hook: void TARGET_SCHED_FINISH_GLOBAL (FILE *FILE, int
- VERBOSE)
- This is the cleanup hook corresponding to
- `TARGET_SCHED_INIT_GLOBAL'. FILE is either a null pointer, or a
- stdio stream to write any debug output to. VERBOSE is the verbose
- level provided by `-fsched-verbose-N'.
-
- -- Target Hook: int TARGET_SCHED_DFA_PRE_CYCLE_INSN (void)
- The hook returns an RTL insn. The automaton state used in the
- pipeline hazard recognizer is changed as if the insn were scheduled
- when the new simulated processor cycle starts. Usage of the hook
- may simplify the automaton pipeline description for some VLIW
- processors. If the hook is defined, it is used only for the
- automaton based pipeline description. The default is not to
- change the state when the new simulated processor cycle starts.
-
- -- Target Hook: void TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN (void)
- The hook can be used to initialize data used by the previous hook.
-
- -- Target Hook: int TARGET_SCHED_DFA_POST_CYCLE_INSN (void)
- The hook is analogous to `TARGET_SCHED_DFA_PRE_CYCLE_INSN' but used
- to changed the state as if the insn were scheduled when the new
- simulated processor cycle finishes.
-
- -- Target Hook: void TARGET_SCHED_INIT_DFA_POST_CYCLE_INSN (void)
- The hook is analogous to `TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN' but
- used to initialize data used by the previous hook.
-
- -- Target Hook: void TARGET_SCHED_DFA_PRE_CYCLE_ADVANCE (void)
- The hook to notify target that the current simulated cycle is
- about to finish. The hook is analogous to
- `TARGET_SCHED_DFA_PRE_CYCLE_INSN' but used to change the state in
- more complicated situations - e.g., when advancing state on a
- single insn is not enough.
-
- -- Target Hook: void TARGET_SCHED_DFA_POST_CYCLE_ADVANCE (void)
- The hook to notify target that new simulated cycle has just
- started. The hook is analogous to
- `TARGET_SCHED_DFA_POST_CYCLE_INSN' but used to change the state in
- more complicated situations - e.g., when advancing state on a
- single insn is not enough.
-
- -- Target Hook: int TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD
- (void)
- This hook controls better choosing an insn from the ready insn
- queue for the DFA-based insn scheduler. Usually the scheduler
- chooses the first insn from the queue. If the hook returns a
- positive value, an additional scheduler code tries all
- permutations of `TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD
- ()' subsequent ready insns to choose an insn whose issue will
- result in maximal number of issued insns on the same cycle. For
- the VLIW processor, the code could actually solve the problem of
- packing simple insns into the VLIW insn. Of course, if the rules
- of VLIW packing are described in the automaton.
-
- This code also could be used for superscalar RISC processors. Let
- us consider a superscalar RISC processor with 3 pipelines. Some
- insns can be executed in pipelines A or B, some insns can be
- executed only in pipelines B or C, and one insn can be executed in
- pipeline B. The processor may issue the 1st insn into A and the
- 2nd one into B. In this case, the 3rd insn will wait for freeing B
- until the next cycle. If the scheduler issues the 3rd insn the
- first, the processor could issue all 3 insns per cycle.
-
- Actually this code demonstrates advantages of the automaton based
- pipeline hazard recognizer. We try quickly and easy many insn
- schedules to choose the best one.
-
- The default is no multipass scheduling.
-
- -- Target Hook: int
-TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD (rtx)
- This hook controls what insns from the ready insn queue will be
- considered for the multipass insn scheduling. If the hook returns
- zero for insn passed as the parameter, the insn will be not chosen
- to be issued.
-
- The default is that any ready insns can be chosen to be issued.
-
- -- Target Hook: int TARGET_SCHED_DFA_NEW_CYCLE (FILE *, int, rtx, int,
- int, int *)
- This hook is called by the insn scheduler before issuing insn
- passed as the third parameter on given cycle. If the hook returns
- nonzero, the insn is not issued on given processors cycle.
- Instead of that, the processor cycle is advanced. If the value
- passed through the last parameter is zero, the insn ready queue is
- not sorted on the new cycle start as usually. The first parameter
- passes file for debugging output. The second one passes the
- scheduler verbose level of the debugging output. The forth and
- the fifth parameter values are correspondingly processor cycle on
- which the previous insn has been issued and the current processor
- cycle.
-
- -- Target Hook: bool TARGET_SCHED_IS_COSTLY_DEPENDENCE (struct dep_def
- *_DEP, int COST, int DISTANCE)
- This hook is used to define which dependences are considered
- costly by the target, so costly that it is not advisable to
- schedule the insns that are involved in the dependence too close
- to one another. The parameters to this hook are as follows: The
- first parameter _DEP is the dependence being evaluated. The
- second parameter COST is the cost of the dependence, and the third
- parameter DISTANCE is the distance in cycles between the two insns.
- The hook returns `true' if considering the distance between the two
- insns the dependence between them is considered costly by the
- target, and `false' otherwise.
-
- Defining this hook can be useful in multiple-issue out-of-order
- machines, where (a) it's practically hopeless to predict the
- actual data/resource delays, however: (b) there's a better chance
- to predict the actual grouping that will be formed, and (c)
- correctly emulating the grouping can be very important. In such
- targets one may want to allow issuing dependent insns closer to
- one another--i.e., closer than the dependence distance; however,
- not in cases of "costly dependences", which this hooks allows to
- define.
-
- -- Target Hook: void TARGET_SCHED_H_I_D_EXTENDED (void)
- This hook is called by the insn scheduler after emitting a new
- instruction to the instruction stream. The hook notifies a target
- backend to extend its per instruction data structures.
-
- -- Target Hook: void * TARGET_SCHED_ALLOC_SCHED_CONTEXT (void)
- Return a pointer to a store large enough to hold target scheduling
- context.
-
- -- Target Hook: void TARGET_SCHED_INIT_SCHED_CONTEXT (void *TC, bool
- CLEAN_P)
- Initialize store pointed to by TC to hold target scheduling
- context. It CLEAN_P is true then initialize TC as if scheduler is
- at the beginning of the block. Otherwise, make a copy of the
- current context in TC.
-
- -- Target Hook: void TARGET_SCHED_SET_SCHED_CONTEXT (void *TC)
- Copy target scheduling context pointer to by TC to the current
- context.
-
- -- Target Hook: void TARGET_SCHED_CLEAR_SCHED_CONTEXT (void *TC)
- Deallocate internal data in target scheduling context pointed to
- by TC.
-
- -- Target Hook: void TARGET_SCHED_FREE_SCHED_CONTEXT (void *TC)
- Deallocate a store for target scheduling context pointed to by TC.
-
- -- Target Hook: void * TARGET_SCHED_ALLOC_SCHED_CONTEXT (void)
- Return a pointer to a store large enough to hold target scheduling
- context.
-
- -- Target Hook: void TARGET_SCHED_INIT_SCHED_CONTEXT (void *TC, bool
- CLEAN_P)
- Initialize store pointed to by TC to hold target scheduling
- context. It CLEAN_P is true then initialize TC as if scheduler is
- at the beginning of the block. Otherwise, make a copy of the
- current context in TC.
-
- -- Target Hook: void TARGET_SCHED_SET_SCHED_CONTEXT (void *TC)
- Copy target scheduling context pointer to by TC to the current
- context.
-
- -- Target Hook: void TARGET_SCHED_CLEAR_SCHED_CONTEXT (void *TC)
- Deallocate internal data in target scheduling context pointed to
- by TC.
-
- -- Target Hook: void TARGET_SCHED_FREE_SCHED_CONTEXT (void *TC)
- Deallocate a store for target scheduling context pointed to by TC.
-
- -- Target Hook: int TARGET_SCHED_SPECULATE_INSN (rtx INSN, int
- REQUEST, rtx *NEW_PAT)
- This hook is called by the insn scheduler when INSN has only
- speculative dependencies and therefore can be scheduled
- speculatively. The hook is used to check if the pattern of INSN
- has a speculative version and, in case of successful check, to
- generate that speculative pattern. The hook should return 1, if
- the instruction has a speculative form, or -1, if it doesn't.
- REQUEST describes the type of requested speculation. If the
- return value equals 1 then NEW_PAT is assigned the generated
- speculative pattern.
-
- -- Target Hook: int TARGET_SCHED_NEEDS_BLOCK_P (rtx INSN)
- This hook is called by the insn scheduler during generation of
- recovery code for INSN. It should return nonzero, if the
- corresponding check instruction should branch to recovery code, or
- zero otherwise.
-
- -- Target Hook: rtx TARGET_SCHED_GEN_CHECK (rtx INSN, rtx LABEL, int
- MUTATE_P)
- This hook is called by the insn scheduler to generate a pattern
- for recovery check instruction. If MUTATE_P is zero, then INSN is
- a speculative instruction for which the check should be generated.
- LABEL is either a label of a basic block, where recovery code
- should be emitted, or a null pointer, when requested check doesn't
- branch to recovery code (a simple check). If MUTATE_P is nonzero,
- then a pattern for a branchy check corresponding to a simple check
- denoted by INSN should be generated. In this case LABEL can't be
- null.
-
- -- Target Hook: int
-TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD_SPEC (rtx INSN)
- This hook is used as a workaround for
- `TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD' not being
- called on the first instruction of the ready list. The hook is
- used to discard speculative instruction that stand first in the
- ready list from being scheduled on the current cycle. For
- non-speculative instructions, the hook should always return
- nonzero. For example, in the ia64 backend the hook is used to
- cancel data speculative insns when the ALAT table is nearly full.
-
- -- Target Hook: void TARGET_SCHED_SET_SCHED_FLAGS (unsigned int
- *FLAGS, spec_info_t SPEC_INFO)
- This hook is used by the insn scheduler to find out what features
- should be enabled/used. FLAGS initially may have either the
- SCHED_RGN or SCHED_EBB bit set. This denotes the scheduler pass
- for which the data should be provided. The target backend should
- modify FLAGS by modifying the bits corresponding to the following
- features: USE_DEPS_LIST, USE_GLAT, DETACH_LIFE_INFO, and
- DO_SPECULATION. For the DO_SPECULATION feature an additional
- structure SPEC_INFO should be filled by the target. The structure
- describes speculation types that can be used in the scheduler.
-
- -- Target Hook: int TARGET_SCHED_SMS_RES_MII (struct ddg *G)
- This hook is called by the swing modulo scheduler to calculate a
- resource-based lower bound which is based on the resources
- available in the machine and the resources required by each
- instruction. The target backend can use G to calculate such
- bound. A very simple lower bound will be used in case this hook
- is not implemented: the total number of instructions divided by
- the issue rate.
-
-\1f
-File: gccint.info, Node: Sections, Next: PIC, Prev: Scheduling, Up: Target Macros
-
-17.19 Dividing the Output into Sections (Texts, Data, ...)
-==========================================================
-
-An object file is divided into sections containing different types of
-data. In the most common case, there are three sections: the "text
-section", which holds instructions and read-only data; the "data
-section", which holds initialized writable data; and the "bss section",
-which holds uninitialized data. Some systems have other kinds of
-sections.
-
- `varasm.c' provides several well-known sections, such as
-`text_section', `data_section' and `bss_section'. The normal way of
-controlling a `FOO_section' variable is to define the associated
-`FOO_SECTION_ASM_OP' macro, as described below. The macros are only
-read once, when `varasm.c' initializes itself, so their values must be
-run-time constants. They may however depend on command-line flags.
-
- _Note:_ Some run-time files, such `crtstuff.c', also make use of the
-`FOO_SECTION_ASM_OP' macros, and expect them to be string literals.
-
- Some assemblers require a different string to be written every time a
-section is selected. If your assembler falls into this category, you
-should define the `TARGET_ASM_INIT_SECTIONS' hook and use
-`get_unnamed_section' to set up the sections.
-
- You must always create a `text_section', either by defining
-`TEXT_SECTION_ASM_OP' or by initializing `text_section' in
-`TARGET_ASM_INIT_SECTIONS'. The same is true of `data_section' and
-`DATA_SECTION_ASM_OP'. If you do not create a distinct
-`readonly_data_section', the default is to reuse `text_section'.
-
- All the other `varasm.c' sections are optional, and are null if the
-target does not provide them.
-
- -- Macro: TEXT_SECTION_ASM_OP
- A C expression whose value is a string, including spacing,
- containing the assembler operation that should precede
- instructions and read-only data. Normally `"\t.text"' is right.
-
- -- Macro: HOT_TEXT_SECTION_NAME
- If defined, a C string constant for the name of the section
- containing most frequently executed functions of the program. If
- not defined, GCC will provide a default definition if the target
- supports named sections.
-
- -- Macro: UNLIKELY_EXECUTED_TEXT_SECTION_NAME
- If defined, a C string constant for the name of the section
- containing unlikely executed functions in the program.
-
- -- Macro: DATA_SECTION_ASM_OP
- A C expression whose value is a string, including spacing,
- containing the assembler operation to identify the following data
- as writable initialized data. Normally `"\t.data"' is right.
-
- -- Macro: SDATA_SECTION_ASM_OP
- If defined, a C expression whose value is a string, including
- spacing, containing the assembler operation to identify the
- following data as initialized, writable small data.
-
- -- Macro: READONLY_DATA_SECTION_ASM_OP
- A C expression whose value is a string, including spacing,
- containing the assembler operation to identify the following data
- as read-only initialized data.
-
- -- Macro: BSS_SECTION_ASM_OP
- If defined, a C expression whose value is a string, including
- spacing, containing the assembler operation to identify the
- following data as uninitialized global data. If not defined, and
- neither `ASM_OUTPUT_BSS' nor `ASM_OUTPUT_ALIGNED_BSS' are defined,
- uninitialized global data will be output in the data section if
- `-fno-common' is passed, otherwise `ASM_OUTPUT_COMMON' will be
- used.
-
- -- Macro: SBSS_SECTION_ASM_OP
- If defined, a C expression whose value is a string, including
- spacing, containing the assembler operation to identify the
- following data as uninitialized, writable small data.
-
- -- Macro: INIT_SECTION_ASM_OP
- If defined, a C expression whose value is a string, including
- spacing, containing the assembler operation to identify the
- following data as initialization code. If not defined, GCC will
- assume such a section does not exist. This section has no
- corresponding `init_section' variable; it is used entirely in
- runtime code.
-
- -- Macro: FINI_SECTION_ASM_OP
- If defined, a C expression whose value is a string, including
- spacing, containing the assembler operation to identify the
- following data as finalization code. If not defined, GCC will
- assume such a section does not exist. This section has no
- corresponding `fini_section' variable; it is used entirely in
- runtime code.
-
- -- Macro: INIT_ARRAY_SECTION_ASM_OP
- If defined, a C expression whose value is a string, including
- spacing, containing the assembler operation to identify the
- following data as part of the `.init_array' (or equivalent)
- section. If not defined, GCC will assume such a section does not
- exist. Do not define both this macro and `INIT_SECTION_ASM_OP'.
-
- -- Macro: FINI_ARRAY_SECTION_ASM_OP
- If defined, a C expression whose value is a string, including
- spacing, containing the assembler operation to identify the
- following data as part of the `.fini_array' (or equivalent)
- section. If not defined, GCC will assume such a section does not
- exist. Do not define both this macro and `FINI_SECTION_ASM_OP'.
-
- -- Macro: CRT_CALL_STATIC_FUNCTION (SECTION_OP, FUNCTION)
- If defined, an ASM statement that switches to a different section
- via SECTION_OP, calls FUNCTION, and switches back to the text
- section. This is used in `crtstuff.c' if `INIT_SECTION_ASM_OP' or
- `FINI_SECTION_ASM_OP' to calls to initialization and finalization
- functions from the init and fini sections. By default, this macro
- uses a simple function call. Some ports need hand-crafted
- assembly code to avoid dependencies on registers initialized in
- the function prologue or to ensure that constant pools don't end
- up too far way in the text section.
-
- -- Macro: TARGET_LIBGCC_SDATA_SECTION
- If defined, a string which names the section into which small
- variables defined in crtstuff and libgcc should go. This is useful
- when the target has options for optimizing access to small data,
- and you want the crtstuff and libgcc routines to be conservative
- in what they expect of your application yet liberal in what your
- application expects. For example, for targets with a `.sdata'
- section (like MIPS), you could compile crtstuff with `-G 0' so
- that it doesn't require small data support from your application,
- but use this macro to put small data into `.sdata' so that your
- application can access these variables whether it uses small data
- or not.
-
- -- Macro: FORCE_CODE_SECTION_ALIGN
- If defined, an ASM statement that aligns a code section to some
- arbitrary boundary. This is used to force all fragments of the
- `.init' and `.fini' sections to have to same alignment and thus
- prevent the linker from having to add any padding.
-
- -- Macro: JUMP_TABLES_IN_TEXT_SECTION
- Define this macro to be an expression with a nonzero value if jump
- tables (for `tablejump' insns) should be output in the text
- section, along with the assembler instructions. Otherwise, the
- readonly data section is used.
-
- This macro is irrelevant if there is no separate readonly data
- section.
-
- -- Target Hook: void TARGET_ASM_INIT_SECTIONS (void)
- Define this hook if you need to do something special to set up the
- `varasm.c' sections, or if your target has some special sections
- of its own that you need to create.
-
- GCC calls this hook after processing the command line, but before
- writing any assembly code, and before calling any of the
- section-returning hooks described below.
-
- -- Target Hook: TARGET_ASM_RELOC_RW_MASK (void)
- Return a mask describing how relocations should be treated when
- selecting sections. Bit 1 should be set if global relocations
- should be placed in a read-write section; bit 0 should be set if
- local relocations should be placed in a read-write section.
-
- The default version of this function returns 3 when `-fpic' is in
- effect, and 0 otherwise. The hook is typically redefined when the
- target cannot support (some kinds of) dynamic relocations in
- read-only sections even in executables.
-
- -- Target Hook: section * TARGET_ASM_SELECT_SECTION (tree EXP, int
- RELOC, unsigned HOST_WIDE_INT ALIGN)
- Return the section into which EXP should be placed. You can
- assume that EXP is either a `VAR_DECL' node or a constant of some
- sort. RELOC indicates whether the initial value of EXP requires
- link-time relocations. Bit 0 is set when variable contains local
- relocations only, while bit 1 is set for global relocations.
- ALIGN is the constant alignment in bits.
-
- The default version of this function takes care of putting
- read-only variables in `readonly_data_section'.
-
- See also USE_SELECT_SECTION_FOR_FUNCTIONS.
-
- -- Macro: USE_SELECT_SECTION_FOR_FUNCTIONS
- Define this macro if you wish TARGET_ASM_SELECT_SECTION to be
- called for `FUNCTION_DECL's as well as for variables and constants.
-
- In the case of a `FUNCTION_DECL', RELOC will be zero if the
- function has been determined to be likely to be called, and
- nonzero if it is unlikely to be called.
-
- -- Target Hook: void TARGET_ASM_UNIQUE_SECTION (tree DECL, int RELOC)
- Build up a unique section name, expressed as a `STRING_CST' node,
- and assign it to `DECL_SECTION_NAME (DECL)'. As with
- `TARGET_ASM_SELECT_SECTION', RELOC indicates whether the initial
- value of EXP requires link-time relocations.
-
- The default version of this function appends the symbol name to the
- ELF section name that would normally be used for the symbol. For
- example, the function `foo' would be placed in `.text.foo'.
- Whatever the actual target object format, this is often good
- enough.
-
- -- Target Hook: section * TARGET_ASM_FUNCTION_RODATA_SECTION (tree
- DECL)
- Return the readonly data section associated with
- `DECL_SECTION_NAME (DECL)'. The default version of this function
- selects `.gnu.linkonce.r.name' if the function's section is
- `.gnu.linkonce.t.name', `.rodata.name' if function is in
- `.text.name', and the normal readonly-data section otherwise.
-
- -- Target Hook: section * TARGET_ASM_SELECT_RTX_SECTION (enum
- machine_mode MODE, rtx X, unsigned HOST_WIDE_INT ALIGN)
- Return the section into which a constant X, of mode MODE, should
- be placed. You can assume that X is some kind of constant in RTL.
- The argument MODE is redundant except in the case of a `const_int'
- rtx. ALIGN is the constant alignment in bits.
-
- The default version of this function takes care of putting symbolic
- constants in `flag_pic' mode in `data_section' and everything else
- in `readonly_data_section'.
-
- -- Target Hook: void TARGET_MANGLE_DECL_ASSEMBLER_NAME (tree DECL,
- tree ID)
- Define this hook if you need to postprocess the assembler name
- generated by target-independent code. The ID provided to this
- hook will be the computed name (e.g., the macro `DECL_NAME' of the
- DECL in C, or the mangled name of the DECL in C++). The return
- value of the hook is an `IDENTIFIER_NODE' for the appropriate
- mangled name on your target system. The default implementation of
- this hook just returns the ID provided.
-
- -- Target Hook: void TARGET_ENCODE_SECTION_INFO (tree DECL, rtx RTL,
- int NEW_DECL_P)
- Define this hook if references to a symbol or a constant must be
- treated differently depending on something about the variable or
- function named by the symbol (such as what section it is in).
-
- The hook is executed immediately after rtl has been created for
- DECL, which may be a variable or function declaration or an entry
- in the constant pool. In either case, RTL is the rtl in question.
- Do _not_ use `DECL_RTL (DECL)' in this hook; that field may not
- have been initialized yet.
-
- In the case of a constant, it is safe to assume that the rtl is a
- `mem' whose address is a `symbol_ref'. Most decls will also have
- this form, but that is not guaranteed. Global register variables,
- for instance, will have a `reg' for their rtl. (Normally the
- right thing to do with such unusual rtl is leave it alone.)
-
- The NEW_DECL_P argument will be true if this is the first time
- that `TARGET_ENCODE_SECTION_INFO' has been invoked on this decl.
- It will be false for subsequent invocations, which will happen for
- duplicate declarations. Whether or not anything must be done for
- the duplicate declaration depends on whether the hook examines
- `DECL_ATTRIBUTES'. NEW_DECL_P is always true when the hook is
- called for a constant.
-
- The usual thing for this hook to do is to record flags in the
- `symbol_ref', using `SYMBOL_REF_FLAG' or `SYMBOL_REF_FLAGS'.
- Historically, the name string was modified if it was necessary to
- encode more than one bit of information, but this practice is now
- discouraged; use `SYMBOL_REF_FLAGS'.
-
- The default definition of this hook, `default_encode_section_info'
- in `varasm.c', sets a number of commonly-useful bits in
- `SYMBOL_REF_FLAGS'. Check whether the default does what you need
- before overriding it.
-
- -- Target Hook: const char *TARGET_STRIP_NAME_ENCODING (const char
- *name)
- Decode NAME and return the real name part, sans the characters
- that `TARGET_ENCODE_SECTION_INFO' may have added.
-
- -- Target Hook: bool TARGET_IN_SMALL_DATA_P (tree EXP)
- Returns true if EXP should be placed into a "small data" section.
- The default version of this hook always returns false.
-
- -- Variable: Target Hook bool TARGET_HAVE_SRODATA_SECTION
- Contains the value true if the target places read-only "small
- data" into a separate section. The default value is false.
-
- -- Target Hook: bool TARGET_BINDS_LOCAL_P (tree EXP)
- Returns true if EXP names an object for which name resolution
- rules must resolve to the current "module" (dynamic shared library
- or executable image).
-
- The default version of this hook implements the name resolution
- rules for ELF, which has a looser model of global name binding
- than other currently supported object file formats.
-
- -- Variable: Target Hook bool TARGET_HAVE_TLS
- Contains the value true if the target supports thread-local
- storage. The default value is false.
-
-\1f
-File: gccint.info, Node: PIC, Next: Assembler Format, Prev: Sections, Up: Target Macros
-
-17.20 Position Independent Code
-===============================
-
-This section describes macros that help implement generation of position
-independent code. Simply defining these macros is not enough to
-generate valid PIC; you must also add support to the macros
-`GO_IF_LEGITIMATE_ADDRESS' and `PRINT_OPERAND_ADDRESS', as well as
-`LEGITIMIZE_ADDRESS'. You must modify the definition of `movsi' to do
-something appropriate when the source operand contains a symbolic
-address. You may also need to alter the handling of switch statements
-so that they use relative addresses.
-
- -- Macro: PIC_OFFSET_TABLE_REGNUM
- The register number of the register used to address a table of
- static data addresses in memory. In some cases this register is
- defined by a processor's "application binary interface" (ABI).
- When this macro is defined, RTL is generated for this register
- once, as with the stack pointer and frame pointer registers. If
- this macro is not defined, it is up to the machine-dependent files
- to allocate such a register (if necessary). Note that this
- register must be fixed when in use (e.g. when `flag_pic' is true).
-
- -- Macro: PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
- Define this macro if the register defined by
- `PIC_OFFSET_TABLE_REGNUM' is clobbered by calls. Do not define
- this macro if `PIC_OFFSET_TABLE_REGNUM' is not defined.
-
- -- Macro: LEGITIMATE_PIC_OPERAND_P (X)
- A C expression that is nonzero if X is a legitimate immediate
- operand on the target machine when generating position independent
- code. You can assume that X satisfies `CONSTANT_P', so you need
- not check this. You can also assume FLAG_PIC is true, so you need
- not check it either. You need not define this macro if all
- constants (including `SYMBOL_REF') can be immediate operands when
- generating position independent code.
-
-\1f
-File: gccint.info, Node: Assembler Format, Next: Debugging Info, Prev: PIC, Up: Target Macros
-
-17.21 Defining the Output Assembler Language
-============================================
-
-This section describes macros whose principal purpose is to describe how
-to write instructions in assembler language--rather than what the
-instructions do.
-
-* Menu:
-
-* File Framework:: Structural information for the assembler file.
-* Data Output:: Output of constants (numbers, strings, addresses).
-* Uninitialized Data:: Output of uninitialized variables.
-* Label Output:: Output and generation of labels.
-* Initialization:: General principles of initialization
- and termination routines.
-* Macros for Initialization::
- Specific macros that control the handling of
- initialization and termination routines.
-* Instruction Output:: Output of actual instructions.
-* Dispatch Tables:: Output of jump tables.
-* Exception Region Output:: Output of exception region code.
-* Alignment Output:: Pseudo ops for alignment and skipping data.
-
-\1f
-File: gccint.info, Node: File Framework, Next: Data Output, Up: Assembler Format
-
-17.21.1 The Overall Framework of an Assembler File
---------------------------------------------------
-
-This describes the overall framework of an assembly file.
-
- -- Target Hook: void TARGET_ASM_FILE_START ()
- Output to `asm_out_file' any text which the assembler expects to
- find at the beginning of a file. The default behavior is
- controlled by two flags, documented below. Unless your target's
- assembler is quite unusual, if you override the default, you
- should call `default_file_start' at some point in your target
- hook. This lets other target files rely on these variables.
-
- -- Target Hook: bool TARGET_ASM_FILE_START_APP_OFF
- If this flag is true, the text of the macro `ASM_APP_OFF' will be
- printed as the very first line in the assembly file, unless
- `-fverbose-asm' is in effect. (If that macro has been defined to
- the empty string, this variable has no effect.) With the normal
- definition of `ASM_APP_OFF', the effect is to notify the GNU
- assembler that it need not bother stripping comments or extra
- whitespace from its input. This allows it to work a bit faster.
-
- The default is false. You should not set it to true unless you
- have verified that your port does not generate any extra
- whitespace or comments that will cause GAS to issue errors in
- NO_APP mode.
-
- -- Target Hook: bool TARGET_ASM_FILE_START_FILE_DIRECTIVE
- If this flag is true, `output_file_directive' will be called for
- the primary source file, immediately after printing `ASM_APP_OFF'
- (if that is enabled). Most ELF assemblers expect this to be done.
- The default is false.
-
- -- Target Hook: void TARGET_ASM_FILE_END ()
- Output to `asm_out_file' any text which the assembler expects to
- find at the end of a file. The default is to output nothing.
-
- -- Function: void file_end_indicate_exec_stack ()
- Some systems use a common convention, the `.note.GNU-stack'
- special section, to indicate whether or not an object file relies
- on the stack being executable. If your system uses this
- convention, you should define `TARGET_ASM_FILE_END' to this
- function. If you need to do other things in that hook, have your
- hook function call this function.
-
- -- Macro: ASM_COMMENT_START
- A C string constant describing how to begin a comment in the target
- assembler language. The compiler assumes that the comment will
- end at the end of the line.
-
- -- Macro: ASM_APP_ON
- A C string constant for text to be output before each `asm'
- statement or group of consecutive ones. Normally this is
- `"#APP"', which is a comment that has no effect on most assemblers
- but tells the GNU assembler that it must check the lines that
- follow for all valid assembler constructs.
-
- -- Macro: ASM_APP_OFF
- A C string constant for text to be output after each `asm'
- statement or group of consecutive ones. Normally this is
- `"#NO_APP"', which tells the GNU assembler to resume making the
- time-saving assumptions that are valid for ordinary compiler
- output.
-
- -- Macro: ASM_OUTPUT_SOURCE_FILENAME (STREAM, NAME)
- A C statement to output COFF information or DWARF debugging
- information which indicates that filename NAME is the current
- source file to the stdio stream STREAM.
-
- This macro need not be defined if the standard form of output for
- the file format in use is appropriate.
-
- -- Macro: OUTPUT_QUOTED_STRING (STREAM, STRING)
- A C statement to output the string STRING to the stdio stream
- STREAM. If you do not call the function `output_quoted_string' in
- your config files, GCC will only call it to output filenames to
- the assembler source. So you can use it to canonicalize the format
- of the filename using this macro.
-
- -- Macro: ASM_OUTPUT_IDENT (STREAM, STRING)
- A C statement to output something to the assembler file to handle a
- `#ident' directive containing the text STRING. If this macro is
- not defined, nothing is output for a `#ident' directive.
-
- -- Target Hook: void TARGET_ASM_NAMED_SECTION (const char *NAME,
- unsigned int FLAGS, unsigned int ALIGN)
- Output assembly directives to switch to section NAME. The section
- should have attributes as specified by FLAGS, which is a bit mask
- of the `SECTION_*' flags defined in `output.h'. If ALIGN is
- nonzero, it contains an alignment in bytes to be used for the
- section, otherwise some target default should be used. Only
- targets that must specify an alignment within the section
- directive need pay attention to ALIGN - we will still use
- `ASM_OUTPUT_ALIGN'.
-
- -- Target Hook: bool TARGET_HAVE_NAMED_SECTIONS
- This flag is true if the target supports
- `TARGET_ASM_NAMED_SECTION'.
-
- -- Target Hook: bool TARGET_HAVE_SWITCHABLE_BSS_SECTIONS
- This flag is true if we can create zeroed data by switching to a
- BSS section and then using `ASM_OUTPUT_SKIP' to allocate the space.
- This is true on most ELF targets.
-
- -- Target Hook: unsigned int TARGET_SECTION_TYPE_FLAGS (tree DECL,
- const char *NAME, int RELOC)
- Choose a set of section attributes for use by
- `TARGET_ASM_NAMED_SECTION' based on a variable or function decl, a
- section name, and whether or not the declaration's initializer may
- contain runtime relocations. DECL may be null, in which case
- read-write data should be assumed.
-
- The default version of this function handles choosing code vs data,
- read-only vs read-write data, and `flag_pic'. You should only
- need to override this if your target has special flags that might
- be set via `__attribute__'.
-
- -- Target Hook: int TARGET_ASM_RECORD_GCC_SWITCHES (print_switch_type
- TYPE, const char * TEXT)
- Provides the target with the ability to record the gcc command line
- switches that have been passed to the compiler, and options that
- are enabled. The TYPE argument specifies what is being recorded.
- It can take the following values:
-
- `SWITCH_TYPE_PASSED'
- TEXT is a command line switch that has been set by the user.
-
- `SWITCH_TYPE_ENABLED'
- TEXT is an option which has been enabled. This might be as a
- direct result of a command line switch, or because it is
- enabled by default or because it has been enabled as a side
- effect of a different command line switch. For example, the
- `-O2' switch enables various different individual
- optimization passes.
-
- `SWITCH_TYPE_DESCRIPTIVE'
- TEXT is either NULL or some descriptive text which should be
- ignored. If TEXT is NULL then it is being used to warn the
- target hook that either recording is starting or ending. The
- first time TYPE is SWITCH_TYPE_DESCRIPTIVE and TEXT is NULL,
- the warning is for start up and the second time the warning
- is for wind down. This feature is to allow the target hook
- to make any necessary preparations before it starts to record
- switches and to perform any necessary tidying up after it has
- finished recording switches.
-
- `SWITCH_TYPE_LINE_START'
- This option can be ignored by this target hook.
-
- `SWITCH_TYPE_LINE_END'
- This option can be ignored by this target hook.
-
- The hook's return value must be zero. Other return values may be
- supported in the future.
-
- By default this hook is set to NULL, but an example implementation
- is provided for ELF based targets. Called ELF_RECORD_GCC_SWITCHES,
- it records the switches as ASCII text inside a new, string
- mergeable section in the assembler output file. The name of the
- new section is provided by the
- `TARGET_ASM_RECORD_GCC_SWITCHES_SECTION' target hook.
-
- -- Target Hook: const char * TARGET_ASM_RECORD_GCC_SWITCHES_SECTION
- This is the name of the section that will be created by the example
- ELF implementation of the `TARGET_ASM_RECORD_GCC_SWITCHES' target
- hook.
-
-\1f
-File: gccint.info, Node: Data Output, Next: Uninitialized Data, Prev: File Framework, Up: Assembler Format
-
-17.21.2 Output of Data
-----------------------
-
- -- Target Hook: const char * TARGET_ASM_BYTE_OP
- -- Target Hook: const char * TARGET_ASM_ALIGNED_HI_OP
- -- Target Hook: const char * TARGET_ASM_ALIGNED_SI_OP
- -- Target Hook: const char * TARGET_ASM_ALIGNED_DI_OP
- -- Target Hook: const char * TARGET_ASM_ALIGNED_TI_OP
- -- Target Hook: const char * TARGET_ASM_UNALIGNED_HI_OP
- -- Target Hook: const char * TARGET_ASM_UNALIGNED_SI_OP
- -- Target Hook: const char * TARGET_ASM_UNALIGNED_DI_OP
- -- Target Hook: const char * TARGET_ASM_UNALIGNED_TI_OP
- These hooks specify assembly directives for creating certain kinds
- of integer object. The `TARGET_ASM_BYTE_OP' directive creates a
- byte-sized object, the `TARGET_ASM_ALIGNED_HI_OP' one creates an
- aligned two-byte object, and so on. Any of the hooks may be
- `NULL', indicating that no suitable directive is available.
-
- The compiler will print these strings at the start of a new line,
- followed immediately by the object's initial value. In most cases,
- the string should contain a tab, a pseudo-op, and then another tab.
-
- -- Target Hook: bool TARGET_ASM_INTEGER (rtx X, unsigned int SIZE, int
- ALIGNED_P)
- The `assemble_integer' function uses this hook to output an
- integer object. X is the object's value, SIZE is its size in
- bytes and ALIGNED_P indicates whether it is aligned. The function
- should return `true' if it was able to output the object. If it
- returns false, `assemble_integer' will try to split the object
- into smaller parts.
-
- The default implementation of this hook will use the
- `TARGET_ASM_BYTE_OP' family of strings, returning `false' when the
- relevant string is `NULL'.
-
- -- Macro: OUTPUT_ADDR_CONST_EXTRA (STREAM, X, FAIL)
- A C statement to recognize RTX patterns that `output_addr_const'
- can't deal with, and output assembly code to STREAM corresponding
- to the pattern X. This may be used to allow machine-dependent
- `UNSPEC's to appear within constants.
-
- If `OUTPUT_ADDR_CONST_EXTRA' fails to recognize a pattern, it must
- `goto fail', so that a standard error message is printed. If it
- prints an error message itself, by calling, for example,
- `output_operand_lossage', it may just complete normally.
-
- -- Macro: ASM_OUTPUT_ASCII (STREAM, PTR, LEN)
- A C statement to output to the stdio stream STREAM an assembler
- instruction to assemble a string constant containing the LEN bytes
- at PTR. PTR will be a C expression of type `char *' and LEN a C
- expression of type `int'.
-
- If the assembler has a `.ascii' pseudo-op as found in the Berkeley
- Unix assembler, do not define the macro `ASM_OUTPUT_ASCII'.
-
- -- Macro: ASM_OUTPUT_FDESC (STREAM, DECL, N)
- A C statement to output word N of a function descriptor for DECL.
- This must be defined if `TARGET_VTABLE_USES_DESCRIPTORS' is
- defined, and is otherwise unused.
-
- -- Macro: CONSTANT_POOL_BEFORE_FUNCTION
- You may define this macro as a C expression. You should define the
- expression to have a nonzero value if GCC should output the
- constant pool for a function before the code for the function, or
- a zero value if GCC should output the constant pool after the
- function. If you do not define this macro, the usual case, GCC
- will output the constant pool before the function.
-
- -- Macro: ASM_OUTPUT_POOL_PROLOGUE (FILE, FUNNAME, FUNDECL, SIZE)
- A C statement to output assembler commands to define the start of
- the constant pool for a function. FUNNAME is a string giving the
- name of the function. Should the return type of the function be
- required, it can be obtained via FUNDECL. SIZE is the size, in
- bytes, of the constant pool that will be written immediately after
- this call.
-
- If no constant-pool prefix is required, the usual case, this macro
- need not be defined.
-
- -- Macro: ASM_OUTPUT_SPECIAL_POOL_ENTRY (FILE, X, MODE, ALIGN,
- LABELNO, JUMPTO)
- A C statement (with or without semicolon) to output a constant in
- the constant pool, if it needs special treatment. (This macro
- need not do anything for RTL expressions that can be output
- normally.)
-
- The argument FILE is the standard I/O stream to output the
- assembler code on. X is the RTL expression for the constant to
- output, and MODE is the machine mode (in case X is a `const_int').
- ALIGN is the required alignment for the value X; you should output
- an assembler directive to force this much alignment.
-
- The argument LABELNO is a number to use in an internal label for
- the address of this pool entry. The definition of this macro is
- responsible for outputting the label definition at the proper
- place. Here is how to do this:
-
- `(*targetm.asm_out.internal_label)' (FILE, "LC", LABELNO);
-
- When you output a pool entry specially, you should end with a
- `goto' to the label JUMPTO. This will prevent the same pool entry
- from being output a second time in the usual manner.
-
- You need not define this macro if it would do nothing.
-
- -- Macro: ASM_OUTPUT_POOL_EPILOGUE (FILE FUNNAME FUNDECL SIZE)
- A C statement to output assembler commands to at the end of the
- constant pool for a function. FUNNAME is a string giving the name
- of the function. Should the return type of the function be
- required, you can obtain it via FUNDECL. SIZE is the size, in
- bytes, of the constant pool that GCC wrote immediately before this
- call.
-
- If no constant-pool epilogue is required, the usual case, you need
- not define this macro.
-
- -- Macro: IS_ASM_LOGICAL_LINE_SEPARATOR (C, STR)
- Define this macro as a C expression which is nonzero if C is used
- as a logical line separator by the assembler. STR points to the
- position in the string where C was found; this can be used if a
- line separator uses multiple characters.
-
- If you do not define this macro, the default is that only the
- character `;' is treated as a logical line separator.
-
- -- Target Hook: const char * TARGET_ASM_OPEN_PAREN
- -- Target Hook: const char * TARGET_ASM_CLOSE_PAREN
- These target hooks are C string constants, describing the syntax
- in the assembler for grouping arithmetic expressions. If not
- overridden, they default to normal parentheses, which is correct
- for most assemblers.
-
- These macros are provided by `real.h' for writing the definitions of
-`ASM_OUTPUT_DOUBLE' and the like:
-
- -- Macro: REAL_VALUE_TO_TARGET_SINGLE (X, L)
- -- Macro: REAL_VALUE_TO_TARGET_DOUBLE (X, L)
- -- Macro: REAL_VALUE_TO_TARGET_LONG_DOUBLE (X, L)
- -- Macro: REAL_VALUE_TO_TARGET_DECIMAL32 (X, L)
- -- Macro: REAL_VALUE_TO_TARGET_DECIMAL64 (X, L)
- -- Macro: REAL_VALUE_TO_TARGET_DECIMAL128 (X, L)
- These translate X, of type `REAL_VALUE_TYPE', to the target's
- floating point representation, and store its bit pattern in the
- variable L. For `REAL_VALUE_TO_TARGET_SINGLE' and
- `REAL_VALUE_TO_TARGET_DECIMAL32', this variable should be a simple
- `long int'. For the others, it should be an array of `long int'.
- The number of elements in this array is determined by the size of
- the desired target floating point data type: 32 bits of it go in
- each `long int' array element. Each array element holds 32 bits
- of the result, even if `long int' is wider than 32 bits on the
- host machine.
-
- The array element values are designed so that you can print them
- out using `fprintf' in the order they should appear in the target
- machine's memory.
-
-\1f
-File: gccint.info, Node: Uninitialized Data, Next: Label Output, Prev: Data Output, Up: Assembler Format
-
-17.21.3 Output of Uninitialized Variables
------------------------------------------
-
-Each of the macros in this section is used to do the whole job of
-outputting a single uninitialized variable.
-
- -- Macro: ASM_OUTPUT_COMMON (STREAM, NAME, SIZE, ROUNDED)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM the assembler definition of a common-label named NAME whose
- size is SIZE bytes. The variable ROUNDED is the size rounded up
- to whatever alignment the caller wants.
-
- Use the expression `assemble_name (STREAM, NAME)' to output the
- name itself; before and after that, output the additional
- assembler syntax for defining the name, and a newline.
-
- This macro controls how the assembler definitions of uninitialized
- common global variables are output.
-
- -- Macro: ASM_OUTPUT_ALIGNED_COMMON (STREAM, NAME, SIZE, ALIGNMENT)
- Like `ASM_OUTPUT_COMMON' except takes the required alignment as a
- separate, explicit argument. If you define this macro, it is used
- in place of `ASM_OUTPUT_COMMON', and gives you more flexibility in
- handling the required alignment of the variable. The alignment is
- specified as the number of bits.
-
- -- Macro: ASM_OUTPUT_ALIGNED_DECL_COMMON (STREAM, DECL, NAME, SIZE,
- ALIGNMENT)
- Like `ASM_OUTPUT_ALIGNED_COMMON' except that DECL of the variable
- to be output, if there is one, or `NULL_TREE' if there is no
- corresponding variable. If you define this macro, GCC will use it
- in place of both `ASM_OUTPUT_COMMON' and
- `ASM_OUTPUT_ALIGNED_COMMON'. Define this macro when you need to
- see the variable's decl in order to chose what to output.
-
- -- Macro: ASM_OUTPUT_BSS (STREAM, DECL, NAME, SIZE, ROUNDED)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM the assembler definition of uninitialized global DECL named
- NAME whose size is SIZE bytes. The variable ROUNDED is the size
- rounded up to whatever alignment the caller wants.
-
- Try to use function `asm_output_bss' defined in `varasm.c' when
- defining this macro. If unable, use the expression `assemble_name
- (STREAM, NAME)' to output the name itself; before and after that,
- output the additional assembler syntax for defining the name, and
- a newline.
-
- There are two ways of handling global BSS. One is to define either
- this macro or its aligned counterpart, `ASM_OUTPUT_ALIGNED_BSS'.
- The other is to have `TARGET_ASM_SELECT_SECTION' return a
- switchable BSS section (*note
- TARGET_HAVE_SWITCHABLE_BSS_SECTIONS::). You do not need to do
- both.
-
- Some languages do not have `common' data, and require a non-common
- form of global BSS in order to handle uninitialized globals
- efficiently. C++ is one example of this. However, if the target
- does not support global BSS, the front end may choose to make
- globals common in order to save space in the object file.
-
- -- Macro: ASM_OUTPUT_ALIGNED_BSS (STREAM, DECL, NAME, SIZE, ALIGNMENT)
- Like `ASM_OUTPUT_BSS' except takes the required alignment as a
- separate, explicit argument. If you define this macro, it is used
- in place of `ASM_OUTPUT_BSS', and gives you more flexibility in
- handling the required alignment of the variable. The alignment is
- specified as the number of bits.
-
- Try to use function `asm_output_aligned_bss' defined in file
- `varasm.c' when defining this macro.
-
- -- Macro: ASM_OUTPUT_LOCAL (STREAM, NAME, SIZE, ROUNDED)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM the assembler definition of a local-common-label named NAME
- whose size is SIZE bytes. The variable ROUNDED is the size
- rounded up to whatever alignment the caller wants.
-
- Use the expression `assemble_name (STREAM, NAME)' to output the
- name itself; before and after that, output the additional
- assembler syntax for defining the name, and a newline.
-
- This macro controls how the assembler definitions of uninitialized
- static variables are output.
-
- -- Macro: ASM_OUTPUT_ALIGNED_LOCAL (STREAM, NAME, SIZE, ALIGNMENT)
- Like `ASM_OUTPUT_LOCAL' except takes the required alignment as a
- separate, explicit argument. If you define this macro, it is used
- in place of `ASM_OUTPUT_LOCAL', and gives you more flexibility in
- handling the required alignment of the variable. The alignment is
- specified as the number of bits.
-
- -- Macro: ASM_OUTPUT_ALIGNED_DECL_LOCAL (STREAM, DECL, NAME, SIZE,
- ALIGNMENT)
- Like `ASM_OUTPUT_ALIGNED_DECL' except that DECL of the variable to
- be output, if there is one, or `NULL_TREE' if there is no
- corresponding variable. If you define this macro, GCC will use it
- in place of both `ASM_OUTPUT_DECL' and `ASM_OUTPUT_ALIGNED_DECL'.
- Define this macro when you need to see the variable's decl in
- order to chose what to output.
-
-\1f
-File: gccint.info, Node: Label Output, Next: Initialization, Prev: Uninitialized Data, Up: Assembler Format
-
-17.21.4 Output and Generation of Labels
----------------------------------------
-
-This is about outputting labels.
-
- -- Macro: ASM_OUTPUT_LABEL (STREAM, NAME)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM the assembler definition of a label named NAME. Use the
- expression `assemble_name (STREAM, NAME)' to output the name
- itself; before and after that, output the additional assembler
- syntax for defining the name, and a newline. A default definition
- of this macro is provided which is correct for most systems.
-
- -- Macro: ASM_OUTPUT_INTERNAL_LABEL (STREAM, NAME)
- Identical to `ASM_OUTPUT_LABEL', except that NAME is known to
- refer to a compiler-generated label. The default definition uses
- `assemble_name_raw', which is like `assemble_name' except that it
- is more efficient.
-
- -- Macro: SIZE_ASM_OP
- A C string containing the appropriate assembler directive to
- specify the size of a symbol, without any arguments. On systems
- that use ELF, the default (in `config/elfos.h') is `"\t.size\t"';
- on other systems, the default is not to define this macro.
-
- Define this macro only if it is correct to use the default
- definitions of `ASM_OUTPUT_SIZE_DIRECTIVE' and
- `ASM_OUTPUT_MEASURED_SIZE' for your system. If you need your own
- custom definitions of those macros, or if you do not need explicit
- symbol sizes at all, do not define this macro.
-
- -- Macro: ASM_OUTPUT_SIZE_DIRECTIVE (STREAM, NAME, SIZE)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM a directive telling the assembler that the size of the
- symbol NAME is SIZE. SIZE is a `HOST_WIDE_INT'. If you define
- `SIZE_ASM_OP', a default definition of this macro is provided.
-
- -- Macro: ASM_OUTPUT_MEASURED_SIZE (STREAM, NAME)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM a directive telling the assembler to calculate the size of
- the symbol NAME by subtracting its address from the current
- address.
-
- If you define `SIZE_ASM_OP', a default definition of this macro is
- provided. The default assumes that the assembler recognizes a
- special `.' symbol as referring to the current address, and can
- calculate the difference between this and another symbol. If your
- assembler does not recognize `.' or cannot do calculations with
- it, you will need to redefine `ASM_OUTPUT_MEASURED_SIZE' to use
- some other technique.
-
- -- Macro: TYPE_ASM_OP
- A C string containing the appropriate assembler directive to
- specify the type of a symbol, without any arguments. On systems
- that use ELF, the default (in `config/elfos.h') is `"\t.type\t"';
- on other systems, the default is not to define this macro.
-
- Define this macro only if it is correct to use the default
- definition of `ASM_OUTPUT_TYPE_DIRECTIVE' for your system. If you
- need your own custom definition of this macro, or if you do not
- need explicit symbol types at all, do not define this macro.
-
- -- Macro: TYPE_OPERAND_FMT
- A C string which specifies (using `printf' syntax) the format of
- the second operand to `TYPE_ASM_OP'. On systems that use ELF, the
- default (in `config/elfos.h') is `"@%s"'; on other systems, the
- default is not to define this macro.
-
- Define this macro only if it is correct to use the default
- definition of `ASM_OUTPUT_TYPE_DIRECTIVE' for your system. If you
- need your own custom definition of this macro, or if you do not
- need explicit symbol types at all, do not define this macro.
-
- -- Macro: ASM_OUTPUT_TYPE_DIRECTIVE (STREAM, TYPE)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM a directive telling the assembler that the type of the
- symbol NAME is TYPE. TYPE is a C string; currently, that string
- is always either `"function"' or `"object"', but you should not
- count on this.
-
- If you define `TYPE_ASM_OP' and `TYPE_OPERAND_FMT', a default
- definition of this macro is provided.
-
- -- Macro: ASM_DECLARE_FUNCTION_NAME (STREAM, NAME, DECL)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM any text necessary for declaring the name NAME of a
- function which is being defined. This macro is responsible for
- outputting the label definition (perhaps using
- `ASM_OUTPUT_LABEL'). The argument DECL is the `FUNCTION_DECL'
- tree node representing the function.
-
- If this macro is not defined, then the function name is defined in
- the usual manner as a label (by means of `ASM_OUTPUT_LABEL').
-
- You may wish to use `ASM_OUTPUT_TYPE_DIRECTIVE' in the definition
- of this macro.
-
- -- Macro: ASM_DECLARE_FUNCTION_SIZE (STREAM, NAME, DECL)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM any text necessary for declaring the size of a function
- which is being defined. The argument NAME is the name of the
- function. The argument DECL is the `FUNCTION_DECL' tree node
- representing the function.
-
- If this macro is not defined, then the function size is not
- defined.
-
- You may wish to use `ASM_OUTPUT_MEASURED_SIZE' in the definition
- of this macro.
-
- -- Macro: ASM_DECLARE_OBJECT_NAME (STREAM, NAME, DECL)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM any text necessary for declaring the name NAME of an
- initialized variable which is being defined. This macro must
- output the label definition (perhaps using `ASM_OUTPUT_LABEL').
- The argument DECL is the `VAR_DECL' tree node representing the
- variable.
-
- If this macro is not defined, then the variable name is defined in
- the usual manner as a label (by means of `ASM_OUTPUT_LABEL').
-
- You may wish to use `ASM_OUTPUT_TYPE_DIRECTIVE' and/or
- `ASM_OUTPUT_SIZE_DIRECTIVE' in the definition of this macro.
-
- -- Macro: ASM_DECLARE_CONSTANT_NAME (STREAM, NAME, EXP, SIZE)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM any text necessary for declaring the name NAME of a
- constant which is being defined. This macro is responsible for
- outputting the label definition (perhaps using
- `ASM_OUTPUT_LABEL'). The argument EXP is the value of the
- constant, and SIZE is the size of the constant in bytes. NAME
- will be an internal label.
-
- If this macro is not defined, then the NAME is defined in the
- usual manner as a label (by means of `ASM_OUTPUT_LABEL').
-
- You may wish to use `ASM_OUTPUT_TYPE_DIRECTIVE' in the definition
- of this macro.
-
- -- Macro: ASM_DECLARE_REGISTER_GLOBAL (STREAM, DECL, REGNO, NAME)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM any text necessary for claiming a register REGNO for a
- global variable DECL with name NAME.
-
- If you don't define this macro, that is equivalent to defining it
- to do nothing.
-
- -- Macro: ASM_FINISH_DECLARE_OBJECT (STREAM, DECL, TOPLEVEL, ATEND)
- A C statement (sans semicolon) to finish up declaring a variable
- name once the compiler has processed its initializer fully and
- thus has had a chance to determine the size of an array when
- controlled by an initializer. This is used on systems where it's
- necessary to declare something about the size of the object.
-
- If you don't define this macro, that is equivalent to defining it
- to do nothing.
-
- You may wish to use `ASM_OUTPUT_SIZE_DIRECTIVE' and/or
- `ASM_OUTPUT_MEASURED_SIZE' in the definition of this macro.
-
- -- Target Hook: void TARGET_ASM_GLOBALIZE_LABEL (FILE *STREAM, const
- char *NAME)
- This target hook is a function to output to the stdio stream
- STREAM some commands that will make the label NAME global; that
- is, available for reference from other files.
-
- The default implementation relies on a proper definition of
- `GLOBAL_ASM_OP'.
-
- -- Target Hook: void TARGET_ASM_GLOBALIZE_DECL_NAME (FILE *STREAM,
- tree DECL)
- This target hook is a function to output to the stdio stream
- STREAM some commands that will make the name associated with DECL
- global; that is, available for reference from other files.
-
- The default implementation uses the TARGET_ASM_GLOBALIZE_LABEL
- target hook.
-
- -- Macro: ASM_WEAKEN_LABEL (STREAM, NAME)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM some commands that will make the label NAME weak; that is,
- available for reference from other files but only used if no other
- definition is available. Use the expression `assemble_name
- (STREAM, NAME)' to output the name itself; before and after that,
- output the additional assembler syntax for making that name weak,
- and a newline.
-
- If you don't define this macro or `ASM_WEAKEN_DECL', GCC will not
- support weak symbols and you should not define the `SUPPORTS_WEAK'
- macro.
-
- -- Macro: ASM_WEAKEN_DECL (STREAM, DECL, NAME, VALUE)
- Combines (and replaces) the function of `ASM_WEAKEN_LABEL' and
- `ASM_OUTPUT_WEAK_ALIAS', allowing access to the associated function
- or variable decl. If VALUE is not `NULL', this C statement should
- output to the stdio stream STREAM assembler code which defines
- (equates) the weak symbol NAME to have the value VALUE. If VALUE
- is `NULL', it should output commands to make NAME weak.
-
- -- Macro: ASM_OUTPUT_WEAKREF (STREAM, DECL, NAME, VALUE)
- Outputs a directive that enables NAME to be used to refer to
- symbol VALUE with weak-symbol semantics. `decl' is the
- declaration of `name'.
-
- -- Macro: SUPPORTS_WEAK
- A C expression which evaluates to true if the target supports weak
- symbols.
-
- If you don't define this macro, `defaults.h' provides a default
- definition. If either `ASM_WEAKEN_LABEL' or `ASM_WEAKEN_DECL' is
- defined, the default definition is `1'; otherwise, it is `0'.
- Define this macro if you want to control weak symbol support with
- a compiler flag such as `-melf'.
-
- -- Macro: MAKE_DECL_ONE_ONLY (DECL)
- A C statement (sans semicolon) to mark DECL to be emitted as a
- public symbol such that extra copies in multiple translation units
- will be discarded by the linker. Define this macro if your object
- file format provides support for this concept, such as the `COMDAT'
- section flags in the Microsoft Windows PE/COFF format, and this
- support requires changes to DECL, such as putting it in a separate
- section.
-
- -- Macro: SUPPORTS_ONE_ONLY
- A C expression which evaluates to true if the target supports
- one-only semantics.
-
- If you don't define this macro, `varasm.c' provides a default
- definition. If `MAKE_DECL_ONE_ONLY' is defined, the default
- definition is `1'; otherwise, it is `0'. Define this macro if you
- want to control one-only symbol support with a compiler flag, or if
- setting the `DECL_ONE_ONLY' flag is enough to mark a declaration to
- be emitted as one-only.
-
- -- Target Hook: void TARGET_ASM_ASSEMBLE_VISIBILITY (tree DECL, const
- char *VISIBILITY)
- This target hook is a function to output to ASM_OUT_FILE some
- commands that will make the symbol(s) associated with DECL have
- hidden, protected or internal visibility as specified by
- VISIBILITY.
-
- -- Macro: TARGET_WEAK_NOT_IN_ARCHIVE_TOC
- A C expression that evaluates to true if the target's linker
- expects that weak symbols do not appear in a static archive's
- table of contents. The default is `0'.
-
- Leaving weak symbols out of an archive's table of contents means
- that, if a symbol will only have a definition in one translation
- unit and will have undefined references from other translation
- units, that symbol should not be weak. Defining this macro to be
- nonzero will thus have the effect that certain symbols that would
- normally be weak (explicit template instantiations, and vtables
- for polymorphic classes with noninline key methods) will instead
- be nonweak.
-
- The C++ ABI requires this macro to be zero. Define this macro for
- targets where full C++ ABI compliance is impossible and where
- linker restrictions require weak symbols to be left out of a
- static archive's table of contents.
-
- -- Macro: ASM_OUTPUT_EXTERNAL (STREAM, DECL, NAME)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM any text necessary for declaring the name of an external
- symbol named NAME which is referenced in this compilation but not
- defined. The value of DECL is the tree node for the declaration.
-
- This macro need not be defined if it does not need to output
- anything. The GNU assembler and most Unix assemblers don't
- require anything.
-
- -- Target Hook: void TARGET_ASM_EXTERNAL_LIBCALL (rtx SYMREF)
- This target hook is a function to output to ASM_OUT_FILE an
- assembler pseudo-op to declare a library function name external.
- The name of the library function is given by SYMREF, which is a
- `symbol_ref'.
-
- -- Target Hook: void TARGET_ASM_MARK_DECL_PRESERVED (tree DECL)
- This target hook is a function to output to ASM_OUT_FILE an
- assembler directive to annotate used symbol. Darwin target use
- .no_dead_code_strip directive.
-
- -- Macro: ASM_OUTPUT_LABELREF (STREAM, NAME)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM a reference in assembler syntax to a label named NAME.
- This should add `_' to the front of the name, if that is customary
- on your operating system, as it is in most Berkeley Unix systems.
- This macro is used in `assemble_name'.
-
- -- Macro: ASM_OUTPUT_SYMBOL_REF (STREAM, SYM)
- A C statement (sans semicolon) to output a reference to
- `SYMBOL_REF' SYM. If not defined, `assemble_name' will be used to
- output the name of the symbol. This macro may be used to modify
- the way a symbol is referenced depending on information encoded by
- `TARGET_ENCODE_SECTION_INFO'.
-
- -- Macro: ASM_OUTPUT_LABEL_REF (STREAM, BUF)
- A C statement (sans semicolon) to output a reference to BUF, the
- result of `ASM_GENERATE_INTERNAL_LABEL'. If not defined,
- `assemble_name' will be used to output the name of the symbol.
- This macro is not used by `output_asm_label', or the `%l'
- specifier that calls it; the intention is that this macro should
- be set when it is necessary to output a label differently when its
- address is being taken.
-
- -- Target Hook: void TARGET_ASM_INTERNAL_LABEL (FILE *STREAM, const
- char *PREFIX, unsigned long LABELNO)
- A function to output to the stdio stream STREAM a label whose name
- is made from the string PREFIX and the number LABELNO.
-
- It is absolutely essential that these labels be distinct from the
- labels used for user-level functions and variables. Otherwise,
- certain programs will have name conflicts with internal labels.
-
- It is desirable to exclude internal labels from the symbol table
- of the object file. Most assemblers have a naming convention for
- labels that should be excluded; on many systems, the letter `L' at
- the beginning of a label has this effect. You should find out what
- convention your system uses, and follow it.
-
- The default version of this function utilizes
- `ASM_GENERATE_INTERNAL_LABEL'.
-
- -- Macro: ASM_OUTPUT_DEBUG_LABEL (STREAM, PREFIX, NUM)
- A C statement to output to the stdio stream STREAM a debug info
- label whose name is made from the string PREFIX and the number
- NUM. This is useful for VLIW targets, where debug info labels may
- need to be treated differently than branch target labels. On some
- systems, branch target labels must be at the beginning of
- instruction bundles, but debug info labels can occur in the middle
- of instruction bundles.
-
- If this macro is not defined, then
- `(*targetm.asm_out.internal_label)' will be used.
-
- -- Macro: ASM_GENERATE_INTERNAL_LABEL (STRING, PREFIX, NUM)
- A C statement to store into the string STRING a label whose name
- is made from the string PREFIX and the number NUM.
-
- This string, when output subsequently by `assemble_name', should
- produce the output that `(*targetm.asm_out.internal_label)' would
- produce with the same PREFIX and NUM.
-
- If the string begins with `*', then `assemble_name' will output
- the rest of the string unchanged. It is often convenient for
- `ASM_GENERATE_INTERNAL_LABEL' to use `*' in this way. If the
- string doesn't start with `*', then `ASM_OUTPUT_LABELREF' gets to
- output the string, and may change it. (Of course,
- `ASM_OUTPUT_LABELREF' is also part of your machine description, so
- you should know what it does on your machine.)
-
- -- Macro: ASM_FORMAT_PRIVATE_NAME (OUTVAR, NAME, NUMBER)
- A C expression to assign to OUTVAR (which is a variable of type
- `char *') a newly allocated string made from the string NAME and
- the number NUMBER, with some suitable punctuation added. Use
- `alloca' to get space for the string.
-
- The string will be used as an argument to `ASM_OUTPUT_LABELREF' to
- produce an assembler label for an internal static variable whose
- name is NAME. Therefore, the string must be such as to result in
- valid assembler code. The argument NUMBER is different each time
- this macro is executed; it prevents conflicts between
- similarly-named internal static variables in different scopes.
-
- Ideally this string should not be a valid C identifier, to prevent
- any conflict with the user's own symbols. Most assemblers allow
- periods or percent signs in assembler symbols; putting at least
- one of these between the name and the number will suffice.
-
- If this macro is not defined, a default definition will be provided
- which is correct for most systems.
-
- -- Macro: ASM_OUTPUT_DEF (STREAM, NAME, VALUE)
- A C statement to output to the stdio stream STREAM assembler code
- which defines (equates) the symbol NAME to have the value VALUE.
-
- If `SET_ASM_OP' is defined, a default definition is provided which
- is correct for most systems.
-
- -- Macro: ASM_OUTPUT_DEF_FROM_DECLS (STREAM, DECL_OF_NAME,
- DECL_OF_VALUE)
- A C statement to output to the stdio stream STREAM assembler code
- which defines (equates) the symbol whose tree node is DECL_OF_NAME
- to have the value of the tree node DECL_OF_VALUE. This macro will
- be used in preference to `ASM_OUTPUT_DEF' if it is defined and if
- the tree nodes are available.
-
- If `SET_ASM_OP' is defined, a default definition is provided which
- is correct for most systems.
-
- -- Macro: TARGET_DEFERRED_OUTPUT_DEFS (DECL_OF_NAME, DECL_OF_VALUE)
- A C statement that evaluates to true if the assembler code which
- defines (equates) the symbol whose tree node is DECL_OF_NAME to
- have the value of the tree node DECL_OF_VALUE should be emitted
- near the end of the current compilation unit. The default is to
- not defer output of defines. This macro affects defines output by
- `ASM_OUTPUT_DEF' and `ASM_OUTPUT_DEF_FROM_DECLS'.
-
- -- Macro: ASM_OUTPUT_WEAK_ALIAS (STREAM, NAME, VALUE)
- A C statement to output to the stdio stream STREAM assembler code
- which defines (equates) the weak symbol NAME to have the value
- VALUE. If VALUE is `NULL', it defines NAME as an undefined weak
- symbol.
-
- Define this macro if the target only supports weak aliases; define
- `ASM_OUTPUT_DEF' instead if possible.
-
- -- Macro: OBJC_GEN_METHOD_LABEL (BUF, IS_INST, CLASS_NAME, CAT_NAME,
- SEL_NAME)
- Define this macro to override the default assembler names used for
- Objective-C methods.
-
- The default name is a unique method number followed by the name of
- the class (e.g. `_1_Foo'). For methods in categories, the name of
- the category is also included in the assembler name (e.g.
- `_1_Foo_Bar').
-
- These names are safe on most systems, but make debugging difficult
- since the method's selector is not present in the name.
- Therefore, particular systems define other ways of computing names.
-
- BUF is an expression of type `char *' which gives you a buffer in
- which to store the name; its length is as long as CLASS_NAME,
- CAT_NAME and SEL_NAME put together, plus 50 characters extra.
-
- The argument IS_INST specifies whether the method is an instance
- method or a class method; CLASS_NAME is the name of the class;
- CAT_NAME is the name of the category (or `NULL' if the method is
- not in a category); and SEL_NAME is the name of the selector.
-
- On systems where the assembler can handle quoted names, you can
- use this macro to provide more human-readable names.
-
- -- Macro: ASM_DECLARE_CLASS_REFERENCE (STREAM, NAME)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM commands to declare that the label NAME is an Objective-C
- class reference. This is only needed for targets whose linkers
- have special support for NeXT-style runtimes.
-
- -- Macro: ASM_DECLARE_UNRESOLVED_REFERENCE (STREAM, NAME)
- A C statement (sans semicolon) to output to the stdio stream
- STREAM commands to declare that the label NAME is an unresolved
- Objective-C class reference. This is only needed for targets
- whose linkers have special support for NeXT-style runtimes.
-
-\1f
-File: gccint.info, Node: Initialization, Next: Macros for Initialization, Prev: Label Output, Up: Assembler Format
-
-17.21.5 How Initialization Functions Are Handled
-------------------------------------------------
-
-The compiled code for certain languages includes "constructors" (also
-called "initialization routines")--functions to initialize data in the
-program when the program is started. These functions need to be called
-before the program is "started"--that is to say, before `main' is
-called.
-
- Compiling some languages generates "destructors" (also called
-"termination routines") that should be called when the program
-terminates.
-
- To make the initialization and termination functions work, the compiler
-must output something in the assembler code to cause those functions to
-be called at the appropriate time. When you port the compiler to a new
-system, you need to specify how to do this.
-
- There are two major ways that GCC currently supports the execution of
-initialization and termination functions. Each way has two variants.
-Much of the structure is common to all four variations.
-
- The linker must build two lists of these functions--a list of
-initialization functions, called `__CTOR_LIST__', and a list of
-termination functions, called `__DTOR_LIST__'.
-
- Each list always begins with an ignored function pointer (which may
-hold 0, -1, or a count of the function pointers after it, depending on
-the environment). This is followed by a series of zero or more function
-pointers to constructors (or destructors), followed by a function
-pointer containing zero.
-
- Depending on the operating system and its executable file format,
-either `crtstuff.c' or `libgcc2.c' traverses these lists at startup
-time and exit time. Constructors are called in reverse order of the
-list; destructors in forward order.
-
- The best way to handle static constructors works only for object file
-formats which provide arbitrarily-named sections. A section is set
-aside for a list of constructors, and another for a list of destructors.
-Traditionally these are called `.ctors' and `.dtors'. Each object file
-that defines an initialization function also puts a word in the
-constructor section to point to that function. The linker accumulates
-all these words into one contiguous `.ctors' section. Termination
-functions are handled similarly.
-
- This method will be chosen as the default by `target-def.h' if
-`TARGET_ASM_NAMED_SECTION' is defined. A target that does not support
-arbitrary sections, but does support special designated constructor and
-destructor sections may define `CTORS_SECTION_ASM_OP' and
-`DTORS_SECTION_ASM_OP' to achieve the same effect.
-
- When arbitrary sections are available, there are two variants,
-depending upon how the code in `crtstuff.c' is called. On systems that
-support a ".init" section which is executed at program startup, parts
-of `crtstuff.c' are compiled into that section. The program is linked
-by the `gcc' driver like this:
-
- ld -o OUTPUT_FILE crti.o crtbegin.o ... -lgcc crtend.o crtn.o
-
- The prologue of a function (`__init') appears in the `.init' section
-of `crti.o'; the epilogue appears in `crtn.o'. Likewise for the
-function `__fini' in the ".fini" section. Normally these files are
-provided by the operating system or by the GNU C library, but are
-provided by GCC for a few targets.
-
- The objects `crtbegin.o' and `crtend.o' are (for most targets)
-compiled from `crtstuff.c'. They contain, among other things, code
-fragments within the `.init' and `.fini' sections that branch to
-routines in the `.text' section. The linker will pull all parts of a
-section together, which results in a complete `__init' function that
-invokes the routines we need at startup.
-
- To use this variant, you must define the `INIT_SECTION_ASM_OP' macro
-properly.
-
- If no init section is available, when GCC compiles any function called
-`main' (or more accurately, any function designated as a program entry
-point by the language front end calling `expand_main_function'), it
-inserts a procedure call to `__main' as the first executable code after
-the function prologue. The `__main' function is defined in `libgcc2.c'
-and runs the global constructors.
-
- In file formats that don't support arbitrary sections, there are again
-two variants. In the simplest variant, the GNU linker (GNU `ld') and
-an `a.out' format must be used. In this case, `TARGET_ASM_CONSTRUCTOR'
-is defined to produce a `.stabs' entry of type `N_SETT', referencing
-the name `__CTOR_LIST__', and with the address of the void function
-containing the initialization code as its value. The GNU linker
-recognizes this as a request to add the value to a "set"; the values
-are accumulated, and are eventually placed in the executable as a
-vector in the format described above, with a leading (ignored) count
-and a trailing zero element. `TARGET_ASM_DESTRUCTOR' is handled
-similarly. Since no init section is available, the absence of
-`INIT_SECTION_ASM_OP' causes the compilation of `main' to call `__main'
-as above, starting the initialization process.
-
- The last variant uses neither arbitrary sections nor the GNU linker.
-This is preferable when you want to do dynamic linking and when using
-file formats which the GNU linker does not support, such as `ECOFF'. In
-this case, `TARGET_HAVE_CTORS_DTORS' is false, initialization and
-termination functions are recognized simply by their names. This
-requires an extra program in the linkage step, called `collect2'. This
-program pretends to be the linker, for use with GCC; it does its job by
-running the ordinary linker, but also arranges to include the vectors of
-initialization and termination functions. These functions are called
-via `__main' as described above. In order to use this method,
-`use_collect2' must be defined in the target in `config.gcc'.
-
- The following section describes the specific macros that control and
-customize the handling of initialization and termination functions.
-
-\1f
-File: gccint.info, Node: Macros for Initialization, Next: Instruction Output, Prev: Initialization, Up: Assembler Format
-
-17.21.6 Macros Controlling Initialization Routines
---------------------------------------------------
-
-Here are the macros that control how the compiler handles initialization
-and termination functions:
-
- -- Macro: INIT_SECTION_ASM_OP
- If defined, a C string constant, including spacing, for the
- assembler operation to identify the following data as
- initialization code. If not defined, GCC will assume such a
- section does not exist. When you are using special sections for
- initialization and termination functions, this macro also controls
- how `crtstuff.c' and `libgcc2.c' arrange to run the initialization
- functions.
-
- -- Macro: HAS_INIT_SECTION
- If defined, `main' will not call `__main' as described above.
- This macro should be defined for systems that control start-up code
- on a symbol-by-symbol basis, such as OSF/1, and should not be
- defined explicitly for systems that support `INIT_SECTION_ASM_OP'.
-
- -- Macro: LD_INIT_SWITCH
- If defined, a C string constant for a switch that tells the linker
- that the following symbol is an initialization routine.
-
- -- Macro: LD_FINI_SWITCH
- If defined, a C string constant for a switch that tells the linker
- that the following symbol is a finalization routine.
-
- -- Macro: COLLECT_SHARED_INIT_FUNC (STREAM, FUNC)
- If defined, a C statement that will write a function that can be
- automatically called when a shared library is loaded. The function
- should call FUNC, which takes no arguments. If not defined, and
- the object format requires an explicit initialization function,
- then a function called `_GLOBAL__DI' will be generated.
-
- This function and the following one are used by collect2 when
- linking a shared library that needs constructors or destructors,
- or has DWARF2 exception tables embedded in the code.
-
- -- Macro: COLLECT_SHARED_FINI_FUNC (STREAM, FUNC)
- If defined, a C statement that will write a function that can be
- automatically called when a shared library is unloaded. The
- function should call FUNC, which takes no arguments. If not
- defined, and the object format requires an explicit finalization
- function, then a function called `_GLOBAL__DD' will be generated.
-
- -- Macro: INVOKE__main
- If defined, `main' will call `__main' despite the presence of
- `INIT_SECTION_ASM_OP'. This macro should be defined for systems
- where the init section is not actually run automatically, but is
- still useful for collecting the lists of constructors and
- destructors.
-
- -- Macro: SUPPORTS_INIT_PRIORITY
- If nonzero, the C++ `init_priority' attribute is supported and the
- compiler should emit instructions to control the order of
- initialization of objects. If zero, the compiler will issue an
- error message upon encountering an `init_priority' attribute.
-
- -- Target Hook: bool TARGET_HAVE_CTORS_DTORS
- This value is true if the target supports some "native" method of
- collecting constructors and destructors to be run at startup and
- exit. It is false if we must use `collect2'.
-
- -- Target Hook: void TARGET_ASM_CONSTRUCTOR (rtx SYMBOL, int PRIORITY)
- If defined, a function that outputs assembler code to arrange to
- call the function referenced by SYMBOL at initialization time.
-
- Assume that SYMBOL is a `SYMBOL_REF' for a function taking no
- arguments and with no return value. If the target supports
- initialization priorities, PRIORITY is a value between 0 and
- `MAX_INIT_PRIORITY'; otherwise it must be `DEFAULT_INIT_PRIORITY'.
-
- If this macro is not defined by the target, a suitable default will
- be chosen if (1) the target supports arbitrary section names, (2)
- the target defines `CTORS_SECTION_ASM_OP', or (3) `USE_COLLECT2'
- is not defined.
-
- -- Target Hook: void TARGET_ASM_DESTRUCTOR (rtx SYMBOL, int PRIORITY)
- This is like `TARGET_ASM_CONSTRUCTOR' but used for termination
- functions rather than initialization functions.
-
- If `TARGET_HAVE_CTORS_DTORS' is true, the initialization routine
-generated for the generated object file will have static linkage.
-
- If your system uses `collect2' as the means of processing
-constructors, then that program normally uses `nm' to scan an object
-file for constructor functions to be called.
-
- On certain kinds of systems, you can define this macro to make
-`collect2' work faster (and, in some cases, make it work at all):
-
- -- Macro: OBJECT_FORMAT_COFF
- Define this macro if the system uses COFF (Common Object File
- Format) object files, so that `collect2' can assume this format
- and scan object files directly for dynamic constructor/destructor
- functions.
-
- This macro is effective only in a native compiler; `collect2' as
- part of a cross compiler always uses `nm' for the target machine.
-
- -- Macro: REAL_NM_FILE_NAME
- Define this macro as a C string constant containing the file name
- to use to execute `nm'. The default is to search the path
- normally for `nm'.
-
- If your system supports shared libraries and has a program to list
- the dynamic dependencies of a given library or executable, you can
- define these macros to enable support for running initialization
- and termination functions in shared libraries:
-
- -- Macro: LDD_SUFFIX
- Define this macro to a C string constant containing the name of
- the program which lists dynamic dependencies, like `"ldd"' under
- SunOS 4.
-
- -- Macro: PARSE_LDD_OUTPUT (PTR)
- Define this macro to be C code that extracts filenames from the
- output of the program denoted by `LDD_SUFFIX'. PTR is a variable
- of type `char *' that points to the beginning of a line of output
- from `LDD_SUFFIX'. If the line lists a dynamic dependency, the
- code must advance PTR to the beginning of the filename on that
- line. Otherwise, it must set PTR to `NULL'.
-
- -- Macro: SHLIB_SUFFIX
- Define this macro to a C string constant containing the default
- shared library extension of the target (e.g., `".so"'). `collect2'
- strips version information after this suffix when generating global
- constructor and destructor names. This define is only needed on
- targets that use `collect2' to process constructors and
- destructors.
-
-\1f
-File: gccint.info, Node: Instruction Output, Next: Dispatch Tables, Prev: Macros for Initialization, Up: Assembler Format
-
-17.21.7 Output of Assembler Instructions
-----------------------------------------
-
-This describes assembler instruction output.
-
- -- Macro: REGISTER_NAMES
- A C initializer containing the assembler's names for the machine
- registers, each one as a C string constant. This is what
- translates register numbers in the compiler into assembler
- language.
-
- -- Macro: ADDITIONAL_REGISTER_NAMES
- If defined, a C initializer for an array of structures containing
- a name and a register number. This macro defines additional names
- for hard registers, thus allowing the `asm' option in declarations
- to refer to registers using alternate names.
-
- -- Macro: ASM_OUTPUT_OPCODE (STREAM, PTR)
- Define this macro if you are using an unusual assembler that
- requires different names for the machine instructions.
-
- The definition is a C statement or statements which output an
- assembler instruction opcode to the stdio stream STREAM. The
- macro-operand PTR is a variable of type `char *' which points to
- the opcode name in its "internal" form--the form that is written
- in the machine description. The definition should output the
- opcode name to STREAM, performing any translation you desire, and
- increment the variable PTR to point at the end of the opcode so
- that it will not be output twice.
-
- In fact, your macro definition may process less than the entire
- opcode name, or more than the opcode name; but if you want to
- process text that includes `%'-sequences to substitute operands,
- you must take care of the substitution yourself. Just be sure to
- increment PTR over whatever text should not be output normally.
-
- If you need to look at the operand values, they can be found as the
- elements of `recog_data.operand'.
-
- If the macro definition does nothing, the instruction is output in
- the usual way.
-
- -- Macro: FINAL_PRESCAN_INSN (INSN, OPVEC, NOPERANDS)
- If defined, a C statement to be executed just prior to the output
- of assembler code for INSN, to modify the extracted operands so
- they will be output differently.
-
- Here the argument OPVEC is the vector containing the operands
- extracted from INSN, and NOPERANDS is the number of elements of
- the vector which contain meaningful data for this insn. The
- contents of this vector are what will be used to convert the insn
- template into assembler code, so you can change the assembler
- output by changing the contents of the vector.
-
- This macro is useful when various assembler syntaxes share a single
- file of instruction patterns; by defining this macro differently,
- you can cause a large class of instructions to be output
- differently (such as with rearranged operands). Naturally,
- variations in assembler syntax affecting individual insn patterns
- ought to be handled by writing conditional output routines in
- those patterns.
-
- If this macro is not defined, it is equivalent to a null statement.
-
- -- Macro: PRINT_OPERAND (STREAM, X, CODE)
- A C compound statement to output to stdio stream STREAM the
- assembler syntax for an instruction operand X. X is an RTL
- expression.
-
- CODE is a value that can be used to specify one of several ways of
- printing the operand. It is used when identical operands must be
- printed differently depending on the context. CODE comes from the
- `%' specification that was used to request printing of the
- operand. If the specification was just `%DIGIT' then CODE is 0;
- if the specification was `%LTR DIGIT' then CODE is the ASCII code
- for LTR.
-
- If X is a register, this macro should print the register's name.
- The names can be found in an array `reg_names' whose type is `char
- *[]'. `reg_names' is initialized from `REGISTER_NAMES'.
-
- When the machine description has a specification `%PUNCT' (a `%'
- followed by a punctuation character), this macro is called with a
- null pointer for X and the punctuation character for CODE.
-
- -- Macro: PRINT_OPERAND_PUNCT_VALID_P (CODE)
- A C expression which evaluates to true if CODE is a valid
- punctuation character for use in the `PRINT_OPERAND' macro. If
- `PRINT_OPERAND_PUNCT_VALID_P' is not defined, it means that no
- punctuation characters (except for the standard one, `%') are used
- in this way.
-
- -- Macro: PRINT_OPERAND_ADDRESS (STREAM, X)
- A C compound statement to output to stdio stream STREAM the
- assembler syntax for an instruction operand that is a memory
- reference whose address is X. X is an RTL expression.
-
- On some machines, the syntax for a symbolic address depends on the
- section that the address refers to. On these machines, define the
- hook `TARGET_ENCODE_SECTION_INFO' to store the information into the
- `symbol_ref', and then check for it here. *Note Assembler
- Format::.
-
- -- Macro: DBR_OUTPUT_SEQEND (FILE)
- A C statement, to be executed after all slot-filler instructions
- have been output. If necessary, call `dbr_sequence_length' to
- determine the number of slots filled in a sequence (zero if not
- currently outputting a sequence), to decide how many no-ops to
- output, or whatever.
-
- Don't define this macro if it has nothing to do, but it is helpful
- in reading assembly output if the extent of the delay sequence is
- made explicit (e.g. with white space).
-
- Note that output routines for instructions with delay slots must be
-prepared to deal with not being output as part of a sequence (i.e. when
-the scheduling pass is not run, or when no slot fillers could be
-found.) The variable `final_sequence' is null when not processing a
-sequence, otherwise it contains the `sequence' rtx being output.
-
- -- Macro: REGISTER_PREFIX
- -- Macro: LOCAL_LABEL_PREFIX
- -- Macro: USER_LABEL_PREFIX
- -- Macro: IMMEDIATE_PREFIX
- If defined, C string expressions to be used for the `%R', `%L',
- `%U', and `%I' options of `asm_fprintf' (see `final.c'). These
- are useful when a single `md' file must support multiple assembler
- formats. In that case, the various `tm.h' files can define these
- macros differently.
-
- -- Macro: ASM_FPRINTF_EXTENSIONS (FILE, ARGPTR, FORMAT)
- If defined this macro should expand to a series of `case'
- statements which will be parsed inside the `switch' statement of
- the `asm_fprintf' function. This allows targets to define extra
- printf formats which may useful when generating their assembler
- statements. Note that uppercase letters are reserved for future
- generic extensions to asm_fprintf, and so are not available to
- target specific code. The output file is given by the parameter
- FILE. The varargs input pointer is ARGPTR and the rest of the
- format string, starting the character after the one that is being
- switched upon, is pointed to by FORMAT.
-
- -- Macro: ASSEMBLER_DIALECT
- If your target supports multiple dialects of assembler language
- (such as different opcodes), define this macro as a C expression
- that gives the numeric index of the assembler language dialect to
- use, with zero as the first variant.
-
- If this macro is defined, you may use constructs of the form
- `{option0|option1|option2...}'
- in the output templates of patterns (*note Output Template::) or
- in the first argument of `asm_fprintf'. This construct outputs
- `option0', `option1', `option2', etc., if the value of
- `ASSEMBLER_DIALECT' is zero, one, two, etc. Any special characters
- within these strings retain their usual meaning. If there are
- fewer alternatives within the braces than the value of
- `ASSEMBLER_DIALECT', the construct outputs nothing.
-
- If you do not define this macro, the characters `{', `|' and `}'
- do not have any special meaning when used in templates or operands
- to `asm_fprintf'.
-
- Define the macros `REGISTER_PREFIX', `LOCAL_LABEL_PREFIX',
- `USER_LABEL_PREFIX' and `IMMEDIATE_PREFIX' if you can express the
- variations in assembler language syntax with that mechanism.
- Define `ASSEMBLER_DIALECT' and use the `{option0|option1}' syntax
- if the syntax variant are larger and involve such things as
- different opcodes or operand order.
-
- -- Macro: ASM_OUTPUT_REG_PUSH (STREAM, REGNO)
- A C expression to output to STREAM some assembler code which will
- push hard register number REGNO onto the stack. The code need not
- be optimal, since this macro is used only when profiling.
-
- -- Macro: ASM_OUTPUT_REG_POP (STREAM, REGNO)
- A C expression to output to STREAM some assembler code which will
- pop hard register number REGNO off of the stack. The code need
- not be optimal, since this macro is used only when profiling.
-
-\1f
-File: gccint.info, Node: Dispatch Tables, Next: Exception Region Output, Prev: Instruction Output, Up: Assembler Format
-
-17.21.8 Output of Dispatch Tables
----------------------------------
-
-This concerns dispatch tables.
-
- -- Macro: ASM_OUTPUT_ADDR_DIFF_ELT (STREAM, BODY, VALUE, REL)
- A C statement to output to the stdio stream STREAM an assembler
- pseudo-instruction to generate a difference between two labels.
- VALUE and REL are the numbers of two internal labels. The
- definitions of these labels are output using
- `(*targetm.asm_out.internal_label)', and they must be printed in
- the same way here. For example,
-
- fprintf (STREAM, "\t.word L%d-L%d\n",
- VALUE, REL)
-
- You must provide this macro on machines where the addresses in a
- dispatch table are relative to the table's own address. If
- defined, GCC will also use this macro on all machines when
- producing PIC. BODY is the body of the `ADDR_DIFF_VEC'; it is
- provided so that the mode and flags can be read.
-
- -- Macro: ASM_OUTPUT_ADDR_VEC_ELT (STREAM, VALUE)
- This macro should be provided on machines where the addresses in a
- dispatch table are absolute.
-
- The definition should be a C statement to output to the stdio
- stream STREAM an assembler pseudo-instruction to generate a
- reference to a label. VALUE is the number of an internal label
- whose definition is output using
- `(*targetm.asm_out.internal_label)'. For example,
-
- fprintf (STREAM, "\t.word L%d\n", VALUE)
-
- -- Macro: ASM_OUTPUT_CASE_LABEL (STREAM, PREFIX, NUM, TABLE)
- Define this if the label before a jump-table needs to be output
- specially. The first three arguments are the same as for
- `(*targetm.asm_out.internal_label)'; the fourth argument is the
- jump-table which follows (a `jump_insn' containing an `addr_vec'
- or `addr_diff_vec').
-
- This feature is used on system V to output a `swbeg' statement for
- the table.
-
- If this macro is not defined, these labels are output with
- `(*targetm.asm_out.internal_label)'.
-
- -- Macro: ASM_OUTPUT_CASE_END (STREAM, NUM, TABLE)
- Define this if something special must be output at the end of a
- jump-table. The definition should be a C statement to be executed
- after the assembler code for the table is written. It should write
- the appropriate code to stdio stream STREAM. The argument TABLE
- is the jump-table insn, and NUM is the label-number of the
- preceding label.
-
- If this macro is not defined, nothing special is output at the end
- of the jump-table.
-
- -- Target Hook: void TARGET_ASM_EMIT_UNWIND_LABEL (STREAM, DECL,
- FOR_EH, EMPTY)
- This target hook emits a label at the beginning of each FDE. It
- should be defined on targets where FDEs need special labels, and it
- should write the appropriate label, for the FDE associated with the
- function declaration DECL, to the stdio stream STREAM. The third
- argument, FOR_EH, is a boolean: true if this is for an exception
- table. The fourth argument, EMPTY, is a boolean: true if this is
- a placeholder label for an omitted FDE.
-
- The default is that FDEs are not given nonlocal labels.
-
- -- Target Hook: void TARGET_ASM_EMIT_EXCEPT_TABLE_LABEL (STREAM)
- This target hook emits a label at the beginning of the exception
- table. It should be defined on targets where it is desirable for
- the table to be broken up according to function.
-
- The default is that no label is emitted.
-
- -- Target Hook: void TARGET_UNWIND_EMIT (FILE * STREAM, rtx INSN)
- This target hook emits and assembly directives required to unwind
- the given instruction. This is only used when TARGET_UNWIND_INFO
- is set.
-
-\1f
-File: gccint.info, Node: Exception Region Output, Next: Alignment Output, Prev: Dispatch Tables, Up: Assembler Format
-
-17.21.9 Assembler Commands for Exception Regions
-------------------------------------------------
-
-This describes commands marking the start and the end of an exception
-region.
-
- -- Macro: EH_FRAME_SECTION_NAME
- If defined, a C string constant for the name of the section
- containing exception handling frame unwind information. If not
- defined, GCC will provide a default definition if the target
- supports named sections. `crtstuff.c' uses this macro to switch
- to the appropriate section.
-
- You should define this symbol if your target supports DWARF 2 frame
- unwind information and the default definition does not work.
-
- -- Macro: EH_FRAME_IN_DATA_SECTION
- If defined, DWARF 2 frame unwind information will be placed in the
- data section even though the target supports named sections. This
- might be necessary, for instance, if the system linker does garbage
- collection and sections cannot be marked as not to be collected.
-
- Do not define this macro unless `TARGET_ASM_NAMED_SECTION' is also
- defined.
-
- -- Macro: EH_TABLES_CAN_BE_READ_ONLY
- Define this macro to 1 if your target is such that no frame unwind
- information encoding used with non-PIC code will ever require a
- runtime relocation, but the linker may not support merging
- read-only and read-write sections into a single read-write section.
-
- -- Macro: MASK_RETURN_ADDR
- An rtx used to mask the return address found via
- `RETURN_ADDR_RTX', so that it does not contain any extraneous set
- bits in it.
-
- -- Macro: DWARF2_UNWIND_INFO
- Define this macro to 0 if your target supports DWARF 2 frame unwind
- information, but it does not yet work with exception handling.
- Otherwise, if your target supports this information (if it defines
- `INCOMING_RETURN_ADDR_RTX' and either `UNALIGNED_INT_ASM_OP' or
- `OBJECT_FORMAT_ELF'), GCC will provide a default definition of 1.
-
- If `TARGET_UNWIND_INFO' is defined, the target specific unwinder
- will be used in all cases. Defining this macro will enable the
- generation of DWARF 2 frame debugging information.
-
- If `TARGET_UNWIND_INFO' is not defined, and this macro is defined
- to 1, the DWARF 2 unwinder will be the default exception handling
- mechanism; otherwise, the `setjmp'/`longjmp'-based scheme will be
- used by default.
-
- -- Macro: TARGET_UNWIND_INFO
- Define this macro if your target has ABI specified unwind tables.
- Usually these will be output by `TARGET_UNWIND_EMIT'.
-
- -- Variable: Target Hook bool TARGET_UNWIND_TABLES_DEFAULT
- This variable should be set to `true' if the target ABI requires
- unwinding tables even when exceptions are not used.
-
- -- Macro: MUST_USE_SJLJ_EXCEPTIONS
- This macro need only be defined if `DWARF2_UNWIND_INFO' is
- runtime-variable. In that case, `except.h' cannot correctly
- determine the corresponding definition of
- `MUST_USE_SJLJ_EXCEPTIONS', so the target must provide it directly.
-
- -- Macro: DONT_USE_BUILTIN_SETJMP
- Define this macro to 1 if the `setjmp'/`longjmp'-based scheme
- should use the `setjmp'/`longjmp' functions from the C library
- instead of the `__builtin_setjmp'/`__builtin_longjmp' machinery.
-
- -- Macro: DWARF_CIE_DATA_ALIGNMENT
- This macro need only be defined if the target might save registers
- in the function prologue at an offset to the stack pointer that is
- not aligned to `UNITS_PER_WORD'. The definition should be the
- negative minimum alignment if `STACK_GROWS_DOWNWARD' is defined,
- and the positive minimum alignment otherwise. *Note SDB and
- DWARF::. Only applicable if the target supports DWARF 2 frame
- unwind information.
-
- -- Variable: Target Hook bool TARGET_TERMINATE_DW2_EH_FRAME_INFO
- Contains the value true if the target should add a zero word onto
- the end of a Dwarf-2 frame info section when used for exception
- handling. Default value is false if `EH_FRAME_SECTION_NAME' is
- defined, and true otherwise.
-
- -- Target Hook: rtx TARGET_DWARF_REGISTER_SPAN (rtx REG)
- Given a register, this hook should return a parallel of registers
- to represent where to find the register pieces. Define this hook
- if the register and its mode are represented in Dwarf in
- non-contiguous locations, or if the register should be represented
- in more than one register in Dwarf. Otherwise, this hook should
- return `NULL_RTX'. If not defined, the default is to return
- `NULL_RTX'.
-
- -- Target Hook: void TARGET_INIT_DWARF_REG_SIZES_EXTRA (tree ADDRESS)
- If some registers are represented in Dwarf-2 unwind information in
- multiple pieces, define this hook to fill in information about the
- sizes of those pieces in the table used by the unwinder at runtime.
- It will be called by `expand_builtin_init_dwarf_reg_sizes' after
- filling in a single size corresponding to each hard register;
- ADDRESS is the address of the table.
-
- -- Target Hook: bool TARGET_ASM_TTYPE (rtx SYM)
- This hook is used to output a reference from a frame unwinding
- table to the type_info object identified by SYM. It should return
- `true' if the reference was output. Returning `false' will cause
- the reference to be output using the normal Dwarf2 routines.
-
- -- Target Hook: bool TARGET_ARM_EABI_UNWINDER
- This hook should be set to `true' on targets that use an ARM EABI
- based unwinding library, and `false' on other targets. This
- effects the format of unwinding tables, and how the unwinder in
- entered after running a cleanup. The default is `false'.
-
-\1f
-File: gccint.info, Node: Alignment Output, Prev: Exception Region Output, Up: Assembler Format
-
-17.21.10 Assembler Commands for Alignment
------------------------------------------
-
-This describes commands for alignment.
-
- -- Macro: JUMP_ALIGN (LABEL)
- The alignment (log base 2) to put in front of LABEL, which is a
- common destination of jumps and has no fallthru incoming edge.
-
- This macro need not be defined if you don't want any special
- alignment to be done at such a time. Most machine descriptions do
- not currently define the macro.
-
- Unless it's necessary to inspect the LABEL parameter, it is better
- to set the variable ALIGN_JUMPS in the target's
- `OVERRIDE_OPTIONS'. Otherwise, you should try to honor the user's
- selection in ALIGN_JUMPS in a `JUMP_ALIGN' implementation.
-
- -- Macro: LABEL_ALIGN_AFTER_BARRIER (LABEL)
- The alignment (log base 2) to put in front of LABEL, which follows
- a `BARRIER'.
-
- This macro need not be defined if you don't want any special
- alignment to be done at such a time. Most machine descriptions do
- not currently define the macro.
-
- -- Macro: LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP
- The maximum number of bytes to skip when applying
- `LABEL_ALIGN_AFTER_BARRIER'. This works only if
- `ASM_OUTPUT_MAX_SKIP_ALIGN' is defined.
-
- -- Macro: LOOP_ALIGN (LABEL)
- The alignment (log base 2) to put in front of LABEL, which follows
- a `NOTE_INSN_LOOP_BEG' note.
-
- This macro need not be defined if you don't want any special
- alignment to be done at such a time. Most machine descriptions do
- not currently define the macro.
-
- Unless it's necessary to inspect the LABEL parameter, it is better
- to set the variable `align_loops' in the target's
- `OVERRIDE_OPTIONS'. Otherwise, you should try to honor the user's
- selection in `align_loops' in a `LOOP_ALIGN' implementation.
-
- -- Macro: LOOP_ALIGN_MAX_SKIP
- The maximum number of bytes to skip when applying `LOOP_ALIGN'.
- This works only if `ASM_OUTPUT_MAX_SKIP_ALIGN' is defined.
-
- -- Macro: LABEL_ALIGN (LABEL)
- The alignment (log base 2) to put in front of LABEL. If
- `LABEL_ALIGN_AFTER_BARRIER' / `LOOP_ALIGN' specify a different
- alignment, the maximum of the specified values is used.
-
- Unless it's necessary to inspect the LABEL parameter, it is better
- to set the variable `align_labels' in the target's
- `OVERRIDE_OPTIONS'. Otherwise, you should try to honor the user's
- selection in `align_labels' in a `LABEL_ALIGN' implementation.
-
- -- Macro: LABEL_ALIGN_MAX_SKIP
- The maximum number of bytes to skip when applying `LABEL_ALIGN'.
- This works only if `ASM_OUTPUT_MAX_SKIP_ALIGN' is defined.
-
- -- Macro: ASM_OUTPUT_SKIP (STREAM, NBYTES)
- A C statement to output to the stdio stream STREAM an assembler
- instruction to advance the location counter by NBYTES bytes.
- Those bytes should be zero when loaded. NBYTES will be a C
- expression of type `unsigned HOST_WIDE_INT'.
-
- -- Macro: ASM_NO_SKIP_IN_TEXT
- Define this macro if `ASM_OUTPUT_SKIP' should not be used in the
- text section because it fails to put zeros in the bytes that are
- skipped. This is true on many Unix systems, where the pseudo-op
- to skip bytes produces no-op instructions rather than zeros when
- used in the text section.
-
- -- Macro: ASM_OUTPUT_ALIGN (STREAM, POWER)
- A C statement to output to the stdio stream STREAM an assembler
- command to advance the location counter to a multiple of 2 to the
- POWER bytes. POWER will be a C expression of type `int'.
-
- -- Macro: ASM_OUTPUT_ALIGN_WITH_NOP (STREAM, POWER)
- Like `ASM_OUTPUT_ALIGN', except that the "nop" instruction is used
- for padding, if necessary.
-
- -- Macro: ASM_OUTPUT_MAX_SKIP_ALIGN (STREAM, POWER, MAX_SKIP)
- A C statement to output to the stdio stream STREAM an assembler
- command to advance the location counter to a multiple of 2 to the
- POWER bytes, but only if MAX_SKIP or fewer bytes are needed to
- satisfy the alignment request. POWER and MAX_SKIP will be a C
- expression of type `int'.
-
-\1f
-File: gccint.info, Node: Debugging Info, Next: Floating Point, Prev: Assembler Format, Up: Target Macros
-
-17.22 Controlling Debugging Information Format
-==============================================
-
-This describes how to specify debugging information.
-
-* Menu:
-
-* All Debuggers:: Macros that affect all debugging formats uniformly.
-* DBX Options:: Macros enabling specific options in DBX format.
-* DBX Hooks:: Hook macros for varying DBX format.
-* File Names and DBX:: Macros controlling output of file names in DBX format.
-* SDB and DWARF:: Macros for SDB (COFF) and DWARF formats.
-* VMS Debug:: Macros for VMS debug format.
-
-\1f
-File: gccint.info, Node: All Debuggers, Next: DBX Options, Up: Debugging Info
-
-17.22.1 Macros Affecting All Debugging Formats
-----------------------------------------------
-
-These macros affect all debugging formats.
-
- -- Macro: DBX_REGISTER_NUMBER (REGNO)
- A C expression that returns the DBX register number for the
- compiler register number REGNO. In the default macro provided,
- the value of this expression will be REGNO itself. But sometimes
- there are some registers that the compiler knows about and DBX
- does not, or vice versa. In such cases, some register may need to
- have one number in the compiler and another for DBX.
-
- If two registers have consecutive numbers inside GCC, and they can
- be used as a pair to hold a multiword value, then they _must_ have
- consecutive numbers after renumbering with `DBX_REGISTER_NUMBER'.
- Otherwise, debuggers will be unable to access such a pair, because
- they expect register pairs to be consecutive in their own
- numbering scheme.
-
- If you find yourself defining `DBX_REGISTER_NUMBER' in way that
- does not preserve register pairs, then what you must do instead is
- redefine the actual register numbering scheme.
-
- -- Macro: DEBUGGER_AUTO_OFFSET (X)
- A C expression that returns the integer offset value for an
- automatic variable having address X (an RTL expression). The
- default computation assumes that X is based on the frame-pointer
- and gives the offset from the frame-pointer. This is required for
- targets that produce debugging output for DBX or COFF-style
- debugging output for SDB and allow the frame-pointer to be
- eliminated when the `-g' options is used.
-
- -- Macro: DEBUGGER_ARG_OFFSET (OFFSET, X)
- A C expression that returns the integer offset value for an
- argument having address X (an RTL expression). The nominal offset
- is OFFSET.
-
- -- Macro: PREFERRED_DEBUGGING_TYPE
- A C expression that returns the type of debugging output GCC should
- produce when the user specifies just `-g'. Define this if you
- have arranged for GCC to support more than one format of debugging
- output. Currently, the allowable values are `DBX_DEBUG',
- `SDB_DEBUG', `DWARF_DEBUG', `DWARF2_DEBUG', `XCOFF_DEBUG',
- `VMS_DEBUG', and `VMS_AND_DWARF2_DEBUG'.
-
- When the user specifies `-ggdb', GCC normally also uses the value
- of this macro to select the debugging output format, but with two
- exceptions. If `DWARF2_DEBUGGING_INFO' is defined, GCC uses the
- value `DWARF2_DEBUG'. Otherwise, if `DBX_DEBUGGING_INFO' is
- defined, GCC uses `DBX_DEBUG'.
-
- The value of this macro only affects the default debugging output;
- the user can always get a specific type of output by using
- `-gstabs', `-gcoff', `-gdwarf-2', `-gxcoff', or `-gvms'.
-
-\1f
-File: gccint.info, Node: DBX Options, Next: DBX Hooks, Prev: All Debuggers, Up: Debugging Info
-
-17.22.2 Specific Options for DBX Output
----------------------------------------
-
-These are specific options for DBX output.
-
- -- Macro: DBX_DEBUGGING_INFO
- Define this macro if GCC should produce debugging output for DBX
- in response to the `-g' option.
-
- -- Macro: XCOFF_DEBUGGING_INFO
- Define this macro if GCC should produce XCOFF format debugging
- output in response to the `-g' option. This is a variant of DBX
- format.
-
- -- Macro: DEFAULT_GDB_EXTENSIONS
- Define this macro to control whether GCC should by default generate
- GDB's extended version of DBX debugging information (assuming
- DBX-format debugging information is enabled at all). If you don't
- define the macro, the default is 1: always generate the extended
- information if there is any occasion to.
-
- -- Macro: DEBUG_SYMS_TEXT
- Define this macro if all `.stabs' commands should be output while
- in the text section.
-
- -- Macro: ASM_STABS_OP
- A C string constant, including spacing, naming the assembler
- pseudo op to use instead of `"\t.stabs\t"' to define an ordinary
- debugging symbol. If you don't define this macro, `"\t.stabs\t"'
- is used. This macro applies only to DBX debugging information
- format.
-
- -- Macro: ASM_STABD_OP
- A C string constant, including spacing, naming the assembler
- pseudo op to use instead of `"\t.stabd\t"' to define a debugging
- symbol whose value is the current location. If you don't define
- this macro, `"\t.stabd\t"' is used. This macro applies only to
- DBX debugging information format.
-
- -- Macro: ASM_STABN_OP
- A C string constant, including spacing, naming the assembler
- pseudo op to use instead of `"\t.stabn\t"' to define a debugging
- symbol with no name. If you don't define this macro,
- `"\t.stabn\t"' is used. This macro applies only to DBX debugging
- information format.
-
- -- Macro: DBX_NO_XREFS
- Define this macro if DBX on your system does not support the
- construct `xsTAGNAME'. On some systems, this construct is used to
- describe a forward reference to a structure named TAGNAME. On
- other systems, this construct is not supported at all.
-
- -- Macro: DBX_CONTIN_LENGTH
- A symbol name in DBX-format debugging information is normally
- continued (split into two separate `.stabs' directives) when it
- exceeds a certain length (by default, 80 characters). On some
- operating systems, DBX requires this splitting; on others,
- splitting must not be done. You can inhibit splitting by defining
- this macro with the value zero. You can override the default
- splitting-length by defining this macro as an expression for the
- length you desire.
-
- -- Macro: DBX_CONTIN_CHAR
- Normally continuation is indicated by adding a `\' character to
- the end of a `.stabs' string when a continuation follows. To use
- a different character instead, define this macro as a character
- constant for the character you want to use. Do not define this
- macro if backslash is correct for your system.
-
- -- Macro: DBX_STATIC_STAB_DATA_SECTION
- Define this macro if it is necessary to go to the data section
- before outputting the `.stabs' pseudo-op for a non-global static
- variable.
-
- -- Macro: DBX_TYPE_DECL_STABS_CODE
- The value to use in the "code" field of the `.stabs' directive for
- a typedef. The default is `N_LSYM'.
-
- -- Macro: DBX_STATIC_CONST_VAR_CODE
- The value to use in the "code" field of the `.stabs' directive for
- a static variable located in the text section. DBX format does not
- provide any "right" way to do this. The default is `N_FUN'.
-
- -- Macro: DBX_REGPARM_STABS_CODE
- The value to use in the "code" field of the `.stabs' directive for
- a parameter passed in registers. DBX format does not provide any
- "right" way to do this. The default is `N_RSYM'.
-
- -- Macro: DBX_REGPARM_STABS_LETTER
- The letter to use in DBX symbol data to identify a symbol as a
- parameter passed in registers. DBX format does not customarily
- provide any way to do this. The default is `'P''.
-
- -- Macro: DBX_FUNCTION_FIRST
- Define this macro if the DBX information for a function and its
- arguments should precede the assembler code for the function.
- Normally, in DBX format, the debugging information entirely
- follows the assembler code.
-
- -- Macro: DBX_BLOCKS_FUNCTION_RELATIVE
- Define this macro, with value 1, if the value of a symbol
- describing the scope of a block (`N_LBRAC' or `N_RBRAC') should be
- relative to the start of the enclosing function. Normally, GCC
- uses an absolute address.
-
- -- Macro: DBX_LINES_FUNCTION_RELATIVE
- Define this macro, with value 1, if the value of a symbol
- indicating the current line number (`N_SLINE') should be relative
- to the start of the enclosing function. Normally, GCC uses an
- absolute address.
-
- -- Macro: DBX_USE_BINCL
- Define this macro if GCC should generate `N_BINCL' and `N_EINCL'
- stabs for included header files, as on Sun systems. This macro
- also directs GCC to output a type number as a pair of a file
- number and a type number within the file. Normally, GCC does not
- generate `N_BINCL' or `N_EINCL' stabs, and it outputs a single
- number for a type number.
-
-\1f
-File: gccint.info, Node: DBX Hooks, Next: File Names and DBX, Prev: DBX Options, Up: Debugging Info
-
-17.22.3 Open-Ended Hooks for DBX Format
----------------------------------------
-
-These are hooks for DBX format.
-
- -- Macro: DBX_OUTPUT_LBRAC (STREAM, NAME)
- Define this macro to say how to output to STREAM the debugging
- information for the start of a scope level for variable names. The
- argument NAME is the name of an assembler symbol (for use with
- `assemble_name') whose value is the address where the scope begins.
-
- -- Macro: DBX_OUTPUT_RBRAC (STREAM, NAME)
- Like `DBX_OUTPUT_LBRAC', but for the end of a scope level.
-
- -- Macro: DBX_OUTPUT_NFUN (STREAM, LSCOPE_LABEL, DECL)
- Define this macro if the target machine requires special handling
- to output an `N_FUN' entry for the function DECL.
-
- -- Macro: DBX_OUTPUT_SOURCE_LINE (STREAM, LINE, COUNTER)
- A C statement to output DBX debugging information before code for
- line number LINE of the current source file to the stdio stream
- STREAM. COUNTER is the number of time the macro was invoked,
- including the current invocation; it is intended to generate
- unique labels in the assembly output.
-
- This macro should not be defined if the default output is correct,
- or if it can be made correct by defining
- `DBX_LINES_FUNCTION_RELATIVE'.
-
- -- Macro: NO_DBX_FUNCTION_END
- Some stabs encapsulation formats (in particular ECOFF), cannot
- handle the `.stabs "",N_FUN,,0,0,Lscope-function-1' gdb dbx
- extension construct. On those machines, define this macro to turn
- this feature off without disturbing the rest of the gdb extensions.
-
- -- Macro: NO_DBX_BNSYM_ENSYM
- Some assemblers cannot handle the `.stabd BNSYM/ENSYM,0,0' gdb dbx
- extension construct. On those machines, define this macro to turn
- this feature off without disturbing the rest of the gdb extensions.
-
-\1f
-File: gccint.info, Node: File Names and DBX, Next: SDB and DWARF, Prev: DBX Hooks, Up: Debugging Info
-
-17.22.4 File Names in DBX Format
---------------------------------
-
-This describes file names in DBX format.
-
- -- Macro: DBX_OUTPUT_MAIN_SOURCE_FILENAME (STREAM, NAME)
- A C statement to output DBX debugging information to the stdio
- stream STREAM, which indicates that file NAME is the main source
- file--the file specified as the input file for compilation. This
- macro is called only once, at the beginning of compilation.
-
- This macro need not be defined if the standard form of output for
- DBX debugging information is appropriate.
-
- It may be necessary to refer to a label equal to the beginning of
- the text section. You can use `assemble_name (stream,
- ltext_label_name)' to do so. If you do this, you must also set
- the variable USED_LTEXT_LABEL_NAME to `true'.
-
- -- Macro: NO_DBX_MAIN_SOURCE_DIRECTORY
- Define this macro, with value 1, if GCC should not emit an
- indication of the current directory for compilation and current
- source language at the beginning of the file.
-
- -- Macro: NO_DBX_GCC_MARKER
- Define this macro, with value 1, if GCC should not emit an
- indication that this object file was compiled by GCC. The default
- is to emit an `N_OPT' stab at the beginning of every source file,
- with `gcc2_compiled.' for the string and value 0.
-
- -- Macro: DBX_OUTPUT_MAIN_SOURCE_FILE_END (STREAM, NAME)
- A C statement to output DBX debugging information at the end of
- compilation of the main source file NAME. Output should be
- written to the stdio stream STREAM.
-
- If you don't define this macro, nothing special is output at the
- end of compilation, which is correct for most machines.
-
- -- Macro: DBX_OUTPUT_NULL_N_SO_AT_MAIN_SOURCE_FILE_END
- Define this macro _instead of_ defining
- `DBX_OUTPUT_MAIN_SOURCE_FILE_END', if what needs to be output at
- the end of compilation is a `N_SO' stab with an empty string,
- whose value is the highest absolute text address in the file.
-
-\1f
-File: gccint.info, Node: SDB and DWARF, Next: VMS Debug, Prev: File Names and DBX, Up: Debugging Info
-
-17.22.5 Macros for SDB and DWARF Output
----------------------------------------
-
-Here are macros for SDB and DWARF output.
-
- -- Macro: SDB_DEBUGGING_INFO
- Define this macro if GCC should produce COFF-style debugging output
- for SDB in response to the `-g' option.
-
- -- Macro: DWARF2_DEBUGGING_INFO
- Define this macro if GCC should produce dwarf version 2 format
- debugging output in response to the `-g' option.
-
- -- Target Hook: int TARGET_DWARF_CALLING_CONVENTION (tree
- FUNCTION)
- Define this to enable the dwarf attribute
- `DW_AT_calling_convention' to be emitted for each function.
- Instead of an integer return the enum value for the `DW_CC_'
- tag.
-
- To support optional call frame debugging information, you must also
- define `INCOMING_RETURN_ADDR_RTX' and either set
- `RTX_FRAME_RELATED_P' on the prologue insns if you use RTL for the
- prologue, or call `dwarf2out_def_cfa' and `dwarf2out_reg_save' as
- appropriate from `TARGET_ASM_FUNCTION_PROLOGUE' if you don't.
-
- -- Macro: DWARF2_FRAME_INFO
- Define this macro to a nonzero value if GCC should always output
- Dwarf 2 frame information. If `DWARF2_UNWIND_INFO' (*note
- Exception Region Output:: is nonzero, GCC will output this
- information not matter how you define `DWARF2_FRAME_INFO'.
-
- -- Macro: DWARF2_ASM_LINE_DEBUG_INFO
- Define this macro to be a nonzero value if the assembler can
- generate Dwarf 2 line debug info sections. This will result in
- much more compact line number tables, and hence is desirable if it
- works.
-
- -- Macro: ASM_OUTPUT_DWARF_DELTA (STREAM, SIZE, LABEL1, LABEL2)
- A C statement to issue assembly directives that create a difference
- LAB1 minus LAB2, using an integer of the given SIZE.
-
- -- Macro: ASM_OUTPUT_DWARF_OFFSET (STREAM, SIZE, LABEL, SECTION)
- A C statement to issue assembly directives that create a
- section-relative reference to the given LABEL, using an integer of
- the given SIZE. The label is known to be defined in the given
- SECTION.
-
- -- Macro: ASM_OUTPUT_DWARF_PCREL (STREAM, SIZE, LABEL)
- A C statement to issue assembly directives that create a
- self-relative reference to the given LABEL, using an integer of
- the given SIZE.
-
- -- Target Hook: void TARGET_ASM_OUTPUT_DWARF_DTPREL (FILE *FILE, int
- SIZE, rtx X)
- If defined, this target hook is a function which outputs a
- DTP-relative reference to the given TLS symbol of the specified
- size.
-
- -- Macro: PUT_SDB_...
- Define these macros to override the assembler syntax for the
- special SDB assembler directives. See `sdbout.c' for a list of
- these macros and their arguments. If the standard syntax is used,
- you need not define them yourself.
-
- -- Macro: SDB_DELIM
- Some assemblers do not support a semicolon as a delimiter, even
- between SDB assembler directives. In that case, define this macro
- to be the delimiter to use (usually `\n'). It is not necessary to
- define a new set of `PUT_SDB_OP' macros if this is the only change
- required.
-
- -- Macro: SDB_ALLOW_UNKNOWN_REFERENCES
- Define this macro to allow references to unknown structure, union,
- or enumeration tags to be emitted. Standard COFF does not allow
- handling of unknown references, MIPS ECOFF has support for it.
-
- -- Macro: SDB_ALLOW_FORWARD_REFERENCES
- Define this macro to allow references to structure, union, or
- enumeration tags that have not yet been seen to be handled. Some
- assemblers choke if forward tags are used, while some require it.
-
- -- Macro: SDB_OUTPUT_SOURCE_LINE (STREAM, LINE)
- A C statement to output SDB debugging information before code for
- line number LINE of the current source file to the stdio stream
- STREAM. The default is to emit an `.ln' directive.
-
-\1f
-File: gccint.info, Node: VMS Debug, Prev: SDB and DWARF, Up: Debugging Info
-
-17.22.6 Macros for VMS Debug Format
------------------------------------
-
-Here are macros for VMS debug format.
-
- -- Macro: VMS_DEBUGGING_INFO
- Define this macro if GCC should produce debugging output for VMS
- in response to the `-g' option. The default behavior for VMS is
- to generate minimal debug info for a traceback in the absence of
- `-g' unless explicitly overridden with `-g0'. This behavior is
- controlled by `OPTIMIZATION_OPTIONS' and `OVERRIDE_OPTIONS'.
-
-\1f
-File: gccint.info, Node: Floating Point, Next: Mode Switching, Prev: Debugging Info, Up: Target Macros
-
-17.23 Cross Compilation and Floating Point
-==========================================
-
-While all modern machines use twos-complement representation for
-integers, there are a variety of representations for floating point
-numbers. This means that in a cross-compiler the representation of
-floating point numbers in the compiled program may be different from
-that used in the machine doing the compilation.
-
- Because different representation systems may offer different amounts of
-range and precision, all floating point constants must be represented in
-the target machine's format. Therefore, the cross compiler cannot
-safely use the host machine's floating point arithmetic; it must emulate
-the target's arithmetic. To ensure consistency, GCC always uses
-emulation to work with floating point values, even when the host and
-target floating point formats are identical.
-
- The following macros are provided by `real.h' for the compiler to use.
-All parts of the compiler which generate or optimize floating-point
-calculations must use these macros. They may evaluate their operands
-more than once, so operands must not have side effects.
-
- -- Macro: REAL_VALUE_TYPE
- The C data type to be used to hold a floating point value in the
- target machine's format. Typically this is a `struct' containing
- an array of `HOST_WIDE_INT', but all code should treat it as an
- opaque quantity.
-
- -- Macro: int REAL_VALUES_EQUAL (REAL_VALUE_TYPE X, REAL_VALUE_TYPE Y)
- Compares for equality the two values, X and Y. If the target
- floating point format supports negative zeroes and/or NaNs,
- `REAL_VALUES_EQUAL (-0.0, 0.0)' is true, and `REAL_VALUES_EQUAL
- (NaN, NaN)' is false.
-
- -- Macro: int REAL_VALUES_LESS (REAL_VALUE_TYPE X, REAL_VALUE_TYPE Y)
- Tests whether X is less than Y.
-
- -- Macro: HOST_WIDE_INT REAL_VALUE_FIX (REAL_VALUE_TYPE X)
- Truncates X to a signed integer, rounding toward zero.
-
- -- Macro: unsigned HOST_WIDE_INT REAL_VALUE_UNSIGNED_FIX
- (REAL_VALUE_TYPE X)
- Truncates X to an unsigned integer, rounding toward zero. If X is
- negative, returns zero.
-
- -- Macro: REAL_VALUE_TYPE REAL_VALUE_ATOF (const char *STRING, enum
- machine_mode MODE)
- Converts STRING into a floating point number in the target
- machine's representation for mode MODE. This routine can handle
- both decimal and hexadecimal floating point constants, using the
- syntax defined by the C language for both.
-
- -- Macro: int REAL_VALUE_NEGATIVE (REAL_VALUE_TYPE X)
- Returns 1 if X is negative (including negative zero), 0 otherwise.
-
- -- Macro: int REAL_VALUE_ISINF (REAL_VALUE_TYPE X)
- Determines whether X represents infinity (positive or negative).
-
- -- Macro: int REAL_VALUE_ISNAN (REAL_VALUE_TYPE X)
- Determines whether X represents a "NaN" (not-a-number).
-
- -- Macro: void REAL_ARITHMETIC (REAL_VALUE_TYPE OUTPUT, enum tree_code
- CODE, REAL_VALUE_TYPE X, REAL_VALUE_TYPE Y)
- Calculates an arithmetic operation on the two floating point values
- X and Y, storing the result in OUTPUT (which must be a variable).
-
- The operation to be performed is specified by CODE. Only the
- following codes are supported: `PLUS_EXPR', `MINUS_EXPR',
- `MULT_EXPR', `RDIV_EXPR', `MAX_EXPR', `MIN_EXPR'.
-
- If `REAL_ARITHMETIC' is asked to evaluate division by zero and the
- target's floating point format cannot represent infinity, it will
- call `abort'. Callers should check for this situation first, using
- `MODE_HAS_INFINITIES'. *Note Storage Layout::.
-
- -- Macro: REAL_VALUE_TYPE REAL_VALUE_NEGATE (REAL_VALUE_TYPE X)
- Returns the negative of the floating point value X.
-
- -- Macro: REAL_VALUE_TYPE REAL_VALUE_ABS (REAL_VALUE_TYPE X)
- Returns the absolute value of X.
-
- -- Macro: REAL_VALUE_TYPE REAL_VALUE_TRUNCATE (REAL_VALUE_TYPE MODE,
- enum machine_mode X)
- Truncates the floating point value X to fit in MODE. The return
- value is still a full-size `REAL_VALUE_TYPE', but it has an
- appropriate bit pattern to be output as a floating constant whose
- precision accords with mode MODE.
-
- -- Macro: void REAL_VALUE_TO_INT (HOST_WIDE_INT LOW, HOST_WIDE_INT
- HIGH, REAL_VALUE_TYPE X)
- Converts a floating point value X into a double-precision integer
- which is then stored into LOW and HIGH. If the value is not
- integral, it is truncated.
-
- -- Macro: void REAL_VALUE_FROM_INT (REAL_VALUE_TYPE X, HOST_WIDE_INT
- LOW, HOST_WIDE_INT HIGH, enum machine_mode MODE)
- Converts a double-precision integer found in LOW and HIGH, into a
- floating point value which is then stored into X. The value is
- truncated to fit in mode MODE.
-
-\1f
-File: gccint.info, Node: Mode Switching, Next: Target Attributes, Prev: Floating Point, Up: Target Macros
-
-17.24 Mode Switching Instructions
-=================================
-
-The following macros control mode switching optimizations:
-
- -- Macro: OPTIMIZE_MODE_SWITCHING (ENTITY)
- Define this macro if the port needs extra instructions inserted
- for mode switching in an optimizing compilation.
-
- For an example, the SH4 can perform both single and double
- precision floating point operations, but to perform a single
- precision operation, the FPSCR PR bit has to be cleared, while for
- a double precision operation, this bit has to be set. Changing
- the PR bit requires a general purpose register as a scratch
- register, hence these FPSCR sets have to be inserted before
- reload, i.e. you can't put this into instruction emitting or
- `TARGET_MACHINE_DEPENDENT_REORG'.
-
- You can have multiple entities that are mode-switched, and select
- at run time which entities actually need it.
- `OPTIMIZE_MODE_SWITCHING' should return nonzero for any ENTITY
- that needs mode-switching. If you define this macro, you also
- have to define `NUM_MODES_FOR_MODE_SWITCHING', `MODE_NEEDED',
- `MODE_PRIORITY_TO_MODE' and `EMIT_MODE_SET'. `MODE_AFTER',
- `MODE_ENTRY', and `MODE_EXIT' are optional.
-
- -- Macro: NUM_MODES_FOR_MODE_SWITCHING
- If you define `OPTIMIZE_MODE_SWITCHING', you have to define this as
- initializer for an array of integers. Each initializer element N
- refers to an entity that needs mode switching, and specifies the
- number of different modes that might need to be set for this
- entity. The position of the initializer in the
- initializer--starting counting at zero--determines the integer
- that is used to refer to the mode-switched entity in question. In
- macros that take mode arguments / yield a mode result, modes are
- represented as numbers 0 ... N - 1. N is used to specify that no
- mode switch is needed / supplied.
-
- -- Macro: MODE_NEEDED (ENTITY, INSN)
- ENTITY is an integer specifying a mode-switched entity. If
- `OPTIMIZE_MODE_SWITCHING' is defined, you must define this macro to
- return an integer value not larger than the corresponding element
- in `NUM_MODES_FOR_MODE_SWITCHING', to denote the mode that ENTITY
- must be switched into prior to the execution of INSN.
-
- -- Macro: MODE_AFTER (MODE, INSN)
- If this macro is defined, it is evaluated for every INSN during
- mode switching. It determines the mode that an insn results in (if
- different from the incoming mode).
-
- -- Macro: MODE_ENTRY (ENTITY)
- If this macro is defined, it is evaluated for every ENTITY that
- needs mode switching. It should evaluate to an integer, which is
- a mode that ENTITY is assumed to be switched to at function entry.
- If `MODE_ENTRY' is defined then `MODE_EXIT' must be defined.
-
- -- Macro: MODE_EXIT (ENTITY)
- If this macro is defined, it is evaluated for every ENTITY that
- needs mode switching. It should evaluate to an integer, which is
- a mode that ENTITY is assumed to be switched to at function exit.
- If `MODE_EXIT' is defined then `MODE_ENTRY' must be defined.
-
- -- Macro: MODE_PRIORITY_TO_MODE (ENTITY, N)
- This macro specifies the order in which modes for ENTITY are
- processed. 0 is the highest priority,
- `NUM_MODES_FOR_MODE_SWITCHING[ENTITY] - 1' the lowest. The value
- of the macro should be an integer designating a mode for ENTITY.
- For any fixed ENTITY, `mode_priority_to_mode' (ENTITY, N) shall be
- a bijection in 0 ... `num_modes_for_mode_switching[ENTITY] - 1'.
-
- -- Macro: EMIT_MODE_SET (ENTITY, MODE, HARD_REGS_LIVE)
- Generate one or more insns to set ENTITY to MODE. HARD_REG_LIVE
- is the set of hard registers live at the point where the insn(s)
- are to be inserted.
-
-\1f
-File: gccint.info, Node: Target Attributes, Next: Emulated TLS, Prev: Mode Switching, Up: Target Macros
-
-17.25 Defining target-specific uses of `__attribute__'
-======================================================
-
-Target-specific attributes may be defined for functions, data and types.
-These are described using the following target hooks; they also need to
-be documented in `extend.texi'.
-
- -- Target Hook: const struct attribute_spec * TARGET_ATTRIBUTE_TABLE
- If defined, this target hook points to an array of `struct
- attribute_spec' (defined in `tree.h') specifying the machine
- specific attributes for this target and some of the restrictions
- on the entities to which these attributes are applied and the
- arguments they take.
-
- -- Target Hook: int TARGET_COMP_TYPE_ATTRIBUTES (tree TYPE1, tree
- TYPE2)
- If defined, this target hook is a function which returns zero if
- the attributes on TYPE1 and TYPE2 are incompatible, one if they
- are compatible, and two if they are nearly compatible (which
- causes a warning to be generated). If this is not defined,
- machine-specific attributes are supposed always to be compatible.
-
- -- Target Hook: void TARGET_SET_DEFAULT_TYPE_ATTRIBUTES (tree TYPE)
- If defined, this target hook is a function which assigns default
- attributes to newly defined TYPE.
-
- -- Target Hook: tree TARGET_MERGE_TYPE_ATTRIBUTES (tree TYPE1, tree
- TYPE2)
- Define this target hook if the merging of type attributes needs
- special handling. If defined, the result is a list of the combined
- `TYPE_ATTRIBUTES' of TYPE1 and TYPE2. It is assumed that
- `comptypes' has already been called and returned 1. This function
- may call `merge_attributes' to handle machine-independent merging.
-
- -- Target Hook: tree TARGET_MERGE_DECL_ATTRIBUTES (tree OLDDECL, tree
- NEWDECL)
- Define this target hook if the merging of decl attributes needs
- special handling. If defined, the result is a list of the combined
- `DECL_ATTRIBUTES' of OLDDECL and NEWDECL. NEWDECL is a duplicate
- declaration of OLDDECL. Examples of when this is needed are when
- one attribute overrides another, or when an attribute is nullified
- by a subsequent definition. This function may call
- `merge_attributes' to handle machine-independent merging.
-
- If the only target-specific handling you require is `dllimport'
- for Microsoft Windows targets, you should define the macro
- `TARGET_DLLIMPORT_DECL_ATTRIBUTES' to `1'. The compiler will then
- define a function called `merge_dllimport_decl_attributes' which
- can then be defined as the expansion of
- `TARGET_MERGE_DECL_ATTRIBUTES'. You can also add
- `handle_dll_attribute' in the attribute table for your port to
- perform initial processing of the `dllimport' and `dllexport'
- attributes. This is done in `i386/cygwin.h' and `i386/i386.c',
- for example.
-
- -- Target Hook: bool TARGET_VALID_DLLIMPORT_ATTRIBUTE_P (tree DECL)
- DECL is a variable or function with `__attribute__((dllimport))'
- specified. Use this hook if the target needs to add extra
- validation checks to `handle_dll_attribute'.
-
- -- Macro: TARGET_DECLSPEC
- Define this macro to a nonzero value if you want to treat
- `__declspec(X)' as equivalent to `__attribute((X))'. By default,
- this behavior is enabled only for targets that define
- `TARGET_DLLIMPORT_DECL_ATTRIBUTES'. The current implementation of
- `__declspec' is via a built-in macro, but you should not rely on
- this implementation detail.
-
- -- Target Hook: void TARGET_INSERT_ATTRIBUTES (tree NODE, tree
- *ATTR_PTR)
- Define this target hook if you want to be able to add attributes
- to a decl when it is being created. This is normally useful for
- back ends which wish to implement a pragma by using the attributes
- which correspond to the pragma's effect. The NODE argument is the
- decl which is being created. The ATTR_PTR argument is a pointer
- to the attribute list for this decl. The list itself should not
- be modified, since it may be shared with other decls, but
- attributes may be chained on the head of the list and `*ATTR_PTR'
- modified to point to the new attributes, or a copy of the list may
- be made if further changes are needed.
-
- -- Target Hook: bool TARGET_FUNCTION_ATTRIBUTE_INLINABLE_P (tree
- FNDECL)
- This target hook returns `true' if it is ok to inline FNDECL into
- the current function, despite its having target-specific
- attributes, `false' otherwise. By default, if a function has a
- target specific attribute attached to it, it will not be inlined.
-
- -- Target Hook: bool TARGET_VALID_OPTION_ATTRIBUTE_P (tree FNDECL,
- tree NAME, tree ARGS, int FLAGS)
- This hook is called to parse the `attribute(option("..."))', and
- it allows the function to set different target machine compile time
- options for the current function that might be different than the
- options specified on the command line. The hook should return
- `true' if the options are valid.
-
- The hook should set the DECL_FUNCTION_SPECIFIC_TARGET field in the
- function declaration to hold a pointer to a target specific STRUCT
- CL_TARGET_OPTION structure.
-
- -- Target Hook: void TARGET_OPTION_SAVE (struct cl_target_option *PTR)
- This hook is called to save any additional target specific
- information in the STRUCT CL_TARGET_OPTION structure for function
- specific options. *Note Option file format::.
-
- -- Target Hook: void TARGET_OPTION_RESTORE (struct cl_target_option
- *PTR)
- This hook is called to restore any additional target specific
- information in the STRUCT CL_TARGET_OPTION structure for function
- specific options.
-
- -- Target Hook: void TARGET_OPTION_PRINT (struct cl_target_option *PTR)
- This hook is called to print any additional target specific
- information in the STRUCT CL_TARGET_OPTION structure for function
- specific options.
-
- -- Target Hook: bool TARGET_OPTION_PRAGMA_PARSE (target ARGS)
- This target hook parses the options for `#pragma GCC option' to
- set the machine specific options for functions that occur later in
- the input stream. The options should be the same as handled by the
- `TARGET_VALID_OPTION_ATTRIBUTE_P' hook.
-
- -- Target Hook: bool TARGET_CAN_INLINE_P (tree CALLER, tree CALLEE)
- This target hook returns `false' if the CALLER function cannot
- inline CALLEE, based on target specific information. By default,
- inlining is not allowed if the callee function has function
- specific target options and the caller does not use the same
- options.
-
-\1f
-File: gccint.info, Node: Emulated TLS, Next: MIPS Coprocessors, Prev: Target Attributes, Up: Target Macros
-
-17.26 Emulating TLS
-===================
-
-For targets whose psABI does not provide Thread Local Storage via
-specific relocations and instruction sequences, an emulation layer is
-used. A set of target hooks allows this emulation layer to be
-configured for the requirements of a particular target. For instance
-the psABI may in fact specify TLS support in terms of an emulation
-layer.
-
- The emulation layer works by creating a control object for every TLS
-object. To access the TLS object, a lookup function is provided which,
-when given the address of the control object, will return the address
-of the current thread's instance of the TLS object.
-
- -- Target Hook: const char * TARGET_EMUTLS_GET_ADDRESS
- Contains the name of the helper function that uses a TLS control
- object to locate a TLS instance. The default causes libgcc's
- emulated TLS helper function to be used.
-
- -- Target Hook: const char * TARGET_EMUTLS_REGISTER_COMMON
- Contains the name of the helper function that should be used at
- program startup to register TLS objects that are implicitly
- initialized to zero. If this is `NULL', all TLS objects will have
- explicit initializers. The default causes libgcc's emulated TLS
- registration function to be used.
-
- -- Target Hook: const char * TARGET_EMUTLS_VAR_SECTION
- Contains the name of the section in which TLS control variables
- should be placed. The default of `NULL' allows these to be placed
- in any section.
-
- -- Target Hook: const char * TARGET_EMUTLS_TMPL_SECTION
- Contains the name of the section in which TLS initializers should
- be placed. The default of `NULL' allows these to be placed in any
- section.
-
- -- Target Hook: const char * TARGET_EMUTLS_VAR_PREFIX
- Contains the prefix to be prepended to TLS control variable names.
- The default of `NULL' uses a target-specific prefix.
-
- -- Target Hook: const char * TARGET_EMUTLS_TMPL_PREFIX
- Contains the prefix to be prepended to TLS initializer objects.
- The default of `NULL' uses a target-specific prefix.
-
- -- Target Hook: tree TARGET_EMUTLS_VAR_FIELDS (tree TYPE, tree *NAME)
- Specifies a function that generates the FIELD_DECLs for a TLS
- control object type. TYPE is the RECORD_TYPE the fields are for
- and NAME should be filled with the structure tag, if the default of
- `__emutls_object' is unsuitable. The default creates a type
- suitable for libgcc's emulated TLS function.
-
- -- Target Hook: tree TARGET_EMUTLS_VAR_INIT (tree VAR, tree DECL, tree
- TMPL_ADDR)
- Specifies a function that generates the CONSTRUCTOR to initialize a
- TLS control object. VAR is the TLS control object, DECL is the
- TLS object and TMPL_ADDR is the address of the initializer. The
- default initializes libgcc's emulated TLS control object.
-
- -- Target Hook: bool TARGET_EMUTLS_VAR_ALIGN_FIXED
- Specifies whether the alignment of TLS control variable objects is
- fixed and should not be increased as some backends may do to
- optimize single objects. The default is false.
-
- -- Target Hook: bool TARGET_EMUTLS_DEBUG_FORM_TLS_ADDRESS
- Specifies whether a DWARF `DW_OP_form_tls_address' location
- descriptor may be used to describe emulated TLS control objects.
-
-\1f
-File: gccint.info, Node: MIPS Coprocessors, Next: PCH Target, Prev: Emulated TLS, Up: Target Macros
-
-17.27 Defining coprocessor specifics for MIPS targets.
-======================================================
-
-The MIPS specification allows MIPS implementations to have as many as 4
-coprocessors, each with as many as 32 private registers. GCC supports
-accessing these registers and transferring values between the registers
-and memory using asm-ized variables. For example:
-
- register unsigned int cp0count asm ("c0r1");
- unsigned int d;
-
- d = cp0count + 3;
-
- ("c0r1" is the default name of register 1 in coprocessor 0; alternate
-names may be added as described below, or the default names may be
-overridden entirely in `SUBTARGET_CONDITIONAL_REGISTER_USAGE'.)
-
- Coprocessor registers are assumed to be epilogue-used; sets to them
-will be preserved even if it does not appear that the register is used
-again later in the function.
-
- Another note: according to the MIPS spec, coprocessor 1 (if present) is
-the FPU. One accesses COP1 registers through standard mips
-floating-point support; they are not included in this mechanism.
-
- There is one macro used in defining the MIPS coprocessor interface
-which you may want to override in subtargets; it is described below.
-
- -- Macro: ALL_COP_ADDITIONAL_REGISTER_NAMES
- A comma-separated list (with leading comma) of pairs describing the
- alternate names of coprocessor registers. The format of each
- entry should be
- { ALTERNATENAME, REGISTER_NUMBER}
- Default: empty.
-
-\1f
-File: gccint.info, Node: PCH Target, Next: C++ ABI, Prev: MIPS Coprocessors, Up: Target Macros
-
-17.28 Parameters for Precompiled Header Validity Checking
-=========================================================
-
- -- Target Hook: void *TARGET_GET_PCH_VALIDITY (size_t *SZ)
- This hook returns the data needed by `TARGET_PCH_VALID_P' and sets
- `*SZ' to the size of the data in bytes.
-
- -- Target Hook: const char *TARGET_PCH_VALID_P (const void *DATA,
- size_t SZ)
- This hook checks whether the options used to create a PCH file are
- compatible with the current settings. It returns `NULL' if so and
- a suitable error message if not. Error messages will be presented
- to the user and must be localized using `_(MSG)'.
-
- DATA is the data that was returned by `TARGET_GET_PCH_VALIDITY'
- when the PCH file was created and SZ is the size of that data in
- bytes. It's safe to assume that the data was created by the same
- version of the compiler, so no format checking is needed.
-
- The default definition of `default_pch_valid_p' should be suitable
- for most targets.
-
- -- Target Hook: const char *TARGET_CHECK_PCH_TARGET_FLAGS (int
- PCH_FLAGS)
- If this hook is nonnull, the default implementation of
- `TARGET_PCH_VALID_P' will use it to check for compatible values of
- `target_flags'. PCH_FLAGS specifies the value that `target_flags'
- had when the PCH file was created. The return value is the same
- as for `TARGET_PCH_VALID_P'.
-
-\1f
-File: gccint.info, Node: C++ ABI, Next: Misc, Prev: PCH Target, Up: Target Macros
-
-17.29 C++ ABI parameters
-========================
-
- -- Target Hook: tree TARGET_CXX_GUARD_TYPE (void)
- Define this hook to override the integer type used for guard
- variables. These are used to implement one-time construction of
- static objects. The default is long_long_integer_type_node.
-
- -- Target Hook: bool TARGET_CXX_GUARD_MASK_BIT (void)
- This hook determines how guard variables are used. It should
- return `false' (the default) if first byte should be used. A
- return value of `true' indicates the least significant bit should
- be used.
-
- -- Target Hook: tree TARGET_CXX_GET_COOKIE_SIZE (tree TYPE)
- This hook returns the size of the cookie to use when allocating an
- array whose elements have the indicated TYPE. Assumes that it is
- already known that a cookie is needed. The default is `max(sizeof
- (size_t), alignof(type))', as defined in section 2.7 of the
- IA64/Generic C++ ABI.
-
- -- Target Hook: bool TARGET_CXX_COOKIE_HAS_SIZE (void)
- This hook should return `true' if the element size should be
- stored in array cookies. The default is to return `false'.
-
- -- Target Hook: int TARGET_CXX_IMPORT_EXPORT_CLASS (tree TYPE, int
- IMPORT_EXPORT)
- If defined by a backend this hook allows the decision made to
- export class TYPE to be overruled. Upon entry IMPORT_EXPORT will
- contain 1 if the class is going to be exported, -1 if it is going
- to be imported and 0 otherwise. This function should return the
- modified value and perform any other actions necessary to support
- the backend's targeted operating system.
-
- -- Target Hook: bool TARGET_CXX_CDTOR_RETURNS_THIS (void)
- This hook should return `true' if constructors and destructors
- return the address of the object created/destroyed. The default
- is to return `false'.
-
- -- Target Hook: bool TARGET_CXX_KEY_METHOD_MAY_BE_INLINE (void)
- This hook returns true if the key method for a class (i.e., the
- method which, if defined in the current translation unit, causes
- the virtual table to be emitted) may be an inline function. Under
- the standard Itanium C++ ABI the key method may be an inline
- function so long as the function is not declared inline in the
- class definition. Under some variants of the ABI, an inline
- function can never be the key method. The default is to return
- `true'.
-
- -- Target Hook: void TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY (tree
- DECL)
- DECL is a virtual table, virtual table table, typeinfo object, or
- other similar implicit class data object that will be emitted with
- external linkage in this translation unit. No ELF visibility has
- been explicitly specified. If the target needs to specify a
- visibility other than that of the containing class, use this hook
- to set `DECL_VISIBILITY' and `DECL_VISIBILITY_SPECIFIED'.
-
- -- Target Hook: bool TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT (void)
- This hook returns true (the default) if virtual tables and other
- similar implicit class data objects are always COMDAT if they have
- external linkage. If this hook returns false, then class data for
- classes whose virtual table will be emitted in only one translation
- unit will not be COMDAT.
-
- -- Target Hook: bool TARGET_CXX_LIBRARY_RTTI_COMDAT (void)
- This hook returns true (the default) if the RTTI information for
- the basic types which is defined in the C++ runtime should always
- be COMDAT, false if it should not be COMDAT.
-
- -- Target Hook: bool TARGET_CXX_USE_AEABI_ATEXIT (void)
- This hook returns true if `__aeabi_atexit' (as defined by the ARM
- EABI) should be used to register static destructors when
- `-fuse-cxa-atexit' is in effect. The default is to return false
- to use `__cxa_atexit'.
-
- -- Target Hook: bool TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT (void)
- This hook returns true if the target `atexit' function can be used
- in the same manner as `__cxa_atexit' to register C++ static
- destructors. This requires that `atexit'-registered functions in
- shared libraries are run in the correct order when the libraries
- are unloaded. The default is to return false.
-
- -- Target Hook: void TARGET_CXX_ADJUST_CLASS_AT_DEFINITION (tree TYPE)
- TYPE is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that has
- just been defined. Use this hook to make adjustments to the class
- (eg, tweak visibility or perform any other required target
- modifications).
-
-\1f
-File: gccint.info, Node: Misc, Prev: C++ ABI, Up: Target Macros
-
-17.30 Miscellaneous Parameters
-==============================
-
-Here are several miscellaneous parameters.
-
- -- Macro: HAS_LONG_COND_BRANCH
- Define this boolean macro to indicate whether or not your
- architecture has conditional branches that can span all of memory.
- It is used in conjunction with an optimization that partitions hot
- and cold basic blocks into separate sections of the executable.
- If this macro is set to false, gcc will convert any conditional
- branches that attempt to cross between sections into unconditional
- branches or indirect jumps.
-
- -- Macro: HAS_LONG_UNCOND_BRANCH
- Define this boolean macro to indicate whether or not your
- architecture has unconditional branches that can span all of
- memory. It is used in conjunction with an optimization that
- partitions hot and cold basic blocks into separate sections of the
- executable. If this macro is set to false, gcc will convert any
- unconditional branches that attempt to cross between sections into
- indirect jumps.
-
- -- Macro: CASE_VECTOR_MODE
- An alias for a machine mode name. This is the machine mode that
- elements of a jump-table should have.
-
- -- Macro: CASE_VECTOR_SHORTEN_MODE (MIN_OFFSET, MAX_OFFSET, BODY)
- Optional: return the preferred mode for an `addr_diff_vec' when
- the minimum and maximum offset are known. If you define this, it
- enables extra code in branch shortening to deal with
- `addr_diff_vec'. To make this work, you also have to define
- `INSN_ALIGN' and make the alignment for `addr_diff_vec' explicit.
- The BODY argument is provided so that the offset_unsigned and scale
- flags can be updated.
-
- -- Macro: CASE_VECTOR_PC_RELATIVE
- Define this macro to be a C expression to indicate when jump-tables
- should contain relative addresses. You need not define this macro
- if jump-tables never contain relative addresses, or jump-tables
- should contain relative addresses only when `-fPIC' or `-fPIC' is
- in effect.
-
- -- Macro: CASE_VALUES_THRESHOLD
- Define this to be the smallest number of different values for
- which it is best to use a jump-table instead of a tree of
- conditional branches. The default is four for machines with a
- `casesi' instruction and five otherwise. This is best for most
- machines.
-
- -- Macro: CASE_USE_BIT_TESTS
- Define this macro to be a C expression to indicate whether C switch
- statements may be implemented by a sequence of bit tests. This is
- advantageous on processors that can efficiently implement left
- shift of 1 by the number of bits held in a register, but
- inappropriate on targets that would require a loop. By default,
- this macro returns `true' if the target defines an `ashlsi3'
- pattern, and `false' otherwise.
-
- -- Macro: WORD_REGISTER_OPERATIONS
- Define this macro if operations between registers with integral
- mode smaller than a word are always performed on the entire
- register. Most RISC machines have this property and most CISC
- machines do not.
-
- -- Macro: LOAD_EXTEND_OP (MEM_MODE)
- Define this macro to be a C expression indicating when insns that
- read memory in MEM_MODE, an integral mode narrower than a word,
- set the bits outside of MEM_MODE to be either the sign-extension
- or the zero-extension of the data read. Return `SIGN_EXTEND' for
- values of MEM_MODE for which the insn sign-extends, `ZERO_EXTEND'
- for which it zero-extends, and `UNKNOWN' for other modes.
-
- This macro is not called with MEM_MODE non-integral or with a width
- greater than or equal to `BITS_PER_WORD', so you may return any
- value in this case. Do not define this macro if it would always
- return `UNKNOWN'. On machines where this macro is defined, you
- will normally define it as the constant `SIGN_EXTEND' or
- `ZERO_EXTEND'.
-
- You may return a non-`UNKNOWN' value even if for some hard
- registers the sign extension is not performed, if for the
- `REGNO_REG_CLASS' of these hard registers
- `CANNOT_CHANGE_MODE_CLASS' returns nonzero when the FROM mode is
- MEM_MODE and the TO mode is any integral mode larger than this but
- not larger than `word_mode'.
-
- You must return `UNKNOWN' if for some hard registers that allow
- this mode, `CANNOT_CHANGE_MODE_CLASS' says that they cannot change
- to `word_mode', but that they can change to another integral mode
- that is larger then MEM_MODE but still smaller than `word_mode'.
-
- -- Macro: SHORT_IMMEDIATES_SIGN_EXTEND
- Define this macro if loading short immediate values into registers
- sign extends.
-
- -- Macro: FIXUNS_TRUNC_LIKE_FIX_TRUNC
- Define this macro if the same instructions that convert a floating
- point number to a signed fixed point number also convert validly
- to an unsigned one.
-
- -- Target Hook: int TARGET_MIN_DIVISIONS_FOR_RECIP_MUL (enum
- machine_mode MODE)
- When `-ffast-math' is in effect, GCC tries to optimize divisions
- by the same divisor, by turning them into multiplications by the
- reciprocal. This target hook specifies the minimum number of
- divisions that should be there for GCC to perform the optimization
- for a variable of mode MODE. The default implementation returns 3
- if the machine has an instruction for the division, and 2 if it
- does not.
-
- -- Macro: MOVE_MAX
- The maximum number of bytes that a single instruction can move
- quickly between memory and registers or between two memory
- locations.
-
- -- Macro: MAX_MOVE_MAX
- The maximum number of bytes that a single instruction can move
- quickly between memory and registers or between two memory
- locations. If this is undefined, the default is `MOVE_MAX'.
- Otherwise, it is the constant value that is the largest value that
- `MOVE_MAX' can have at run-time.
-
- -- Macro: SHIFT_COUNT_TRUNCATED
- A C expression that is nonzero if on this machine the number of
- bits actually used for the count of a shift operation is equal to
- the number of bits needed to represent the size of the object
- being shifted. When this macro is nonzero, the compiler will
- assume that it is safe to omit a sign-extend, zero-extend, and
- certain bitwise `and' instructions that truncates the count of a
- shift operation. On machines that have instructions that act on
- bit-fields at variable positions, which may include `bit test'
- instructions, a nonzero `SHIFT_COUNT_TRUNCATED' also enables
- deletion of truncations of the values that serve as arguments to
- bit-field instructions.
-
- If both types of instructions truncate the count (for shifts) and
- position (for bit-field operations), or if no variable-position
- bit-field instructions exist, you should define this macro.
-
- However, on some machines, such as the 80386 and the 680x0,
- truncation only applies to shift operations and not the (real or
- pretended) bit-field operations. Define `SHIFT_COUNT_TRUNCATED'
- to be zero on such machines. Instead, add patterns to the `md'
- file that include the implied truncation of the shift instructions.
-
- You need not define this macro if it would always have the value
- of zero.
-
- -- Target Hook: int TARGET_SHIFT_TRUNCATION_MASK (enum machine_mode
- MODE)
- This function describes how the standard shift patterns for MODE
- deal with shifts by negative amounts or by more than the width of
- the mode. *Note shift patterns::.
-
- On many machines, the shift patterns will apply a mask M to the
- shift count, meaning that a fixed-width shift of X by Y is
- equivalent to an arbitrary-width shift of X by Y & M. If this is
- true for mode MODE, the function should return M, otherwise it
- should return 0. A return value of 0 indicates that no particular
- behavior is guaranteed.
-
- Note that, unlike `SHIFT_COUNT_TRUNCATED', this function does
- _not_ apply to general shift rtxes; it applies only to instructions
- that are generated by the named shift patterns.
-
- The default implementation of this function returns
- `GET_MODE_BITSIZE (MODE) - 1' if `SHIFT_COUNT_TRUNCATED' and 0
- otherwise. This definition is always safe, but if
- `SHIFT_COUNT_TRUNCATED' is false, and some shift patterns
- nevertheless truncate the shift count, you may get better code by
- overriding it.
-
- -- Macro: TRULY_NOOP_TRUNCATION (OUTPREC, INPREC)
- A C expression which is nonzero if on this machine it is safe to
- "convert" an integer of INPREC bits to one of OUTPREC bits (where
- OUTPREC is smaller than INPREC) by merely operating on it as if it
- had only OUTPREC bits.
-
- On many machines, this expression can be 1.
-
- When `TRULY_NOOP_TRUNCATION' returns 1 for a pair of sizes for
- modes for which `MODES_TIEABLE_P' is 0, suboptimal code can result.
- If this is the case, making `TRULY_NOOP_TRUNCATION' return 0 in
- such cases may improve things.
-
- -- Target Hook: int TARGET_MODE_REP_EXTENDED (enum machine_mode MODE,
- enum machine_mode REP_MODE)
- The representation of an integral mode can be such that the values
- are always extended to a wider integral mode. Return
- `SIGN_EXTEND' if values of MODE are represented in sign-extended
- form to REP_MODE. Return `UNKNOWN' otherwise. (Currently, none
- of the targets use zero-extended representation this way so unlike
- `LOAD_EXTEND_OP', `TARGET_MODE_REP_EXTENDED' is expected to return
- either `SIGN_EXTEND' or `UNKNOWN'. Also no target extends MODE to
- MODE_REP so that MODE_REP is not the next widest integral mode and
- currently we take advantage of this fact.)
-
- Similarly to `LOAD_EXTEND_OP' you may return a non-`UNKNOWN' value
- even if the extension is not performed on certain hard registers
- as long as for the `REGNO_REG_CLASS' of these hard registers
- `CANNOT_CHANGE_MODE_CLASS' returns nonzero.
-
- Note that `TARGET_MODE_REP_EXTENDED' and `LOAD_EXTEND_OP' describe
- two related properties. If you define `TARGET_MODE_REP_EXTENDED
- (mode, word_mode)' you probably also want to define
- `LOAD_EXTEND_OP (mode)' to return the same type of extension.
-
- In order to enforce the representation of `mode',
- `TRULY_NOOP_TRUNCATION' should return false when truncating to
- `mode'.
-
- -- Macro: STORE_FLAG_VALUE
- A C expression describing the value returned by a comparison
- operator with an integral mode and stored by a store-flag
- instruction (`sCOND') when the condition is true. This
- description must apply to _all_ the `sCOND' patterns and all the
- comparison operators whose results have a `MODE_INT' mode.
-
- A value of 1 or -1 means that the instruction implementing the
- comparison operator returns exactly 1 or -1 when the comparison is
- true and 0 when the comparison is false. Otherwise, the value
- indicates which bits of the result are guaranteed to be 1 when the
- comparison is true. This value is interpreted in the mode of the
- comparison operation, which is given by the mode of the first
- operand in the `sCOND' pattern. Either the low bit or the sign
- bit of `STORE_FLAG_VALUE' be on. Presently, only those bits are
- used by the compiler.
-
- If `STORE_FLAG_VALUE' is neither 1 or -1, the compiler will
- generate code that depends only on the specified bits. It can also
- replace comparison operators with equivalent operations if they
- cause the required bits to be set, even if the remaining bits are
- undefined. For example, on a machine whose comparison operators
- return an `SImode' value and where `STORE_FLAG_VALUE' is defined as
- `0x80000000', saying that just the sign bit is relevant, the
- expression
-
- (ne:SI (and:SI X (const_int POWER-OF-2)) (const_int 0))
-
- can be converted to
-
- (ashift:SI X (const_int N))
-
- where N is the appropriate shift count to move the bit being
- tested into the sign bit.
-
- There is no way to describe a machine that always sets the
- low-order bit for a true value, but does not guarantee the value
- of any other bits, but we do not know of any machine that has such
- an instruction. If you are trying to port GCC to such a machine,
- include an instruction to perform a logical-and of the result with
- 1 in the pattern for the comparison operators and let us know at
- <gcc@gcc.gnu.org>.
-
- Often, a machine will have multiple instructions that obtain a
- value from a comparison (or the condition codes). Here are rules
- to guide the choice of value for `STORE_FLAG_VALUE', and hence the
- instructions to be used:
-
- * Use the shortest sequence that yields a valid definition for
- `STORE_FLAG_VALUE'. It is more efficient for the compiler to
- "normalize" the value (convert it to, e.g., 1 or 0) than for
- the comparison operators to do so because there may be
- opportunities to combine the normalization with other
- operations.
-
- * For equal-length sequences, use a value of 1 or -1, with -1
- being slightly preferred on machines with expensive jumps and
- 1 preferred on other machines.
-
- * As a second choice, choose a value of `0x80000001' if
- instructions exist that set both the sign and low-order bits
- but do not define the others.
-
- * Otherwise, use a value of `0x80000000'.
-
- Many machines can produce both the value chosen for
- `STORE_FLAG_VALUE' and its negation in the same number of
- instructions. On those machines, you should also define a pattern
- for those cases, e.g., one matching
-
- (set A (neg:M (ne:M B C)))
-
- Some machines can also perform `and' or `plus' operations on
- condition code values with less instructions than the corresponding
- `sCOND' insn followed by `and' or `plus'. On those machines,
- define the appropriate patterns. Use the names `incscc' and
- `decscc', respectively, for the patterns which perform `plus' or
- `minus' operations on condition code values. See `rs6000.md' for
- some examples. The GNU Superoptizer can be used to find such
- instruction sequences on other machines.
-
- If this macro is not defined, the default value, 1, is used. You
- need not define `STORE_FLAG_VALUE' if the machine has no store-flag
- instructions, or if the value generated by these instructions is 1.
-
- -- Macro: FLOAT_STORE_FLAG_VALUE (MODE)
- A C expression that gives a nonzero `REAL_VALUE_TYPE' value that is
- returned when comparison operators with floating-point results are
- true. Define this macro on machines that have comparison
- operations that return floating-point values. If there are no
- such operations, do not define this macro.
-
- -- Macro: VECTOR_STORE_FLAG_VALUE (MODE)
- A C expression that gives a rtx representing the nonzero true
- element for vector comparisons. The returned rtx should be valid
- for the inner mode of MODE which is guaranteed to be a vector
- mode. Define this macro on machines that have vector comparison
- operations that return a vector result. If there are no such
- operations, do not define this macro. Typically, this macro is
- defined as `const1_rtx' or `constm1_rtx'. This macro may return
- `NULL_RTX' to prevent the compiler optimizing such vector
- comparison operations for the given mode.
-
- -- Macro: CLZ_DEFINED_VALUE_AT_ZERO (MODE, VALUE)
- -- Macro: CTZ_DEFINED_VALUE_AT_ZERO (MODE, VALUE)
- A C expression that indicates whether the architecture defines a
- value for `clz' or `ctz' with a zero operand. A result of `0'
- indicates the value is undefined. If the value is defined for
- only the RTL expression, the macro should evaluate to `1'; if the
- value applies also to the corresponding optab entry (which is
- normally the case if it expands directly into the corresponding
- RTL), then the macro should evaluate to `2'. In the cases where
- the value is defined, VALUE should be set to this value.
-
- If this macro is not defined, the value of `clz' or `ctz' at zero
- is assumed to be undefined.
-
- This macro must be defined if the target's expansion for `ffs'
- relies on a particular value to get correct results. Otherwise it
- is not necessary, though it may be used to optimize some corner
- cases, and to provide a default expansion for the `ffs' optab.
-
- Note that regardless of this macro the "definedness" of `clz' and
- `ctz' at zero do _not_ extend to the builtin functions visible to
- the user. Thus one may be free to adjust the value at will to
- match the target expansion of these operations without fear of
- breaking the API.
-
- -- Macro: Pmode
- An alias for the machine mode for pointers. On most machines,
- define this to be the integer mode corresponding to the width of a
- hardware pointer; `SImode' on 32-bit machine or `DImode' on 64-bit
- machines. On some machines you must define this to be one of the
- partial integer modes, such as `PSImode'.
-
- The width of `Pmode' must be at least as large as the value of
- `POINTER_SIZE'. If it is not equal, you must define the macro
- `POINTERS_EXTEND_UNSIGNED' to specify how pointers are extended to
- `Pmode'.
-
- -- Macro: FUNCTION_MODE
- An alias for the machine mode used for memory references to
- functions being called, in `call' RTL expressions. On most CISC
- machines, where an instruction can begin at any byte address, this
- should be `QImode'. On most RISC machines, where all instructions
- have fixed size and alignment, this should be a mode with the same
- size and alignment as the machine instruction words - typically
- `SImode' or `HImode'.
-
- -- Macro: STDC_0_IN_SYSTEM_HEADERS
- In normal operation, the preprocessor expands `__STDC__' to the
- constant 1, to signify that GCC conforms to ISO Standard C. On
- some hosts, like Solaris, the system compiler uses a different
- convention, where `__STDC__' is normally 0, but is 1 if the user
- specifies strict conformance to the C Standard.
-
- Defining `STDC_0_IN_SYSTEM_HEADERS' makes GNU CPP follows the host
- convention when processing system header files, but when
- processing user files `__STDC__' will always expand to 1.
-
- -- Macro: NO_IMPLICIT_EXTERN_C
- Define this macro if the system header files support C++ as well
- as C. This macro inhibits the usual method of using system header
- files in C++, which is to pretend that the file's contents are
- enclosed in `extern "C" {...}'.
-
- -- Macro: REGISTER_TARGET_PRAGMAS ()
- Define this macro if you want to implement any target-specific
- pragmas. If defined, it is a C expression which makes a series of
- calls to `c_register_pragma' or `c_register_pragma_with_expansion'
- for each pragma. The macro may also do any setup required for the
- pragmas.
-
- The primary reason to define this macro is to provide
- compatibility with other compilers for the same target. In
- general, we discourage definition of target-specific pragmas for
- GCC.
-
- If the pragma can be implemented by attributes then you should
- consider defining the target hook `TARGET_INSERT_ATTRIBUTES' as
- well.
-
- Preprocessor macros that appear on pragma lines are not expanded.
- All `#pragma' directives that do not match any registered pragma
- are silently ignored, unless the user specifies
- `-Wunknown-pragmas'.
-
- -- Function: void c_register_pragma (const char *SPACE, const char
- *NAME, void (*CALLBACK) (struct cpp_reader *))
- -- Function: void c_register_pragma_with_expansion (const char *SPACE,
- const char *NAME, void (*CALLBACK) (struct cpp_reader *))
- Each call to `c_register_pragma' or
- `c_register_pragma_with_expansion' establishes one pragma. The
- CALLBACK routine will be called when the preprocessor encounters a
- pragma of the form
-
- #pragma [SPACE] NAME ...
-
- SPACE is the case-sensitive namespace of the pragma, or `NULL' to
- put the pragma in the global namespace. The callback routine
- receives PFILE as its first argument, which can be passed on to
- cpplib's functions if necessary. You can lex tokens after the
- NAME by calling `pragma_lex'. Tokens that are not read by the
- callback will be silently ignored. The end of the line is
- indicated by a token of type `CPP_EOF'. Macro expansion occurs on
- the arguments of pragmas registered with
- `c_register_pragma_with_expansion' but not on the arguments of
- pragmas registered with `c_register_pragma'.
-
- Note that the use of `pragma_lex' is specific to the C and C++
- compilers. It will not work in the Java or Fortran compilers, or
- any other language compilers for that matter. Thus if
- `pragma_lex' is going to be called from target-specific code, it
- must only be done so when building the C and C++ compilers. This
- can be done by defining the variables `c_target_objs' and
- `cxx_target_objs' in the target entry in the `config.gcc' file.
- These variables should name the target-specific, language-specific
- object file which contains the code that uses `pragma_lex'. Note
- it will also be necessary to add a rule to the makefile fragment
- pointed to by `tmake_file' that shows how to build this object
- file.
-
- -- Macro: HANDLE_SYSV_PRAGMA
- Define this macro (to a value of 1) if you want the System V style
- pragmas `#pragma pack(<n>)' and `#pragma weak <name> [=<value>]'
- to be supported by gcc.
-
- The pack pragma specifies the maximum alignment (in bytes) of
- fields within a structure, in much the same way as the
- `__aligned__' and `__packed__' `__attribute__'s do. A pack value
- of zero resets the behavior to the default.
-
- A subtlety for Microsoft Visual C/C++ style bit-field packing
- (e.g. -mms-bitfields) for targets that support it: When a
- bit-field is inserted into a packed record, the whole size of the
- underlying type is used by one or more same-size adjacent
- bit-fields (that is, if its long:3, 32 bits is used in the record,
- and any additional adjacent long bit-fields are packed into the
- same chunk of 32 bits. However, if the size changes, a new field
- of that size is allocated).
-
- If both MS bit-fields and `__attribute__((packed))' are used, the
- latter will take precedence. If `__attribute__((packed))' is used
- on a single field when MS bit-fields are in use, it will take
- precedence for that field, but the alignment of the rest of the
- structure may affect its placement.
-
- The weak pragma only works if `SUPPORTS_WEAK' and
- `ASM_WEAKEN_LABEL' are defined. If enabled it allows the creation
- of specifically named weak labels, optionally with a value.
-
- -- Macro: HANDLE_PRAGMA_PACK_PUSH_POP
- Define this macro (to a value of 1) if you want to support the
- Win32 style pragmas `#pragma pack(push[,N])' and `#pragma
- pack(pop)'. The `pack(push,[N])' pragma specifies the maximum
- alignment (in bytes) of fields within a structure, in much the
- same way as the `__aligned__' and `__packed__' `__attribute__'s
- do. A pack value of zero resets the behavior to the default.
- Successive invocations of this pragma cause the previous values to
- be stacked, so that invocations of `#pragma pack(pop)' will return
- to the previous value.
-
- -- Macro: HANDLE_PRAGMA_PACK_WITH_EXPANSION
- Define this macro, as well as `HANDLE_SYSV_PRAGMA', if macros
- should be expanded in the arguments of `#pragma pack'.
-
- -- Macro: TARGET_DEFAULT_PACK_STRUCT
- If your target requires a structure packing default other than 0
- (meaning the machine default), define this macro to the necessary
- value (in bytes). This must be a value that would also be valid
- to use with `#pragma pack()' (that is, a small power of two).
-
- -- Macro: DOLLARS_IN_IDENTIFIERS
- Define this macro to control use of the character `$' in
- identifier names for the C family of languages. 0 means `$' is
- not allowed by default; 1 means it is allowed. 1 is the default;
- there is no need to define this macro in that case.
-
- -- Macro: NO_DOLLAR_IN_LABEL
- Define this macro if the assembler does not accept the character
- `$' in label names. By default constructors and destructors in
- G++ have `$' in the identifiers. If this macro is defined, `.' is
- used instead.
-
- -- Macro: NO_DOT_IN_LABEL
- Define this macro if the assembler does not accept the character
- `.' in label names. By default constructors and destructors in G++
- have names that use `.'. If this macro is defined, these names
- are rewritten to avoid `.'.
-
- -- Macro: INSN_SETS_ARE_DELAYED (INSN)
- Define this macro as a C expression that is nonzero if it is safe
- for the delay slot scheduler to place instructions in the delay
- slot of INSN, even if they appear to use a resource set or
- clobbered in INSN. INSN is always a `jump_insn' or an `insn'; GCC
- knows that every `call_insn' has this behavior. On machines where
- some `insn' or `jump_insn' is really a function call and hence has
- this behavior, you should define this macro.
-
- You need not define this macro if it would always return zero.
-
- -- Macro: INSN_REFERENCES_ARE_DELAYED (INSN)
- Define this macro as a C expression that is nonzero if it is safe
- for the delay slot scheduler to place instructions in the delay
- slot of INSN, even if they appear to set or clobber a resource
- referenced in INSN. INSN is always a `jump_insn' or an `insn'.
- On machines where some `insn' or `jump_insn' is really a function
- call and its operands are registers whose use is actually in the
- subroutine it calls, you should define this macro. Doing so
- allows the delay slot scheduler to move instructions which copy
- arguments into the argument registers into the delay slot of INSN.
-
- You need not define this macro if it would always return zero.
-
- -- Macro: MULTIPLE_SYMBOL_SPACES
- Define this macro as a C expression that is nonzero if, in some
- cases, global symbols from one translation unit may not be bound
- to undefined symbols in another translation unit without user
- intervention. For instance, under Microsoft Windows symbols must
- be explicitly imported from shared libraries (DLLs).
-
- You need not define this macro if it would always evaluate to zero.
-
- -- Target Hook: tree TARGET_MD_ASM_CLOBBERS (tree OUTPUTS, tree
- INPUTS, tree CLOBBERS)
- This target hook should add to CLOBBERS `STRING_CST' trees for any
- hard regs the port wishes to automatically clobber for an asm. It
- should return the result of the last `tree_cons' used to add a
- clobber. The OUTPUTS, INPUTS and CLOBBER lists are the
- corresponding parameters to the asm and may be inspected to avoid
- clobbering a register that is an input or output of the asm. You
- can use `tree_overlaps_hard_reg_set', declared in `tree.h', to test
- for overlap with regards to asm-declared registers.
-
- -- Macro: MATH_LIBRARY
- Define this macro as a C string constant for the linker argument
- to link in the system math library, or `""' if the target does not
- have a separate math library.
-
- You need only define this macro if the default of `"-lm"' is wrong.
-
- -- Macro: LIBRARY_PATH_ENV
- Define this macro as a C string constant for the environment
- variable that specifies where the linker should look for libraries.
-
- You need only define this macro if the default of `"LIBRARY_PATH"'
- is wrong.
-
- -- Macro: TARGET_POSIX_IO
- Define this macro if the target supports the following POSIX file
- functions, access, mkdir and file locking with fcntl / F_SETLKW.
- Defining `TARGET_POSIX_IO' will enable the test coverage code to
- use file locking when exiting a program, which avoids race
- conditions if the program has forked. It will also create
- directories at run-time for cross-profiling.
-
- -- Macro: MAX_CONDITIONAL_EXECUTE
- A C expression for the maximum number of instructions to execute
- via conditional execution instructions instead of a branch. A
- value of `BRANCH_COST'+1 is the default if the machine does not
- use cc0, and 1 if it does use cc0.
-
- -- Macro: IFCVT_MODIFY_TESTS (CE_INFO, TRUE_EXPR, FALSE_EXPR)
- Used if the target needs to perform machine-dependent
- modifications on the conditionals used for turning basic blocks
- into conditionally executed code. CE_INFO points to a data
- structure, `struct ce_if_block', which contains information about
- the currently processed blocks. TRUE_EXPR and FALSE_EXPR are the
- tests that are used for converting the then-block and the
- else-block, respectively. Set either TRUE_EXPR or FALSE_EXPR to a
- null pointer if the tests cannot be converted.
-
- -- Macro: IFCVT_MODIFY_MULTIPLE_TESTS (CE_INFO, BB, TRUE_EXPR,
- FALSE_EXPR)
- Like `IFCVT_MODIFY_TESTS', but used when converting more
- complicated if-statements into conditions combined by `and' and
- `or' operations. BB contains the basic block that contains the
- test that is currently being processed and about to be turned into
- a condition.
-
- -- Macro: IFCVT_MODIFY_INSN (CE_INFO, PATTERN, INSN)
- A C expression to modify the PATTERN of an INSN that is to be
- converted to conditional execution format. CE_INFO points to a
- data structure, `struct ce_if_block', which contains information
- about the currently processed blocks.
-
- -- Macro: IFCVT_MODIFY_FINAL (CE_INFO)
- A C expression to perform any final machine dependent
- modifications in converting code to conditional execution. The
- involved basic blocks can be found in the `struct ce_if_block'
- structure that is pointed to by CE_INFO.
-
- -- Macro: IFCVT_MODIFY_CANCEL (CE_INFO)
- A C expression to cancel any machine dependent modifications in
- converting code to conditional execution. The involved basic
- blocks can be found in the `struct ce_if_block' structure that is
- pointed to by CE_INFO.
-
- -- Macro: IFCVT_INIT_EXTRA_FIELDS (CE_INFO)
- A C expression to initialize any extra fields in a `struct
- ce_if_block' structure, which are defined by the
- `IFCVT_EXTRA_FIELDS' macro.
-
- -- Macro: IFCVT_EXTRA_FIELDS
- If defined, it should expand to a set of field declarations that
- will be added to the `struct ce_if_block' structure. These should
- be initialized by the `IFCVT_INIT_EXTRA_FIELDS' macro.
-
- -- Target Hook: void TARGET_MACHINE_DEPENDENT_REORG ()
- If non-null, this hook performs a target-specific pass over the
- instruction stream. The compiler will run it at all optimization
- levels, just before the point at which it normally does
- delayed-branch scheduling.
-
- The exact purpose of the hook varies from target to target. Some
- use it to do transformations that are necessary for correctness,
- such as laying out in-function constant pools or avoiding hardware
- hazards. Others use it as an opportunity to do some
- machine-dependent optimizations.
-
- You need not implement the hook if it has nothing to do. The
- default definition is null.
-
- -- Target Hook: void TARGET_INIT_BUILTINS ()
- Define this hook if you have any machine-specific built-in
- functions that need to be defined. It should be a function that
- performs the necessary setup.
-
- Machine specific built-in functions can be useful to expand
- special machine instructions that would otherwise not normally be
- generated because they have no equivalent in the source language
- (for example, SIMD vector instructions or prefetch instructions).
-
- To create a built-in function, call the function
- `lang_hooks.builtin_function' which is defined by the language
- front end. You can use any type nodes set up by
- `build_common_tree_nodes' and `build_common_tree_nodes_2'; only
- language front ends that use those two functions will call
- `TARGET_INIT_BUILTINS'.
-
- -- Target Hook: rtx TARGET_EXPAND_BUILTIN (tree EXP, rtx TARGET, rtx
- SUBTARGET, enum machine_mode MODE, int IGNORE)
- Expand a call to a machine specific built-in function that was set
- up by `TARGET_INIT_BUILTINS'. EXP is the expression for the
- function call; the result should go to TARGET if that is
- convenient, and have mode MODE if that is convenient. SUBTARGET
- may be used as the target for computing one of EXP's operands.
- IGNORE is nonzero if the value is to be ignored. This function
- should return the result of the call to the built-in function.
-
- -- Target Hook: tree TARGET_RESOLVE_OVERLOADED_BUILTIN (tree FNDECL,
- tree ARGLIST)
- Select a replacement for a machine specific built-in function that
- was set up by `TARGET_INIT_BUILTINS'. This is done _before_
- regular type checking, and so allows the target to implement a
- crude form of function overloading. FNDECL is the declaration of
- the built-in function. ARGLIST is the list of arguments passed to
- the built-in function. The result is a complete expression that
- implements the operation, usually another `CALL_EXPR'.
-
- -- Target Hook: tree TARGET_FOLD_BUILTIN (tree FNDECL, tree ARGLIST,
- bool IGNORE)
- Fold a call to a machine specific built-in function that was set
- up by `TARGET_INIT_BUILTINS'. FNDECL is the declaration of the
- built-in function. ARGLIST is the list of arguments passed to the
- built-in function. The result is another tree containing a
- simplified expression for the call's result. If IGNORE is true
- the value will be ignored.
-
- -- Target Hook: const char * TARGET_INVALID_WITHIN_DOLOOP (rtx INSN)
- Take an instruction in INSN and return NULL if it is valid within a
- low-overhead loop, otherwise return a string why doloop could not
- be applied.
-
- Many targets use special registers for low-overhead looping. For
- any instruction that clobbers these this function should return a
- string indicating the reason why the doloop could not be applied.
- By default, the RTL loop optimizer does not use a present doloop
- pattern for loops containing function calls or branch on table
- instructions.
-
- -- Macro: MD_CAN_REDIRECT_BRANCH (BRANCH1, BRANCH2)
- Take a branch insn in BRANCH1 and another in BRANCH2. Return true
- if redirecting BRANCH1 to the destination of BRANCH2 is possible.
-
- On some targets, branches may have a limited range. Optimizing the
- filling of delay slots can result in branches being redirected,
- and this may in turn cause a branch offset to overflow.
-
- -- Target Hook: bool TARGET_COMMUTATIVE_P (rtx X, OUTER_CODE)
- This target hook returns `true' if X is considered to be
- commutative. Usually, this is just COMMUTATIVE_P (X), but the HP
- PA doesn't consider PLUS to be commutative inside a MEM.
- OUTER_CODE is the rtx code of the enclosing rtl, if known,
- otherwise it is UNKNOWN.
-
- -- Target Hook: rtx TARGET_ALLOCATE_INITIAL_VALUE (rtx HARD_REG)
- When the initial value of a hard register has been copied in a
- pseudo register, it is often not necessary to actually allocate
- another register to this pseudo register, because the original
- hard register or a stack slot it has been saved into can be used.
- `TARGET_ALLOCATE_INITIAL_VALUE' is called at the start of register
- allocation once for each hard register that had its initial value
- copied by using `get_func_hard_reg_initial_val' or
- `get_hard_reg_initial_val'. Possible values are `NULL_RTX', if
- you don't want to do any special allocation, a `REG' rtx--that
- would typically be the hard register itself, if it is known not to
- be clobbered--or a `MEM'. If you are returning a `MEM', this is
- only a hint for the allocator; it might decide to use another
- register anyways. You may use `current_function_leaf_function' in
- the hook, functions that use `REG_N_SETS', to determine if the hard
- register in question will not be clobbered. The default value of
- this hook is `NULL', which disables any special allocation.
-
- -- Target Hook: int TARGET_UNSPEC_MAY_TRAP_P (const_rtx X, unsigned
- FLAGS)
- This target hook returns nonzero if X, an `unspec' or
- `unspec_volatile' operation, might cause a trap. Targets can use
- this hook to enhance precision of analysis for `unspec' and
- `unspec_volatile' operations. You may call `may_trap_p_1' to
- analyze inner elements of X in which case FLAGS should be passed
- along.
-
- -- Target Hook: void TARGET_SET_CURRENT_FUNCTION (tree DECL)
- The compiler invokes this hook whenever it changes its current
- function context (`cfun'). You can define this function if the
- back end needs to perform any initialization or reset actions on a
- per-function basis. For example, it may be used to implement
- function attributes that affect register usage or code generation
- patterns. The argument DECL is the declaration for the new
- function context, and may be null to indicate that the compiler
- has left a function context and is returning to processing at the
- top level. The default hook function does nothing.
-
- GCC sets `cfun' to a dummy function context during initialization
- of some parts of the back end. The hook function is not invoked
- in this situation; you need not worry about the hook being invoked
- recursively, or when the back end is in a partially-initialized
- state.
-
- -- Macro: TARGET_OBJECT_SUFFIX
- Define this macro to be a C string representing the suffix for
- object files on your target machine. If you do not define this
- macro, GCC will use `.o' as the suffix for object files.
-
- -- Macro: TARGET_EXECUTABLE_SUFFIX
- Define this macro to be a C string representing the suffix to be
- automatically added to executable files on your target machine.
- If you do not define this macro, GCC will use the null string as
- the suffix for executable files.
-
- -- Macro: COLLECT_EXPORT_LIST
- If defined, `collect2' will scan the individual object files
- specified on its command line and create an export list for the
- linker. Define this macro for systems like AIX, where the linker
- discards object files that are not referenced from `main' and uses
- export lists.
-
- -- Macro: MODIFY_JNI_METHOD_CALL (MDECL)
- Define this macro to a C expression representing a variant of the
- method call MDECL, if Java Native Interface (JNI) methods must be
- invoked differently from other methods on your target. For
- example, on 32-bit Microsoft Windows, JNI methods must be invoked
- using the `stdcall' calling convention and this macro is then
- defined as this expression:
-
- build_type_attribute_variant (MDECL,
- build_tree_list
- (get_identifier ("stdcall"),
- NULL))
-
- -- Target Hook: bool TARGET_CANNOT_MODIFY_JUMPS_P (void)
- This target hook returns `true' past the point in which new jump
- instructions could be created. On machines that require a
- register for every jump such as the SHmedia ISA of SH5, this point
- would typically be reload, so this target hook should be defined
- to a function such as:
-
- static bool
- cannot_modify_jumps_past_reload_p ()
- {
- return (reload_completed || reload_in_progress);
- }
-
- -- Target Hook: int TARGET_BRANCH_TARGET_REGISTER_CLASS (void)
- This target hook returns a register class for which branch target
- register optimizations should be applied. All registers in this
- class should be usable interchangeably. After reload, registers
- in this class will be re-allocated and loads will be hoisted out
- of loops and be subjected to inter-block scheduling.
-
- -- Target Hook: bool TARGET_BRANCH_TARGET_REGISTER_CALLEE_SAVED (bool
- AFTER_PROLOGUE_EPILOGUE_GEN)
- Branch target register optimization will by default exclude
- callee-saved registers that are not already live during the
- current function; if this target hook returns true, they will be
- included. The target code must than make sure that all target
- registers in the class returned by
- `TARGET_BRANCH_TARGET_REGISTER_CLASS' that might need saving are
- saved. AFTER_PROLOGUE_EPILOGUE_GEN indicates if prologues and
- epilogues have already been generated. Note, even if you only
- return true when AFTER_PROLOGUE_EPILOGUE_GEN is false, you still
- are likely to have to make special provisions in
- `INITIAL_ELIMINATION_OFFSET' to reserve space for caller-saved
- target registers.
-
- -- Target Hook: bool TARGET_HAVE_CONDITIONAL_EXECUTION (void)
- This target hook returns true if the target supports conditional
- execution. This target hook is required only when the target has
- several different modes and they have different conditional
- execution capability, such as ARM.
-
- -- Macro: POWI_MAX_MULTS
- If defined, this macro is interpreted as a signed integer C
- expression that specifies the maximum number of floating point
- multiplications that should be emitted when expanding
- exponentiation by an integer constant inline. When this value is
- defined, exponentiation requiring more than this number of
- multiplications is implemented by calling the system library's
- `pow', `powf' or `powl' routines. The default value places no
- upper bound on the multiplication count.
-
- -- Macro: void TARGET_EXTRA_INCLUDES (const char *SYSROOT, const char
- *IPREFIX, int STDINC)
- This target hook should register any extra include files for the
- target. The parameter STDINC indicates if normal include files
- are present. The parameter SYSROOT is the system root directory.
- The parameter IPREFIX is the prefix for the gcc directory.
-
- -- Macro: void TARGET_EXTRA_PRE_INCLUDES (const char *SYSROOT, const
- char *IPREFIX, int STDINC)
- This target hook should register any extra include files for the
- target before any standard headers. The parameter STDINC
- indicates if normal include files are present. The parameter
- SYSROOT is the system root directory. The parameter IPREFIX is
- the prefix for the gcc directory.
-
- -- Macro: void TARGET_OPTF (char *PATH)
- This target hook should register special include paths for the
- target. The parameter PATH is the include to register. On Darwin
- systems, this is used for Framework includes, which have semantics
- that are different from `-I'.
-
- -- Target Hook: bool TARGET_USE_LOCAL_THUNK_ALIAS_P (tree FNDECL)
- This target hook returns `true' if it is safe to use a local alias
- for a virtual function FNDECL when constructing thunks, `false'
- otherwise. By default, the hook returns `true' for all functions,
- if a target supports aliases (i.e. defines `ASM_OUTPUT_DEF'),
- `false' otherwise,
-
- -- Macro: TARGET_FORMAT_TYPES
- If defined, this macro is the name of a global variable containing
- target-specific format checking information for the `-Wformat'
- option. The default is to have no target-specific format checks.
-
- -- Macro: TARGET_N_FORMAT_TYPES
- If defined, this macro is the number of entries in
- `TARGET_FORMAT_TYPES'.
-
- -- Macro: TARGET_OVERRIDES_FORMAT_ATTRIBUTES
- If defined, this macro is the name of a global variable containing
- target-specific format overrides for the `-Wformat' option. The
- default is to have no target-specific format overrides. If defined,
- `TARGET_FORMAT_TYPES' must be defined, too.
-
- -- Macro: TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT
- If defined, this macro specifies the number of entries in
- `TARGET_OVERRIDES_FORMAT_ATTRIBUTES'.
-
- -- Macro: TARGET_OVERRIDES_FORMAT_INIT
- If defined, this macro specifies the optional initialization
- routine for target specific customizations of the system printf
- and scanf formatter settings.
-
- -- Target Hook: bool TARGET_RELAXED_ORDERING
- If set to `true', means that the target's memory model does not
- guarantee that loads which do not depend on one another will access
- main memory in the order of the instruction stream; if ordering is
- important, an explicit memory barrier must be used. This is true
- of many recent processors which implement a policy of "relaxed,"
- "weak," or "release" memory consistency, such as Alpha, PowerPC,
- and ia64. The default is `false'.
-
- -- Target Hook: const char *TARGET_INVALID_ARG_FOR_UNPROTOTYPED_FN
- (tree TYPELIST, tree FUNCDECL, tree VAL)
- If defined, this macro returns the diagnostic message when it is
- illegal to pass argument VAL to function FUNCDECL with prototype
- TYPELIST.
-
- -- Target Hook: const char * TARGET_INVALID_CONVERSION (tree FROMTYPE,
- tree TOTYPE)
- If defined, this macro returns the diagnostic message when it is
- invalid to convert from FROMTYPE to TOTYPE, or `NULL' if validity
- should be determined by the front end.
-
- -- Target Hook: const char * TARGET_INVALID_UNARY_OP (int OP, tree
- TYPE)
- If defined, this macro returns the diagnostic message when it is
- invalid to apply operation OP (where unary plus is denoted by
- `CONVERT_EXPR') to an operand of type TYPE, or `NULL' if validity
- should be determined by the front end.
-
- -- Target Hook: const char * TARGET_INVALID_BINARY_OP (int OP, tree
- TYPE1, tree TYPE2)
- If defined, this macro returns the diagnostic message when it is
- invalid to apply operation OP to operands of types TYPE1 and
- TYPE2, or `NULL' if validity should be determined by the front end.
-
- -- Macro: TARGET_USE_JCR_SECTION
- This macro determines whether to use the JCR section to register
- Java classes. By default, TARGET_USE_JCR_SECTION is defined to 1
- if both SUPPORTS_WEAK and TARGET_HAVE_NAMED_SECTIONS are true,
- else 0.
-
- -- Macro: OBJC_JBLEN
- This macro determines the size of the objective C jump buffer for
- the NeXT runtime. By default, OBJC_JBLEN is defined to an
- innocuous value.
-
- -- Macro: LIBGCC2_UNWIND_ATTRIBUTE
- Define this macro if any target-specific attributes need to be
- attached to the functions in `libgcc' that provide low-level
- support for call stack unwinding. It is used in declarations in
- `unwind-generic.h' and the associated definitions of those
- functions.
-
- -- Target Hook: void TARGET_UPDATE_STACK_BOUNDARY (void)
- Define this macro to update the current function stack boundary if
- necessary.
-
- -- Target Hook: rtx TARGET_GET_DRAP_RTX (void)
- Define this macro to an rtx for Dynamic Realign Argument Pointer
- if a different argument pointer register is needed to access the
- function's argument list when stack is aligned.
-
- -- Target Hook: bool TARGET_ALLOCATE_STACK_SLOTS_FOR_ARGS (void)
- When optimization is disabled, this hook indicates whether or not
- arguments should be allocated to stack slots. Normally, GCC
- allocates stacks slots for arguments when not optimizing in order
- to make debugging easier. However, when a function is declared
- with `__attribute__((naked))', there is no stack frame, and the
- compiler cannot safely move arguments from the registers in which
- they are passed to the stack. Therefore, this hook should return
- true in general, but false for naked functions. The default
- implementation always returns true.
-
- -- Target Hook: rtx TARGET_GET_PIC_REG (void)
- Return the pic_reg pseudo register which holds the base address of
- GOT. It is only required by the simplify-got optimization.
-
- -- Target Hook: void TARGET_CLEAR_PIC_REG (void)
- After successful simplify-got optimization, the pic_reg is
- useless. So a target can use this hook to clear pic_reg.
-
- -- Target Hook: rtx TARGET_LOADED_GLOBAL_VAR (rtx insn, rtx *
- offset_reg)
- This hook is used to detect if the given INSN loads a global
- variable's address from GOT with the form of
-
- (set ADDRESS_REG (mem (plus pic_reg OFF)))
-
- If so store OFF into the memory pointed to by OFFSET_REG and
- return the global variable whose address will be loaded. Otherwise
- return `NULL_RTX'.
-
- -- Target Hook: bool TARGET_CAN_SIMPLIFY_GOT_ACCESS (int N_SYMBOL, int
- N_ACCESS)
- This hook determines if it satisfy the target dependent conditions
- to do simplify-got when given the number of global variable
- accessing and the number of accessed symbols. If the returned
- value is false the GOT access insns will not be rewritten.
- Otherwise we will rewrite these insns.
-
- -- Target Hook: void TARGET_LOAD_GLOBAL_ADDRESS (rtx SYMBOL, rtx
- OFFSET_REG, rtx ADDRESS_REG, rtx LOAD_INSN)
- This hook does the actual rewriting of GOT access insn LOAD_INSN.
- The global variable is SYMBOL. The global address should be loaded
- into ADDRESS_REG. The register OFFSET_REG was previously used to
- hold the offset from GOT base to the GOT entry of the global
- variable. Now it can be used as a scratch register.
-
-\1f
-File: gccint.info, Node: Host Config, Next: Fragments, Prev: Target Macros, Up: Top
-
-18 Host Configuration
-*********************
-
-Most details about the machine and system on which the compiler is
-actually running are detected by the `configure' script. Some things
-are impossible for `configure' to detect; these are described in two
-ways, either by macros defined in a file named `xm-MACHINE.h' or by
-hook functions in the file specified by the OUT_HOST_HOOK_OBJ variable
-in `config.gcc'. (The intention is that very few hosts will need a
-header file but nearly every fully supported host will need to override
-some hooks.)
-
- If you need to define only a few macros, and they have simple
-definitions, consider using the `xm_defines' variable in your
-`config.gcc' entry instead of creating a host configuration header.
-*Note System Config::.
-
-* Menu:
-
-* Host Common:: Things every host probably needs implemented.
-* Filesystem:: Your host can't have the letter `a' in filenames?
-* Host Misc:: Rare configuration options for hosts.
-
-\1f
-File: gccint.info, Node: Host Common, Next: Filesystem, Up: Host Config
-
-18.1 Host Common
-================
-
-Some things are just not portable, even between similar operating
-systems, and are too difficult for autoconf to detect. They get
-implemented using hook functions in the file specified by the
-HOST_HOOK_OBJ variable in `config.gcc'.
-
- -- Host Hook: void HOST_HOOKS_EXTRA_SIGNALS (void)
- This host hook is used to set up handling for extra signals. The
- most common thing to do in this hook is to detect stack overflow.
-
- -- Host Hook: void * HOST_HOOKS_GT_PCH_GET_ADDRESS (size_t SIZE, int
- FD)
- This host hook returns the address of some space that is likely to
- be free in some subsequent invocation of the compiler. We intend
- to load the PCH data at this address such that the data need not
- be relocated. The area should be able to hold SIZE bytes. If the
- host uses `mmap', FD is an open file descriptor that can be used
- for probing.
-
- -- Host Hook: int HOST_HOOKS_GT_PCH_USE_ADDRESS (void * ADDRESS,
- size_t SIZE, int FD, size_t OFFSET)
- This host hook is called when a PCH file is about to be loaded.
- We want to load SIZE bytes from FD at OFFSET into memory at
- ADDRESS. The given address will be the result of a previous
- invocation of `HOST_HOOKS_GT_PCH_GET_ADDRESS'. Return -1 if we
- couldn't allocate SIZE bytes at ADDRESS. Return 0 if the memory
- is allocated but the data is not loaded. Return 1 if the hook has
- performed everything.
-
- If the implementation uses reserved address space, free any
- reserved space beyond SIZE, regardless of the return value. If no
- PCH will be loaded, this hook may be called with SIZE zero, in
- which case all reserved address space should be freed.
-
- Do not try to handle values of ADDRESS that could not have been
- returned by this executable; just return -1. Such values usually
- indicate an out-of-date PCH file (built by some other GCC
- executable), and such a PCH file won't work.
-
- -- Host Hook: size_t HOST_HOOKS_GT_PCH_ALLOC_GRANULARITY (void);
- This host hook returns the alignment required for allocating
- virtual memory. Usually this is the same as getpagesize, but on
- some hosts the alignment for reserving memory differs from the
- pagesize for committing memory.
-
-\1f
-File: gccint.info, Node: Filesystem, Next: Host Misc, Prev: Host Common, Up: Host Config
-
-18.2 Host Filesystem
-====================
-
-GCC needs to know a number of things about the semantics of the host
-machine's filesystem. Filesystems with Unix and MS-DOS semantics are
-automatically detected. For other systems, you can define the
-following macros in `xm-MACHINE.h'.
-
-`HAVE_DOS_BASED_FILE_SYSTEM'
- This macro is automatically defined by `system.h' if the host file
- system obeys the semantics defined by MS-DOS instead of Unix. DOS
- file systems are case insensitive, file specifications may begin
- with a drive letter, and both forward slash and backslash (`/' and
- `\') are directory separators.
-
-`DIR_SEPARATOR'
-`DIR_SEPARATOR_2'
- If defined, these macros expand to character constants specifying
- separators for directory names within a file specification.
- `system.h' will automatically give them appropriate values on Unix
- and MS-DOS file systems. If your file system is neither of these,
- define one or both appropriately in `xm-MACHINE.h'.
-
- However, operating systems like VMS, where constructing a pathname
- is more complicated than just stringing together directory names
- separated by a special character, should not define either of these
- macros.
-
-`PATH_SEPARATOR'
- If defined, this macro should expand to a character constant
- specifying the separator for elements of search paths. The default
- value is a colon (`:'). DOS-based systems usually, but not
- always, use semicolon (`;').
-
-`VMS'
- Define this macro if the host system is VMS.
-
-`HOST_OBJECT_SUFFIX'
- Define this macro to be a C string representing the suffix for
- object files on your host machine. If you do not define this
- macro, GCC will use `.o' as the suffix for object files.
-
-`HOST_EXECUTABLE_SUFFIX'
- Define this macro to be a C string representing the suffix for
- executable files on your host machine. If you do not define this
- macro, GCC will use the null string as the suffix for executable
- files.
-
-`HOST_BIT_BUCKET'
- A pathname defined by the host operating system, which can be
- opened as a file and written to, but all the information written
- is discarded. This is commonly known as a "bit bucket" or "null
- device". If you do not define this macro, GCC will use
- `/dev/null' as the bit bucket. If the host does not support a bit
- bucket, define this macro to an invalid filename.
-
-`UPDATE_PATH_HOST_CANONICALIZE (PATH)'
- If defined, a C statement (sans semicolon) that performs
- host-dependent canonicalization when a path used in a compilation
- driver or preprocessor is canonicalized. PATH is a malloc-ed path
- to be canonicalized. If the C statement does canonicalize PATH
- into a different buffer, the old path should be freed and the new
- buffer should have been allocated with malloc.
-
-`DUMPFILE_FORMAT'
- Define this macro to be a C string representing the format to use
- for constructing the index part of debugging dump file names. The
- resultant string must fit in fifteen bytes. The full filename
- will be the concatenation of: the prefix of the assembler file
- name, the string resulting from applying this format to an index
- number, and a string unique to each dump file kind, e.g. `rtl'.
-
- If you do not define this macro, GCC will use `.%02d.'. You should
- define this macro if using the default will create an invalid file
- name.
-
-`DELETE_IF_ORDINARY'
- Define this macro to be a C statement (sans semicolon) that
- performs host-dependent removal of ordinary temp files in the
- compilation driver.
-
- If you do not define this macro, GCC will use the default version.
- You should define this macro if the default version does not
- reliably remove the temp file as, for example, on VMS which allows
- multiple versions of a file.
-
-`HOST_LACKS_INODE_NUMBERS'
- Define this macro if the host filesystem does not report
- meaningful inode numbers in struct stat.
-
-\1f
-File: gccint.info, Node: Host Misc, Prev: Filesystem, Up: Host Config
-
-18.3 Host Misc
-==============
-
-`FATAL_EXIT_CODE'
- A C expression for the status code to be returned when the compiler
- exits after serious errors. The default is the system-provided
- macro `EXIT_FAILURE', or `1' if the system doesn't define that
- macro. Define this macro only if these defaults are incorrect.
-
-`SUCCESS_EXIT_CODE'
- A C expression for the status code to be returned when the compiler
- exits without serious errors. (Warnings are not serious errors.)
- The default is the system-provided macro `EXIT_SUCCESS', or `0' if
- the system doesn't define that macro. Define this macro only if
- these defaults are incorrect.
-
-`USE_C_ALLOCA'
- Define this macro if GCC should use the C implementation of
- `alloca' provided by `libiberty.a'. This only affects how some
- parts of the compiler itself allocate memory. It does not change
- code generation.
-
- When GCC is built with a compiler other than itself, the C `alloca'
- is always used. This is because most other implementations have
- serious bugs. You should define this macro only on a system where
- no stack-based `alloca' can possibly work. For instance, if a
- system has a small limit on the size of the stack, GCC's builtin
- `alloca' will not work reliably.
-
-`COLLECT2_HOST_INITIALIZATION'
- If defined, a C statement (sans semicolon) that performs
- host-dependent initialization when `collect2' is being initialized.
-
-`GCC_DRIVER_HOST_INITIALIZATION'
- If defined, a C statement (sans semicolon) that performs
- host-dependent initialization when a compilation driver is being
- initialized.
-
-`HOST_LONG_LONG_FORMAT'
- If defined, the string used to indicate an argument of type `long
- long' to functions like `printf'. The default value is `"ll"'.
-
- In addition, if `configure' generates an incorrect definition of any
-of the macros in `auto-host.h', you can override that definition in a
-host configuration header. If you need to do this, first see if it is
-possible to fix `configure'.
-
-\1f
-File: gccint.info, Node: Fragments, Next: Collect2, Prev: Host Config, Up: Top
-
-19 Makefile Fragments
-*********************
-
-When you configure GCC using the `configure' script, it will construct
-the file `Makefile' from the template file `Makefile.in'. When it does
-this, it can incorporate makefile fragments from the `config'
-directory. These are used to set Makefile parameters that are not
-amenable to being calculated by autoconf. The list of fragments to
-incorporate is set by `config.gcc' (and occasionally `config.build' and
-`config.host'); *Note System Config::.
-
- Fragments are named either `t-TARGET' or `x-HOST', depending on
-whether they are relevant to configuring GCC to produce code for a
-particular target, or to configuring GCC to run on a particular host.
-Here TARGET and HOST are mnemonics which usually have some relationship
-to the canonical system name, but no formal connection.
-
- If these files do not exist, it means nothing needs to be added for a
-given target or host. Most targets need a few `t-TARGET' fragments,
-but needing `x-HOST' fragments is rare.
-
-* Menu:
-
-* Target Fragment:: Writing `t-TARGET' files.
-* Host Fragment:: Writing `x-HOST' files.
-
-\1f
-File: gccint.info, Node: Target Fragment, Next: Host Fragment, Up: Fragments
-
-19.1 Target Makefile Fragments
-==============================
-
-Target makefile fragments can set these Makefile variables.
-
-`LIBGCC2_CFLAGS'
- Compiler flags to use when compiling `libgcc2.c'.
-
-`LIB2FUNCS_EXTRA'
- A list of source file names to be compiled or assembled and
- inserted into `libgcc.a'.
-
-`Floating Point Emulation'
- To have GCC include software floating point libraries in `libgcc.a'
- define `FPBIT' and `DPBIT' along with a few rules as follows:
- # We want fine grained libraries, so use the new code
- # to build the floating point emulation libraries.
- FPBIT = fp-bit.c
- DPBIT = dp-bit.c
-
-
- fp-bit.c: $(srcdir)/config/fp-bit.c
- echo '#define FLOAT' > fp-bit.c
- cat $(srcdir)/config/fp-bit.c >> fp-bit.c
-
- dp-bit.c: $(srcdir)/config/fp-bit.c
- cat $(srcdir)/config/fp-bit.c > dp-bit.c
-
- You may need to provide additional #defines at the beginning of
- `fp-bit.c' and `dp-bit.c' to control target endianness and other
- options.
-
-`CRTSTUFF_T_CFLAGS'
- Special flags used when compiling `crtstuff.c'. *Note
- Initialization::.
-
-`CRTSTUFF_T_CFLAGS_S'
- Special flags used when compiling `crtstuff.c' for shared linking.
- Used if you use `crtbeginS.o' and `crtendS.o' in `EXTRA-PARTS'.
- *Note Initialization::.
-
-`MULTILIB_OPTIONS'
- For some targets, invoking GCC in different ways produces objects
- that can not be linked together. For example, for some targets GCC
- produces both big and little endian code. For these targets, you
- must arrange for multiple versions of `libgcc.a' to be compiled,
- one for each set of incompatible options. When GCC invokes the
- linker, it arranges to link in the right version of `libgcc.a',
- based on the command line options used.
-
- The `MULTILIB_OPTIONS' macro lists the set of options for which
- special versions of `libgcc.a' must be built. Write options that
- are mutually incompatible side by side, separated by a slash.
- Write options that may be used together separated by a space. The
- build procedure will build all combinations of compatible options.
-
- For example, if you set `MULTILIB_OPTIONS' to `m68000/m68020
- msoft-float', `Makefile' will build special versions of `libgcc.a'
- using the following sets of options: `-m68000', `-m68020',
- `-msoft-float', `-m68000 -msoft-float', and `-m68020 -msoft-float'.
-
-`MULTILIB_DIRNAMES'
- If `MULTILIB_OPTIONS' is used, this variable specifies the
- directory names that should be used to hold the various libraries.
- Write one element in `MULTILIB_DIRNAMES' for each element in
- `MULTILIB_OPTIONS'. If `MULTILIB_DIRNAMES' is not used, the
- default value will be `MULTILIB_OPTIONS', with all slashes treated
- as spaces.
-
- For example, if `MULTILIB_OPTIONS' is set to `m68000/m68020
- msoft-float', then the default value of `MULTILIB_DIRNAMES' is
- `m68000 m68020 msoft-float'. You may specify a different value if
- you desire a different set of directory names.
-
-`MULTILIB_MATCHES'
- Sometimes the same option may be written in two different ways.
- If an option is listed in `MULTILIB_OPTIONS', GCC needs to know
- about any synonyms. In that case, set `MULTILIB_MATCHES' to a
- list of items of the form `option=option' to describe all relevant
- synonyms. For example, `m68000=mc68000 m68020=mc68020'.
-
-`MULTILIB_EXCEPTIONS'
- Sometimes when there are multiple sets of `MULTILIB_OPTIONS' being
- specified, there are combinations that should not be built. In
- that case, set `MULTILIB_EXCEPTIONS' to be all of the switch
- exceptions in shell case syntax that should not be built.
-
- For example the ARM processor cannot execute both hardware floating
- point instructions and the reduced size THUMB instructions at the
- same time, so there is no need to build libraries with both of
- these options enabled. Therefore `MULTILIB_EXCEPTIONS' is set to:
- *mthumb/*mhard-float*
-
-`MULTILIB_EXTRA_OPTS'
- Sometimes it is desirable that when building multiple versions of
- `libgcc.a' certain options should always be passed on to the
- compiler. In that case, set `MULTILIB_EXTRA_OPTS' to be the list
- of options to be used for all builds. If you set this, you should
- probably set `CRTSTUFF_T_CFLAGS' to a dash followed by it.
-
-`NATIVE_SYSTEM_HEADER_DIR'
- If the default location for system headers is not `/usr/include',
- you must set this to the directory containing the headers. This
- value should match the value of the `SYSTEM_INCLUDE_DIR' macro.
-
-`SPECS'
- Unfortunately, setting `MULTILIB_EXTRA_OPTS' is not enough, since
- it does not affect the build of target libraries, at least not the
- build of the default multilib. One possible work-around is to use
- `DRIVER_SELF_SPECS' to bring options from the `specs' file as if
- they had been passed in the compiler driver command line.
- However, you don't want to be adding these options after the
- toolchain is installed, so you can instead tweak the `specs' file
- that will be used during the toolchain build, while you still
- install the original, built-in `specs'. The trick is to set
- `SPECS' to some other filename (say `specs.install'), that will
- then be created out of the built-in specs, and introduce a
- `Makefile' rule to generate the `specs' file that's going to be
- used at build time out of your `specs.install'.
-
-`T_CFLAGS'
- These are extra flags to pass to the C compiler. They are used
- both when building GCC, and when compiling things with the
- just-built GCC. This variable is deprecated and should not be
- used.
-
-\1f
-File: gccint.info, Node: Host Fragment, Prev: Target Fragment, Up: Fragments
-
-19.2 Host Makefile Fragments
-============================
-
-The use of `x-HOST' fragments is discouraged. You should only use it
-for makefile dependencies.
-
-\1f
-File: gccint.info, Node: Collect2, Next: Header Dirs, Prev: Fragments, Up: Top
-
-20 `collect2'
-*************
-
-GCC uses a utility called `collect2' on nearly all systems to arrange
-to call various initialization functions at start time.
-
- The program `collect2' works by linking the program once and looking
-through the linker output file for symbols with particular names
-indicating they are constructor functions. If it finds any, it creates
-a new temporary `.c' file containing a table of them, compiles it, and
-links the program a second time including that file.
-
- The actual calls to the constructors are carried out by a subroutine
-called `__main', which is called (automatically) at the beginning of
-the body of `main' (provided `main' was compiled with GNU CC). Calling
-`__main' is necessary, even when compiling C code, to allow linking C
-and C++ object code together. (If you use `-nostdlib', you get an
-unresolved reference to `__main', since it's defined in the standard
-GCC library. Include `-lgcc' at the end of your compiler command line
-to resolve this reference.)
-
- The program `collect2' is installed as `ld' in the directory where the
-passes of the compiler are installed. When `collect2' needs to find
-the _real_ `ld', it tries the following file names:
-
- * `real-ld' in the directories listed in the compiler's search
- directories.
-
- * `real-ld' in the directories listed in the environment variable
- `PATH'.
-
- * The file specified in the `REAL_LD_FILE_NAME' configuration macro,
- if specified.
-
- * `ld' in the compiler's search directories, except that `collect2'
- will not execute itself recursively.
-
- * `ld' in `PATH'.
-
- "The compiler's search directories" means all the directories where
-`gcc' searches for passes of the compiler. This includes directories
-that you specify with `-B'.
-
- Cross-compilers search a little differently:
-
- * `real-ld' in the compiler's search directories.
-
- * `TARGET-real-ld' in `PATH'.
-
- * The file specified in the `REAL_LD_FILE_NAME' configuration macro,
- if specified.
-
- * `ld' in the compiler's search directories.
-
- * `TARGET-ld' in `PATH'.
-
- `collect2' explicitly avoids running `ld' using the file name under
-which `collect2' itself was invoked. In fact, it remembers up a list
-of such names--in case one copy of `collect2' finds another copy (or
-version) of `collect2' installed as `ld' in a second place in the
-search path.
-
- `collect2' searches for the utilities `nm' and `strip' using the same
-algorithm as above for `ld'.
-
-\1f
-File: gccint.info, Node: Header Dirs, Next: Type Information, Prev: Collect2, Up: Top
-
-21 Standard Header File Directories
-***********************************
-
-`GCC_INCLUDE_DIR' means the same thing for native and cross. It is
-where GCC stores its private include files, and also where GCC stores
-the fixed include files. A cross compiled GCC runs `fixincludes' on
-the header files in `$(tooldir)/include'. (If the cross compilation
-header files need to be fixed, they must be installed before GCC is
-built. If the cross compilation header files are already suitable for
-GCC, nothing special need be done).
-
- `GPLUSPLUS_INCLUDE_DIR' means the same thing for native and cross. It
-is where `g++' looks first for header files. The C++ library installs
-only target independent header files in that directory.
-
- `LOCAL_INCLUDE_DIR' is used only by native compilers. GCC doesn't
-install anything there. It is normally `/usr/local/include'. This is
-where local additions to a packaged system should place header files.
-
- `CROSS_INCLUDE_DIR' is used only by cross compilers. GCC doesn't
-install anything there.
-
- `TOOL_INCLUDE_DIR' is used for both native and cross compilers. It is
-the place for other packages to install header files that GCC will use.
-For a cross-compiler, this is the equivalent of `/usr/include'. When
-you build a cross-compiler, `fixincludes' processes any header files in
-this directory.
-
-\1f
-File: gccint.info, Node: Type Information, Next: Plugins, Prev: Header Dirs, Up: Top
-
-22 Memory Management and Type Information
-*****************************************
-
-GCC uses some fairly sophisticated memory management techniques, which
-involve determining information about GCC's data structures from GCC's
-source code and using this information to perform garbage collection and
-implement precompiled headers.
-
- A full C parser would be too complicated for this task, so a limited
-subset of C is interpreted and special markers are used to determine
-what parts of the source to look at. All `struct' and `union'
-declarations that define data structures that are allocated under
-control of the garbage collector must be marked. All global variables
-that hold pointers to garbage-collected memory must also be marked.
-Finally, all global variables that need to be saved and restored by a
-precompiled header must be marked. (The precompiled header mechanism
-can only save static variables if they're scalar. Complex data
-structures must be allocated in garbage-collected memory to be saved in
-a precompiled header.)
-
- The full format of a marker is
- GTY (([OPTION] [(PARAM)], [OPTION] [(PARAM)] ...))
- but in most cases no options are needed. The outer double parentheses
-are still necessary, though: `GTY(())'. Markers can appear:
-
- * In a structure definition, before the open brace;
-
- * In a global variable declaration, after the keyword `static' or
- `extern'; and
-
- * In a structure field definition, before the name of the field.
-
- Here are some examples of marking simple data structures and globals.
-
- struct TAG GTY(())
- {
- FIELDS...
- };
-
- typedef struct TAG GTY(())
- {
- FIELDS...
- } *TYPENAME;
-
- static GTY(()) struct TAG *LIST; /* points to GC memory */
- static GTY(()) int COUNTER; /* save counter in a PCH */
-
- The parser understands simple typedefs such as `typedef struct TAG
-*NAME;' and `typedef int NAME;'. These don't need to be marked.
-
-* Menu:
-
-* GTY Options:: What goes inside a `GTY(())'.
-* GGC Roots:: Making global variables GGC roots.
-* Files:: How the generated files work.
-* Invoking the garbage collector:: How to invoke the garbage collector.
-
-\1f
-File: gccint.info, Node: GTY Options, Next: GGC Roots, Up: Type Information
-
-22.1 The Inside of a `GTY(())'
-==============================
-
-Sometimes the C code is not enough to fully describe the type
-structure. Extra information can be provided with `GTY' options and
-additional markers. Some options take a parameter, which may be either
-a string or a type name, depending on the parameter. If an option
-takes no parameter, it is acceptable either to omit the parameter
-entirely, or to provide an empty string as a parameter. For example,
-`GTY ((skip))' and `GTY ((skip ("")))' are equivalent.
-
- When the parameter is a string, often it is a fragment of C code. Four
-special escapes may be used in these strings, to refer to pieces of the
-data structure being marked:
-
-`%h'
- The current structure.
-
-`%1'
- The structure that immediately contains the current structure.
-
-`%0'
- The outermost structure that contains the current structure.
-
-`%a'
- A partial expression of the form `[i1][i2]...' that indexes the
- array item currently being marked.
-
- For instance, suppose that you have a structure of the form
- struct A {
- ...
- };
- struct B {
- struct A foo[12];
- };
- and `b' is a variable of type `struct B'. When marking `b.foo[11]',
-`%h' would expand to `b.foo[11]', `%0' and `%1' would both expand to
-`b', and `%a' would expand to `[11]'.
-
- As in ordinary C, adjacent strings will be concatenated; this is
-helpful when you have a complicated expression.
- GTY ((chain_next ("TREE_CODE (&%h.generic) == INTEGER_TYPE"
- " ? TYPE_NEXT_VARIANT (&%h.generic)"
- " : TREE_CHAIN (&%h.generic)")))
-
- The available options are:
-
-`length ("EXPRESSION")'
- There are two places the type machinery will need to be explicitly
- told the length of an array. The first case is when a structure
- ends in a variable-length array, like this:
- struct rtvec_def GTY(()) {
- int num_elem; /* number of elements */
- rtx GTY ((length ("%h.num_elem"))) elem[1];
- };
-
- In this case, the `length' option is used to override the specified
- array length (which should usually be `1'). The parameter of the
- option is a fragment of C code that calculates the length.
-
- The second case is when a structure or a global variable contains a
- pointer to an array, like this:
- tree *
- GTY ((length ("%h.regno_pointer_align_length"))) regno_decl;
- In this case, `regno_decl' has been allocated by writing something
- like
- x->regno_decl =
- ggc_alloc (x->regno_pointer_align_length * sizeof (tree));
- and the `length' provides the length of the field.
-
- This second use of `length' also works on global variables, like: static GTY((length ("reg_base_value_size")))
- rtx *reg_base_value;
-
-`skip'
- If `skip' is applied to a field, the type machinery will ignore it.
- This is somewhat dangerous; the only safe use is in a union when
- one field really isn't ever used.
-
-`desc ("EXPRESSION")'
-`tag ("CONSTANT")'
-`default'
- The type machinery needs to be told which field of a `union' is
- currently active. This is done by giving each field a constant
- `tag' value, and then specifying a discriminator using `desc'.
- The value of the expression given by `desc' is compared against
- each `tag' value, each of which should be different. If no `tag'
- is matched, the field marked with `default' is used if there is
- one, otherwise no field in the union will be marked.
-
- In the `desc' option, the "current structure" is the union that it
- discriminates. Use `%1' to mean the structure containing it.
- There are no escapes available to the `tag' option, since it is a
- constant.
-
- For example,
- struct tree_binding GTY(())
- {
- struct tree_common common;
- union tree_binding_u {
- tree GTY ((tag ("0"))) scope;
- struct cp_binding_level * GTY ((tag ("1"))) level;
- } GTY ((desc ("BINDING_HAS_LEVEL_P ((tree)&%0)"))) xscope;
- tree value;
- };
-
- In this example, the value of BINDING_HAS_LEVEL_P when applied to a
- `struct tree_binding *' is presumed to be 0 or 1. If 1, the type
- mechanism will treat the field `level' as being present and if 0,
- will treat the field `scope' as being present.
-
-`param_is (TYPE)'
-`use_param'
- Sometimes it's convenient to define some data structure to work on
- generic pointers (that is, `PTR') and then use it with a specific
- type. `param_is' specifies the real type pointed to, and
- `use_param' says where in the generic data structure that type
- should be put.
-
- For instance, to have a `htab_t' that points to trees, one would
- write the definition of `htab_t' like this:
- typedef struct GTY(()) {
- ...
- void ** GTY ((use_param, ...)) entries;
- ...
- } htab_t;
- and then declare variables like this:
- static htab_t GTY ((param_is (union tree_node))) ict;
-
-`paramN_is (TYPE)'
-`use_paramN'
- In more complicated cases, the data structure might need to work on
- several different types, which might not necessarily all be
- pointers. For this, `param1_is' through `param9_is' may be used to
- specify the real type of a field identified by `use_param1' through
- `use_param9'.
-
-`use_params'
- When a structure contains another structure that is parameterized,
- there's no need to do anything special, the inner structure
- inherits the parameters of the outer one. When a structure
- contains a pointer to a parameterized structure, the type
- machinery won't automatically detect this (it could, it just
- doesn't yet), so it's necessary to tell it that the pointed-to
- structure should use the same parameters as the outer structure.
- This is done by marking the pointer with the `use_params' option.
-
-`deletable'
- `deletable', when applied to a global variable, indicates that when
- garbage collection runs, there's no need to mark anything pointed
- to by this variable, it can just be set to `NULL' instead. This
- is used to keep a list of free structures around for re-use.
-
-`if_marked ("EXPRESSION")'
- Suppose you want some kinds of object to be unique, and so you put
- them in a hash table. If garbage collection marks the hash table,
- these objects will never be freed, even if the last other
- reference to them goes away. GGC has special handling to deal
- with this: if you use the `if_marked' option on a global hash
- table, GGC will call the routine whose name is the parameter to
- the option on each hash table entry. If the routine returns
- nonzero, the hash table entry will be marked as usual. If the
- routine returns zero, the hash table entry will be deleted.
-
- The routine `ggc_marked_p' can be used to determine if an element
- has been marked already; in fact, the usual case is to use
- `if_marked ("ggc_marked_p")'.
-
-`mark_hook ("HOOK-ROUTINE-NAME")'
- If provided for a structure or union type, the given
- HOOK-ROUTINE-NAME (between double-quotes) is the name of a routine
- called when the garbage collector has just marked the data as
- reachable. This routine should not change the data, or call any ggc
- routine. Its only argument is a pointer to the just marked (const)
- structure or union.
-
-`maybe_undef'
- When applied to a field, `maybe_undef' indicates that it's OK if
- the structure that this fields points to is never defined, so long
- as this field is always `NULL'. This is used to avoid requiring
- backends to define certain optional structures. It doesn't work
- with language frontends.
-
-`nested_ptr (TYPE, "TO EXPRESSION", "FROM EXPRESSION")'
- The type machinery expects all pointers to point to the start of an
- object. Sometimes for abstraction purposes it's convenient to have
- a pointer which points inside an object. So long as it's possible
- to convert the original object to and from the pointer, such
- pointers can still be used. TYPE is the type of the original
- object, the TO EXPRESSION returns the pointer given the original
- object, and the FROM EXPRESSION returns the original object given
- the pointer. The pointer will be available using the `%h' escape.
-
-`chain_next ("EXPRESSION")'
-`chain_prev ("EXPRESSION")'
-`chain_circular ("EXPRESSION")'
- It's helpful for the type machinery to know if objects are often
- chained together in long lists; this lets it generate code that
- uses less stack space by iterating along the list instead of
- recursing down it. `chain_next' is an expression for the next
- item in the list, `chain_prev' is an expression for the previous
- item. For singly linked lists, use only `chain_next'; for doubly
- linked lists, use both. The machinery requires that taking the
- next item of the previous item gives the original item.
- `chain_circular' is similar to `chain_next', but can be used for
- circular single linked lists.
-
-`reorder ("FUNCTION NAME")'
- Some data structures depend on the relative ordering of pointers.
- If the precompiled header machinery needs to change that ordering,
- it will call the function referenced by the `reorder' option,
- before changing the pointers in the object that's pointed to by
- the field the option applies to. The function must take four
- arguments, with the signature
- `void *, void *, gt_pointer_operator, void *'. The first
- parameter is a pointer to the structure that contains the object
- being updated, or the object itself if there is no containing
- structure. The second parameter is a cookie that should be
- ignored. The third parameter is a routine that, given a pointer,
- will update it to its correct new value. The fourth parameter is
- a cookie that must be passed to the second parameter.
-
- PCH cannot handle data structures that depend on the absolute
- values of pointers. `reorder' functions can be expensive. When
- possible, it is better to depend on properties of the data, like
- an ID number or the hash of a string instead.
-
-`special ("NAME")'
- The `special' option is used to mark types that have to be dealt
- with by special case machinery. The parameter is the name of the
- special case. See `gengtype.c' for further details. Avoid adding
- new special cases unless there is no other alternative.
-
-\1f
-File: gccint.info, Node: GGC Roots, Next: Files, Prev: GTY Options, Up: Type Information
-
-22.2 Marking Roots for the Garbage Collector
-============================================
-
-In addition to keeping track of types, the type machinery also locates
-the global variables ("roots") that the garbage collector starts at.
-Roots must be declared using one of the following syntaxes:
-
- * `extern GTY(([OPTIONS])) TYPE NAME;'
-
- * `static GTY(([OPTIONS])) TYPE NAME;'
- The syntax
- * `GTY(([OPTIONS])) TYPE NAME;'
- is _not_ accepted. There should be an `extern' declaration of such a
-variable in a header somewhere--mark that, not the definition. Or, if
-the variable is only used in one file, make it `static'.
-
-\1f
-File: gccint.info, Node: Files, Next: Invoking the garbage collector, Prev: GGC Roots, Up: Type Information
-
-22.3 Source Files Containing Type Information
-=============================================
-
-Whenever you add `GTY' markers to a source file that previously had
-none, or create a new source file containing `GTY' markers, there are
-three things you need to do:
-
- 1. You need to add the file to the list of source files the type
- machinery scans. There are four cases:
-
- a. For a back-end file, this is usually done automatically; if
- not, you should add it to `target_gtfiles' in the appropriate
- port's entries in `config.gcc'.
-
- b. For files shared by all front ends, add the filename to the
- `GTFILES' variable in `Makefile.in'.
-
- c. For files that are part of one front end, add the filename to
- the `gtfiles' variable defined in the appropriate
- `config-lang.in'. For C, the file is `c-config-lang.in'.
- Headers should appear before non-headers in this list.
-
- d. For files that are part of some but not all front ends, add
- the filename to the `gtfiles' variable of _all_ the front ends
- that use it.
-
- 2. If the file was a header file, you'll need to check that it's
- included in the right place to be visible to the generated files.
- For a back-end header file, this should be done automatically.
- For a front-end header file, it needs to be included by the same
- file that includes `gtype-LANG.h'. For other header files, it
- needs to be included in `gtype-desc.c', which is a generated file,
- so add it to `ifiles' in `open_base_file' in `gengtype.c'.
-
- For source files that aren't header files, the machinery will
- generate a header file that should be included in the source file
- you just changed. The file will be called `gt-PATH.h' where PATH
- is the pathname relative to the `gcc' directory with slashes
- replaced by -, so for example the header file to be included in
- `cp/parser.c' is called `gt-cp-parser.c'. The generated header
- file should be included after everything else in the source file.
- Don't forget to mention this file as a dependency in the
- `Makefile'!
-
-
- For language frontends, there is another file that needs to be included
-somewhere. It will be called `gtype-LANG.h', where LANG is the name of
-the subdirectory the language is contained in.
-
- Plugins can add additional root tables. Run the `gengtype' utility in
-plugin mode as `gengtype -p SOURCE-DIR FILE-LIST PLUGIN*.C' with your
-plugin files PLUGIN*.C using `GTY' to generate the corresponding
-GT-PLUGIN*.H files. The GCC build tree is needed to be present in that
-mode.
-
-\1f
-File: gccint.info, Node: Invoking the garbage collector, Prev: Files, Up: Type Information
-
-22.4 How to invoke the garbage collector
-========================================
-
-The GCC garbage collector GGC is only invoked explicitly. In contrast
-with many other garbage collectors, it is not implicitly invoked by
-allocation routines when a lot of memory has been consumed. So the only
-way to have GGC reclaim storage it to call the `ggc_collect' function
-explicitly. This call is an expensive operation, as it may have to scan
-the entire heap. Beware that local variables (on the GCC call stack)
-are not followed by such an invocation (as many other garbage
-collectors do): you should reference all your data from static or
-external `GTY'-ed variables, and it is advised to call `ggc_collect'
-with a shallow call stack. The GGC is an exact mark and sweep garbage
-collector (so it does not scan the call stack for pointers). In
-practice GCC passes don't often call `ggc_collect' themselves, because
-it is called by the pass manager between passes.
-
-\1f
-File: gccint.info, Node: Plugins, Next: Funding, Prev: Type Information, Up: Top
-
-23 Plugins
-**********
-
-23.1 Loading Plugins
-====================
-
-Plugins are supported on platforms that support `-ldl -rdynamic'. They
-are loaded by the compiler using `dlopen' and invoked at pre-determined
-locations in the compilation process.
-
- Plugins are loaded with
-
- `-fplugin=/path/to/NAME.so' `-fplugin-arg-NAME-<key1>[=<value1>]'
-
- The plugin arguments are parsed by GCC and passed to respective
-plugins as key-value pairs. Multiple plugins can be invoked by
-specifying multiple `-fplugin' arguments.
-
-23.2 Plugin API
-===============
-
-Plugins are activated by the compiler at specific events as defined in
-`gcc-plugin.h'. For each event of interest, the plugin should call
-`register_callback' specifying the name of the event and address of the
-callback function that will handle that event.
-
- The header `gcc-plugin.h' must be the first gcc header to be included.
-
-23.2.1 Plugin initialization
-----------------------------
-
-Every plugin should export a function called `plugin_init' that is
-called right after the plugin is loaded. This function is responsible
-for registering all the callbacks required by the plugin and do any
-other required initialization.
-
- This function is called from `compile_file' right before invoking the
-parser. The arguments to `plugin_init' are:
-
- * `plugin_info': Plugin invocation information.
-
- * `version': GCC version.
-
- The `plugin_info' struct is defined as follows:
-
- struct plugin_name_args
- {
- char *base_name; /* Short name of the plugin
- (filename without .so suffix). */
- const char *full_name; /* Path to the plugin as specified with
- -fplugin=. */
- int argc; /* Number of arguments specified with
- -fplugin-arg-.... */
- struct plugin_argument *argv; /* Array of ARGC key-value pairs. */
- const char *version; /* Version string provided by plugin. */
- const char *help; /* Help string provided by plugin. */
- }
-
- If initialization fails, `plugin_init' must return a non-zero value.
-Otherwise, it should return 0.
-
- The version of the GCC compiler loading the plugin is described by the
-following structure:
-
- struct plugin_gcc_version
- {
- const char *basever;
- const char *datestamp;
- const char *devphase;
- const char *revision;
- const char *configuration_arguments;
- };
-
- The function `plugin_default_version_check' takes two pointers to such
-structure and compare them field by field. It can be used by the
-plugin's `plugin_init' function.
-
-23.2.2 Plugin callbacks
------------------------
-
-Callback functions have the following prototype:
-
- /* The prototype for a plugin callback function.
- gcc_data - event-specific data provided by GCC
- user_data - plugin-specific data provided by the plug-in. */
- typedef void (*plugin_callback_func)(void *gcc_data, void *user_data);
-
- Callbacks can be invoked at the following pre-determined events:
-
- enum plugin_event
- {
- PLUGIN_PASS_MANAGER_SETUP, /* To hook into pass manager. */
- PLUGIN_FINISH_TYPE, /* After finishing parsing a type. */
- PLUGIN_FINISH_UNIT, /* Useful for summary processing. */
- PLUGIN_CXX_CP_PRE_GENERICIZE, /* Allows to see low level AST in C++ FE. */
- PLUGIN_FINISH, /* Called before GCC exits. */
- PLUGIN_INFO, /* Information about the plugin. */
- PLUGIN_GGC_START, /* Called at start of GCC Garbage Collection. */
- PLUGIN_GGC_MARKING, /* Extend the GGC marking. */
- PLUGIN_GGC_END, /* Called at end of GGC. */
- PLUGIN_REGISTER_GGC_ROOTS, /* Register an extra GGC root table. */
- PLUGIN_ATTRIBUTES, /* Called during attribute registration */
- PLUGIN_START_UNIT, /* Called before processing a translation unit. */
- PLUGIN_EVENT_LAST /* Dummy event used for indexing callback
- array. */
- };
-
- To register a callback, the plugin calls `register_callback' with the
-arguments:
-
- * `char *name': Plugin name.
-
- * `enum plugin_event event': The event code.
-
- * `plugin_callback_func callback': The function that handles `event'.
-
- * `void *user_data': Pointer to plugin-specific data.
-
- For the PLUGIN_PASS_MANAGER_SETUP, PLUGIN_INFO, and
-PLUGIN_REGISTER_GGC_ROOTS pseudo-events the `callback' should be null,
-and the `user_data' is specific.
-
-23.3 Interacting with the pass manager
-======================================
-
-There needs to be a way to add/reorder/remove passes dynamically. This
-is useful for both analysis plugins (plugging in after a certain pass
-such as CFG or an IPA pass) and optimization plugins.
-
- Basic support for inserting new passes or replacing existing passes is
-provided. A plugin registers a new pass with GCC by calling
-`register_callback' with the `PLUGIN_PASS_MANAGER_SETUP' event and a
-pointer to a `struct plugin_pass' object defined as follows
-
- enum pass_positioning_ops
- {
- PASS_POS_INSERT_AFTER, // Insert after the reference pass.
- PASS_POS_INSERT_BEFORE, // Insert before the reference pass.
- PASS_POS_REPLACE // Replace the reference pass.
- };
-
- struct plugin_pass
- {
- struct opt_pass *pass; /* New pass provided by the plugin. */
- const char *reference_pass_name; /* Name of the reference pass for hooking
- up the new pass. */
- int ref_pass_instance_number; /* Insert the pass at the specified
- instance number of the reference pass. */
- /* Do it for every instance if it is 0. */
- enum pass_positioning_ops pos_op; /* how to insert the new pass. */
- };
-
-
- /* Sample plugin code that registers a new pass. */
- int
- plugin_init (struct plugin_name_args *plugin_info,
- struct plugin_gcc_version *version)
- {
- struct plugin_pass pass_info;
-
- ...
-
- /* Code to fill in the pass_info object with new pass information. */
-
- ...
-
- /* Register the new pass. */
- register_callback (plugin_info->base_name, PLUGIN_PASS_MANAGER_SETUP, NULL, &pass_info);
-
- ...
- }
-
-23.4 Interacting with the GCC Garbage Collector
-===============================================
-
-Some plugins may want to be informed when GGC (the GCC Garbage
-Collector) is running. They can register callbacks for the
-`PLUGIN_GGC_START' and `PLUGIN_GGC_END' events (for which the callback
-is called with a null `gcc_data') to be notified of the start or end of
-the GCC garbage collection.
-
- Some plugins may need to have GGC mark additional data. This can be
-done by registering a callback (called with a null `gcc_data') for the
-`PLUGIN_GGC_MARKING' event. Such callbacks can call the `ggc_set_mark'
-routine, preferably thru the `ggc_mark' macro (and conversely, these
-routines should usually not be used in plugins outside of the
-`PLUGIN_GGC_MARKING' event).
-
- Some plugins may need to add extra GGC root tables, e.g. to handle
-their own `GTY'-ed data. This can be done with the
-`PLUGIN_REGISTER_GGC_ROOTS' pseudo-event with a null callback and the
-extra root table as `user_data'. Running the `gengtype -p SOURCE-DIR
-FILE-LIST PLUGIN*.C ...' utility generates this extra root table.
-
- You should understand the details of memory management inside GCC
-before using `PLUGIN_GGC_MARKING' or `PLUGIN_REGISTER_GGC_ROOTS'.
-
-23.5 Giving information about a plugin
-======================================
-
-A plugin should give some information to the user about itself. This
-uses the following structure:
-
- struct plugin_info
- {
- const char *version;
- const char *help;
- };
-
- Such a structure is passed as the `user_data' by the plugin's init
-routine using `register_callback' with the `PLUGIN_INFO' pseudo-event
-and a null callback.
-
-23.6 Registering custom attributes
-==================================
-
-For analysis purposes it is useful to be able to add custom attributes.
-
- The `PLUGIN_ATTRIBUTES' callback is called during attribute
-registration. Use the `register_attribute' function to register custom
-attributes.
-
- /* Attribute handler callback */
- static tree
- handle_user_attribute (tree *node, tree name, tree args,
- int flags, bool *no_add_attrs)
- {
- return NULL_TREE;
- }
-
- /* Attribute definition */
- static struct attribute_spec user_attr =
- { "user", 1, 1, false, false, false, handle_user_attribute };
-
- /* Plugin callback called during attribute registration.
- Registered with register_callback (plugin_name, PLUGIN_ATTRIBUTES, register_attributes, NULL)
- */
- static void
- register_attributes (void *event_data, void *data)
- {
- warning (0, G_("Callback to register attributes"));
- register_attribute (&user_attr);
- }
-
-23.7 Building GCC plugins
-=========================
-
-If plugins are enabled, GCC installs the headers needed to build a
-plugin (somehwere in the installation tree, e.g. under `/usr/local').
-In particular a `plugin/include' directory is installed, containing all
-the header files needed to build plugins.
-
- On most systems, you can query this `plugin' directory by invoking
-`gcc -print-file-name=plugin' (replace if needed `gcc' with the
-appropriate program path).
-
- The following GNU Makefile excerpt shows how to build a simple plugin:
-
- GCC=gcc
- PLUGIN_SOURCE_FILES= plugin1.c plugin2.c
- PLUGIN_OBJECT_FILES= $(patsubst %.c,%.o,$(PLUGIN_SOURCE_FILES))
- GCCPLUGINS_DIR:= $(shell $(GCC) -print-file-name=plugin)
- CFLAGS+= -I$(GCCPLUGINS_DIR)/include -fPIC -O2
-
- plugin.so: $(PLUGIN_OBJECT_FILES)
- $(GCC) -shared $^ -o $
-
- A single source file plugin may be built with `gcc -I`gcc
--print-file-name=plugin`/include -fPIC -shared -O2 plugin.c -o
-plugin.so', using backquote shell syntax to query the `plugin'
-directory.
-
- Plugins needing to use `gengtype' require a GCC build directory for
-the same version of GCC that they will be linked against.
-
-\1f
-File: gccint.info, Node: Funding, Next: GNU Project, Prev: Plugins, Up: Top
-
-Funding Free Software
-*********************
-
-If you want to have more free software a few years from now, it makes
-sense for you to help encourage people to contribute funds for its
-development. The most effective approach known is to encourage
-commercial redistributors to donate.
-
- Users of free software systems can boost the pace of development by
-encouraging for-a-fee distributors to donate part of their selling price
-to free software developers--the Free Software Foundation, and others.
-
- The way to convince distributors to do this is to demand it and expect
-it from them. So when you compare distributors, judge them partly by
-how much they give to free software development. Show distributors
-they must compete to be the one who gives the most.
-
- To make this approach work, you must insist on numbers that you can
-compare, such as, "We will donate ten dollars to the Frobnitz project
-for each disk sold." Don't be satisfied with a vague promise, such as
-"A portion of the profits are donated," since it doesn't give a basis
-for comparison.
-
- Even a precise fraction "of the profits from this disk" is not very
-meaningful, since creative accounting and unrelated business decisions
-can greatly alter what fraction of the sales price counts as profit.
-If the price you pay is $50, ten percent of the profit is probably less
-than a dollar; it might be a few cents, or nothing at all.
-
- Some redistributors do development work themselves. This is useful
-too; but to keep everyone honest, you need to inquire how much they do,
-and what kind. Some kinds of development make much more long-term
-difference than others. For example, maintaining a separate version of
-a program contributes very little; maintaining the standard version of a
-program for the whole community contributes much. Easy new ports
-contribute little, since someone else would surely do them; difficult
-ports such as adding a new CPU to the GNU Compiler Collection
-contribute more; major new features or packages contribute the most.
-
- By establishing the idea that supporting further development is "the
-proper thing to do" when distributing free software for a fee, we can
-assure a steady flow of resources into making more free software.
-
- Copyright (C) 1994 Free Software Foundation, Inc.
- Verbatim copying and redistribution of this section is permitted
- without royalty; alteration is not permitted.
-
-\1f
-File: gccint.info, Node: GNU Project, Next: Copying, Prev: Funding, Up: Top
-
-The GNU Project and GNU/Linux
-*****************************
-
-The GNU Project was launched in 1984 to develop a complete Unix-like
-operating system which is free software: the GNU system. (GNU is a
-recursive acronym for "GNU's Not Unix"; it is pronounced "guh-NEW".)
-Variants of the GNU operating system, which use the kernel Linux, are
-now widely used; though these systems are often referred to as "Linux",
-they are more accurately called GNU/Linux systems.
-
- For more information, see:
- `http://www.gnu.org/'
- `http://www.gnu.org/gnu/linux-and-gnu.html'
-
-\1f
-File: gccint.info, Node: Copying, Next: GNU Free Documentation License, Prev: GNU Project, Up: Top
-
-GNU General Public License
-**************************
-
- Version 3, 29 June 2007
-
- Copyright (C) 2007 Free Software Foundation, Inc. `http://fsf.org/'
-
- Everyone is permitted to copy and distribute verbatim copies of this
- license document, but changing it is not allowed.
-
-Preamble
-========
-
-The GNU General Public License is a free, copyleft license for software
-and other kinds of works.
-
- The licenses for most software and other practical works are designed
-to take away your freedom to share and change the works. By contrast,
-the GNU General Public License is intended to guarantee your freedom to
-share and change all versions of a program-to make sure it remains free
-software for all its users. We, the Free Software Foundation, use the
-GNU General Public License for most of our software; it applies also to
-any other work released this way by its authors. You can apply it to
-your programs, too.
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-TERMS AND CONDITIONS
-====================
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-
-END OF TERMS AND CONDITIONS
-===========================
-
-How to Apply These Terms to Your New Programs
-=============================================
-
-If you develop a new program, and you want it to be of the greatest
-possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these
-terms.
-
- To do so, attach the following notices to the program. It is safest
-to attach them to the start of each source file to most effectively
-state the exclusion of warranty; and each file should have at least the
-"copyright" line and a pointer to where the full notice is found.
-
- ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES.
- Copyright (C) YEAR NAME OF AUTHOR
-
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or (at
- your option) any later version.
-
- This program is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see `http://www.gnu.org/licenses/'.
-
- Also add information on how to contact you by electronic and paper
-mail.
-
- If the program does terminal interaction, make it output a short
-notice like this when it starts in an interactive mode:
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- PROGRAM Copyright (C) YEAR NAME OF AUTHOR
- This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
- This is free software, and you are welcome to redistribute it
- under certain conditions; type `show c' for details.
-
- The hypothetical commands `show w' and `show c' should show the
-appropriate parts of the General Public License. Of course, your
-program's commands might be different; for a GUI interface, you would
-use an "about box".
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- You should also get your employer (if you work as a programmer) or
-school, if any, to sign a "copyright disclaimer" for the program, if
-necessary. For more information on this, and how to apply and follow
-the GNU GPL, see `http://www.gnu.org/licenses/'.
-
- The GNU General Public License does not permit incorporating your
-program into proprietary programs. If your program is a subroutine
-library, you may consider it more useful to permit linking proprietary
-applications with the library. If this is what you want to do, use the
-GNU Lesser General Public License instead of this License. But first,
-please read `http://www.gnu.org/philosophy/why-not-lgpl.html'.
-
-\1f
-File: gccint.info, Node: GNU Free Documentation License, Next: Contributors, Prev: Copying, Up: Top
-
-GNU Free Documentation License
-******************************
-
- Version 1.2, November 2002
-
- Copyright (C) 2000,2001,2002 Free Software Foundation, Inc.
- 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
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- Everyone is permitted to copy and distribute verbatim copies
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- 0. PREAMBLE
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- include the original English version of this License and the
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- void, and will automatically terminate your rights under this
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- Texts. A copy of the license is included in the section entitled ``GNU
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-replace the "with...Texts." line with this:
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-\1f
-File: gccint.info, Node: Contributors, Next: Option Index, Prev: GNU Free Documentation License, Up: Top
-
-Contributors to GCC
-*******************
-
-The GCC project would like to thank its many contributors. Without
-them the project would not have been nearly as successful as it has
-been. Any omissions in this list are accidental. Feel free to contact
-<law@redhat.com> or <gerald@pfeifer.com> if you have been left out or
-some of your contributions are not listed. Please keep this list in
-alphabetical order.
-
- * Analog Devices helped implement the support for complex data types
- and iterators.
-
- * John David Anglin for threading-related fixes and improvements to
- libstdc++-v3, and the HP-UX port.
-
- * James van Artsdalen wrote the code that makes efficient use of the
- Intel 80387 register stack.
-
- * Abramo and Roberto Bagnara for the SysV68 Motorola 3300 Delta
- Series port.
-
- * Alasdair Baird for various bug fixes.
-
- * Giovanni Bajo for analyzing lots of complicated C++ problem
- reports.
-
- * Peter Barada for his work to improve code generation for new
- ColdFire cores.
-
- * Gerald Baumgartner added the signature extension to the C++ front
- end.
-
- * Godmar Back for his Java improvements and encouragement.
-
- * Scott Bambrough for help porting the Java compiler.
-
- * Wolfgang Bangerth for processing tons of bug reports.
-
- * Jon Beniston for his Microsoft Windows port of Java.
-
- * Daniel Berlin for better DWARF2 support, faster/better
- optimizations, improved alias analysis, plus migrating GCC to
- Bugzilla.
-
- * Geoff Berry for his Java object serialization work and various
- patches.
-
- * Uros Bizjak for the implementation of x87 math built-in functions
- and for various middle end and i386 back end improvements and bug
- fixes.
-
- * Eric Blake for helping to make GCJ and libgcj conform to the
- specifications.
-
- * Janne Blomqvist for contributions to GNU Fortran.
-
- * Segher Boessenkool for various fixes.
-
- * Hans-J. Boehm for his garbage collector, IA-64 libffi port, and
- other Java work.
-
- * Neil Booth for work on cpplib, lang hooks, debug hooks and other
- miscellaneous clean-ups.
-
- * Steven Bosscher for integrating the GNU Fortran front end into GCC
- and for contributing to the tree-ssa branch.
-
- * Eric Botcazou for fixing middle- and backend bugs left and right.
-
- * Per Bothner for his direction via the steering committee and
- various improvements to the infrastructure for supporting new
- languages. Chill front end implementation. Initial
- implementations of cpplib, fix-header, config.guess, libio, and
- past C++ library (libg++) maintainer. Dreaming up, designing and
- implementing much of GCJ.
-
- * Devon Bowen helped port GCC to the Tahoe.
-
- * Don Bowman for mips-vxworks contributions.
-
- * Dave Brolley for work on cpplib and Chill.
-
- * Paul Brook for work on the ARM architecture and maintaining GNU
- Fortran.
-
- * Robert Brown implemented the support for Encore 32000 systems.
-
- * Christian Bruel for improvements to local store elimination.
-
- * Herman A.J. ten Brugge for various fixes.
-
- * Joerg Brunsmann for Java compiler hacking and help with the GCJ
- FAQ.
-
- * Joe Buck for his direction via the steering committee.
-
- * Craig Burley for leadership of the G77 Fortran effort.
-
- * Stephan Buys for contributing Doxygen notes for libstdc++.
-
- * Paolo Carlini for libstdc++ work: lots of efficiency improvements
- to the C++ strings, streambufs and formatted I/O, hard detective
- work on the frustrating localization issues, and keeping up with
- the problem reports.
-
- * John Carr for his alias work, SPARC hacking, infrastructure
- improvements, previous contributions to the steering committee,
- loop optimizations, etc.
-
- * Stephane Carrez for 68HC11 and 68HC12 ports.
-
- * Steve Chamberlain for support for the Renesas SH and H8 processors
- and the PicoJava processor, and for GCJ config fixes.
-
- * Glenn Chambers for help with the GCJ FAQ.
-
- * John-Marc Chandonia for various libgcj patches.
-
- * Scott Christley for his Objective-C contributions.
-
- * Eric Christopher for his Java porting help and clean-ups.
-
- * Branko Cibej for more warning contributions.
-
- * The GNU Classpath project for all of their merged runtime code.
-
- * Nick Clifton for arm, mcore, fr30, v850, m32r work, `--help', and
- other random hacking.
-
- * Michael Cook for libstdc++ cleanup patches to reduce warnings.
-
- * R. Kelley Cook for making GCC buildable from a read-only directory
- as well as other miscellaneous build process and documentation
- clean-ups.
-
- * Ralf Corsepius for SH testing and minor bug fixing.
-
- * Stan Cox for care and feeding of the x86 port and lots of behind
- the scenes hacking.
-
- * Alex Crain provided changes for the 3b1.
-
- * Ian Dall for major improvements to the NS32k port.
-
- * Paul Dale for his work to add uClinux platform support to the m68k
- backend.
-
- * Dario Dariol contributed the four varieties of sample programs
- that print a copy of their source.
-
- * Russell Davidson for fstream and stringstream fixes in libstdc++.
-
- * Bud Davis for work on the G77 and GNU Fortran compilers.
-
- * Mo DeJong for GCJ and libgcj bug fixes.
-
- * DJ Delorie for the DJGPP port, build and libiberty maintenance,
- various bug fixes, and the M32C port.
-
- * Arnaud Desitter for helping to debug GNU Fortran.
-
- * Gabriel Dos Reis for contributions to G++, contributions and
- maintenance of GCC diagnostics infrastructure, libstdc++-v3,
- including `valarray<>', `complex<>', maintaining the numerics
- library (including that pesky `<limits>' :-) and keeping
- up-to-date anything to do with numbers.
-
- * Ulrich Drepper for his work on glibc, testing of GCC using glibc,
- ISO C99 support, CFG dumping support, etc., plus support of the
- C++ runtime libraries including for all kinds of C interface
- issues, contributing and maintaining `complex<>', sanity checking
- and disbursement, configuration architecture, libio maintenance,
- and early math work.
-
- * Zdenek Dvorak for a new loop unroller and various fixes.
-
- * Richard Earnshaw for his ongoing work with the ARM.
-
- * David Edelsohn for his direction via the steering committee,
- ongoing work with the RS6000/PowerPC port, help cleaning up Haifa
- loop changes, doing the entire AIX port of libstdc++ with his bare
- hands, and for ensuring GCC properly keeps working on AIX.
-
- * Kevin Ediger for the floating point formatting of num_put::do_put
- in libstdc++.
-
- * Phil Edwards for libstdc++ work including configuration hackery,
- documentation maintainer, chief breaker of the web pages, the
- occasional iostream bug fix, and work on shared library symbol
- versioning.
-
- * Paul Eggert for random hacking all over GCC.
-
- * Mark Elbrecht for various DJGPP improvements, and for libstdc++
- configuration support for locales and fstream-related fixes.
-
- * Vadim Egorov for libstdc++ fixes in strings, streambufs, and
- iostreams.
-
- * Christian Ehrhardt for dealing with bug reports.
-
- * Ben Elliston for his work to move the Objective-C runtime into its
- own subdirectory and for his work on autoconf.
-
- * Revital Eres for work on the PowerPC 750CL port.
-
- * Marc Espie for OpenBSD support.
-
- * Doug Evans for much of the global optimization framework, arc,
- m32r, and SPARC work.
-
- * Christopher Faylor for his work on the Cygwin port and for caring
- and feeding the gcc.gnu.org box and saving its users tons of spam.
-
- * Fred Fish for BeOS support and Ada fixes.
-
- * Ivan Fontes Garcia for the Portuguese translation of the GCJ FAQ.
-
- * Peter Gerwinski for various bug fixes and the Pascal front end.
-
- * Kaveh R. Ghazi for his direction via the steering committee,
- amazing work to make `-W -Wall -W* -Werror' useful, and
- continuously testing GCC on a plethora of platforms. Kaveh
- extends his gratitude to the CAIP Center at Rutgers University for
- providing him with computing resources to work on Free Software
- since the late 1980s.
-
- * John Gilmore for a donation to the FSF earmarked improving GNU
- Java.
-
- * Judy Goldberg for c++ contributions.
-
- * Torbjorn Granlund for various fixes and the c-torture testsuite,
- multiply- and divide-by-constant optimization, improved long long
- support, improved leaf function register allocation, and his
- direction via the steering committee.
-
- * Anthony Green for his `-Os' contributions and Java front end work.
-
- * Stu Grossman for gdb hacking, allowing GCJ developers to debug
- Java code.
-
- * Michael K. Gschwind contributed the port to the PDP-11.
-
- * Ron Guilmette implemented the `protoize' and `unprotoize' tools,
- the support for Dwarf symbolic debugging information, and much of
- the support for System V Release 4. He has also worked heavily on
- the Intel 386 and 860 support.
-
- * Mostafa Hagog for Swing Modulo Scheduling (SMS) and post reload
- GCSE.
-
- * Bruno Haible for improvements in the runtime overhead for EH, new
- warnings and assorted bug fixes.
-
- * Andrew Haley for his amazing Java compiler and library efforts.
-
- * Chris Hanson assisted in making GCC work on HP-UX for the 9000
- series 300.
-
- * Michael Hayes for various thankless work he's done trying to get
- the c30/c40 ports functional. Lots of loop and unroll
- improvements and fixes.
-
- * Dara Hazeghi for wading through myriads of target-specific bug
- reports.
-
- * Kate Hedstrom for staking the G77 folks with an initial testsuite.
-
- * Richard Henderson for his ongoing SPARC, alpha, ia32, and ia64
- work, loop opts, and generally fixing lots of old problems we've
- ignored for years, flow rewrite and lots of further stuff,
- including reviewing tons of patches.
-
- * Aldy Hernandez for working on the PowerPC port, SIMD support, and
- various fixes.
-
- * Nobuyuki Hikichi of Software Research Associates, Tokyo,
- contributed the support for the Sony NEWS machine.
-
- * Kazu Hirata for caring and feeding the Renesas H8/300 port and
- various fixes.
-
- * Katherine Holcomb for work on GNU Fortran.
-
- * Manfred Hollstein for his ongoing work to keep the m88k alive, lots
- of testing and bug fixing, particularly of GCC configury code.
-
- * Steve Holmgren for MachTen patches.
-
- * Jan Hubicka for his x86 port improvements.
-
- * Falk Hueffner for working on C and optimization bug reports.
-
- * Bernardo Innocenti for his m68k work, including merging of
- ColdFire improvements and uClinux support.
-
- * Christian Iseli for various bug fixes.
-
- * Kamil Iskra for general m68k hacking.
-
- * Lee Iverson for random fixes and MIPS testing.
-
- * Andreas Jaeger for testing and benchmarking of GCC and various bug
- fixes.
-
- * Jakub Jelinek for his SPARC work and sibling call optimizations as
- well as lots of bug fixes and test cases, and for improving the
- Java build system.
-
- * Janis Johnson for ia64 testing and fixes, her quality improvement
- sidetracks, and web page maintenance.
-
- * Kean Johnston for SCO OpenServer support and various fixes.
-
- * Tim Josling for the sample language treelang based originally on
- Richard Kenner's "toy" language.
-
- * Nicolai Josuttis for additional libstdc++ documentation.
-
- * Klaus Kaempf for his ongoing work to make alpha-vms a viable
- target.
-
- * Steven G. Kargl for work on GNU Fortran.
-
- * David Kashtan of SRI adapted GCC to VMS.
-
- * Ryszard Kabatek for many, many libstdc++ bug fixes and
- optimizations of strings, especially member functions, and for
- auto_ptr fixes.
-
- * Geoffrey Keating for his ongoing work to make the PPC work for
- GNU/Linux and his automatic regression tester.
-
- * Brendan Kehoe for his ongoing work with G++ and for a lot of early
- work in just about every part of libstdc++.
-
- * Oliver M. Kellogg of Deutsche Aerospace contributed the port to the
- MIL-STD-1750A.
-
- * Richard Kenner of the New York University Ultracomputer Research
- Laboratory wrote the machine descriptions for the AMD 29000, the
- DEC Alpha, the IBM RT PC, and the IBM RS/6000 as well as the
- support for instruction attributes. He also made changes to
- better support RISC processors including changes to common
- subexpression elimination, strength reduction, function calling
- sequence handling, and condition code support, in addition to
- generalizing the code for frame pointer elimination and delay slot
- scheduling. Richard Kenner was also the head maintainer of GCC
- for several years.
-
- * Mumit Khan for various contributions to the Cygwin and Mingw32
- ports and maintaining binary releases for Microsoft Windows hosts,
- and for massive libstdc++ porting work to Cygwin/Mingw32.
-
- * Robin Kirkham for cpu32 support.
-
- * Mark Klein for PA improvements.
-
- * Thomas Koenig for various bug fixes.
-
- * Bruce Korb for the new and improved fixincludes code.
-
- * Benjamin Kosnik for his G++ work and for leading the libstdc++-v3
- effort.
-
- * Charles LaBrec contributed the support for the Integrated Solutions
- 68020 system.
-
- * Asher Langton and Mike Kumbera for contributing Cray pointer
- support to GNU Fortran, and for other GNU Fortran improvements.
-
- * Jeff Law for his direction via the steering committee,
- coordinating the entire egcs project and GCC 2.95, rolling out
- snapshots and releases, handling merges from GCC2, reviewing tons
- of patches that might have fallen through the cracks else, and
- random but extensive hacking.
-
- * Marc Lehmann for his direction via the steering committee and
- helping with analysis and improvements of x86 performance.
-
- * Victor Leikehman for work on GNU Fortran.
-
- * Ted Lemon wrote parts of the RTL reader and printer.
-
- * Kriang Lerdsuwanakij for C++ improvements including template as
- template parameter support, and many C++ fixes.
-
- * Warren Levy for tremendous work on libgcj (Java Runtime Library)
- and random work on the Java front end.
-
- * Alain Lichnewsky ported GCC to the MIPS CPU.
-
- * Oskar Liljeblad for hacking on AWT and his many Java bug reports
- and patches.
-
- * Robert Lipe for OpenServer support, new testsuites, testing, etc.
-
- * Chen Liqin for various S+core related fixes/improvement, and for
- maintaining the S+core port.
-
- * Weiwen Liu for testing and various bug fixes.
-
- * Manuel Lo'pez-Iba'n~ez for improving `-Wconversion' and many other
- diagnostics fixes and improvements.
-
- * Dave Love for his ongoing work with the Fortran front end and
- runtime libraries.
-
- * Martin von Lo"wis for internal consistency checking infrastructure,
- various C++ improvements including namespace support, and tons of
- assistance with libstdc++/compiler merges.
-
- * H.J. Lu for his previous contributions to the steering committee,
- many x86 bug reports, prototype patches, and keeping the GNU/Linux
- ports working.
-
- * Greg McGary for random fixes and (someday) bounded pointers.
-
- * Andrew MacLeod for his ongoing work in building a real EH system,
- various code generation improvements, work on the global
- optimizer, etc.
-
- * Vladimir Makarov for hacking some ugly i960 problems, PowerPC
- hacking improvements to compile-time performance, overall
- knowledge and direction in the area of instruction scheduling, and
- design and implementation of the automaton based instruction
- scheduler.
-
- * Bob Manson for his behind the scenes work on dejagnu.
-
- * Philip Martin for lots of libstdc++ string and vector iterator
- fixes and improvements, and string clean up and testsuites.
-
- * All of the Mauve project contributors, for Java test code.
-
- * Bryce McKinlay for numerous GCJ and libgcj fixes and improvements.
-
- * Adam Megacz for his work on the Microsoft Windows port of GCJ.
-
- * Michael Meissner for LRS framework, ia32, m32r, v850, m88k, MIPS,
- powerpc, haifa, ECOFF debug support, and other assorted hacking.
-
- * Jason Merrill for his direction via the steering committee and
- leading the G++ effort.
-
- * Martin Michlmayr for testing GCC on several architectures using the
- entire Debian archive.
-
- * David Miller for his direction via the steering committee, lots of
- SPARC work, improvements in jump.c and interfacing with the Linux
- kernel developers.
-
- * Gary Miller ported GCC to Charles River Data Systems machines.
-
- * Alfred Minarik for libstdc++ string and ios bug fixes, and turning
- the entire libstdc++ testsuite namespace-compatible.
-
- * Mark Mitchell for his direction via the steering committee,
- mountains of C++ work, load/store hoisting out of loops, alias
- analysis improvements, ISO C `restrict' support, and serving as
- release manager for GCC 3.x.
-
- * Alan Modra for various GNU/Linux bits and testing.
-
- * Toon Moene for his direction via the steering committee, Fortran
- maintenance, and his ongoing work to make us make Fortran run fast.
-
- * Jason Molenda for major help in the care and feeding of all the
- services on the gcc.gnu.org (formerly egcs.cygnus.com)
- machine--mail, web services, ftp services, etc etc. Doing all
- this work on scrap paper and the backs of envelopes would have
- been... difficult.
-
- * Catherine Moore for fixing various ugly problems we have sent her
- way, including the haifa bug which was killing the Alpha & PowerPC
- Linux kernels.
-
- * Mike Moreton for his various Java patches.
-
- * David Mosberger-Tang for various Alpha improvements, and for the
- initial IA-64 port.
-
- * Stephen Moshier contributed the floating point emulator that
- assists in cross-compilation and permits support for floating
- point numbers wider than 64 bits and for ISO C99 support.
-
- * Bill Moyer for his behind the scenes work on various issues.
-
- * Philippe De Muyter for his work on the m68k port.
-
- * Joseph S. Myers for his work on the PDP-11 port, format checking
- and ISO C99 support, and continuous emphasis on (and contributions
- to) documentation.
-
- * Nathan Myers for his work on libstdc++-v3: architecture and
- authorship through the first three snapshots, including
- implementation of locale infrastructure, string, shadow C headers,
- and the initial project documentation (DESIGN, CHECKLIST, and so
- forth). Later, more work on MT-safe string and shadow headers.
-
- * Felix Natter for documentation on porting libstdc++.
-
- * Nathanael Nerode for cleaning up the configuration/build process.
-
- * NeXT, Inc. donated the front end that supports the Objective-C
- language.
-
- * Hans-Peter Nilsson for the CRIS and MMIX ports, improvements to
- the search engine setup, various documentation fixes and other
- small fixes.
-
- * Geoff Noer for his work on getting cygwin native builds working.
-
- * Diego Novillo for his work on Tree SSA, OpenMP, SPEC performance
- tracking web pages, GIMPLE tuples, and assorted fixes.
-
- * David O'Brien for the FreeBSD/alpha, FreeBSD/AMD x86-64,
- FreeBSD/ARM, FreeBSD/PowerPC, and FreeBSD/SPARC64 ports and
- related infrastructure improvements.
-
- * Alexandre Oliva for various build infrastructure improvements,
- scripts and amazing testing work, including keeping libtool issues
- sane and happy.
-
- * Stefan Olsson for work on mt_alloc.
-
- * Melissa O'Neill for various NeXT fixes.
-
- * Rainer Orth for random MIPS work, including improvements to GCC's
- o32 ABI support, improvements to dejagnu's MIPS support, Java
- configuration clean-ups and porting work, etc.
-
- * Hartmut Penner for work on the s390 port.
-
- * Paul Petersen wrote the machine description for the Alliant FX/8.
-
- * Alexandre Petit-Bianco for implementing much of the Java compiler
- and continued Java maintainership.
-
- * Matthias Pfaller for major improvements to the NS32k port.
-
- * Gerald Pfeifer for his direction via the steering committee,
- pointing out lots of problems we need to solve, maintenance of the
- web pages, and taking care of documentation maintenance in general.
-
- * Andrew Pinski for processing bug reports by the dozen.
-
- * Ovidiu Predescu for his work on the Objective-C front end and
- runtime libraries.
-
- * Jerry Quinn for major performance improvements in C++ formatted
- I/O.
-
- * Ken Raeburn for various improvements to checker, MIPS ports and
- various cleanups in the compiler.
-
- * Rolf W. Rasmussen for hacking on AWT.
-
- * David Reese of Sun Microsystems contributed to the Solaris on
- PowerPC port.
-
- * Volker Reichelt for keeping up with the problem reports.
-
- * Joern Rennecke for maintaining the sh port, loop, regmove & reload
- hacking.
-
- * Loren J. Rittle for improvements to libstdc++-v3 including the
- FreeBSD port, threading fixes, thread-related configury changes,
- critical threading documentation, and solutions to really tricky
- I/O problems, as well as keeping GCC properly working on FreeBSD
- and continuous testing.
-
- * Craig Rodrigues for processing tons of bug reports.
-
- * Ola Ro"nnerup for work on mt_alloc.
-
- * Gavin Romig-Koch for lots of behind the scenes MIPS work.
-
- * David Ronis inspired and encouraged Craig to rewrite the G77
- documentation in texinfo format by contributing a first pass at a
- translation of the old `g77-0.5.16/f/DOC' file.
-
- * Ken Rose for fixes to GCC's delay slot filling code.
-
- * Paul Rubin wrote most of the preprocessor.
-
- * Pe'tur Runo'lfsson for major performance improvements in C++
- formatted I/O and large file support in C++ filebuf.
-
- * Chip Salzenberg for libstdc++ patches and improvements to locales,
- traits, Makefiles, libio, libtool hackery, and "long long" support.
-
- * Juha Sarlin for improvements to the H8 code generator.
-
- * Greg Satz assisted in making GCC work on HP-UX for the 9000 series
- 300.
-
- * Roger Sayle for improvements to constant folding and GCC's RTL
- optimizers as well as for fixing numerous bugs.
-
- * Bradley Schatz for his work on the GCJ FAQ.
-
- * Peter Schauer wrote the code to allow debugging to work on the
- Alpha.
-
- * William Schelter did most of the work on the Intel 80386 support.
-
- * Tobias Schlu"ter for work on GNU Fortran.
-
- * Bernd Schmidt for various code generation improvements and major
- work in the reload pass as well a serving as release manager for
- GCC 2.95.3.
-
- * Peter Schmid for constant testing of libstdc++--especially
- application testing, going above and beyond what was requested for
- the release criteria--and libstdc++ header file tweaks.
-
- * Jason Schroeder for jcf-dump patches.
-
- * Andreas Schwab for his work on the m68k port.
-
- * Lars Segerlund for work on GNU Fortran.
-
- * Joel Sherrill for his direction via the steering committee, RTEMS
- contributions and RTEMS testing.
-
- * Nathan Sidwell for many C++ fixes/improvements.
-
- * Jeffrey Siegal for helping RMS with the original design of GCC,
- some code which handles the parse tree and RTL data structures,
- constant folding and help with the original VAX & m68k ports.
-
- * Kenny Simpson for prompting libstdc++ fixes due to defect reports
- from the LWG (thereby keeping GCC in line with updates from the
- ISO).
-
- * Franz Sirl for his ongoing work with making the PPC port stable
- for GNU/Linux.
-
- * Andrey Slepuhin for assorted AIX hacking.
-
- * Trevor Smigiel for contributing the SPU port.
-
- * Christopher Smith did the port for Convex machines.
-
- * Danny Smith for his major efforts on the Mingw (and Cygwin) ports.
-
- * Randy Smith finished the Sun FPA support.
-
- * Scott Snyder for queue, iterator, istream, and string fixes and
- libstdc++ testsuite entries. Also for providing the patch to G77
- to add rudimentary support for `INTEGER*1', `INTEGER*2', and
- `LOGICAL*1'.
-
- * Brad Spencer for contributions to the GLIBCPP_FORCE_NEW technique.
-
- * Richard Stallman, for writing the original GCC and launching the
- GNU project.
-
- * Jan Stein of the Chalmers Computer Society provided support for
- Genix, as well as part of the 32000 machine description.
-
- * Nigel Stephens for various mips16 related fixes/improvements.
-
- * Jonathan Stone wrote the machine description for the Pyramid
- computer.
-
- * Graham Stott for various infrastructure improvements.
-
- * John Stracke for his Java HTTP protocol fixes.
-
- * Mike Stump for his Elxsi port, G++ contributions over the years
- and more recently his vxworks contributions
-
- * Jeff Sturm for Java porting help, bug fixes, and encouragement.
-
- * Shigeya Suzuki for this fixes for the bsdi platforms.
-
- * Ian Lance Taylor for his mips16 work, general configury hacking,
- fixincludes, etc.
-
- * Holger Teutsch provided the support for the Clipper CPU.
-
- * Gary Thomas for his ongoing work to make the PPC work for
- GNU/Linux.
-
- * Philipp Thomas for random bug fixes throughout the compiler
-
- * Jason Thorpe for thread support in libstdc++ on NetBSD.
-
- * Kresten Krab Thorup wrote the run time support for the Objective-C
- language and the fantastic Java bytecode interpreter.
-
- * Michael Tiemann for random bug fixes, the first instruction
- scheduler, initial C++ support, function integration, NS32k, SPARC
- and M88k machine description work, delay slot scheduling.
-
- * Andreas Tobler for his work porting libgcj to Darwin.
-
- * Teemu Torma for thread safe exception handling support.
-
- * Leonard Tower wrote parts of the parser, RTL generator, and RTL
- definitions, and of the VAX machine description.
-
- * Daniel Towner and Hariharan Sandanagobalane contributed and
- maintain the picoChip port.
-
- * Tom Tromey for internationalization support and for his many Java
- contributions and libgcj maintainership.
-
- * Lassi Tuura for improvements to config.guess to determine HP
- processor types.
-
- * Petter Urkedal for libstdc++ CXXFLAGS, math, and algorithms fixes.
-
- * Andy Vaught for the design and initial implementation of the GNU
- Fortran front end.
-
- * Brent Verner for work with the libstdc++ cshadow files and their
- associated configure steps.
-
- * Todd Vierling for contributions for NetBSD ports.
-
- * Jonathan Wakely for contributing libstdc++ Doxygen notes and XHTML
- guidance.
-
- * Dean Wakerley for converting the install documentation from HTML
- to texinfo in time for GCC 3.0.
-
- * Krister Walfridsson for random bug fixes.
-
- * Feng Wang for contributions to GNU Fortran.
-
- * Stephen M. Webb for time and effort on making libstdc++ shadow
- files work with the tricky Solaris 8+ headers, and for pushing the
- build-time header tree.
-
- * John Wehle for various improvements for the x86 code generator,
- related infrastructure improvements to help x86 code generation,
- value range propagation and other work, WE32k port.
-
- * Ulrich Weigand for work on the s390 port.
-
- * Zack Weinberg for major work on cpplib and various other bug fixes.
-
- * Matt Welsh for help with Linux Threads support in GCJ.
-
- * Urban Widmark for help fixing java.io.
-
- * Mark Wielaard for new Java library code and his work integrating
- with Classpath.
-
- * Dale Wiles helped port GCC to the Tahoe.
-
- * Bob Wilson from Tensilica, Inc. for the Xtensa port.
-
- * Jim Wilson for his direction via the steering committee, tackling
- hard problems in various places that nobody else wanted to work
- on, strength reduction and other loop optimizations.
-
- * Paul Woegerer and Tal Agmon for the CRX port.
-
- * Carlo Wood for various fixes.
-
- * Tom Wood for work on the m88k port.
-
- * Canqun Yang for work on GNU Fortran.
-
- * Masanobu Yuhara of Fujitsu Laboratories implemented the machine
- description for the Tron architecture (specifically, the Gmicro).
-
- * Kevin Zachmann helped port GCC to the Tahoe.
-
- * Ayal Zaks for Swing Modulo Scheduling (SMS).
-
- * Xiaoqiang Zhang for work on GNU Fortran.
-
- * Gilles Zunino for help porting Java to Irix.
-
-
- The following people are recognized for their contributions to GNAT,
-the Ada front end of GCC:
- * Bernard Banner
-
- * Romain Berrendonner
-
- * Geert Bosch
-
- * Emmanuel Briot
-
- * Joel Brobecker
-
- * Ben Brosgol
-
- * Vincent Celier
-
- * Arnaud Charlet
-
- * Chien Chieng
-
- * Cyrille Comar
-
- * Cyrille Crozes
-
- * Robert Dewar
-
- * Gary Dismukes
-
- * Robert Duff
-
- * Ed Falis
-
- * Ramon Fernandez
-
- * Sam Figueroa
-
- * Vasiliy Fofanov
-
- * Michael Friess
-
- * Franco Gasperoni
-
- * Ted Giering
-
- * Matthew Gingell
-
- * Laurent Guerby
-
- * Jerome Guitton
-
- * Olivier Hainque
-
- * Jerome Hugues
-
- * Hristian Kirtchev
-
- * Jerome Lambourg
-
- * Bruno Leclerc
-
- * Albert Lee
-
- * Sean McNeil
-
- * Javier Miranda
-
- * Laurent Nana
-
- * Pascal Obry
-
- * Dong-Ik Oh
-
- * Laurent Pautet
-
- * Brett Porter
-
- * Thomas Quinot
-
- * Nicolas Roche
-
- * Pat Rogers
-
- * Jose Ruiz
-
- * Douglas Rupp
-
- * Sergey Rybin
-
- * Gail Schenker
-
- * Ed Schonberg
-
- * Nicolas Setton
-
- * Samuel Tardieu
-
-
- The following people are recognized for their contributions of new
-features, bug reports, testing and integration of classpath/libgcj for
-GCC version 4.1:
- * Lillian Angel for `JTree' implementation and lots Free Swing
- additions and bug fixes.
-
- * Wolfgang Baer for `GapContent' bug fixes.
-
- * Anthony Balkissoon for `JList', Free Swing 1.5 updates and mouse
- event fixes, lots of Free Swing work including `JTable' editing.
-
- * Stuart Ballard for RMI constant fixes.
-
- * Goffredo Baroncelli for `HTTPURLConnection' fixes.
-
- * Gary Benson for `MessageFormat' fixes.
-
- * Daniel Bonniot for `Serialization' fixes.
-
- * Chris Burdess for lots of gnu.xml and http protocol fixes, `StAX'
- and `DOM xml:id' support.
-
- * Ka-Hing Cheung for `TreePath' and `TreeSelection' fixes.
-
- * Archie Cobbs for build fixes, VM interface updates,
- `URLClassLoader' updates.
-
- * Kelley Cook for build fixes.
-
- * Martin Cordova for Suggestions for better `SocketTimeoutException'.
-
- * David Daney for `BitSet' bug fixes, `HttpURLConnection' rewrite
- and improvements.
-
- * Thomas Fitzsimmons for lots of upgrades to the gtk+ AWT and Cairo
- 2D support. Lots of imageio framework additions, lots of AWT and
- Free Swing bug fixes.
-
- * Jeroen Frijters for `ClassLoader' and nio cleanups, serialization
- fixes, better `Proxy' support, bug fixes and IKVM integration.
-
- * Santiago Gala for `AccessControlContext' fixes.
-
- * Nicolas Geoffray for `VMClassLoader' and `AccessController'
- improvements.
-
- * David Gilbert for `basic' and `metal' icon and plaf support and
- lots of documenting, Lots of Free Swing and metal theme additions.
- `MetalIconFactory' implementation.
-
- * Anthony Green for `MIDI' framework, `ALSA' and `DSSI' providers.
-
- * Andrew Haley for `Serialization' and `URLClassLoader' fixes, gcj
- build speedups.
-
- * Kim Ho for `JFileChooser' implementation.
-
- * Andrew John Hughes for `Locale' and net fixes, URI RFC2986
- updates, `Serialization' fixes, `Properties' XML support and
- generic branch work, VMIntegration guide update.
-
- * Bastiaan Huisman for `TimeZone' bug fixing.
-
- * Andreas Jaeger for mprec updates.
-
- * Paul Jenner for better `-Werror' support.
-
- * Ito Kazumitsu for `NetworkInterface' implementation and updates.
-
- * Roman Kennke for `BoxLayout', `GrayFilter' and `SplitPane', plus
- bug fixes all over. Lots of Free Swing work including styled text.
-
- * Simon Kitching for `String' cleanups and optimization suggestions.
-
- * Michael Koch for configuration fixes, `Locale' updates, bug and
- build fixes.
-
- * Guilhem Lavaux for configuration, thread and channel fixes and
- Kaffe integration. JCL native `Pointer' updates. Logger bug fixes.
-
- * David Lichteblau for JCL support library global/local reference
- cleanups.
-
- * Aaron Luchko for JDWP updates and documentation fixes.
-
- * Ziga Mahkovec for `Graphics2D' upgraded to Cairo 0.5 and new regex
- features.
-
- * Sven de Marothy for BMP imageio support, CSS and `TextLayout'
- fixes. `GtkImage' rewrite, 2D, awt, free swing and date/time fixes
- and implementing the Qt4 peers.
-
- * Casey Marshall for crypto algorithm fixes, `FileChannel' lock,
- `SystemLogger' and `FileHandler' rotate implementations, NIO
- `FileChannel.map' support, security and policy updates.
-
- * Bryce McKinlay for RMI work.
-
- * Audrius Meskauskas for lots of Free Corba, RMI and HTML work plus
- testing and documenting.
-
- * Kalle Olavi Niemitalo for build fixes.
-
- * Rainer Orth for build fixes.
-
- * Andrew Overholt for `File' locking fixes.
-
- * Ingo Proetel for `Image', `Logger' and `URLClassLoader' updates.
-
- * Olga Rodimina for `MenuSelectionManager' implementation.
-
- * Jan Roehrich for `BasicTreeUI' and `JTree' fixes.
-
- * Julian Scheid for documentation updates and gjdoc support.
-
- * Christian Schlichtherle for zip fixes and cleanups.
-
- * Robert Schuster for documentation updates and beans fixes,
- `TreeNode' enumerations and `ActionCommand' and various fixes, XML
- and URL, AWT and Free Swing bug fixes.
-
- * Keith Seitz for lots of JDWP work.
-
- * Christian Thalinger for 64-bit cleanups, Configuration and VM
- interface fixes and `CACAO' integration, `fdlibm' updates.
-
- * Gael Thomas for `VMClassLoader' boot packages support suggestions.
-
- * Andreas Tobler for Darwin and Solaris testing and fixing, `Qt4'
- support for Darwin/OS X, `Graphics2D' support, `gtk+' updates.
-
- * Dalibor Topic for better `DEBUG' support, build cleanups and Kaffe
- integration. `Qt4' build infrastructure, `SHA1PRNG' and
- `GdkPixbugDecoder' updates.
-
- * Tom Tromey for Eclipse integration, generics work, lots of bug
- fixes and gcj integration including coordinating The Big Merge.
-
- * Mark Wielaard for bug fixes, packaging and release management,
- `Clipboard' implementation, system call interrupts and network
- timeouts and `GdkPixpufDecoder' fixes.
-
-
- In addition to the above, all of which also contributed time and
-energy in testing GCC, we would like to thank the following for their
-contributions to testing:
-
- * Michael Abd-El-Malek
-
- * Thomas Arend
-
- * Bonzo Armstrong
-
- * Steven Ashe
-
- * Chris Baldwin
-
- * David Billinghurst
-
- * Jim Blandy
-
- * Stephane Bortzmeyer
-
- * Horst von Brand
-
- * Frank Braun
-
- * Rodney Brown
-
- * Sidney Cadot
-
- * Bradford Castalia
-
- * Robert Clark
-
- * Jonathan Corbet
-
- * Ralph Doncaster
-
- * Richard Emberson
-
- * Levente Farkas
-
- * Graham Fawcett
-
- * Mark Fernyhough
-
- * Robert A. French
-
- * Jo"rgen Freyh
-
- * Mark K. Gardner
-
- * Charles-Antoine Gauthier
-
- * Yung Shing Gene
-
- * David Gilbert
-
- * Simon Gornall
-
- * Fred Gray
-
- * John Griffin
-
- * Patrik Hagglund
-
- * Phil Hargett
-
- * Amancio Hasty
-
- * Takafumi Hayashi
-
- * Bryan W. Headley
-
- * Kevin B. Hendricks
-
- * Joep Jansen
-
- * Christian Joensson
-
- * Michel Kern
-
- * David Kidd
-
- * Tobias Kuipers
-
- * Anand Krishnaswamy
-
- * A. O. V. Le Blanc
-
- * llewelly
-
- * Damon Love
-
- * Brad Lucier
-
- * Matthias Klose
-
- * Martin Knoblauch
-
- * Rick Lutowski
-
- * Jesse Macnish
-
- * Stefan Morrell
-
- * Anon A. Mous
-
- * Matthias Mueller
-
- * Pekka Nikander
-
- * Rick Niles
-
- * Jon Olson
-
- * Magnus Persson
-
- * Chris Pollard
-
- * Richard Polton
-
- * Derk Reefman
-
- * David Rees
-
- * Paul Reilly
-
- * Tom Reilly
-
- * Torsten Rueger
-
- * Danny Sadinoff
-
- * Marc Schifer
-
- * Erik Schnetter
-
- * Wayne K. Schroll
-
- * David Schuler
-
- * Vin Shelton
-
- * Tim Souder
-
- * Adam Sulmicki
-
- * Bill Thorson
-
- * George Talbot
-
- * Pedro A. M. Vazquez
-
- * Gregory Warnes
-
- * Ian Watson
-
- * David E. Young
-
- * And many others
-
- And finally we'd like to thank everyone who uses the compiler, provides
-feedback and generally reminds us why we're doing this work in the first
-place.
-
-\1f
-File: gccint.info, Node: Option Index, Next: Concept Index, Prev: Contributors, Up: Top
-
-Option Index
-************
-
-GCC's command line options are indexed here without any initial `-' or
-`--'. Where an option has both positive and negative forms (such as
-`-fOPTION' and `-fno-OPTION'), relevant entries in the manual are
-indexed under the most appropriate form; it may sometimes be useful to
-look up both forms.
-
-\0\b[index\0\b]
-* Menu:
-
-* msoft-float: Soft float library routines.
- (line 6)
-
-\1f
-File: gccint.info, Node: Concept Index, Prev: Option Index, Up: Top
-
-Concept Index
-*************
-
-\0\b[index\0\b]
-* Menu:
-
-* ! in constraint: Multi-Alternative. (line 47)
-* # in constraint: Modifiers. (line 67)
-* # in template: Output Template. (line 66)
-* #pragma: Misc. (line 381)
-* % in constraint: Modifiers. (line 45)
-* % in GTY option: GTY Options. (line 18)
-* % in template: Output Template. (line 6)
-* & in constraint: Modifiers. (line 25)
-* ( <1>: Sections. (line 160)
-* ( <2>: GIMPLE_CALL. (line 63)
-* ( <3>: GIMPLE_ASM. (line 21)
-* (: Logical Operators. (line 107)
-* (nil): RTL Objects. (line 73)
-* * <1>: Host Common. (line 17)
-* *: Scheduling. (line 246)
-* * in constraint: Modifiers. (line 72)
-* * in template: Output Statement. (line 29)
-* *gimple_assign_lhs_ptr: GIMPLE_ASSIGN. (line 54)
-* *gimple_assign_rhs1_ptr: GIMPLE_ASSIGN. (line 60)
-* *gimple_assign_rhs2_ptr: GIMPLE_ASSIGN. (line 67)
-* *gimple_call_arg_ptr: GIMPLE_CALL. (line 71)
-* *gimple_call_lhs_ptr: GIMPLE_CALL. (line 32)
-* *gimple_catch_types_ptr: GIMPLE_CATCH. (line 16)
-* *gimple_cdt_location_ptr: GIMPLE_CHANGE_DYNAMIC_TYPE.
- (line 28)
-* *gimple_cdt_new_type_ptr: GIMPLE_CHANGE_DYNAMIC_TYPE.
- (line 15)
-* *gimple_eh_filter_types_ptr: GIMPLE_EH_FILTER. (line 15)
-* *gimple_omp_critical_name_ptr: GIMPLE_OMP_CRITICAL.
- (line 16)
-* *gimple_omp_for_clauses_ptr: GIMPLE_OMP_FOR. (line 23)
-* *gimple_omp_for_final_ptr: GIMPLE_OMP_FOR. (line 54)
-* *gimple_omp_for_incr_ptr: GIMPLE_OMP_FOR. (line 64)
-* *gimple_omp_for_index_ptr: GIMPLE_OMP_FOR. (line 34)
-* *gimple_omp_for_initial_ptr: GIMPLE_OMP_FOR. (line 44)
-* *gimple_omp_parallel_child_fn_ptr: GIMPLE_OMP_PARALLEL.
- (line 46)
-* *gimple_omp_parallel_clauses_ptr: GIMPLE_OMP_PARALLEL.
- (line 34)
-* *gimple_omp_parallel_data_arg_ptr: GIMPLE_OMP_PARALLEL.
- (line 58)
-* *gimple_omp_sections_clauses_ptr: GIMPLE_OMP_SECTIONS.
- (line 33)
-* *gimple_omp_sections_control_ptr: GIMPLE_OMP_SECTIONS.
- (line 21)
-* *gimple_omp_single_clauses_ptr: GIMPLE_OMP_SINGLE. (line 17)
-* *gimple_op_ptr: Manipulating GIMPLE statements.
- (line 84)
-* *gimple_ops <1>: Manipulating GIMPLE statements.
- (line 78)
-* *gimple_ops: Logical Operators. (line 82)
-* *gimple_phi_result_ptr: GIMPLE_PHI. (line 22)
-* *gsi_stmt_ptr: Sequence iterators. (line 80)
-* *TARGET_GET_PCH_VALIDITY: PCH Target. (line 7)
-* + in constraint: Modifiers. (line 12)
-* -fsection-anchors <1>: Anchored Addresses. (line 6)
-* -fsection-anchors: Special Accessors. (line 106)
-* /c in RTL dump: Flags. (line 234)
-* /f in RTL dump: Flags. (line 242)
-* /i in RTL dump: Flags. (line 294)
-* /j in RTL dump: Flags. (line 309)
-* /s in RTL dump: Flags. (line 258)
-* /u in RTL dump: Flags. (line 319)
-* /v in RTL dump: Flags. (line 351)
-* 0 in constraint: Simple Constraints. (line 120)
-* < in constraint: Simple Constraints. (line 48)
-* = in constraint: Modifiers. (line 8)
-* > in constraint: Simple Constraints. (line 52)
-* ? in constraint: Multi-Alternative. (line 41)
-* \: Output Template. (line 46)
-* __absvdi2: Integer library routines.
- (line 107)
-* __absvsi2: Integer library routines.
- (line 106)
-* __addda3: Fixed-point fractional library routines.
- (line 45)
-* __adddf3: Soft float library routines.
- (line 23)
-* __adddq3: Fixed-point fractional library routines.
- (line 33)
-* __addha3: Fixed-point fractional library routines.
- (line 43)
-* __addhq3: Fixed-point fractional library routines.
- (line 30)
-* __addqq3: Fixed-point fractional library routines.
- (line 29)
-* __addsa3: Fixed-point fractional library routines.
- (line 44)
-* __addsf3: Soft float library routines.
- (line 22)
-* __addsq3: Fixed-point fractional library routines.
- (line 31)
-* __addta3: Fixed-point fractional library routines.
- (line 47)
-* __addtf3: Soft float library routines.
- (line 25)
-* __adduda3: Fixed-point fractional library routines.
- (line 53)
-* __addudq3: Fixed-point fractional library routines.
- (line 41)
-* __adduha3: Fixed-point fractional library routines.
- (line 49)
-* __adduhq3: Fixed-point fractional library routines.
- (line 37)
-* __adduqq3: Fixed-point fractional library routines.
- (line 35)
-* __addusa3: Fixed-point fractional library routines.
- (line 51)
-* __addusq3: Fixed-point fractional library routines.
- (line 39)
-* __adduta3: Fixed-point fractional library routines.
- (line 55)
-* __addvdi3: Integer library routines.
- (line 111)
-* __addvsi3: Integer library routines.
- (line 110)
-* __addxf3: Soft float library routines.
- (line 27)
-* __ashlda3: Fixed-point fractional library routines.
- (line 351)
-* __ashldi3: Integer library routines.
- (line 14)
-* __ashldq3: Fixed-point fractional library routines.
- (line 340)
-* __ashlha3: Fixed-point fractional library routines.
- (line 349)
-* __ashlhq3: Fixed-point fractional library routines.
- (line 337)
-* __ashlqq3: Fixed-point fractional library routines.
- (line 336)
-* __ashlsa3: Fixed-point fractional library routines.
- (line 350)
-* __ashlsi3: Integer library routines.
- (line 13)
-* __ashlsq3: Fixed-point fractional library routines.
- (line 338)
-* __ashlta3: Fixed-point fractional library routines.
- (line 353)
-* __ashlti3: Integer library routines.
- (line 15)
-* __ashluda3: Fixed-point fractional library routines.
- (line 359)
-* __ashludq3: Fixed-point fractional library routines.
- (line 348)
-* __ashluha3: Fixed-point fractional library routines.
- (line 355)
-* __ashluhq3: Fixed-point fractional library routines.
- (line 344)
-* __ashluqq3: Fixed-point fractional library routines.
- (line 342)
-* __ashlusa3: Fixed-point fractional library routines.
- (line 357)
-* __ashlusq3: Fixed-point fractional library routines.
- (line 346)
-* __ashluta3: Fixed-point fractional library routines.
- (line 361)
-* __ashrda3: Fixed-point fractional library routines.
- (line 371)
-* __ashrdi3: Integer library routines.
- (line 19)
-* __ashrdq3: Fixed-point fractional library routines.
- (line 368)
-* __ashrha3: Fixed-point fractional library routines.
- (line 369)
-* __ashrhq3: Fixed-point fractional library routines.
- (line 365)
-* __ashrqq3: Fixed-point fractional library routines.
- (line 364)
-* __ashrsa3: Fixed-point fractional library routines.
- (line 370)
-* __ashrsi3: Integer library routines.
- (line 18)
-* __ashrsq3: Fixed-point fractional library routines.
- (line 366)
-* __ashrta3: Fixed-point fractional library routines.
- (line 373)
-* __ashrti3: Integer library routines.
- (line 20)
-* __bid_adddd3: Decimal float library routines.
- (line 25)
-* __bid_addsd3: Decimal float library routines.
- (line 21)
-* __bid_addtd3: Decimal float library routines.
- (line 29)
-* __bid_divdd3: Decimal float library routines.
- (line 68)
-* __bid_divsd3: Decimal float library routines.
- (line 64)
-* __bid_divtd3: Decimal float library routines.
- (line 72)
-* __bid_eqdd2: Decimal float library routines.
- (line 259)
-* __bid_eqsd2: Decimal float library routines.
- (line 257)
-* __bid_eqtd2: Decimal float library routines.
- (line 261)
-* __bid_extendddtd2: Decimal float library routines.
- (line 92)
-* __bid_extendddtf: Decimal float library routines.
- (line 140)
-* __bid_extendddxf: Decimal float library routines.
- (line 134)
-* __bid_extenddfdd: Decimal float library routines.
- (line 147)
-* __bid_extenddftd: Decimal float library routines.
- (line 107)
-* __bid_extendsddd2: Decimal float library routines.
- (line 88)
-* __bid_extendsddf: Decimal float library routines.
- (line 128)
-* __bid_extendsdtd2: Decimal float library routines.
- (line 90)
-* __bid_extendsdtf: Decimal float library routines.
- (line 138)
-* __bid_extendsdxf: Decimal float library routines.
- (line 132)
-* __bid_extendsfdd: Decimal float library routines.
- (line 103)
-* __bid_extendsfsd: Decimal float library routines.
- (line 145)
-* __bid_extendsftd: Decimal float library routines.
- (line 105)
-* __bid_extendtftd: Decimal float library routines.
- (line 149)
-* __bid_extendxftd: Decimal float library routines.
- (line 109)
-* __bid_fixdddi: Decimal float library routines.
- (line 170)
-* __bid_fixddsi: Decimal float library routines.
- (line 162)
-* __bid_fixsddi: Decimal float library routines.
- (line 168)
-* __bid_fixsdsi: Decimal float library routines.
- (line 160)
-* __bid_fixtddi: Decimal float library routines.
- (line 172)
-* __bid_fixtdsi: Decimal float library routines.
- (line 164)
-* __bid_fixunsdddi: Decimal float library routines.
- (line 187)
-* __bid_fixunsddsi: Decimal float library routines.
- (line 178)
-* __bid_fixunssddi: Decimal float library routines.
- (line 185)
-* __bid_fixunssdsi: Decimal float library routines.
- (line 176)
-* __bid_fixunstddi: Decimal float library routines.
- (line 189)
-* __bid_fixunstdsi: Decimal float library routines.
- (line 180)
-* __bid_floatdidd: Decimal float library routines.
- (line 205)
-* __bid_floatdisd: Decimal float library routines.
- (line 203)
-* __bid_floatditd: Decimal float library routines.
- (line 207)
-* __bid_floatsidd: Decimal float library routines.
- (line 196)
-* __bid_floatsisd: Decimal float library routines.
- (line 194)
-* __bid_floatsitd: Decimal float library routines.
- (line 198)
-* __bid_floatunsdidd: Decimal float library routines.
- (line 223)
-* __bid_floatunsdisd: Decimal float library routines.
- (line 221)
-* __bid_floatunsditd: Decimal float library routines.
- (line 225)
-* __bid_floatunssidd: Decimal float library routines.
- (line 214)
-* __bid_floatunssisd: Decimal float library routines.
- (line 212)
-* __bid_floatunssitd: Decimal float library routines.
- (line 216)
-* __bid_gedd2: Decimal float library routines.
- (line 277)
-* __bid_gesd2: Decimal float library routines.
- (line 275)
-* __bid_getd2: Decimal float library routines.
- (line 279)
-* __bid_gtdd2: Decimal float library routines.
- (line 304)
-* __bid_gtsd2: Decimal float library routines.
- (line 302)
-* __bid_gttd2: Decimal float library routines.
- (line 306)
-* __bid_ledd2: Decimal float library routines.
- (line 295)
-* __bid_lesd2: Decimal float library routines.
- (line 293)
-* __bid_letd2: Decimal float library routines.
- (line 297)
-* __bid_ltdd2: Decimal float library routines.
- (line 286)
-* __bid_ltsd2: Decimal float library routines.
- (line 284)
-* __bid_lttd2: Decimal float library routines.
- (line 288)
-* __bid_muldd3: Decimal float library routines.
- (line 54)
-* __bid_mulsd3: Decimal float library routines.
- (line 50)
-* __bid_multd3: Decimal float library routines.
- (line 58)
-* __bid_nedd2: Decimal float library routines.
- (line 268)
-* __bid_negdd2: Decimal float library routines.
- (line 78)
-* __bid_negsd2: Decimal float library routines.
- (line 76)
-* __bid_negtd2: Decimal float library routines.
- (line 80)
-* __bid_nesd2: Decimal float library routines.
- (line 266)
-* __bid_netd2: Decimal float library routines.
- (line 270)
-* __bid_subdd3: Decimal float library routines.
- (line 39)
-* __bid_subsd3: Decimal float library routines.
- (line 35)
-* __bid_subtd3: Decimal float library routines.
- (line 43)
-* __bid_truncdddf: Decimal float library routines.
- (line 153)
-* __bid_truncddsd2: Decimal float library routines.
- (line 94)
-* __bid_truncddsf: Decimal float library routines.
- (line 124)
-* __bid_truncdfsd: Decimal float library routines.
- (line 111)
-* __bid_truncsdsf: Decimal float library routines.
- (line 151)
-* __bid_trunctddd2: Decimal float library routines.
- (line 98)
-* __bid_trunctddf: Decimal float library routines.
- (line 130)
-* __bid_trunctdsd2: Decimal float library routines.
- (line 96)
-* __bid_trunctdsf: Decimal float library routines.
- (line 126)
-* __bid_trunctdtf: Decimal float library routines.
- (line 155)
-* __bid_trunctdxf: Decimal float library routines.
- (line 136)
-* __bid_trunctfdd: Decimal float library routines.
- (line 119)
-* __bid_trunctfsd: Decimal float library routines.
- (line 115)
-* __bid_truncxfdd: Decimal float library routines.
- (line 117)
-* __bid_truncxfsd: Decimal float library routines.
- (line 113)
-* __bid_unorddd2: Decimal float library routines.
- (line 235)
-* __bid_unordsd2: Decimal float library routines.
- (line 233)
-* __bid_unordtd2: Decimal float library routines.
- (line 237)
-* __bswapdi2: Integer library routines.
- (line 162)
-* __bswapsi2: Integer library routines.
- (line 161)
-* __builtin_args_info: Varargs. (line 42)
-* __builtin_classify_type: Varargs. (line 76)
-* __builtin_next_arg: Varargs. (line 66)
-* __builtin_saveregs: Varargs. (line 24)
-* __clear_cache: Miscellaneous routines.
- (line 10)
-* __clzdi2: Integer library routines.
- (line 131)
-* __clzsi2: Integer library routines.
- (line 130)
-* __clzti2: Integer library routines.
- (line 132)
-* __cmpda2: Fixed-point fractional library routines.
- (line 451)
-* __cmpdf2: Soft float library routines.
- (line 164)
-* __cmpdi2: Integer library routines.
- (line 87)
-* __cmpdq2: Fixed-point fractional library routines.
- (line 441)
-* __cmpha2: Fixed-point fractional library routines.
- (line 449)
-* __cmphq2: Fixed-point fractional library routines.
- (line 438)
-* __cmpqq2: Fixed-point fractional library routines.
- (line 437)
-* __cmpsa2: Fixed-point fractional library routines.
- (line 450)
-* __cmpsf2: Soft float library routines.
- (line 163)
-* __cmpsq2: Fixed-point fractional library routines.
- (line 439)
-* __cmpta2: Fixed-point fractional library routines.
- (line 453)
-* __cmptf2: Soft float library routines.
- (line 165)
-* __cmpti2: Integer library routines.
- (line 88)
-* __cmpuda2: Fixed-point fractional library routines.
- (line 458)
-* __cmpudq2: Fixed-point fractional library routines.
- (line 448)
-* __cmpuha2: Fixed-point fractional library routines.
- (line 455)
-* __cmpuhq2: Fixed-point fractional library routines.
- (line 444)
-* __cmpuqq2: Fixed-point fractional library routines.
- (line 443)
-* __cmpusa2: Fixed-point fractional library routines.
- (line 456)
-* __cmpusq2: Fixed-point fractional library routines.
- (line 446)
-* __cmputa2: Fixed-point fractional library routines.
- (line 460)
-* __CTOR_LIST__: Initialization. (line 25)
-* __ctzdi2: Integer library routines.
- (line 138)
-* __ctzsi2: Integer library routines.
- (line 137)
-* __ctzti2: Integer library routines.
- (line 139)
-* __divda3: Fixed-point fractional library routines.
- (line 227)
-* __divdc3: Soft float library routines.
- (line 252)
-* __divdf3: Soft float library routines.
- (line 48)
-* __divdi3: Integer library routines.
- (line 25)
-* __divdq3: Fixed-point fractional library routines.
- (line 223)
-* __divha3: Fixed-point fractional library routines.
- (line 225)
-* __divhq3: Fixed-point fractional library routines.
- (line 220)
-* __divqq3: Fixed-point fractional library routines.
- (line 219)
-* __divsa3: Fixed-point fractional library routines.
- (line 226)
-* __divsc3: Soft float library routines.
- (line 250)
-* __divsf3: Soft float library routines.
- (line 47)
-* __divsi3: Integer library routines.
- (line 24)
-* __divsq3: Fixed-point fractional library routines.
- (line 221)
-* __divta3: Fixed-point fractional library routines.
- (line 229)
-* __divtc3: Soft float library routines.
- (line 254)
-* __divtf3: Soft float library routines.
- (line 50)
-* __divti3: Integer library routines.
- (line 26)
-* __divxc3: Soft float library routines.
- (line 256)
-* __divxf3: Soft float library routines.
- (line 52)
-* __dpd_adddd3: Decimal float library routines.
- (line 23)
-* __dpd_addsd3: Decimal float library routines.
- (line 19)
-* __dpd_addtd3: Decimal float library routines.
- (line 27)
-* __dpd_divdd3: Decimal float library routines.
- (line 66)
-* __dpd_divsd3: Decimal float library routines.
- (line 62)
-* __dpd_divtd3: Decimal float library routines.
- (line 70)
-* __dpd_eqdd2: Decimal float library routines.
- (line 258)
-* __dpd_eqsd2: Decimal float library routines.
- (line 256)
-* __dpd_eqtd2: Decimal float library routines.
- (line 260)
-* __dpd_extendddtd2: Decimal float library routines.
- (line 91)
-* __dpd_extendddtf: Decimal float library routines.
- (line 139)
-* __dpd_extendddxf: Decimal float library routines.
- (line 133)
-* __dpd_extenddfdd: Decimal float library routines.
- (line 146)
-* __dpd_extenddftd: Decimal float library routines.
- (line 106)
-* __dpd_extendsddd2: Decimal float library routines.
- (line 87)
-* __dpd_extendsddf: Decimal float library routines.
- (line 127)
-* __dpd_extendsdtd2: Decimal float library routines.
- (line 89)
-* __dpd_extendsdtf: Decimal float library routines.
- (line 137)
-* __dpd_extendsdxf: Decimal float library routines.
- (line 131)
-* __dpd_extendsfdd: Decimal float library routines.
- (line 102)
-* __dpd_extendsfsd: Decimal float library routines.
- (line 144)
-* __dpd_extendsftd: Decimal float library routines.
- (line 104)
-* __dpd_extendtftd: Decimal float library routines.
- (line 148)
-* __dpd_extendxftd: Decimal float library routines.
- (line 108)
-* __dpd_fixdddi: Decimal float library routines.
- (line 169)
-* __dpd_fixddsi: Decimal float library routines.
- (line 161)
-* __dpd_fixsddi: Decimal float library routines.
- (line 167)
-* __dpd_fixsdsi: Decimal float library routines.
- (line 159)
-* __dpd_fixtddi: Decimal float library routines.
- (line 171)
-* __dpd_fixtdsi: Decimal float library routines.
- (line 163)
-* __dpd_fixunsdddi: Decimal float library routines.
- (line 186)
-* __dpd_fixunsddsi: Decimal float library routines.
- (line 177)
-* __dpd_fixunssddi: Decimal float library routines.
- (line 184)
-* __dpd_fixunssdsi: Decimal float library routines.
- (line 175)
-* __dpd_fixunstddi: Decimal float library routines.
- (line 188)
-* __dpd_fixunstdsi: Decimal float library routines.
- (line 179)
-* __dpd_floatdidd: Decimal float library routines.
- (line 204)
-* __dpd_floatdisd: Decimal float library routines.
- (line 202)
-* __dpd_floatditd: Decimal float library routines.
- (line 206)
-* __dpd_floatsidd: Decimal float library routines.
- (line 195)
-* __dpd_floatsisd: Decimal float library routines.
- (line 193)
-* __dpd_floatsitd: Decimal float library routines.
- (line 197)
-* __dpd_floatunsdidd: Decimal float library routines.
- (line 222)
-* __dpd_floatunsdisd: Decimal float library routines.
- (line 220)
-* __dpd_floatunsditd: Decimal float library routines.
- (line 224)
-* __dpd_floatunssidd: Decimal float library routines.
- (line 213)
-* __dpd_floatunssisd: Decimal float library routines.
- (line 211)
-* __dpd_floatunssitd: Decimal float library routines.
- (line 215)
-* __dpd_gedd2: Decimal float library routines.
- (line 276)
-* __dpd_gesd2: Decimal float library routines.
- (line 274)
-* __dpd_getd2: Decimal float library routines.
- (line 278)
-* __dpd_gtdd2: Decimal float library routines.
- (line 303)
-* __dpd_gtsd2: Decimal float library routines.
- (line 301)
-* __dpd_gttd2: Decimal float library routines.
- (line 305)
-* __dpd_ledd2: Decimal float library routines.
- (line 294)
-* __dpd_lesd2: Decimal float library routines.
- (line 292)
-* __dpd_letd2: Decimal float library routines.
- (line 296)
-* __dpd_ltdd2: Decimal float library routines.
- (line 285)
-* __dpd_ltsd2: Decimal float library routines.
- (line 283)
-* __dpd_lttd2: Decimal float library routines.
- (line 287)
-* __dpd_muldd3: Decimal float library routines.
- (line 52)
-* __dpd_mulsd3: Decimal float library routines.
- (line 48)
-* __dpd_multd3: Decimal float library routines.
- (line 56)
-* __dpd_nedd2: Decimal float library routines.
- (line 267)
-* __dpd_negdd2: Decimal float library routines.
- (line 77)
-* __dpd_negsd2: Decimal float library routines.
- (line 75)
-* __dpd_negtd2: Decimal float library routines.
- (line 79)
-* __dpd_nesd2: Decimal float library routines.
- (line 265)
-* __dpd_netd2: Decimal float library routines.
- (line 269)
-* __dpd_subdd3: Decimal float library routines.
- (line 37)
-* __dpd_subsd3: Decimal float library routines.
- (line 33)
-* __dpd_subtd3: Decimal float library routines.
- (line 41)
-* __dpd_truncdddf: Decimal float library routines.
- (line 152)
-* __dpd_truncddsd2: Decimal float library routines.
- (line 93)
-* __dpd_truncddsf: Decimal float library routines.
- (line 123)
-* __dpd_truncdfsd: Decimal float library routines.
- (line 110)
-* __dpd_truncsdsf: Decimal float library routines.
- (line 150)
-* __dpd_trunctddd2: Decimal float library routines.
- (line 97)
-* __dpd_trunctddf: Decimal float library routines.
- (line 129)
-* __dpd_trunctdsd2: Decimal float library routines.
- (line 95)
-* __dpd_trunctdsf: Decimal float library routines.
- (line 125)
-* __dpd_trunctdtf: Decimal float library routines.
- (line 154)
-* __dpd_trunctdxf: Decimal float library routines.
- (line 135)
-* __dpd_trunctfdd: Decimal float library routines.
- (line 118)
-* __dpd_trunctfsd: Decimal float library routines.
- (line 114)
-* __dpd_truncxfdd: Decimal float library routines.
- (line 116)
-* __dpd_truncxfsd: Decimal float library routines.
- (line 112)
-* __dpd_unorddd2: Decimal float library routines.
- (line 234)
-* __dpd_unordsd2: Decimal float library routines.
- (line 232)
-* __dpd_unordtd2: Decimal float library routines.
- (line 236)
-* __DTOR_LIST__: Initialization. (line 25)
-* __eqdf2: Soft float library routines.
- (line 194)
-* __eqsf2: Soft float library routines.
- (line 193)
-* __eqtf2: Soft float library routines.
- (line 195)
-* __extenddftf2: Soft float library routines.
- (line 68)
-* __extenddfxf2: Soft float library routines.
- (line 69)
-* __extendsfdf2: Soft float library routines.
- (line 65)
-* __extendsftf2: Soft float library routines.
- (line 66)
-* __extendsfxf2: Soft float library routines.
- (line 67)
-* __ffsdi2: Integer library routines.
- (line 144)
-* __ffsti2: Integer library routines.
- (line 145)
-* __fixdfdi: Soft float library routines.
- (line 88)
-* __fixdfsi: Soft float library routines.
- (line 81)
-* __fixdfti: Soft float library routines.
- (line 94)
-* __fixsfdi: Soft float library routines.
- (line 87)
-* __fixsfsi: Soft float library routines.
- (line 80)
-* __fixsfti: Soft float library routines.
- (line 93)
-* __fixtfdi: Soft float library routines.
- (line 89)
-* __fixtfsi: Soft float library routines.
- (line 82)
-* __fixtfti: Soft float library routines.
- (line 95)
-* __fixunsdfdi: Soft float library routines.
- (line 108)
-* __fixunsdfsi: Soft float library routines.
- (line 101)
-* __fixunsdfti: Soft float library routines.
- (line 115)
-* __fixunssfdi: Soft float library routines.
- (line 107)
-* __fixunssfsi: Soft float library routines.
- (line 100)
-* __fixunssfti: Soft float library routines.
- (line 114)
-* __fixunstfdi: Soft float library routines.
- (line 109)
-* __fixunstfsi: Soft float library routines.
- (line 102)
-* __fixunstfti: Soft float library routines.
- (line 116)
-* __fixunsxfdi: Soft float library routines.
- (line 110)
-* __fixunsxfsi: Soft float library routines.
- (line 103)
-* __fixunsxfti: Soft float library routines.
- (line 117)
-* __fixxfdi: Soft float library routines.
- (line 90)
-* __fixxfsi: Soft float library routines.
- (line 83)
-* __fixxfti: Soft float library routines.
- (line 96)
-* __floatdidf: Soft float library routines.
- (line 128)
-* __floatdisf: Soft float library routines.
- (line 127)
-* __floatditf: Soft float library routines.
- (line 129)
-* __floatdixf: Soft float library routines.
- (line 130)
-* __floatsidf: Soft float library routines.
- (line 122)
-* __floatsisf: Soft float library routines.
- (line 121)
-* __floatsitf: Soft float library routines.
- (line 123)
-* __floatsixf: Soft float library routines.
- (line 124)
-* __floattidf: Soft float library routines.
- (line 134)
-* __floattisf: Soft float library routines.
- (line 133)
-* __floattitf: Soft float library routines.
- (line 135)
-* __floattixf: Soft float library routines.
- (line 136)
-* __floatundidf: Soft float library routines.
- (line 146)
-* __floatundisf: Soft float library routines.
- (line 145)
-* __floatunditf: Soft float library routines.
- (line 147)
-* __floatundixf: Soft float library routines.
- (line 148)
-* __floatunsidf: Soft float library routines.
- (line 140)
-* __floatunsisf: Soft float library routines.
- (line 139)
-* __floatunsitf: Soft float library routines.
- (line 141)
-* __floatunsixf: Soft float library routines.
- (line 142)
-* __floatuntidf: Soft float library routines.
- (line 152)
-* __floatuntisf: Soft float library routines.
- (line 151)
-* __floatuntitf: Soft float library routines.
- (line 153)
-* __floatuntixf: Soft float library routines.
- (line 154)
-* __fractdadf: Fixed-point fractional library routines.
- (line 636)
-* __fractdadi: Fixed-point fractional library routines.
- (line 633)
-* __fractdadq: Fixed-point fractional library routines.
- (line 616)
-* __fractdaha2: Fixed-point fractional library routines.
- (line 617)
-* __fractdahi: Fixed-point fractional library routines.
- (line 631)
-* __fractdahq: Fixed-point fractional library routines.
- (line 614)
-* __fractdaqi: Fixed-point fractional library routines.
- (line 630)
-* __fractdaqq: Fixed-point fractional library routines.
- (line 613)
-* __fractdasa2: Fixed-point fractional library routines.
- (line 618)
-* __fractdasf: Fixed-point fractional library routines.
- (line 635)
-* __fractdasi: Fixed-point fractional library routines.
- (line 632)
-* __fractdasq: Fixed-point fractional library routines.
- (line 615)
-* __fractdata2: Fixed-point fractional library routines.
- (line 619)
-* __fractdati: Fixed-point fractional library routines.
- (line 634)
-* __fractdauda: Fixed-point fractional library routines.
- (line 627)
-* __fractdaudq: Fixed-point fractional library routines.
- (line 624)
-* __fractdauha: Fixed-point fractional library routines.
- (line 625)
-* __fractdauhq: Fixed-point fractional library routines.
- (line 621)
-* __fractdauqq: Fixed-point fractional library routines.
- (line 620)
-* __fractdausa: Fixed-point fractional library routines.
- (line 626)
-* __fractdausq: Fixed-point fractional library routines.
- (line 622)
-* __fractdauta: Fixed-point fractional library routines.
- (line 629)
-* __fractdfda: Fixed-point fractional library routines.
- (line 1025)
-* __fractdfdq: Fixed-point fractional library routines.
- (line 1022)
-* __fractdfha: Fixed-point fractional library routines.
- (line 1023)
-* __fractdfhq: Fixed-point fractional library routines.
- (line 1020)
-* __fractdfqq: Fixed-point fractional library routines.
- (line 1019)
-* __fractdfsa: Fixed-point fractional library routines.
- (line 1024)
-* __fractdfsq: Fixed-point fractional library routines.
- (line 1021)
-* __fractdfta: Fixed-point fractional library routines.
- (line 1026)
-* __fractdfuda: Fixed-point fractional library routines.
- (line 1033)
-* __fractdfudq: Fixed-point fractional library routines.
- (line 1030)
-* __fractdfuha: Fixed-point fractional library routines.
- (line 1031)
-* __fractdfuhq: Fixed-point fractional library routines.
- (line 1028)
-* __fractdfuqq: Fixed-point fractional library routines.
- (line 1027)
-* __fractdfusa: Fixed-point fractional library routines.
- (line 1032)
-* __fractdfusq: Fixed-point fractional library routines.
- (line 1029)
-* __fractdfuta: Fixed-point fractional library routines.
- (line 1034)
-* __fractdida: Fixed-point fractional library routines.
- (line 975)
-* __fractdidq: Fixed-point fractional library routines.
- (line 972)
-* __fractdiha: Fixed-point fractional library routines.
- (line 973)
-* __fractdihq: Fixed-point fractional library routines.
- (line 970)
-* __fractdiqq: Fixed-point fractional library routines.
- (line 969)
-* __fractdisa: Fixed-point fractional library routines.
- (line 974)
-* __fractdisq: Fixed-point fractional library routines.
- (line 971)
-* __fractdita: Fixed-point fractional library routines.
- (line 976)
-* __fractdiuda: Fixed-point fractional library routines.
- (line 983)
-* __fractdiudq: Fixed-point fractional library routines.
- (line 980)
-* __fractdiuha: Fixed-point fractional library routines.
- (line 981)
-* __fractdiuhq: Fixed-point fractional library routines.
- (line 978)
-* __fractdiuqq: Fixed-point fractional library routines.
- (line 977)
-* __fractdiusa: Fixed-point fractional library routines.
- (line 982)
-* __fractdiusq: Fixed-point fractional library routines.
- (line 979)
-* __fractdiuta: Fixed-point fractional library routines.
- (line 984)
-* __fractdqda: Fixed-point fractional library routines.
- (line 544)
-* __fractdqdf: Fixed-point fractional library routines.
- (line 566)
-* __fractdqdi: Fixed-point fractional library routines.
- (line 563)
-* __fractdqha: Fixed-point fractional library routines.
- (line 542)
-* __fractdqhi: Fixed-point fractional library routines.
- (line 561)
-* __fractdqhq2: Fixed-point fractional library routines.
- (line 540)
-* __fractdqqi: Fixed-point fractional library routines.
- (line 560)
-* __fractdqqq2: Fixed-point fractional library routines.
- (line 539)
-* __fractdqsa: Fixed-point fractional library routines.
- (line 543)
-* __fractdqsf: Fixed-point fractional library routines.
- (line 565)
-* __fractdqsi: Fixed-point fractional library routines.
- (line 562)
-* __fractdqsq2: Fixed-point fractional library routines.
- (line 541)
-* __fractdqta: Fixed-point fractional library routines.
- (line 545)
-* __fractdqti: Fixed-point fractional library routines.
- (line 564)
-* __fractdquda: Fixed-point fractional library routines.
- (line 557)
-* __fractdqudq: Fixed-point fractional library routines.
- (line 552)
-* __fractdquha: Fixed-point fractional library routines.
- (line 554)
-* __fractdquhq: Fixed-point fractional library routines.
- (line 548)
-* __fractdquqq: Fixed-point fractional library routines.
- (line 547)
-* __fractdqusa: Fixed-point fractional library routines.
- (line 555)
-* __fractdqusq: Fixed-point fractional library routines.
- (line 550)
-* __fractdquta: Fixed-point fractional library routines.
- (line 559)
-* __fracthada2: Fixed-point fractional library routines.
- (line 572)
-* __fracthadf: Fixed-point fractional library routines.
- (line 590)
-* __fracthadi: Fixed-point fractional library routines.
- (line 587)
-* __fracthadq: Fixed-point fractional library routines.
- (line 570)
-* __fracthahi: Fixed-point fractional library routines.
- (line 585)
-* __fracthahq: Fixed-point fractional library routines.
- (line 568)
-* __fracthaqi: Fixed-point fractional library routines.
- (line 584)
-* __fracthaqq: Fixed-point fractional library routines.
- (line 567)
-* __fracthasa2: Fixed-point fractional library routines.
- (line 571)
-* __fracthasf: Fixed-point fractional library routines.
- (line 589)
-* __fracthasi: Fixed-point fractional library routines.
- (line 586)
-* __fracthasq: Fixed-point fractional library routines.
- (line 569)
-* __fracthata2: Fixed-point fractional library routines.
- (line 573)
-* __fracthati: Fixed-point fractional library routines.
- (line 588)
-* __fracthauda: Fixed-point fractional library routines.
- (line 581)
-* __fracthaudq: Fixed-point fractional library routines.
- (line 578)
-* __fracthauha: Fixed-point fractional library routines.
- (line 579)
-* __fracthauhq: Fixed-point fractional library routines.
- (line 575)
-* __fracthauqq: Fixed-point fractional library routines.
- (line 574)
-* __fracthausa: Fixed-point fractional library routines.
- (line 580)
-* __fracthausq: Fixed-point fractional library routines.
- (line 576)
-* __fracthauta: Fixed-point fractional library routines.
- (line 583)
-* __fracthida: Fixed-point fractional library routines.
- (line 943)
-* __fracthidq: Fixed-point fractional library routines.
- (line 940)
-* __fracthiha: Fixed-point fractional library routines.
- (line 941)
-* __fracthihq: Fixed-point fractional library routines.
- (line 938)
-* __fracthiqq: Fixed-point fractional library routines.
- (line 937)
-* __fracthisa: Fixed-point fractional library routines.
- (line 942)
-* __fracthisq: Fixed-point fractional library routines.
- (line 939)
-* __fracthita: Fixed-point fractional library routines.
- (line 944)
-* __fracthiuda: Fixed-point fractional library routines.
- (line 951)
-* __fracthiudq: Fixed-point fractional library routines.
- (line 948)
-* __fracthiuha: Fixed-point fractional library routines.
- (line 949)
-* __fracthiuhq: Fixed-point fractional library routines.
- (line 946)
-* __fracthiuqq: Fixed-point fractional library routines.
- (line 945)
-* __fracthiusa: Fixed-point fractional library routines.
- (line 950)
-* __fracthiusq: Fixed-point fractional library routines.
- (line 947)
-* __fracthiuta: Fixed-point fractional library routines.
- (line 952)
-* __fracthqda: Fixed-point fractional library routines.
- (line 498)
-* __fracthqdf: Fixed-point fractional library routines.
- (line 514)
-* __fracthqdi: Fixed-point fractional library routines.
- (line 511)
-* __fracthqdq2: Fixed-point fractional library routines.
- (line 495)
-* __fracthqha: Fixed-point fractional library routines.
- (line 496)
-* __fracthqhi: Fixed-point fractional library routines.
- (line 509)
-* __fracthqqi: Fixed-point fractional library routines.
- (line 508)
-* __fracthqqq2: Fixed-point fractional library routines.
- (line 493)
-* __fracthqsa: Fixed-point fractional library routines.
- (line 497)
-* __fracthqsf: Fixed-point fractional library routines.
- (line 513)
-* __fracthqsi: Fixed-point fractional library routines.
- (line 510)
-* __fracthqsq2: Fixed-point fractional library routines.
- (line 494)
-* __fracthqta: Fixed-point fractional library routines.
- (line 499)
-* __fracthqti: Fixed-point fractional library routines.
- (line 512)
-* __fracthquda: Fixed-point fractional library routines.
- (line 506)
-* __fracthqudq: Fixed-point fractional library routines.
- (line 503)
-* __fracthquha: Fixed-point fractional library routines.
- (line 504)
-* __fracthquhq: Fixed-point fractional library routines.
- (line 501)
-* __fracthquqq: Fixed-point fractional library routines.
- (line 500)
-* __fracthqusa: Fixed-point fractional library routines.
- (line 505)
-* __fracthqusq: Fixed-point fractional library routines.
- (line 502)
-* __fracthquta: Fixed-point fractional library routines.
- (line 507)
-* __fractqida: Fixed-point fractional library routines.
- (line 925)
-* __fractqidq: Fixed-point fractional library routines.
- (line 922)
-* __fractqiha: Fixed-point fractional library routines.
- (line 923)
-* __fractqihq: Fixed-point fractional library routines.
- (line 920)
-* __fractqiqq: Fixed-point fractional library routines.
- (line 919)
-* __fractqisa: Fixed-point fractional library routines.
- (line 924)
-* __fractqisq: Fixed-point fractional library routines.
- (line 921)
-* __fractqita: Fixed-point fractional library routines.
- (line 926)
-* __fractqiuda: Fixed-point fractional library routines.
- (line 934)
-* __fractqiudq: Fixed-point fractional library routines.
- (line 931)
-* __fractqiuha: Fixed-point fractional library routines.
- (line 932)
-* __fractqiuhq: Fixed-point fractional library routines.
- (line 928)
-* __fractqiuqq: Fixed-point fractional library routines.
- (line 927)
-* __fractqiusa: Fixed-point fractional library routines.
- (line 933)
-* __fractqiusq: Fixed-point fractional library routines.
- (line 929)
-* __fractqiuta: Fixed-point fractional library routines.
- (line 936)
-* __fractqqda: Fixed-point fractional library routines.
- (line 474)
-* __fractqqdf: Fixed-point fractional library routines.
- (line 492)
-* __fractqqdi: Fixed-point fractional library routines.
- (line 489)
-* __fractqqdq2: Fixed-point fractional library routines.
- (line 471)
-* __fractqqha: Fixed-point fractional library routines.
- (line 472)
-* __fractqqhi: Fixed-point fractional library routines.
- (line 487)
-* __fractqqhq2: Fixed-point fractional library routines.
- (line 469)
-* __fractqqqi: Fixed-point fractional library routines.
- (line 486)
-* __fractqqsa: Fixed-point fractional library routines.
- (line 473)
-* __fractqqsf: Fixed-point fractional library routines.
- (line 491)
-* __fractqqsi: Fixed-point fractional library routines.
- (line 488)
-* __fractqqsq2: Fixed-point fractional library routines.
- (line 470)
-* __fractqqta: Fixed-point fractional library routines.
- (line 475)
-* __fractqqti: Fixed-point fractional library routines.
- (line 490)
-* __fractqquda: Fixed-point fractional library routines.
- (line 483)
-* __fractqqudq: Fixed-point fractional library routines.
- (line 480)
-* __fractqquha: Fixed-point fractional library routines.
- (line 481)
-* __fractqquhq: Fixed-point fractional library routines.
- (line 477)
-* __fractqquqq: Fixed-point fractional library routines.
- (line 476)
-* __fractqqusa: Fixed-point fractional library routines.
- (line 482)
-* __fractqqusq: Fixed-point fractional library routines.
- (line 478)
-* __fractqquta: Fixed-point fractional library routines.
- (line 485)
-* __fractsada2: Fixed-point fractional library routines.
- (line 596)
-* __fractsadf: Fixed-point fractional library routines.
- (line 612)
-* __fractsadi: Fixed-point fractional library routines.
- (line 609)
-* __fractsadq: Fixed-point fractional library routines.
- (line 594)
-* __fractsaha2: Fixed-point fractional library routines.
- (line 595)
-* __fractsahi: Fixed-point fractional library routines.
- (line 607)
-* __fractsahq: Fixed-point fractional library routines.
- (line 592)
-* __fractsaqi: Fixed-point fractional library routines.
- (line 606)
-* __fractsaqq: Fixed-point fractional library routines.
- (line 591)
-* __fractsasf: Fixed-point fractional library routines.
- (line 611)
-* __fractsasi: Fixed-point fractional library routines.
- (line 608)
-* __fractsasq: Fixed-point fractional library routines.
- (line 593)
-* __fractsata2: Fixed-point fractional library routines.
- (line 597)
-* __fractsati: Fixed-point fractional library routines.
- (line 610)
-* __fractsauda: Fixed-point fractional library routines.
- (line 604)
-* __fractsaudq: Fixed-point fractional library routines.
- (line 601)
-* __fractsauha: Fixed-point fractional library routines.
- (line 602)
-* __fractsauhq: Fixed-point fractional library routines.
- (line 599)
-* __fractsauqq: Fixed-point fractional library routines.
- (line 598)
-* __fractsausa: Fixed-point fractional library routines.
- (line 603)
-* __fractsausq: Fixed-point fractional library routines.
- (line 600)
-* __fractsauta: Fixed-point fractional library routines.
- (line 605)
-* __fractsfda: Fixed-point fractional library routines.
- (line 1009)
-* __fractsfdq: Fixed-point fractional library routines.
- (line 1006)
-* __fractsfha: Fixed-point fractional library routines.
- (line 1007)
-* __fractsfhq: Fixed-point fractional library routines.
- (line 1004)
-* __fractsfqq: Fixed-point fractional library routines.
- (line 1003)
-* __fractsfsa: Fixed-point fractional library routines.
- (line 1008)
-* __fractsfsq: Fixed-point fractional library routines.
- (line 1005)
-* __fractsfta: Fixed-point fractional library routines.
- (line 1010)
-* __fractsfuda: Fixed-point fractional library routines.
- (line 1017)
-* __fractsfudq: Fixed-point fractional library routines.
- (line 1014)
-* __fractsfuha: Fixed-point fractional library routines.
- (line 1015)
-* __fractsfuhq: Fixed-point fractional library routines.
- (line 1012)
-* __fractsfuqq: Fixed-point fractional library routines.
- (line 1011)
-* __fractsfusa: Fixed-point fractional library routines.
- (line 1016)
-* __fractsfusq: Fixed-point fractional library routines.
- (line 1013)
-* __fractsfuta: Fixed-point fractional library routines.
- (line 1018)
-* __fractsida: Fixed-point fractional library routines.
- (line 959)
-* __fractsidq: Fixed-point fractional library routines.
- (line 956)
-* __fractsiha: Fixed-point fractional library routines.
- (line 957)
-* __fractsihq: Fixed-point fractional library routines.
- (line 954)
-* __fractsiqq: Fixed-point fractional library routines.
- (line 953)
-* __fractsisa: Fixed-point fractional library routines.
- (line 958)
-* __fractsisq: Fixed-point fractional library routines.
- (line 955)
-* __fractsita: Fixed-point fractional library routines.
- (line 960)
-* __fractsiuda: Fixed-point fractional library routines.
- (line 967)
-* __fractsiudq: Fixed-point fractional library routines.
- (line 964)
-* __fractsiuha: Fixed-point fractional library routines.
- (line 965)
-* __fractsiuhq: Fixed-point fractional library routines.
- (line 962)
-* __fractsiuqq: Fixed-point fractional library routines.
- (line 961)
-* __fractsiusa: Fixed-point fractional library routines.
- (line 966)
-* __fractsiusq: Fixed-point fractional library routines.
- (line 963)
-* __fractsiuta: Fixed-point fractional library routines.
- (line 968)
-* __fractsqda: Fixed-point fractional library routines.
- (line 520)
-* __fractsqdf: Fixed-point fractional library routines.
- (line 538)
-* __fractsqdi: Fixed-point fractional library routines.
- (line 535)
-* __fractsqdq2: Fixed-point fractional library routines.
- (line 517)
-* __fractsqha: Fixed-point fractional library routines.
- (line 518)
-* __fractsqhi: Fixed-point fractional library routines.
- (line 533)
-* __fractsqhq2: Fixed-point fractional library routines.
- (line 516)
-* __fractsqqi: Fixed-point fractional library routines.
- (line 532)
-* __fractsqqq2: Fixed-point fractional library routines.
- (line 515)
-* __fractsqsa: Fixed-point fractional library routines.
- (line 519)
-* __fractsqsf: Fixed-point fractional library routines.
- (line 537)
-* __fractsqsi: Fixed-point fractional library routines.
- (line 534)
-* __fractsqta: Fixed-point fractional library routines.
- (line 521)
-* __fractsqti: Fixed-point fractional library routines.
- (line 536)
-* __fractsquda: Fixed-point fractional library routines.
- (line 529)
-* __fractsqudq: Fixed-point fractional library routines.
- (line 526)
-* __fractsquha: Fixed-point fractional library routines.
- (line 527)
-* __fractsquhq: Fixed-point fractional library routines.
- (line 523)
-* __fractsquqq: Fixed-point fractional library routines.
- (line 522)
-* __fractsqusa: Fixed-point fractional library routines.
- (line 528)
-* __fractsqusq: Fixed-point fractional library routines.
- (line 524)
-* __fractsquta: Fixed-point fractional library routines.
- (line 531)
-* __fracttada2: Fixed-point fractional library routines.
- (line 643)
-* __fracttadf: Fixed-point fractional library routines.
- (line 664)
-* __fracttadi: Fixed-point fractional library routines.
- (line 661)
-* __fracttadq: Fixed-point fractional library routines.
- (line 640)
-* __fracttaha2: Fixed-point fractional library routines.
- (line 641)
-* __fracttahi: Fixed-point fractional library routines.
- (line 659)
-* __fracttahq: Fixed-point fractional library routines.
- (line 638)
-* __fracttaqi: Fixed-point fractional library routines.
- (line 658)
-* __fracttaqq: Fixed-point fractional library routines.
- (line 637)
-* __fracttasa2: Fixed-point fractional library routines.
- (line 642)
-* __fracttasf: Fixed-point fractional library routines.
- (line 663)
-* __fracttasi: Fixed-point fractional library routines.
- (line 660)
-* __fracttasq: Fixed-point fractional library routines.
- (line 639)
-* __fracttati: Fixed-point fractional library routines.
- (line 662)
-* __fracttauda: Fixed-point fractional library routines.
- (line 655)
-* __fracttaudq: Fixed-point fractional library routines.
- (line 650)
-* __fracttauha: Fixed-point fractional library routines.
- (line 652)
-* __fracttauhq: Fixed-point fractional library routines.
- (line 646)
-* __fracttauqq: Fixed-point fractional library routines.
- (line 645)
-* __fracttausa: Fixed-point fractional library routines.
- (line 653)
-* __fracttausq: Fixed-point fractional library routines.
- (line 648)
-* __fracttauta: Fixed-point fractional library routines.
- (line 657)
-* __fracttida: Fixed-point fractional library routines.
- (line 991)
-* __fracttidq: Fixed-point fractional library routines.
- (line 988)
-* __fracttiha: Fixed-point fractional library routines.
- (line 989)
-* __fracttihq: Fixed-point fractional library routines.
- (line 986)
-* __fracttiqq: Fixed-point fractional library routines.
- (line 985)
-* __fracttisa: Fixed-point fractional library routines.
- (line 990)
-* __fracttisq: Fixed-point fractional library routines.
- (line 987)
-* __fracttita: Fixed-point fractional library routines.
- (line 992)
-* __fracttiuda: Fixed-point fractional library routines.
- (line 1000)
-* __fracttiudq: Fixed-point fractional library routines.
- (line 997)
-* __fracttiuha: Fixed-point fractional library routines.
- (line 998)
-* __fracttiuhq: Fixed-point fractional library routines.
- (line 994)
-* __fracttiuqq: Fixed-point fractional library routines.
- (line 993)
-* __fracttiusa: Fixed-point fractional library routines.
- (line 999)
-* __fracttiusq: Fixed-point fractional library routines.
- (line 995)
-* __fracttiuta: Fixed-point fractional library routines.
- (line 1002)
-* __fractudada: Fixed-point fractional library routines.
- (line 858)
-* __fractudadf: Fixed-point fractional library routines.
- (line 881)
-* __fractudadi: Fixed-point fractional library routines.
- (line 878)
-* __fractudadq: Fixed-point fractional library routines.
- (line 855)
-* __fractudaha: Fixed-point fractional library routines.
- (line 856)
-* __fractudahi: Fixed-point fractional library routines.
- (line 876)
-* __fractudahq: Fixed-point fractional library routines.
- (line 852)
-* __fractudaqi: Fixed-point fractional library routines.
- (line 875)
-* __fractudaqq: Fixed-point fractional library routines.
- (line 851)
-* __fractudasa: Fixed-point fractional library routines.
- (line 857)
-* __fractudasf: Fixed-point fractional library routines.
- (line 880)
-* __fractudasi: Fixed-point fractional library routines.
- (line 877)
-* __fractudasq: Fixed-point fractional library routines.
- (line 853)
-* __fractudata: Fixed-point fractional library routines.
- (line 860)
-* __fractudati: Fixed-point fractional library routines.
- (line 879)
-* __fractudaudq: Fixed-point fractional library routines.
- (line 868)
-* __fractudauha2: Fixed-point fractional library routines.
- (line 870)
-* __fractudauhq: Fixed-point fractional library routines.
- (line 864)
-* __fractudauqq: Fixed-point fractional library routines.
- (line 862)
-* __fractudausa2: Fixed-point fractional library routines.
- (line 872)
-* __fractudausq: Fixed-point fractional library routines.
- (line 866)
-* __fractudauta2: Fixed-point fractional library routines.
- (line 874)
-* __fractudqda: Fixed-point fractional library routines.
- (line 766)
-* __fractudqdf: Fixed-point fractional library routines.
- (line 791)
-* __fractudqdi: Fixed-point fractional library routines.
- (line 787)
-* __fractudqdq: Fixed-point fractional library routines.
- (line 761)
-* __fractudqha: Fixed-point fractional library routines.
- (line 763)
-* __fractudqhi: Fixed-point fractional library routines.
- (line 785)
-* __fractudqhq: Fixed-point fractional library routines.
- (line 757)
-* __fractudqqi: Fixed-point fractional library routines.
- (line 784)
-* __fractudqqq: Fixed-point fractional library routines.
- (line 756)
-* __fractudqsa: Fixed-point fractional library routines.
- (line 764)
-* __fractudqsf: Fixed-point fractional library routines.
- (line 790)
-* __fractudqsi: Fixed-point fractional library routines.
- (line 786)
-* __fractudqsq: Fixed-point fractional library routines.
- (line 759)
-* __fractudqta: Fixed-point fractional library routines.
- (line 768)
-* __fractudqti: Fixed-point fractional library routines.
- (line 789)
-* __fractudquda: Fixed-point fractional library routines.
- (line 780)
-* __fractudquha: Fixed-point fractional library routines.
- (line 776)
-* __fractudquhq2: Fixed-point fractional library routines.
- (line 772)
-* __fractudquqq2: Fixed-point fractional library routines.
- (line 770)
-* __fractudqusa: Fixed-point fractional library routines.
- (line 778)
-* __fractudqusq2: Fixed-point fractional library routines.
- (line 774)
-* __fractudquta: Fixed-point fractional library routines.
- (line 782)
-* __fractuhada: Fixed-point fractional library routines.
- (line 799)
-* __fractuhadf: Fixed-point fractional library routines.
- (line 822)
-* __fractuhadi: Fixed-point fractional library routines.
- (line 819)
-* __fractuhadq: Fixed-point fractional library routines.
- (line 796)
-* __fractuhaha: Fixed-point fractional library routines.
- (line 797)
-* __fractuhahi: Fixed-point fractional library routines.
- (line 817)
-* __fractuhahq: Fixed-point fractional library routines.
- (line 793)
-* __fractuhaqi: Fixed-point fractional library routines.
- (line 816)
-* __fractuhaqq: Fixed-point fractional library routines.
- (line 792)
-* __fractuhasa: Fixed-point fractional library routines.
- (line 798)
-* __fractuhasf: Fixed-point fractional library routines.
- (line 821)
-* __fractuhasi: Fixed-point fractional library routines.
- (line 818)
-* __fractuhasq: Fixed-point fractional library routines.
- (line 794)
-* __fractuhata: Fixed-point fractional library routines.
- (line 801)
-* __fractuhati: Fixed-point fractional library routines.
- (line 820)
-* __fractuhauda2: Fixed-point fractional library routines.
- (line 813)
-* __fractuhaudq: Fixed-point fractional library routines.
- (line 809)
-* __fractuhauhq: Fixed-point fractional library routines.
- (line 805)
-* __fractuhauqq: Fixed-point fractional library routines.
- (line 803)
-* __fractuhausa2: Fixed-point fractional library routines.
- (line 811)
-* __fractuhausq: Fixed-point fractional library routines.
- (line 807)
-* __fractuhauta2: Fixed-point fractional library routines.
- (line 815)
-* __fractuhqda: Fixed-point fractional library routines.
- (line 702)
-* __fractuhqdf: Fixed-point fractional library routines.
- (line 723)
-* __fractuhqdi: Fixed-point fractional library routines.
- (line 720)
-* __fractuhqdq: Fixed-point fractional library routines.
- (line 699)
-* __fractuhqha: Fixed-point fractional library routines.
- (line 700)
-* __fractuhqhi: Fixed-point fractional library routines.
- (line 718)
-* __fractuhqhq: Fixed-point fractional library routines.
- (line 697)
-* __fractuhqqi: Fixed-point fractional library routines.
- (line 717)
-* __fractuhqqq: Fixed-point fractional library routines.
- (line 696)
-* __fractuhqsa: Fixed-point fractional library routines.
- (line 701)
-* __fractuhqsf: Fixed-point fractional library routines.
- (line 722)
-* __fractuhqsi: Fixed-point fractional library routines.
- (line 719)
-* __fractuhqsq: Fixed-point fractional library routines.
- (line 698)
-* __fractuhqta: Fixed-point fractional library routines.
- (line 703)
-* __fractuhqti: Fixed-point fractional library routines.
- (line 721)
-* __fractuhquda: Fixed-point fractional library routines.
- (line 714)
-* __fractuhqudq2: Fixed-point fractional library routines.
- (line 709)
-* __fractuhquha: Fixed-point fractional library routines.
- (line 711)
-* __fractuhquqq2: Fixed-point fractional library routines.
- (line 705)
-* __fractuhqusa: Fixed-point fractional library routines.
- (line 712)
-* __fractuhqusq2: Fixed-point fractional library routines.
- (line 707)
-* __fractuhquta: Fixed-point fractional library routines.
- (line 716)
-* __fractunsdadi: Fixed-point fractional library routines.
- (line 1555)
-* __fractunsdahi: Fixed-point fractional library routines.
- (line 1553)
-* __fractunsdaqi: Fixed-point fractional library routines.
- (line 1552)
-* __fractunsdasi: Fixed-point fractional library routines.
- (line 1554)
-* __fractunsdati: Fixed-point fractional library routines.
- (line 1556)
-* __fractunsdida: Fixed-point fractional library routines.
- (line 1707)
-* __fractunsdidq: Fixed-point fractional library routines.
- (line 1704)
-* __fractunsdiha: Fixed-point fractional library routines.
- (line 1705)
-* __fractunsdihq: Fixed-point fractional library routines.
- (line 1702)
-* __fractunsdiqq: Fixed-point fractional library routines.
- (line 1701)
-* __fractunsdisa: Fixed-point fractional library routines.
- (line 1706)
-* __fractunsdisq: Fixed-point fractional library routines.
- (line 1703)
-* __fractunsdita: Fixed-point fractional library routines.
- (line 1708)
-* __fractunsdiuda: Fixed-point fractional library routines.
- (line 1720)
-* __fractunsdiudq: Fixed-point fractional library routines.
- (line 1715)
-* __fractunsdiuha: Fixed-point fractional library routines.
- (line 1717)
-* __fractunsdiuhq: Fixed-point fractional library routines.
- (line 1711)
-* __fractunsdiuqq: Fixed-point fractional library routines.
- (line 1710)
-* __fractunsdiusa: Fixed-point fractional library routines.
- (line 1718)
-* __fractunsdiusq: Fixed-point fractional library routines.
- (line 1713)
-* __fractunsdiuta: Fixed-point fractional library routines.
- (line 1722)
-* __fractunsdqdi: Fixed-point fractional library routines.
- (line 1539)
-* __fractunsdqhi: Fixed-point fractional library routines.
- (line 1537)
-* __fractunsdqqi: Fixed-point fractional library routines.
- (line 1536)
-* __fractunsdqsi: Fixed-point fractional library routines.
- (line 1538)
-* __fractunsdqti: Fixed-point fractional library routines.
- (line 1541)
-* __fractunshadi: Fixed-point fractional library routines.
- (line 1545)
-* __fractunshahi: Fixed-point fractional library routines.
- (line 1543)
-* __fractunshaqi: Fixed-point fractional library routines.
- (line 1542)
-* __fractunshasi: Fixed-point fractional library routines.
- (line 1544)
-* __fractunshati: Fixed-point fractional library routines.
- (line 1546)
-* __fractunshida: Fixed-point fractional library routines.
- (line 1663)
-* __fractunshidq: Fixed-point fractional library routines.
- (line 1660)
-* __fractunshiha: Fixed-point fractional library routines.
- (line 1661)
-* __fractunshihq: Fixed-point fractional library routines.
- (line 1658)
-* __fractunshiqq: Fixed-point fractional library routines.
- (line 1657)
-* __fractunshisa: Fixed-point fractional library routines.
- (line 1662)
-* __fractunshisq: Fixed-point fractional library routines.
- (line 1659)
-* __fractunshita: Fixed-point fractional library routines.
- (line 1664)
-* __fractunshiuda: Fixed-point fractional library routines.
- (line 1676)
-* __fractunshiudq: Fixed-point fractional library routines.
- (line 1671)
-* __fractunshiuha: Fixed-point fractional library routines.
- (line 1673)
-* __fractunshiuhq: Fixed-point fractional library routines.
- (line 1667)
-* __fractunshiuqq: Fixed-point fractional library routines.
- (line 1666)
-* __fractunshiusa: Fixed-point fractional library routines.
- (line 1674)
-* __fractunshiusq: Fixed-point fractional library routines.
- (line 1669)
-* __fractunshiuta: Fixed-point fractional library routines.
- (line 1678)
-* __fractunshqdi: Fixed-point fractional library routines.
- (line 1529)
-* __fractunshqhi: Fixed-point fractional library routines.
- (line 1527)
-* __fractunshqqi: Fixed-point fractional library routines.
- (line 1526)
-* __fractunshqsi: Fixed-point fractional library routines.
- (line 1528)
-* __fractunshqti: Fixed-point fractional library routines.
- (line 1530)
-* __fractunsqida: Fixed-point fractional library routines.
- (line 1641)
-* __fractunsqidq: Fixed-point fractional library routines.
- (line 1638)
-* __fractunsqiha: Fixed-point fractional library routines.
- (line 1639)
-* __fractunsqihq: Fixed-point fractional library routines.
- (line 1636)
-* __fractunsqiqq: Fixed-point fractional library routines.
- (line 1635)
-* __fractunsqisa: Fixed-point fractional library routines.
- (line 1640)
-* __fractunsqisq: Fixed-point fractional library routines.
- (line 1637)
-* __fractunsqita: Fixed-point fractional library routines.
- (line 1642)
-* __fractunsqiuda: Fixed-point fractional library routines.
- (line 1654)
-* __fractunsqiudq: Fixed-point fractional library routines.
- (line 1649)
-* __fractunsqiuha: Fixed-point fractional library routines.
- (line 1651)
-* __fractunsqiuhq: Fixed-point fractional library routines.
- (line 1645)
-* __fractunsqiuqq: Fixed-point fractional library routines.
- (line 1644)
-* __fractunsqiusa: Fixed-point fractional library routines.
- (line 1652)
-* __fractunsqiusq: Fixed-point fractional library routines.
- (line 1647)
-* __fractunsqiuta: Fixed-point fractional library routines.
- (line 1656)
-* __fractunsqqdi: Fixed-point fractional library routines.
- (line 1524)
-* __fractunsqqhi: Fixed-point fractional library routines.
- (line 1522)
-* __fractunsqqqi: Fixed-point fractional library routines.
- (line 1521)
-* __fractunsqqsi: Fixed-point fractional library routines.
- (line 1523)
-* __fractunsqqti: Fixed-point fractional library routines.
- (line 1525)
-* __fractunssadi: Fixed-point fractional library routines.
- (line 1550)
-* __fractunssahi: Fixed-point fractional library routines.
- (line 1548)
-* __fractunssaqi: Fixed-point fractional library routines.
- (line 1547)
-* __fractunssasi: Fixed-point fractional library routines.
- (line 1549)
-* __fractunssati: Fixed-point fractional library routines.
- (line 1551)
-* __fractunssida: Fixed-point fractional library routines.
- (line 1685)
-* __fractunssidq: Fixed-point fractional library routines.
- (line 1682)
-* __fractunssiha: Fixed-point fractional library routines.
- (line 1683)
-* __fractunssihq: Fixed-point fractional library routines.
- (line 1680)
-* __fractunssiqq: Fixed-point fractional library routines.
- (line 1679)
-* __fractunssisa: Fixed-point fractional library routines.
- (line 1684)
-* __fractunssisq: Fixed-point fractional library routines.
- (line 1681)
-* __fractunssita: Fixed-point fractional library routines.
- (line 1686)
-* __fractunssiuda: Fixed-point fractional library routines.
- (line 1698)
-* __fractunssiudq: Fixed-point fractional library routines.
- (line 1693)
-* __fractunssiuha: Fixed-point fractional library routines.
- (line 1695)
-* __fractunssiuhq: Fixed-point fractional library routines.
- (line 1689)
-* __fractunssiuqq: Fixed-point fractional library routines.
- (line 1688)
-* __fractunssiusa: Fixed-point fractional library routines.
- (line 1696)
-* __fractunssiusq: Fixed-point fractional library routines.
- (line 1691)
-* __fractunssiuta: Fixed-point fractional library routines.
- (line 1700)
-* __fractunssqdi: Fixed-point fractional library routines.
- (line 1534)
-* __fractunssqhi: Fixed-point fractional library routines.
- (line 1532)
-* __fractunssqqi: Fixed-point fractional library routines.
- (line 1531)
-* __fractunssqsi: Fixed-point fractional library routines.
- (line 1533)
-* __fractunssqti: Fixed-point fractional library routines.
- (line 1535)
-* __fractunstadi: Fixed-point fractional library routines.
- (line 1560)
-* __fractunstahi: Fixed-point fractional library routines.
- (line 1558)
-* __fractunstaqi: Fixed-point fractional library routines.
- (line 1557)
-* __fractunstasi: Fixed-point fractional library routines.
- (line 1559)
-* __fractunstati: Fixed-point fractional library routines.
- (line 1562)
-* __fractunstida: Fixed-point fractional library routines.
- (line 1730)
-* __fractunstidq: Fixed-point fractional library routines.
- (line 1727)
-* __fractunstiha: Fixed-point fractional library routines.
- (line 1728)
-* __fractunstihq: Fixed-point fractional library routines.
- (line 1724)
-* __fractunstiqq: Fixed-point fractional library routines.
- (line 1723)
-* __fractunstisa: Fixed-point fractional library routines.
- (line 1729)
-* __fractunstisq: Fixed-point fractional library routines.
- (line 1725)
-* __fractunstita: Fixed-point fractional library routines.
- (line 1732)
-* __fractunstiuda: Fixed-point fractional library routines.
- (line 1746)
-* __fractunstiudq: Fixed-point fractional library routines.
- (line 1740)
-* __fractunstiuha: Fixed-point fractional library routines.
- (line 1742)
-* __fractunstiuhq: Fixed-point fractional library routines.
- (line 1736)
-* __fractunstiuqq: Fixed-point fractional library routines.
- (line 1734)
-* __fractunstiusa: Fixed-point fractional library routines.
- (line 1744)
-* __fractunstiusq: Fixed-point fractional library routines.
- (line 1738)
-* __fractunstiuta: Fixed-point fractional library routines.
- (line 1748)
-* __fractunsudadi: Fixed-point fractional library routines.
- (line 1622)
-* __fractunsudahi: Fixed-point fractional library routines.
- (line 1618)
-* __fractunsudaqi: Fixed-point fractional library routines.
- (line 1616)
-* __fractunsudasi: Fixed-point fractional library routines.
- (line 1620)
-* __fractunsudati: Fixed-point fractional library routines.
- (line 1624)
-* __fractunsudqdi: Fixed-point fractional library routines.
- (line 1596)
-* __fractunsudqhi: Fixed-point fractional library routines.
- (line 1592)
-* __fractunsudqqi: Fixed-point fractional library routines.
- (line 1590)
-* __fractunsudqsi: Fixed-point fractional library routines.
- (line 1594)
-* __fractunsudqti: Fixed-point fractional library routines.
- (line 1598)
-* __fractunsuhadi: Fixed-point fractional library routines.
- (line 1606)
-* __fractunsuhahi: Fixed-point fractional library routines.
- (line 1602)
-* __fractunsuhaqi: Fixed-point fractional library routines.
- (line 1600)
-* __fractunsuhasi: Fixed-point fractional library routines.
- (line 1604)
-* __fractunsuhati: Fixed-point fractional library routines.
- (line 1608)
-* __fractunsuhqdi: Fixed-point fractional library routines.
- (line 1576)
-* __fractunsuhqhi: Fixed-point fractional library routines.
- (line 1574)
-* __fractunsuhqqi: Fixed-point fractional library routines.
- (line 1573)
-* __fractunsuhqsi: Fixed-point fractional library routines.
- (line 1575)
-* __fractunsuhqti: Fixed-point fractional library routines.
- (line 1578)
-* __fractunsuqqdi: Fixed-point fractional library routines.
- (line 1570)
-* __fractunsuqqhi: Fixed-point fractional library routines.
- (line 1566)
-* __fractunsuqqqi: Fixed-point fractional library routines.
- (line 1564)
-* __fractunsuqqsi: Fixed-point fractional library routines.
- (line 1568)
-* __fractunsuqqti: Fixed-point fractional library routines.
- (line 1572)
-* __fractunsusadi: Fixed-point fractional library routines.
- (line 1612)
-* __fractunsusahi: Fixed-point fractional library routines.
- (line 1610)
-* __fractunsusaqi: Fixed-point fractional library routines.
- (line 1609)
-* __fractunsusasi: Fixed-point fractional library routines.
- (line 1611)
-* __fractunsusati: Fixed-point fractional library routines.
- (line 1614)
-* __fractunsusqdi: Fixed-point fractional library routines.
- (line 1586)
-* __fractunsusqhi: Fixed-point fractional library routines.
- (line 1582)
-* __fractunsusqqi: Fixed-point fractional library routines.
- (line 1580)
-* __fractunsusqsi: Fixed-point fractional library routines.
- (line 1584)
-* __fractunsusqti: Fixed-point fractional library routines.
- (line 1588)
-* __fractunsutadi: Fixed-point fractional library routines.
- (line 1632)
-* __fractunsutahi: Fixed-point fractional library routines.
- (line 1628)
-* __fractunsutaqi: Fixed-point fractional library routines.
- (line 1626)
-* __fractunsutasi: Fixed-point fractional library routines.
- (line 1630)
-* __fractunsutati: Fixed-point fractional library routines.
- (line 1634)
-* __fractuqqda: Fixed-point fractional library routines.
- (line 672)
-* __fractuqqdf: Fixed-point fractional library routines.
- (line 695)
-* __fractuqqdi: Fixed-point fractional library routines.
- (line 692)
-* __fractuqqdq: Fixed-point fractional library routines.
- (line 669)
-* __fractuqqha: Fixed-point fractional library routines.
- (line 670)
-* __fractuqqhi: Fixed-point fractional library routines.
- (line 690)
-* __fractuqqhq: Fixed-point fractional library routines.
- (line 666)
-* __fractuqqqi: Fixed-point fractional library routines.
- (line 689)
-* __fractuqqqq: Fixed-point fractional library routines.
- (line 665)
-* __fractuqqsa: Fixed-point fractional library routines.
- (line 671)
-* __fractuqqsf: Fixed-point fractional library routines.
- (line 694)
-* __fractuqqsi: Fixed-point fractional library routines.
- (line 691)
-* __fractuqqsq: Fixed-point fractional library routines.
- (line 667)
-* __fractuqqta: Fixed-point fractional library routines.
- (line 674)
-* __fractuqqti: Fixed-point fractional library routines.
- (line 693)
-* __fractuqquda: Fixed-point fractional library routines.
- (line 686)
-* __fractuqqudq2: Fixed-point fractional library routines.
- (line 680)
-* __fractuqquha: Fixed-point fractional library routines.
- (line 682)
-* __fractuqquhq2: Fixed-point fractional library routines.
- (line 676)
-* __fractuqqusa: Fixed-point fractional library routines.
- (line 684)
-* __fractuqqusq2: Fixed-point fractional library routines.
- (line 678)
-* __fractuqquta: Fixed-point fractional library routines.
- (line 688)
-* __fractusada: Fixed-point fractional library routines.
- (line 829)
-* __fractusadf: Fixed-point fractional library routines.
- (line 850)
-* __fractusadi: Fixed-point fractional library routines.
- (line 847)
-* __fractusadq: Fixed-point fractional library routines.
- (line 826)
-* __fractusaha: Fixed-point fractional library routines.
- (line 827)
-* __fractusahi: Fixed-point fractional library routines.
- (line 845)
-* __fractusahq: Fixed-point fractional library routines.
- (line 824)
-* __fractusaqi: Fixed-point fractional library routines.
- (line 844)
-* __fractusaqq: Fixed-point fractional library routines.
- (line 823)
-* __fractusasa: Fixed-point fractional library routines.
- (line 828)
-* __fractusasf: Fixed-point fractional library routines.
- (line 849)
-* __fractusasi: Fixed-point fractional library routines.
- (line 846)
-* __fractusasq: Fixed-point fractional library routines.
- (line 825)
-* __fractusata: Fixed-point fractional library routines.
- (line 830)
-* __fractusati: Fixed-point fractional library routines.
- (line 848)
-* __fractusauda2: Fixed-point fractional library routines.
- (line 841)
-* __fractusaudq: Fixed-point fractional library routines.
- (line 837)
-* __fractusauha2: Fixed-point fractional library routines.
- (line 839)
-* __fractusauhq: Fixed-point fractional library routines.
- (line 833)
-* __fractusauqq: Fixed-point fractional library routines.
- (line 832)
-* __fractusausq: Fixed-point fractional library routines.
- (line 835)
-* __fractusauta2: Fixed-point fractional library routines.
- (line 843)
-* __fractusqda: Fixed-point fractional library routines.
- (line 731)
-* __fractusqdf: Fixed-point fractional library routines.
- (line 754)
-* __fractusqdi: Fixed-point fractional library routines.
- (line 751)
-* __fractusqdq: Fixed-point fractional library routines.
- (line 728)
-* __fractusqha: Fixed-point fractional library routines.
- (line 729)
-* __fractusqhi: Fixed-point fractional library routines.
- (line 749)
-* __fractusqhq: Fixed-point fractional library routines.
- (line 725)
-* __fractusqqi: Fixed-point fractional library routines.
- (line 748)
-* __fractusqqq: Fixed-point fractional library routines.
- (line 724)
-* __fractusqsa: Fixed-point fractional library routines.
- (line 730)
-* __fractusqsf: Fixed-point fractional library routines.
- (line 753)
-* __fractusqsi: Fixed-point fractional library routines.
- (line 750)
-* __fractusqsq: Fixed-point fractional library routines.
- (line 726)
-* __fractusqta: Fixed-point fractional library routines.
- (line 733)
-* __fractusqti: Fixed-point fractional library routines.
- (line 752)
-* __fractusquda: Fixed-point fractional library routines.
- (line 745)
-* __fractusqudq2: Fixed-point fractional library routines.
- (line 739)
-* __fractusquha: Fixed-point fractional library routines.
- (line 741)
-* __fractusquhq2: Fixed-point fractional library routines.
- (line 737)
-* __fractusquqq2: Fixed-point fractional library routines.
- (line 735)
-* __fractusqusa: Fixed-point fractional library routines.
- (line 743)
-* __fractusquta: Fixed-point fractional library routines.
- (line 747)
-* __fractutada: Fixed-point fractional library routines.
- (line 893)
-* __fractutadf: Fixed-point fractional library routines.
- (line 918)
-* __fractutadi: Fixed-point fractional library routines.
- (line 914)
-* __fractutadq: Fixed-point fractional library routines.
- (line 888)
-* __fractutaha: Fixed-point fractional library routines.
- (line 890)
-* __fractutahi: Fixed-point fractional library routines.
- (line 912)
-* __fractutahq: Fixed-point fractional library routines.
- (line 884)
-* __fractutaqi: Fixed-point fractional library routines.
- (line 911)
-* __fractutaqq: Fixed-point fractional library routines.
- (line 883)
-* __fractutasa: Fixed-point fractional library routines.
- (line 891)
-* __fractutasf: Fixed-point fractional library routines.
- (line 917)
-* __fractutasi: Fixed-point fractional library routines.
- (line 913)
-* __fractutasq: Fixed-point fractional library routines.
- (line 886)
-* __fractutata: Fixed-point fractional library routines.
- (line 895)
-* __fractutati: Fixed-point fractional library routines.
- (line 916)
-* __fractutauda2: Fixed-point fractional library routines.
- (line 909)
-* __fractutaudq: Fixed-point fractional library routines.
- (line 903)
-* __fractutauha2: Fixed-point fractional library routines.
- (line 905)
-* __fractutauhq: Fixed-point fractional library routines.
- (line 899)
-* __fractutauqq: Fixed-point fractional library routines.
- (line 897)
-* __fractutausa2: Fixed-point fractional library routines.
- (line 907)
-* __fractutausq: Fixed-point fractional library routines.
- (line 901)
-* __gedf2: Soft float library routines.
- (line 206)
-* __gesf2: Soft float library routines.
- (line 205)
-* __getf2: Soft float library routines.
- (line 207)
-* __gtdf2: Soft float library routines.
- (line 224)
-* __gtsf2: Soft float library routines.
- (line 223)
-* __gttf2: Soft float library routines.
- (line 225)
-* __ledf2: Soft float library routines.
- (line 218)
-* __lesf2: Soft float library routines.
- (line 217)
-* __letf2: Soft float library routines.
- (line 219)
-* __lshrdi3: Integer library routines.
- (line 31)
-* __lshrsi3: Integer library routines.
- (line 30)
-* __lshrti3: Integer library routines.
- (line 32)
-* __lshruda3: Fixed-point fractional library routines.
- (line 390)
-* __lshrudq3: Fixed-point fractional library routines.
- (line 384)
-* __lshruha3: Fixed-point fractional library routines.
- (line 386)
-* __lshruhq3: Fixed-point fractional library routines.
- (line 380)
-* __lshruqq3: Fixed-point fractional library routines.
- (line 378)
-* __lshrusa3: Fixed-point fractional library routines.
- (line 388)
-* __lshrusq3: Fixed-point fractional library routines.
- (line 382)
-* __lshruta3: Fixed-point fractional library routines.
- (line 392)
-* __ltdf2: Soft float library routines.
- (line 212)
-* __ltsf2: Soft float library routines.
- (line 211)
-* __lttf2: Soft float library routines.
- (line 213)
-* __main: Collect2. (line 15)
-* __moddi3: Integer library routines.
- (line 37)
-* __modsi3: Integer library routines.
- (line 36)
-* __modti3: Integer library routines.
- (line 38)
-* __mulda3: Fixed-point fractional library routines.
- (line 171)
-* __muldc3: Soft float library routines.
- (line 241)
-* __muldf3: Soft float library routines.
- (line 40)
-* __muldi3: Integer library routines.
- (line 43)
-* __muldq3: Fixed-point fractional library routines.
- (line 159)
-* __mulha3: Fixed-point fractional library routines.
- (line 169)
-* __mulhq3: Fixed-point fractional library routines.
- (line 156)
-* __mulqq3: Fixed-point fractional library routines.
- (line 155)
-* __mulsa3: Fixed-point fractional library routines.
- (line 170)
-* __mulsc3: Soft float library routines.
- (line 239)
-* __mulsf3: Soft float library routines.
- (line 39)
-* __mulsi3: Integer library routines.
- (line 42)
-* __mulsq3: Fixed-point fractional library routines.
- (line 157)
-* __multa3: Fixed-point fractional library routines.
- (line 173)
-* __multc3: Soft float library routines.
- (line 243)
-* __multf3: Soft float library routines.
- (line 42)
-* __multi3: Integer library routines.
- (line 44)
-* __muluda3: Fixed-point fractional library routines.
- (line 179)
-* __muludq3: Fixed-point fractional library routines.
- (line 167)
-* __muluha3: Fixed-point fractional library routines.
- (line 175)
-* __muluhq3: Fixed-point fractional library routines.
- (line 163)
-* __muluqq3: Fixed-point fractional library routines.
- (line 161)
-* __mulusa3: Fixed-point fractional library routines.
- (line 177)
-* __mulusq3: Fixed-point fractional library routines.
- (line 165)
-* __muluta3: Fixed-point fractional library routines.
- (line 181)
-* __mulvdi3: Integer library routines.
- (line 115)
-* __mulvsi3: Integer library routines.
- (line 114)
-* __mulxc3: Soft float library routines.
- (line 245)
-* __mulxf3: Soft float library routines.
- (line 44)
-* __nedf2: Soft float library routines.
- (line 200)
-* __negda2: Fixed-point fractional library routines.
- (line 299)
-* __negdf2: Soft float library routines.
- (line 56)
-* __negdi2: Integer library routines.
- (line 47)
-* __negdq2: Fixed-point fractional library routines.
- (line 289)
-* __negha2: Fixed-point fractional library routines.
- (line 297)
-* __neghq2: Fixed-point fractional library routines.
- (line 287)
-* __negqq2: Fixed-point fractional library routines.
- (line 286)
-* __negsa2: Fixed-point fractional library routines.
- (line 298)
-* __negsf2: Soft float library routines.
- (line 55)
-* __negsq2: Fixed-point fractional library routines.
- (line 288)
-* __negta2: Fixed-point fractional library routines.
- (line 300)
-* __negtf2: Soft float library routines.
- (line 57)
-* __negti2: Integer library routines.
- (line 48)
-* __neguda2: Fixed-point fractional library routines.
- (line 305)
-* __negudq2: Fixed-point fractional library routines.
- (line 296)
-* __neguha2: Fixed-point fractional library routines.
- (line 302)
-* __neguhq2: Fixed-point fractional library routines.
- (line 292)
-* __neguqq2: Fixed-point fractional library routines.
- (line 291)
-* __negusa2: Fixed-point fractional library routines.
- (line 303)
-* __negusq2: Fixed-point fractional library routines.
- (line 294)
-* __neguta2: Fixed-point fractional library routines.
- (line 307)
-* __negvdi2: Integer library routines.
- (line 119)
-* __negvsi2: Integer library routines.
- (line 118)
-* __negxf2: Soft float library routines.
- (line 58)
-* __nesf2: Soft float library routines.
- (line 199)
-* __netf2: Soft float library routines.
- (line 201)
-* __paritydi2: Integer library routines.
- (line 151)
-* __paritysi2: Integer library routines.
- (line 150)
-* __parityti2: Integer library routines.
- (line 152)
-* __popcountdi2: Integer library routines.
- (line 157)
-* __popcountsi2: Integer library routines.
- (line 156)
-* __popcountti2: Integer library routines.
- (line 158)
-* __powidf2: Soft float library routines.
- (line 233)
-* __powisf2: Soft float library routines.
- (line 232)
-* __powitf2: Soft float library routines.
- (line 234)
-* __powixf2: Soft float library routines.
- (line 235)
-* __satfractdadq: Fixed-point fractional library routines.
- (line 1153)
-* __satfractdaha2: Fixed-point fractional library routines.
- (line 1154)
-* __satfractdahq: Fixed-point fractional library routines.
- (line 1151)
-* __satfractdaqq: Fixed-point fractional library routines.
- (line 1150)
-* __satfractdasa2: Fixed-point fractional library routines.
- (line 1155)
-* __satfractdasq: Fixed-point fractional library routines.
- (line 1152)
-* __satfractdata2: Fixed-point fractional library routines.
- (line 1156)
-* __satfractdauda: Fixed-point fractional library routines.
- (line 1166)
-* __satfractdaudq: Fixed-point fractional library routines.
- (line 1162)
-* __satfractdauha: Fixed-point fractional library routines.
- (line 1164)
-* __satfractdauhq: Fixed-point fractional library routines.
- (line 1159)
-* __satfractdauqq: Fixed-point fractional library routines.
- (line 1158)
-* __satfractdausa: Fixed-point fractional library routines.
- (line 1165)
-* __satfractdausq: Fixed-point fractional library routines.
- (line 1160)
-* __satfractdauta: Fixed-point fractional library routines.
- (line 1168)
-* __satfractdfda: Fixed-point fractional library routines.
- (line 1506)
-* __satfractdfdq: Fixed-point fractional library routines.
- (line 1503)
-* __satfractdfha: Fixed-point fractional library routines.
- (line 1504)
-* __satfractdfhq: Fixed-point fractional library routines.
- (line 1501)
-* __satfractdfqq: Fixed-point fractional library routines.
- (line 1500)
-* __satfractdfsa: Fixed-point fractional library routines.
- (line 1505)
-* __satfractdfsq: Fixed-point fractional library routines.
- (line 1502)
-* __satfractdfta: Fixed-point fractional library routines.
- (line 1507)
-* __satfractdfuda: Fixed-point fractional library routines.
- (line 1515)
-* __satfractdfudq: Fixed-point fractional library routines.
- (line 1512)
-* __satfractdfuha: Fixed-point fractional library routines.
- (line 1513)
-* __satfractdfuhq: Fixed-point fractional library routines.
- (line 1509)
-* __satfractdfuqq: Fixed-point fractional library routines.
- (line 1508)
-* __satfractdfusa: Fixed-point fractional library routines.
- (line 1514)
-* __satfractdfusq: Fixed-point fractional library routines.
- (line 1510)
-* __satfractdfuta: Fixed-point fractional library routines.
- (line 1517)
-* __satfractdida: Fixed-point fractional library routines.
- (line 1456)
-* __satfractdidq: Fixed-point fractional library routines.
- (line 1453)
-* __satfractdiha: Fixed-point fractional library routines.
- (line 1454)
-* __satfractdihq: Fixed-point fractional library routines.
- (line 1451)
-* __satfractdiqq: Fixed-point fractional library routines.
- (line 1450)
-* __satfractdisa: Fixed-point fractional library routines.
- (line 1455)
-* __satfractdisq: Fixed-point fractional library routines.
- (line 1452)
-* __satfractdita: Fixed-point fractional library routines.
- (line 1457)
-* __satfractdiuda: Fixed-point fractional library routines.
- (line 1464)
-* __satfractdiudq: Fixed-point fractional library routines.
- (line 1461)
-* __satfractdiuha: Fixed-point fractional library routines.
- (line 1462)
-* __satfractdiuhq: Fixed-point fractional library routines.
- (line 1459)
-* __satfractdiuqq: Fixed-point fractional library routines.
- (line 1458)
-* __satfractdiusa: Fixed-point fractional library routines.
- (line 1463)
-* __satfractdiusq: Fixed-point fractional library routines.
- (line 1460)
-* __satfractdiuta: Fixed-point fractional library routines.
- (line 1465)
-* __satfractdqda: Fixed-point fractional library routines.
- (line 1098)
-* __satfractdqha: Fixed-point fractional library routines.
- (line 1096)
-* __satfractdqhq2: Fixed-point fractional library routines.
- (line 1094)
-* __satfractdqqq2: Fixed-point fractional library routines.
- (line 1093)
-* __satfractdqsa: Fixed-point fractional library routines.
- (line 1097)
-* __satfractdqsq2: Fixed-point fractional library routines.
- (line 1095)
-* __satfractdqta: Fixed-point fractional library routines.
- (line 1099)
-* __satfractdquda: Fixed-point fractional library routines.
- (line 1111)
-* __satfractdqudq: Fixed-point fractional library routines.
- (line 1106)
-* __satfractdquha: Fixed-point fractional library routines.
- (line 1108)
-* __satfractdquhq: Fixed-point fractional library routines.
- (line 1102)
-* __satfractdquqq: Fixed-point fractional library routines.
- (line 1101)
-* __satfractdqusa: Fixed-point fractional library routines.
- (line 1109)
-* __satfractdqusq: Fixed-point fractional library routines.
- (line 1104)
-* __satfractdquta: Fixed-point fractional library routines.
- (line 1113)
-* __satfracthada2: Fixed-point fractional library routines.
- (line 1119)
-* __satfracthadq: Fixed-point fractional library routines.
- (line 1117)
-* __satfracthahq: Fixed-point fractional library routines.
- (line 1115)
-* __satfracthaqq: Fixed-point fractional library routines.
- (line 1114)
-* __satfracthasa2: Fixed-point fractional library routines.
- (line 1118)
-* __satfracthasq: Fixed-point fractional library routines.
- (line 1116)
-* __satfracthata2: Fixed-point fractional library routines.
- (line 1120)
-* __satfracthauda: Fixed-point fractional library routines.
- (line 1132)
-* __satfracthaudq: Fixed-point fractional library routines.
- (line 1127)
-* __satfracthauha: Fixed-point fractional library routines.
- (line 1129)
-* __satfracthauhq: Fixed-point fractional library routines.
- (line 1123)
-* __satfracthauqq: Fixed-point fractional library routines.
- (line 1122)
-* __satfracthausa: Fixed-point fractional library routines.
- (line 1130)
-* __satfracthausq: Fixed-point fractional library routines.
- (line 1125)
-* __satfracthauta: Fixed-point fractional library routines.
- (line 1134)
-* __satfracthida: Fixed-point fractional library routines.
- (line 1424)
-* __satfracthidq: Fixed-point fractional library routines.
- (line 1421)
-* __satfracthiha: Fixed-point fractional library routines.
- (line 1422)
-* __satfracthihq: Fixed-point fractional library routines.
- (line 1419)
-* __satfracthiqq: Fixed-point fractional library routines.
- (line 1418)
-* __satfracthisa: Fixed-point fractional library routines.
- (line 1423)
-* __satfracthisq: Fixed-point fractional library routines.
- (line 1420)
-* __satfracthita: Fixed-point fractional library routines.
- (line 1425)
-* __satfracthiuda: Fixed-point fractional library routines.
- (line 1432)
-* __satfracthiudq: Fixed-point fractional library routines.
- (line 1429)
-* __satfracthiuha: Fixed-point fractional library routines.
- (line 1430)
-* __satfracthiuhq: Fixed-point fractional library routines.
- (line 1427)
-* __satfracthiuqq: Fixed-point fractional library routines.
- (line 1426)
-* __satfracthiusa: Fixed-point fractional library routines.
- (line 1431)
-* __satfracthiusq: Fixed-point fractional library routines.
- (line 1428)
-* __satfracthiuta: Fixed-point fractional library routines.
- (line 1433)
-* __satfracthqda: Fixed-point fractional library routines.
- (line 1064)
-* __satfracthqdq2: Fixed-point fractional library routines.
- (line 1061)
-* __satfracthqha: Fixed-point fractional library routines.
- (line 1062)
-* __satfracthqqq2: Fixed-point fractional library routines.
- (line 1059)
-* __satfracthqsa: Fixed-point fractional library routines.
- (line 1063)
-* __satfracthqsq2: Fixed-point fractional library routines.
- (line 1060)
-* __satfracthqta: Fixed-point fractional library routines.
- (line 1065)
-* __satfracthquda: Fixed-point fractional library routines.
- (line 1072)
-* __satfracthqudq: Fixed-point fractional library routines.
- (line 1069)
-* __satfracthquha: Fixed-point fractional library routines.
- (line 1070)
-* __satfracthquhq: Fixed-point fractional library routines.
- (line 1067)
-* __satfracthquqq: Fixed-point fractional library routines.
- (line 1066)
-* __satfracthqusa: Fixed-point fractional library routines.
- (line 1071)
-* __satfracthqusq: Fixed-point fractional library routines.
- (line 1068)
-* __satfracthquta: Fixed-point fractional library routines.
- (line 1073)
-* __satfractqida: Fixed-point fractional library routines.
- (line 1402)
-* __satfractqidq: Fixed-point fractional library routines.
- (line 1399)
-* __satfractqiha: Fixed-point fractional library routines.
- (line 1400)
-* __satfractqihq: Fixed-point fractional library routines.
- (line 1397)
-* __satfractqiqq: Fixed-point fractional library routines.
- (line 1396)
-* __satfractqisa: Fixed-point fractional library routines.
- (line 1401)
-* __satfractqisq: Fixed-point fractional library routines.
- (line 1398)
-* __satfractqita: Fixed-point fractional library routines.
- (line 1403)
-* __satfractqiuda: Fixed-point fractional library routines.
- (line 1415)
-* __satfractqiudq: Fixed-point fractional library routines.
- (line 1410)
-* __satfractqiuha: Fixed-point fractional library routines.
- (line 1412)
-* __satfractqiuhq: Fixed-point fractional library routines.
- (line 1406)
-* __satfractqiuqq: Fixed-point fractional library routines.
- (line 1405)
-* __satfractqiusa: Fixed-point fractional library routines.
- (line 1413)
-* __satfractqiusq: Fixed-point fractional library routines.
- (line 1408)
-* __satfractqiuta: Fixed-point fractional library routines.
- (line 1417)
-* __satfractqqda: Fixed-point fractional library routines.
- (line 1043)
-* __satfractqqdq2: Fixed-point fractional library routines.
- (line 1040)
-* __satfractqqha: Fixed-point fractional library routines.
- (line 1041)
-* __satfractqqhq2: Fixed-point fractional library routines.
- (line 1038)
-* __satfractqqsa: Fixed-point fractional library routines.
- (line 1042)
-* __satfractqqsq2: Fixed-point fractional library routines.
- (line 1039)
-* __satfractqqta: Fixed-point fractional library routines.
- (line 1044)
-* __satfractqquda: Fixed-point fractional library routines.
- (line 1056)
-* __satfractqqudq: Fixed-point fractional library routines.
- (line 1051)
-* __satfractqquha: Fixed-point fractional library routines.
- (line 1053)
-* __satfractqquhq: Fixed-point fractional library routines.
- (line 1047)
-* __satfractqquqq: Fixed-point fractional library routines.
- (line 1046)
-* __satfractqqusa: Fixed-point fractional library routines.
- (line 1054)
-* __satfractqqusq: Fixed-point fractional library routines.
- (line 1049)
-* __satfractqquta: Fixed-point fractional library routines.
- (line 1058)
-* __satfractsada2: Fixed-point fractional library routines.
- (line 1140)
-* __satfractsadq: Fixed-point fractional library routines.
- (line 1138)
-* __satfractsaha2: Fixed-point fractional library routines.
- (line 1139)
-* __satfractsahq: Fixed-point fractional library routines.
- (line 1136)
-* __satfractsaqq: Fixed-point fractional library routines.
- (line 1135)
-* __satfractsasq: Fixed-point fractional library routines.
- (line 1137)
-* __satfractsata2: Fixed-point fractional library routines.
- (line 1141)
-* __satfractsauda: Fixed-point fractional library routines.
- (line 1148)
-* __satfractsaudq: Fixed-point fractional library routines.
- (line 1145)
-* __satfractsauha: Fixed-point fractional library routines.
- (line 1146)
-* __satfractsauhq: Fixed-point fractional library routines.
- (line 1143)
-* __satfractsauqq: Fixed-point fractional library routines.
- (line 1142)
-* __satfractsausa: Fixed-point fractional library routines.
- (line 1147)
-* __satfractsausq: Fixed-point fractional library routines.
- (line 1144)
-* __satfractsauta: Fixed-point fractional library routines.
- (line 1149)
-* __satfractsfda: Fixed-point fractional library routines.
- (line 1490)
-* __satfractsfdq: Fixed-point fractional library routines.
- (line 1487)
-* __satfractsfha: Fixed-point fractional library routines.
- (line 1488)
-* __satfractsfhq: Fixed-point fractional library routines.
- (line 1485)
-* __satfractsfqq: Fixed-point fractional library routines.
- (line 1484)
-* __satfractsfsa: Fixed-point fractional library routines.
- (line 1489)
-* __satfractsfsq: Fixed-point fractional library routines.
- (line 1486)
-* __satfractsfta: Fixed-point fractional library routines.
- (line 1491)
-* __satfractsfuda: Fixed-point fractional library routines.
- (line 1498)
-* __satfractsfudq: Fixed-point fractional library routines.
- (line 1495)
-* __satfractsfuha: Fixed-point fractional library routines.
- (line 1496)
-* __satfractsfuhq: Fixed-point fractional library routines.
- (line 1493)
-* __satfractsfuqq: Fixed-point fractional library routines.
- (line 1492)
-* __satfractsfusa: Fixed-point fractional library routines.
- (line 1497)
-* __satfractsfusq: Fixed-point fractional library routines.
- (line 1494)
-* __satfractsfuta: Fixed-point fractional library routines.
- (line 1499)
-* __satfractsida: Fixed-point fractional library routines.
- (line 1440)
-* __satfractsidq: Fixed-point fractional library routines.
- (line 1437)
-* __satfractsiha: Fixed-point fractional library routines.
- (line 1438)
-* __satfractsihq: Fixed-point fractional library routines.
- (line 1435)
-* __satfractsiqq: Fixed-point fractional library routines.
- (line 1434)
-* __satfractsisa: Fixed-point fractional library routines.
- (line 1439)
-* __satfractsisq: Fixed-point fractional library routines.
- (line 1436)
-* __satfractsita: Fixed-point fractional library routines.
- (line 1441)
-* __satfractsiuda: Fixed-point fractional library routines.
- (line 1448)
-* __satfractsiudq: Fixed-point fractional library routines.
- (line 1445)
-* __satfractsiuha: Fixed-point fractional library routines.
- (line 1446)
-* __satfractsiuhq: Fixed-point fractional library routines.
- (line 1443)
-* __satfractsiuqq: Fixed-point fractional library routines.
- (line 1442)
-* __satfractsiusa: Fixed-point fractional library routines.
- (line 1447)
-* __satfractsiusq: Fixed-point fractional library routines.
- (line 1444)
-* __satfractsiuta: Fixed-point fractional library routines.
- (line 1449)
-* __satfractsqda: Fixed-point fractional library routines.
- (line 1079)
-* __satfractsqdq2: Fixed-point fractional library routines.
- (line 1076)
-* __satfractsqha: Fixed-point fractional library routines.
- (line 1077)
-* __satfractsqhq2: Fixed-point fractional library routines.
- (line 1075)
-* __satfractsqqq2: Fixed-point fractional library routines.
- (line 1074)
-* __satfractsqsa: Fixed-point fractional library routines.
- (line 1078)
-* __satfractsqta: Fixed-point fractional library routines.
- (line 1080)
-* __satfractsquda: Fixed-point fractional library routines.
- (line 1090)
-* __satfractsqudq: Fixed-point fractional library routines.
- (line 1086)
-* __satfractsquha: Fixed-point fractional library routines.
- (line 1088)
-* __satfractsquhq: Fixed-point fractional library routines.
- (line 1083)
-* __satfractsquqq: Fixed-point fractional library routines.
- (line 1082)
-* __satfractsqusa: Fixed-point fractional library routines.
- (line 1089)
-* __satfractsqusq: Fixed-point fractional library routines.
- (line 1084)
-* __satfractsquta: Fixed-point fractional library routines.
- (line 1092)
-* __satfracttada2: Fixed-point fractional library routines.
- (line 1175)
-* __satfracttadq: Fixed-point fractional library routines.
- (line 1172)
-* __satfracttaha2: Fixed-point fractional library routines.
- (line 1173)
-* __satfracttahq: Fixed-point fractional library routines.
- (line 1170)
-* __satfracttaqq: Fixed-point fractional library routines.
- (line 1169)
-* __satfracttasa2: Fixed-point fractional library routines.
- (line 1174)
-* __satfracttasq: Fixed-point fractional library routines.
- (line 1171)
-* __satfracttauda: Fixed-point fractional library routines.
- (line 1187)
-* __satfracttaudq: Fixed-point fractional library routines.
- (line 1182)
-* __satfracttauha: Fixed-point fractional library routines.
- (line 1184)
-* __satfracttauhq: Fixed-point fractional library routines.
- (line 1178)
-* __satfracttauqq: Fixed-point fractional library routines.
- (line 1177)
-* __satfracttausa: Fixed-point fractional library routines.
- (line 1185)
-* __satfracttausq: Fixed-point fractional library routines.
- (line 1180)
-* __satfracttauta: Fixed-point fractional library routines.
- (line 1189)
-* __satfracttida: Fixed-point fractional library routines.
- (line 1472)
-* __satfracttidq: Fixed-point fractional library routines.
- (line 1469)
-* __satfracttiha: Fixed-point fractional library routines.
- (line 1470)
-* __satfracttihq: Fixed-point fractional library routines.
- (line 1467)
-* __satfracttiqq: Fixed-point fractional library routines.
- (line 1466)
-* __satfracttisa: Fixed-point fractional library routines.
- (line 1471)
-* __satfracttisq: Fixed-point fractional library routines.
- (line 1468)
-* __satfracttita: Fixed-point fractional library routines.
- (line 1473)
-* __satfracttiuda: Fixed-point fractional library routines.
- (line 1481)
-* __satfracttiudq: Fixed-point fractional library routines.
- (line 1478)
-* __satfracttiuha: Fixed-point fractional library routines.
- (line 1479)
-* __satfracttiuhq: Fixed-point fractional library routines.
- (line 1475)
-* __satfracttiuqq: Fixed-point fractional library routines.
- (line 1474)
-* __satfracttiusa: Fixed-point fractional library routines.
- (line 1480)
-* __satfracttiusq: Fixed-point fractional library routines.
- (line 1476)
-* __satfracttiuta: Fixed-point fractional library routines.
- (line 1483)
-* __satfractudada: Fixed-point fractional library routines.
- (line 1351)
-* __satfractudadq: Fixed-point fractional library routines.
- (line 1347)
-* __satfractudaha: Fixed-point fractional library routines.
- (line 1349)
-* __satfractudahq: Fixed-point fractional library routines.
- (line 1344)
-* __satfractudaqq: Fixed-point fractional library routines.
- (line 1343)
-* __satfractudasa: Fixed-point fractional library routines.
- (line 1350)
-* __satfractudasq: Fixed-point fractional library routines.
- (line 1345)
-* __satfractudata: Fixed-point fractional library routines.
- (line 1353)
-* __satfractudaudq: Fixed-point fractional library routines.
- (line 1361)
-* __satfractudauha2: Fixed-point fractional library routines.
- (line 1363)
-* __satfractudauhq: Fixed-point fractional library routines.
- (line 1357)
-* __satfractudauqq: Fixed-point fractional library routines.
- (line 1355)
-* __satfractudausa2: Fixed-point fractional library routines.
- (line 1365)
-* __satfractudausq: Fixed-point fractional library routines.
- (line 1359)
-* __satfractudauta2: Fixed-point fractional library routines.
- (line 1367)
-* __satfractudqda: Fixed-point fractional library routines.
- (line 1276)
-* __satfractudqdq: Fixed-point fractional library routines.
- (line 1271)
-* __satfractudqha: Fixed-point fractional library routines.
- (line 1273)
-* __satfractudqhq: Fixed-point fractional library routines.
- (line 1267)
-* __satfractudqqq: Fixed-point fractional library routines.
- (line 1266)
-* __satfractudqsa: Fixed-point fractional library routines.
- (line 1274)
-* __satfractudqsq: Fixed-point fractional library routines.
- (line 1269)
-* __satfractudqta: Fixed-point fractional library routines.
- (line 1278)
-* __satfractudquda: Fixed-point fractional library routines.
- (line 1290)
-* __satfractudquha: Fixed-point fractional library routines.
- (line 1286)
-* __satfractudquhq2: Fixed-point fractional library routines.
- (line 1282)
-* __satfractudquqq2: Fixed-point fractional library routines.
- (line 1280)
-* __satfractudqusa: Fixed-point fractional library routines.
- (line 1288)
-* __satfractudqusq2: Fixed-point fractional library routines.
- (line 1284)
-* __satfractudquta: Fixed-point fractional library routines.
- (line 1292)
-* __satfractuhada: Fixed-point fractional library routines.
- (line 1304)
-* __satfractuhadq: Fixed-point fractional library routines.
- (line 1299)
-* __satfractuhaha: Fixed-point fractional library routines.
- (line 1301)
-* __satfractuhahq: Fixed-point fractional library routines.
- (line 1295)
-* __satfractuhaqq: Fixed-point fractional library routines.
- (line 1294)
-* __satfractuhasa: Fixed-point fractional library routines.
- (line 1302)
-* __satfractuhasq: Fixed-point fractional library routines.
- (line 1297)
-* __satfractuhata: Fixed-point fractional library routines.
- (line 1306)
-* __satfractuhauda2: Fixed-point fractional library routines.
- (line 1318)
-* __satfractuhaudq: Fixed-point fractional library routines.
- (line 1314)
-* __satfractuhauhq: Fixed-point fractional library routines.
- (line 1310)
-* __satfractuhauqq: Fixed-point fractional library routines.
- (line 1308)
-* __satfractuhausa2: Fixed-point fractional library routines.
- (line 1316)
-* __satfractuhausq: Fixed-point fractional library routines.
- (line 1312)
-* __satfractuhauta2: Fixed-point fractional library routines.
- (line 1320)
-* __satfractuhqda: Fixed-point fractional library routines.
- (line 1224)
-* __satfractuhqdq: Fixed-point fractional library routines.
- (line 1221)
-* __satfractuhqha: Fixed-point fractional library routines.
- (line 1222)
-* __satfractuhqhq: Fixed-point fractional library routines.
- (line 1219)
-* __satfractuhqqq: Fixed-point fractional library routines.
- (line 1218)
-* __satfractuhqsa: Fixed-point fractional library routines.
- (line 1223)
-* __satfractuhqsq: Fixed-point fractional library routines.
- (line 1220)
-* __satfractuhqta: Fixed-point fractional library routines.
- (line 1225)
-* __satfractuhquda: Fixed-point fractional library routines.
- (line 1236)
-* __satfractuhqudq2: Fixed-point fractional library routines.
- (line 1231)
-* __satfractuhquha: Fixed-point fractional library routines.
- (line 1233)
-* __satfractuhquqq2: Fixed-point fractional library routines.
- (line 1227)
-* __satfractuhqusa: Fixed-point fractional library routines.
- (line 1234)
-* __satfractuhqusq2: Fixed-point fractional library routines.
- (line 1229)
-* __satfractuhquta: Fixed-point fractional library routines.
- (line 1238)
-* __satfractunsdida: Fixed-point fractional library routines.
- (line 1834)
-* __satfractunsdidq: Fixed-point fractional library routines.
- (line 1831)
-* __satfractunsdiha: Fixed-point fractional library routines.
- (line 1832)
-* __satfractunsdihq: Fixed-point fractional library routines.
- (line 1828)
-* __satfractunsdiqq: Fixed-point fractional library routines.
- (line 1827)
-* __satfractunsdisa: Fixed-point fractional library routines.
- (line 1833)
-* __satfractunsdisq: Fixed-point fractional library routines.
- (line 1829)
-* __satfractunsdita: Fixed-point fractional library routines.
- (line 1836)
-* __satfractunsdiuda: Fixed-point fractional library routines.
- (line 1850)
-* __satfractunsdiudq: Fixed-point fractional library routines.
- (line 1844)
-* __satfractunsdiuha: Fixed-point fractional library routines.
- (line 1846)
-* __satfractunsdiuhq: Fixed-point fractional library routines.
- (line 1840)
-* __satfractunsdiuqq: Fixed-point fractional library routines.
- (line 1838)
-* __satfractunsdiusa: Fixed-point fractional library routines.
- (line 1848)
-* __satfractunsdiusq: Fixed-point fractional library routines.
- (line 1842)
-* __satfractunsdiuta: Fixed-point fractional library routines.
- (line 1852)
-* __satfractunshida: Fixed-point fractional library routines.
- (line 1786)
-* __satfractunshidq: Fixed-point fractional library routines.
- (line 1783)
-* __satfractunshiha: Fixed-point fractional library routines.
- (line 1784)
-* __satfractunshihq: Fixed-point fractional library routines.
- (line 1780)
-* __satfractunshiqq: Fixed-point fractional library routines.
- (line 1779)
-* __satfractunshisa: Fixed-point fractional library routines.
- (line 1785)
-* __satfractunshisq: Fixed-point fractional library routines.
- (line 1781)
-* __satfractunshita: Fixed-point fractional library routines.
- (line 1788)
-* __satfractunshiuda: Fixed-point fractional library routines.
- (line 1802)
-* __satfractunshiudq: Fixed-point fractional library routines.
- (line 1796)
-* __satfractunshiuha: Fixed-point fractional library routines.
- (line 1798)
-* __satfractunshiuhq: Fixed-point fractional library routines.
- (line 1792)
-* __satfractunshiuqq: Fixed-point fractional library routines.
- (line 1790)
-* __satfractunshiusa: Fixed-point fractional library routines.
- (line 1800)
-* __satfractunshiusq: Fixed-point fractional library routines.
- (line 1794)
-* __satfractunshiuta: Fixed-point fractional library routines.
- (line 1804)
-* __satfractunsqida: Fixed-point fractional library routines.
- (line 1760)
-* __satfractunsqidq: Fixed-point fractional library routines.
- (line 1757)
-* __satfractunsqiha: Fixed-point fractional library routines.
- (line 1758)
-* __satfractunsqihq: Fixed-point fractional library routines.
- (line 1754)
-* __satfractunsqiqq: Fixed-point fractional library routines.
- (line 1753)
-* __satfractunsqisa: Fixed-point fractional library routines.
- (line 1759)
-* __satfractunsqisq: Fixed-point fractional library routines.
- (line 1755)
-* __satfractunsqita: Fixed-point fractional library routines.
- (line 1762)
-* __satfractunsqiuda: Fixed-point fractional library routines.
- (line 1776)
-* __satfractunsqiudq: Fixed-point fractional library routines.
- (line 1770)
-* __satfractunsqiuha: Fixed-point fractional library routines.
- (line 1772)
-* __satfractunsqiuhq: Fixed-point fractional library routines.
- (line 1766)
-* __satfractunsqiuqq: Fixed-point fractional library routines.
- (line 1764)
-* __satfractunsqiusa: Fixed-point fractional library routines.
- (line 1774)
-* __satfractunsqiusq: Fixed-point fractional library routines.
- (line 1768)
-* __satfractunsqiuta: Fixed-point fractional library routines.
- (line 1778)
-* __satfractunssida: Fixed-point fractional library routines.
- (line 1811)
-* __satfractunssidq: Fixed-point fractional library routines.
- (line 1808)
-* __satfractunssiha: Fixed-point fractional library routines.
- (line 1809)
-* __satfractunssihq: Fixed-point fractional library routines.
- (line 1806)
-* __satfractunssiqq: Fixed-point fractional library routines.
- (line 1805)
-* __satfractunssisa: Fixed-point fractional library routines.
- (line 1810)
-* __satfractunssisq: Fixed-point fractional library routines.
- (line 1807)
-* __satfractunssita: Fixed-point fractional library routines.
- (line 1812)
-* __satfractunssiuda: Fixed-point fractional library routines.
- (line 1824)
-* __satfractunssiudq: Fixed-point fractional library routines.
- (line 1819)
-* __satfractunssiuha: Fixed-point fractional library routines.
- (line 1821)
-* __satfractunssiuhq: Fixed-point fractional library routines.
- (line 1815)
-* __satfractunssiuqq: Fixed-point fractional library routines.
- (line 1814)
-* __satfractunssiusa: Fixed-point fractional library routines.
- (line 1822)
-* __satfractunssiusq: Fixed-point fractional library routines.
- (line 1817)
-* __satfractunssiuta: Fixed-point fractional library routines.
- (line 1826)
-* __satfractunstida: Fixed-point fractional library routines.
- (line 1864)
-* __satfractunstidq: Fixed-point fractional library routines.
- (line 1859)
-* __satfractunstiha: Fixed-point fractional library routines.
- (line 1861)
-* __satfractunstihq: Fixed-point fractional library routines.
- (line 1855)
-* __satfractunstiqq: Fixed-point fractional library routines.
- (line 1854)
-* __satfractunstisa: Fixed-point fractional library routines.
- (line 1862)
-* __satfractunstisq: Fixed-point fractional library routines.
- (line 1857)
-* __satfractunstita: Fixed-point fractional library routines.
- (line 1866)
-* __satfractunstiuda: Fixed-point fractional library routines.
- (line 1880)
-* __satfractunstiudq: Fixed-point fractional library routines.
- (line 1874)
-* __satfractunstiuha: Fixed-point fractional library routines.
- (line 1876)
-* __satfractunstiuhq: Fixed-point fractional library routines.
- (line 1870)
-* __satfractunstiuqq: Fixed-point fractional library routines.
- (line 1868)
-* __satfractunstiusa: Fixed-point fractional library routines.
- (line 1878)
-* __satfractunstiusq: Fixed-point fractional library routines.
- (line 1872)
-* __satfractunstiuta: Fixed-point fractional library routines.
- (line 1882)
-* __satfractuqqda: Fixed-point fractional library routines.
- (line 1201)
-* __satfractuqqdq: Fixed-point fractional library routines.
- (line 1196)
-* __satfractuqqha: Fixed-point fractional library routines.
- (line 1198)
-* __satfractuqqhq: Fixed-point fractional library routines.
- (line 1192)
-* __satfractuqqqq: Fixed-point fractional library routines.
- (line 1191)
-* __satfractuqqsa: Fixed-point fractional library routines.
- (line 1199)
-* __satfractuqqsq: Fixed-point fractional library routines.
- (line 1194)
-* __satfractuqqta: Fixed-point fractional library routines.
- (line 1203)
-* __satfractuqquda: Fixed-point fractional library routines.
- (line 1215)
-* __satfractuqqudq2: Fixed-point fractional library routines.
- (line 1209)
-* __satfractuqquha: Fixed-point fractional library routines.
- (line 1211)
-* __satfractuqquhq2: Fixed-point fractional library routines.
- (line 1205)
-* __satfractuqqusa: Fixed-point fractional library routines.
- (line 1213)
-* __satfractuqqusq2: Fixed-point fractional library routines.
- (line 1207)
-* __satfractuqquta: Fixed-point fractional library routines.
- (line 1217)
-* __satfractusada: Fixed-point fractional library routines.
- (line 1327)
-* __satfractusadq: Fixed-point fractional library routines.
- (line 1324)
-* __satfractusaha: Fixed-point fractional library routines.
- (line 1325)
-* __satfractusahq: Fixed-point fractional library routines.
- (line 1322)
-* __satfractusaqq: Fixed-point fractional library routines.
- (line 1321)
-* __satfractusasa: Fixed-point fractional library routines.
- (line 1326)
-* __satfractusasq: Fixed-point fractional library routines.
- (line 1323)
-* __satfractusata: Fixed-point fractional library routines.
- (line 1328)
-* __satfractusauda2: Fixed-point fractional library routines.
- (line 1339)
-* __satfractusaudq: Fixed-point fractional library routines.
- (line 1335)
-* __satfractusauha2: Fixed-point fractional library routines.
- (line 1337)
-* __satfractusauhq: Fixed-point fractional library routines.
- (line 1331)
-* __satfractusauqq: Fixed-point fractional library routines.
- (line 1330)
-* __satfractusausq: Fixed-point fractional library routines.
- (line 1333)
-* __satfractusauta2: Fixed-point fractional library routines.
- (line 1341)
-* __satfractusqda: Fixed-point fractional library routines.
- (line 1248)
-* __satfractusqdq: Fixed-point fractional library routines.
- (line 1244)
-* __satfractusqha: Fixed-point fractional library routines.
- (line 1246)
-* __satfractusqhq: Fixed-point fractional library routines.
- (line 1241)
-* __satfractusqqq: Fixed-point fractional library routines.
- (line 1240)
-* __satfractusqsa: Fixed-point fractional library routines.
- (line 1247)
-* __satfractusqsq: Fixed-point fractional library routines.
- (line 1242)
-* __satfractusqta: Fixed-point fractional library routines.
- (line 1250)
-* __satfractusquda: Fixed-point fractional library routines.
- (line 1262)
-* __satfractusqudq2: Fixed-point fractional library routines.
- (line 1256)
-* __satfractusquha: Fixed-point fractional library routines.
- (line 1258)
-* __satfractusquhq2: Fixed-point fractional library routines.
- (line 1254)
-* __satfractusquqq2: Fixed-point fractional library routines.
- (line 1252)
-* __satfractusqusa: Fixed-point fractional library routines.
- (line 1260)
-* __satfractusquta: Fixed-point fractional library routines.
- (line 1264)
-* __satfractutada: Fixed-point fractional library routines.
- (line 1379)
-* __satfractutadq: Fixed-point fractional library routines.
- (line 1374)
-* __satfractutaha: Fixed-point fractional library routines.
- (line 1376)
-* __satfractutahq: Fixed-point fractional library routines.
- (line 1370)
-* __satfractutaqq: Fixed-point fractional library routines.
- (line 1369)
-* __satfractutasa: Fixed-point fractional library routines.
- (line 1377)
-* __satfractutasq: Fixed-point fractional library routines.
- (line 1372)
-* __satfractutata: Fixed-point fractional library routines.
- (line 1381)
-* __satfractutauda2: Fixed-point fractional library routines.
- (line 1395)
-* __satfractutaudq: Fixed-point fractional library routines.
- (line 1389)
-* __satfractutauha2: Fixed-point fractional library routines.
- (line 1391)
-* __satfractutauhq: Fixed-point fractional library routines.
- (line 1385)
-* __satfractutauqq: Fixed-point fractional library routines.
- (line 1383)
-* __satfractutausa2: Fixed-point fractional library routines.
- (line 1393)
-* __satfractutausq: Fixed-point fractional library routines.
- (line 1387)
-* __ssaddda3: Fixed-point fractional library routines.
- (line 67)
-* __ssadddq3: Fixed-point fractional library routines.
- (line 63)
-* __ssaddha3: Fixed-point fractional library routines.
- (line 65)
-* __ssaddhq3: Fixed-point fractional library routines.
- (line 60)
-* __ssaddqq3: Fixed-point fractional library routines.
- (line 59)
-* __ssaddsa3: Fixed-point fractional library routines.
- (line 66)
-* __ssaddsq3: Fixed-point fractional library routines.
- (line 61)
-* __ssaddta3: Fixed-point fractional library routines.
- (line 69)
-* __ssashlda3: Fixed-point fractional library routines.
- (line 402)
-* __ssashldq3: Fixed-point fractional library routines.
- (line 399)
-* __ssashlha3: Fixed-point fractional library routines.
- (line 400)
-* __ssashlhq3: Fixed-point fractional library routines.
- (line 396)
-* __ssashlsa3: Fixed-point fractional library routines.
- (line 401)
-* __ssashlsq3: Fixed-point fractional library routines.
- (line 397)
-* __ssashlta3: Fixed-point fractional library routines.
- (line 404)
-* __ssdivda3: Fixed-point fractional library routines.
- (line 261)
-* __ssdivdq3: Fixed-point fractional library routines.
- (line 257)
-* __ssdivha3: Fixed-point fractional library routines.
- (line 259)
-* __ssdivhq3: Fixed-point fractional library routines.
- (line 254)
-* __ssdivqq3: Fixed-point fractional library routines.
- (line 253)
-* __ssdivsa3: Fixed-point fractional library routines.
- (line 260)
-* __ssdivsq3: Fixed-point fractional library routines.
- (line 255)
-* __ssdivta3: Fixed-point fractional library routines.
- (line 263)
-* __ssmulda3: Fixed-point fractional library routines.
- (line 193)
-* __ssmuldq3: Fixed-point fractional library routines.
- (line 189)
-* __ssmulha3: Fixed-point fractional library routines.
- (line 191)
-* __ssmulhq3: Fixed-point fractional library routines.
- (line 186)
-* __ssmulqq3: Fixed-point fractional library routines.
- (line 185)
-* __ssmulsa3: Fixed-point fractional library routines.
- (line 192)
-* __ssmulsq3: Fixed-point fractional library routines.
- (line 187)
-* __ssmulta3: Fixed-point fractional library routines.
- (line 195)
-* __ssnegda2: Fixed-point fractional library routines.
- (line 316)
-* __ssnegdq2: Fixed-point fractional library routines.
- (line 313)
-* __ssnegha2: Fixed-point fractional library routines.
- (line 314)
-* __ssneghq2: Fixed-point fractional library routines.
- (line 311)
-* __ssnegqq2: Fixed-point fractional library routines.
- (line 310)
-* __ssnegsa2: Fixed-point fractional library routines.
- (line 315)
-* __ssnegsq2: Fixed-point fractional library routines.
- (line 312)
-* __ssnegta2: Fixed-point fractional library routines.
- (line 317)
-* __sssubda3: Fixed-point fractional library routines.
- (line 129)
-* __sssubdq3: Fixed-point fractional library routines.
- (line 125)
-* __sssubha3: Fixed-point fractional library routines.
- (line 127)
-* __sssubhq3: Fixed-point fractional library routines.
- (line 122)
-* __sssubqq3: Fixed-point fractional library routines.
- (line 121)
-* __sssubsa3: Fixed-point fractional library routines.
- (line 128)
-* __sssubsq3: Fixed-point fractional library routines.
- (line 123)
-* __sssubta3: Fixed-point fractional library routines.
- (line 131)
-* __subda3: Fixed-point fractional library routines.
- (line 107)
-* __subdf3: Soft float library routines.
- (line 31)
-* __subdq3: Fixed-point fractional library routines.
- (line 95)
-* __subha3: Fixed-point fractional library routines.
- (line 105)
-* __subhq3: Fixed-point fractional library routines.
- (line 92)
-* __subqq3: Fixed-point fractional library routines.
- (line 91)
-* __subsa3: Fixed-point fractional library routines.
- (line 106)
-* __subsf3: Soft float library routines.
- (line 30)
-* __subsq3: Fixed-point fractional library routines.
- (line 93)
-* __subta3: Fixed-point fractional library routines.
- (line 109)
-* __subtf3: Soft float library routines.
- (line 33)
-* __subuda3: Fixed-point fractional library routines.
- (line 115)
-* __subudq3: Fixed-point fractional library routines.
- (line 103)
-* __subuha3: Fixed-point fractional library routines.
- (line 111)
-* __subuhq3: Fixed-point fractional library routines.
- (line 99)
-* __subuqq3: Fixed-point fractional library routines.
- (line 97)
-* __subusa3: Fixed-point fractional library routines.
- (line 113)
-* __subusq3: Fixed-point fractional library routines.
- (line 101)
-* __subuta3: Fixed-point fractional library routines.
- (line 117)
-* __subvdi3: Integer library routines.
- (line 123)
-* __subvsi3: Integer library routines.
- (line 122)
-* __subxf3: Soft float library routines.
- (line 35)
-* __truncdfsf2: Soft float library routines.
- (line 76)
-* __trunctfdf2: Soft float library routines.
- (line 73)
-* __trunctfsf2: Soft float library routines.
- (line 75)
-* __truncxfdf2: Soft float library routines.
- (line 72)
-* __truncxfsf2: Soft float library routines.
- (line 74)
-* __ucmpdi2: Integer library routines.
- (line 93)
-* __ucmpti2: Integer library routines.
- (line 95)
-* __udivdi3: Integer library routines.
- (line 54)
-* __udivmoddi3: Integer library routines.
- (line 61)
-* __udivsi3: Integer library routines.
- (line 52)
-* __udivti3: Integer library routines.
- (line 56)
-* __udivuda3: Fixed-point fractional library routines.
- (line 246)
-* __udivudq3: Fixed-point fractional library routines.
- (line 240)
-* __udivuha3: Fixed-point fractional library routines.
- (line 242)
-* __udivuhq3: Fixed-point fractional library routines.
- (line 236)
-* __udivuqq3: Fixed-point fractional library routines.
- (line 234)
-* __udivusa3: Fixed-point fractional library routines.
- (line 244)
-* __udivusq3: Fixed-point fractional library routines.
- (line 238)
-* __udivuta3: Fixed-point fractional library routines.
- (line 248)
-* __umoddi3: Integer library routines.
- (line 71)
-* __umodsi3: Integer library routines.
- (line 69)
-* __umodti3: Integer library routines.
- (line 73)
-* __unorddf2: Soft float library routines.
- (line 173)
-* __unordsf2: Soft float library routines.
- (line 172)
-* __unordtf2: Soft float library routines.
- (line 174)
-* __usadduda3: Fixed-point fractional library routines.
- (line 85)
-* __usaddudq3: Fixed-point fractional library routines.
- (line 79)
-* __usadduha3: Fixed-point fractional library routines.
- (line 81)
-* __usadduhq3: Fixed-point fractional library routines.
- (line 75)
-* __usadduqq3: Fixed-point fractional library routines.
- (line 73)
-* __usaddusa3: Fixed-point fractional library routines.
- (line 83)
-* __usaddusq3: Fixed-point fractional library routines.
- (line 77)
-* __usadduta3: Fixed-point fractional library routines.
- (line 87)
-* __usashluda3: Fixed-point fractional library routines.
- (line 421)
-* __usashludq3: Fixed-point fractional library routines.
- (line 415)
-* __usashluha3: Fixed-point fractional library routines.
- (line 417)
-* __usashluhq3: Fixed-point fractional library routines.
- (line 411)
-* __usashluqq3: Fixed-point fractional library routines.
- (line 409)
-* __usashlusa3: Fixed-point fractional library routines.
- (line 419)
-* __usashlusq3: Fixed-point fractional library routines.
- (line 413)
-* __usashluta3: Fixed-point fractional library routines.
- (line 423)
-* __usdivuda3: Fixed-point fractional library routines.
- (line 280)
-* __usdivudq3: Fixed-point fractional library routines.
- (line 274)
-* __usdivuha3: Fixed-point fractional library routines.
- (line 276)
-* __usdivuhq3: Fixed-point fractional library routines.
- (line 270)
-* __usdivuqq3: Fixed-point fractional library routines.
- (line 268)
-* __usdivusa3: Fixed-point fractional library routines.
- (line 278)
-* __usdivusq3: Fixed-point fractional library routines.
- (line 272)
-* __usdivuta3: Fixed-point fractional library routines.
- (line 282)
-* __usmuluda3: Fixed-point fractional library routines.
- (line 212)
-* __usmuludq3: Fixed-point fractional library routines.
- (line 206)
-* __usmuluha3: Fixed-point fractional library routines.
- (line 208)
-* __usmuluhq3: Fixed-point fractional library routines.
- (line 202)
-* __usmuluqq3: Fixed-point fractional library routines.
- (line 200)
-* __usmulusa3: Fixed-point fractional library routines.
- (line 210)
-* __usmulusq3: Fixed-point fractional library routines.
- (line 204)
-* __usmuluta3: Fixed-point fractional library routines.
- (line 214)
-* __usneguda2: Fixed-point fractional library routines.
- (line 331)
-* __usnegudq2: Fixed-point fractional library routines.
- (line 326)
-* __usneguha2: Fixed-point fractional library routines.
- (line 328)
-* __usneguhq2: Fixed-point fractional library routines.
- (line 322)
-* __usneguqq2: Fixed-point fractional library routines.
- (line 321)
-* __usnegusa2: Fixed-point fractional library routines.
- (line 329)
-* __usnegusq2: Fixed-point fractional library routines.
- (line 324)
-* __usneguta2: Fixed-point fractional library routines.
- (line 333)
-* __ussubuda3: Fixed-point fractional library routines.
- (line 148)
-* __ussubudq3: Fixed-point fractional library routines.
- (line 142)
-* __ussubuha3: Fixed-point fractional library routines.
- (line 144)
-* __ussubuhq3: Fixed-point fractional library routines.
- (line 138)
-* __ussubuqq3: Fixed-point fractional library routines.
- (line 136)
-* __ussubusa3: Fixed-point fractional library routines.
- (line 146)
-* __ussubusq3: Fixed-point fractional library routines.
- (line 140)
-* __ussubuta3: Fixed-point fractional library routines.
- (line 150)
-* abort: Portability. (line 21)
-* abs: Arithmetic. (line 195)
-* abs and attributes: Expressions. (line 64)
-* ABS_EXPR: Expression trees. (line 6)
-* absence_set: Processor pipeline description.
- (line 215)
-* absM2 instruction pattern: Standard Names. (line 452)
-* absolute value: Arithmetic. (line 195)
-* access to operands: Accessors. (line 6)
-* access to special operands: Special Accessors. (line 6)
-* accessors: Accessors. (line 6)
-* ACCUM_TYPE_SIZE: Type Layout. (line 88)
-* ACCUMULATE_OUTGOING_ARGS: Stack Arguments. (line 46)
-* ACCUMULATE_OUTGOING_ARGS and stack frames: Function Entry. (line 135)
-* ADA_LONG_TYPE_SIZE: Type Layout. (line 26)
-* Adding a new GIMPLE statement code: Adding a new GIMPLE statement code.
- (line 6)
-* ADDITIONAL_REGISTER_NAMES: Instruction Output. (line 15)
-* addM3 instruction pattern: Standard Names. (line 216)
-* addMODEcc instruction pattern: Standard Names. (line 904)
-* addr_diff_vec: Side Effects. (line 302)
-* addr_diff_vec, length of: Insn Lengths. (line 26)
-* ADDR_EXPR: Expression trees. (line 6)
-* addr_vec: Side Effects. (line 297)
-* addr_vec, length of: Insn Lengths. (line 26)
-* address constraints: Simple Constraints. (line 154)
-* address_operand <1>: Simple Constraints. (line 158)
-* address_operand: Machine-Independent Predicates.
- (line 63)
-* addressing modes: Addressing Modes. (line 6)
-* ADJUST_FIELD_ALIGN: Storage Layout. (line 201)
-* ADJUST_INSN_LENGTH: Insn Lengths. (line 35)
-* ADJUST_REG_ALLOC_ORDER: Allocation Order. (line 23)
-* AGGR_INIT_EXPR: Expression trees. (line 6)
-* aggregates as return values: Aggregate Return. (line 6)
-* alias: Alias analysis. (line 6)
-* ALL_COP_ADDITIONAL_REGISTER_NAMES: MIPS Coprocessors. (line 32)
-* ALL_REGS: Register Classes. (line 17)
-* allocate_stack instruction pattern: Standard Names. (line 1227)
-* alternate entry points: Insns. (line 140)
-* anchored addresses: Anchored Addresses. (line 6)
-* and: Arithmetic. (line 153)
-* and and attributes: Expressions. (line 50)
-* and, canonicalization of: Insn Canonicalizations.
- (line 57)
-* andM3 instruction pattern: Standard Names. (line 222)
-* annotations: Annotations. (line 6)
-* APPLY_RESULT_SIZE: Scalar Return. (line 95)
-* ARG_POINTER_CFA_OFFSET: Frame Layout. (line 194)
-* ARG_POINTER_REGNUM: Frame Registers. (line 41)
-* ARG_POINTER_REGNUM and virtual registers: Regs and Memory. (line 65)
-* arg_pointer_rtx: Frame Registers. (line 85)
-* ARGS_GROW_DOWNWARD: Frame Layout. (line 35)
-* argument passing: Interface. (line 36)
-* arguments in registers: Register Arguments. (line 6)
-* arguments on stack: Stack Arguments. (line 6)
-* arithmetic library: Soft float library routines.
- (line 6)
-* arithmetic shift: Arithmetic. (line 168)
-* arithmetic shift with signed saturation: Arithmetic. (line 168)
-* arithmetic shift with unsigned saturation: Arithmetic. (line 168)
-* arithmetic, in RTL: Arithmetic. (line 6)
-* ARITHMETIC_TYPE_P: Types. (line 76)
-* array: Types. (line 6)
-* ARRAY_RANGE_REF: Expression trees. (line 6)
-* ARRAY_REF: Expression trees. (line 6)
-* ARRAY_TYPE: Types. (line 6)
-* AS_NEEDS_DASH_FOR_PIPED_INPUT: Driver. (line 151)
-* ashift: Arithmetic. (line 168)
-* ashift and attributes: Expressions. (line 64)
-* ashiftrt: Arithmetic. (line 185)
-* ashiftrt and attributes: Expressions. (line 64)
-* ashlM3 instruction pattern: Standard Names. (line 431)
-* ashrM3 instruction pattern: Standard Names. (line 441)
-* ASM_APP_OFF: File Framework. (line 61)
-* ASM_APP_ON: File Framework. (line 54)
-* ASM_COMMENT_START: File Framework. (line 49)
-* ASM_DECLARE_CLASS_REFERENCE: Label Output. (line 436)
-* ASM_DECLARE_CONSTANT_NAME: Label Output. (line 128)
-* ASM_DECLARE_FUNCTION_NAME: Label Output. (line 87)
-* ASM_DECLARE_FUNCTION_SIZE: Label Output. (line 101)
-* ASM_DECLARE_OBJECT_NAME: Label Output. (line 114)
-* ASM_DECLARE_REGISTER_GLOBAL: Label Output. (line 143)
-* ASM_DECLARE_UNRESOLVED_REFERENCE: Label Output. (line 442)
-* ASM_FINAL_SPEC: Driver. (line 144)
-* ASM_FINISH_DECLARE_OBJECT: Label Output. (line 151)
-* ASM_FORMAT_PRIVATE_NAME: Label Output. (line 354)
-* asm_fprintf: Instruction Output. (line 123)
-* ASM_FPRINTF_EXTENSIONS: Instruction Output. (line 134)
-* ASM_GENERATE_INTERNAL_LABEL: Label Output. (line 338)
-* asm_input: Side Effects. (line 284)
-* asm_input and /v: Flags. (line 94)
-* ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX: Exception Handling. (line 82)
-* ASM_NO_SKIP_IN_TEXT: Alignment Output. (line 72)
-* asm_noperands: Insns. (line 266)
-* asm_operands and /v: Flags. (line 94)
-* asm_operands, RTL sharing: Sharing. (line 45)
-* asm_operands, usage: Assembler. (line 6)
-* ASM_OUTPUT_ADDR_DIFF_ELT: Dispatch Tables. (line 9)
-* ASM_OUTPUT_ADDR_VEC_ELT: Dispatch Tables. (line 26)
-* ASM_OUTPUT_ALIGN: Alignment Output. (line 79)
-* ASM_OUTPUT_ALIGN_WITH_NOP: Alignment Output. (line 84)
-* ASM_OUTPUT_ALIGNED_BSS: Uninitialized Data. (line 64)
-* ASM_OUTPUT_ALIGNED_COMMON: Uninitialized Data. (line 23)
-* ASM_OUTPUT_ALIGNED_DECL_COMMON: Uninitialized Data. (line 31)
-* ASM_OUTPUT_ALIGNED_DECL_LOCAL: Uninitialized Data. (line 95)
-* ASM_OUTPUT_ALIGNED_LOCAL: Uninitialized Data. (line 87)
-* ASM_OUTPUT_ASCII: Data Output. (line 50)
-* ASM_OUTPUT_BSS: Uninitialized Data. (line 39)
-* ASM_OUTPUT_CASE_END: Dispatch Tables. (line 51)
-* ASM_OUTPUT_CASE_LABEL: Dispatch Tables. (line 38)
-* ASM_OUTPUT_COMMON: Uninitialized Data. (line 10)
-* ASM_OUTPUT_DEBUG_LABEL: Label Output. (line 326)
-* ASM_OUTPUT_DEF: Label Output. (line 375)
-* ASM_OUTPUT_DEF_FROM_DECLS: Label Output. (line 383)
-* ASM_OUTPUT_DWARF_DELTA: SDB and DWARF. (line 42)
-* ASM_OUTPUT_DWARF_OFFSET: SDB and DWARF. (line 46)
-* ASM_OUTPUT_DWARF_PCREL: SDB and DWARF. (line 52)
-* ASM_OUTPUT_EXTERNAL: Label Output. (line 264)
-* ASM_OUTPUT_FDESC: Data Output. (line 59)
-* ASM_OUTPUT_IDENT: File Framework. (line 83)
-* ASM_OUTPUT_INTERNAL_LABEL: Label Output. (line 17)
-* ASM_OUTPUT_LABEL: Label Output. (line 9)
-* ASM_OUTPUT_LABEL_REF: Label Output. (line 299)
-* ASM_OUTPUT_LABELREF: Label Output. (line 285)
-* ASM_OUTPUT_LOCAL: Uninitialized Data. (line 74)
-* ASM_OUTPUT_MAX_SKIP_ALIGN: Alignment Output. (line 88)
-* ASM_OUTPUT_MEASURED_SIZE: Label Output. (line 41)
-* ASM_OUTPUT_OPCODE: Instruction Output. (line 21)
-* ASM_OUTPUT_POOL_EPILOGUE: Data Output. (line 109)
-* ASM_OUTPUT_POOL_PROLOGUE: Data Output. (line 72)
-* ASM_OUTPUT_REG_POP: Instruction Output. (line 178)
-* ASM_OUTPUT_REG_PUSH: Instruction Output. (line 173)
-* ASM_OUTPUT_SIZE_DIRECTIVE: Label Output. (line 35)
-* ASM_OUTPUT_SKIP: Alignment Output. (line 66)
-* ASM_OUTPUT_SOURCE_FILENAME: File Framework. (line 68)
-* ASM_OUTPUT_SPECIAL_POOL_ENTRY: Data Output. (line 84)
-* ASM_OUTPUT_SYMBOL_REF: Label Output. (line 292)
-* ASM_OUTPUT_TYPE_DIRECTIVE: Label Output. (line 77)
-* ASM_OUTPUT_WEAK_ALIAS: Label Output. (line 401)
-* ASM_OUTPUT_WEAKREF: Label Output. (line 203)
-* ASM_PREFERRED_EH_DATA_FORMAT: Exception Handling. (line 67)
-* ASM_SPEC: Driver. (line 136)
-* ASM_STABD_OP: DBX Options. (line 36)
-* ASM_STABN_OP: DBX Options. (line 43)
-* ASM_STABS_OP: DBX Options. (line 29)
-* ASM_WEAKEN_DECL: Label Output. (line 195)
-* ASM_WEAKEN_LABEL: Label Output. (line 182)
-* assemble_name: Label Output. (line 8)
-* assemble_name_raw: Label Output. (line 16)
-* assembler format: File Framework. (line 6)
-* assembler instructions in RTL: Assembler. (line 6)
-* ASSEMBLER_DIALECT: Instruction Output. (line 146)
-* assigning attribute values to insns: Tagging Insns. (line 6)
-* assignment operator: Function Basics. (line 6)
-* asterisk in template: Output Statement. (line 29)
-* atan2M3 instruction pattern: Standard Names. (line 522)
-* attr <1>: Tagging Insns. (line 54)
-* attr: Expressions. (line 154)
-* attr_flag: Expressions. (line 119)
-* attribute expressions: Expressions. (line 6)
-* attribute specifications: Attr Example. (line 6)
-* attribute specifications example: Attr Example. (line 6)
-* ATTRIBUTE_ALIGNED_VALUE: Storage Layout. (line 183)
-* attributes: Attributes. (line 6)
-* attributes, defining: Defining Attributes.
- (line 6)
-* attributes, target-specific: Target Attributes. (line 6)
-* autoincrement addressing, availability: Portability. (line 21)
-* autoincrement/decrement addressing: Simple Constraints. (line 30)
-* automata_option: Processor pipeline description.
- (line 296)
-* automaton based pipeline description: Processor pipeline description.
- (line 6)
-* automaton based scheduler: Processor pipeline description.
- (line 6)
-* AVOID_CCMODE_COPIES: Values in Registers.
- (line 153)
-* backslash: Output Template. (line 46)
-* barrier: Insns. (line 160)
-* barrier and /f: Flags. (line 125)
-* barrier and /v: Flags. (line 44)
-* BASE_REG_CLASS: Register Classes. (line 107)
-* basic block: Basic Blocks. (line 6)
-* basic-block.h: Control Flow. (line 6)
-* BASIC_BLOCK: Basic Blocks. (line 19)
-* basic_block: Basic Blocks. (line 6)
-* BB_HEAD, BB_END: Maintaining the CFG.
- (line 88)
-* bb_seq: GIMPLE sequences. (line 73)
-* bCOND instruction pattern: Standard Names. (line 941)
-* BIGGEST_ALIGNMENT: Storage Layout. (line 173)
-* BIGGEST_FIELD_ALIGNMENT: Storage Layout. (line 194)
-* BImode: Machine Modes. (line 22)
-* BIND_EXPR: Expression trees. (line 6)
-* BINFO_TYPE: Classes. (line 6)
-* bit-fields: Bit-Fields. (line 6)
-* BIT_AND_EXPR: Expression trees. (line 6)
-* BIT_IOR_EXPR: Expression trees. (line 6)
-* BIT_NOT_EXPR: Expression trees. (line 6)
-* BIT_XOR_EXPR: Expression trees. (line 6)
-* BITFIELD_NBYTES_LIMITED: Storage Layout. (line 382)
-* BITS_BIG_ENDIAN: Storage Layout. (line 12)
-* BITS_BIG_ENDIAN, effect on sign_extract: Bit-Fields. (line 8)
-* BITS_PER_UNIT: Storage Layout. (line 52)
-* BITS_PER_WORD: Storage Layout. (line 57)
-* bitwise complement: Arithmetic. (line 149)
-* bitwise exclusive-or: Arithmetic. (line 163)
-* bitwise inclusive-or: Arithmetic. (line 158)
-* bitwise logical-and: Arithmetic. (line 153)
-* BLKmode: Machine Modes. (line 183)
-* BLKmode, and function return values: Calls. (line 23)
-* block statement iterators <1>: Maintaining the CFG.
- (line 45)
-* block statement iterators: Basic Blocks. (line 68)
-* BLOCK_FOR_INSN, bb_for_stmt: Maintaining the CFG.
- (line 40)
-* BLOCK_REG_PADDING: Register Arguments. (line 228)
-* blockage instruction pattern: Standard Names. (line 1408)
-* Blocks: Blocks. (line 6)
-* bool <1>: Exception Region Output.
- (line 60)
-* bool: Sections. (line 280)
-* BOOL_TYPE_SIZE: Type Layout. (line 44)
-* BOOLEAN_TYPE: Types. (line 6)
-* branch prediction: Profile information.
- (line 24)
-* BRANCH_COST: Costs. (line 52)
-* break_out_memory_refs: Addressing Modes. (line 130)
-* BREAK_STMT: Function Bodies. (line 6)
-* bsi_commit_edge_inserts: Maintaining the CFG.
- (line 118)
-* bsi_end_p: Maintaining the CFG.
- (line 60)
-* bsi_insert_after: Maintaining the CFG.
- (line 72)
-* bsi_insert_before: Maintaining the CFG.
- (line 78)
-* bsi_insert_on_edge: Maintaining the CFG.
- (line 118)
-* bsi_last: Maintaining the CFG.
- (line 56)
-* bsi_next: Maintaining the CFG.
- (line 64)
-* bsi_prev: Maintaining the CFG.
- (line 68)
-* bsi_remove: Maintaining the CFG.
- (line 84)
-* bsi_start: Maintaining the CFG.
- (line 52)
-* BSS_SECTION_ASM_OP: Sections. (line 68)
-* bswap: Arithmetic. (line 232)
-* btruncM2 instruction pattern: Standard Names. (line 540)
-* builtin_longjmp instruction pattern: Standard Names. (line 1313)
-* builtin_setjmp_receiver instruction pattern: Standard Names.
- (line 1303)
-* builtin_setjmp_setup instruction pattern: Standard Names. (line 1292)
-* byte_mode: Machine Modes. (line 336)
-* BYTES_BIG_ENDIAN: Storage Layout. (line 24)
-* BYTES_BIG_ENDIAN, effect on subreg: Regs and Memory. (line 221)
-* C statements for assembler output: Output Statement. (line 6)
-* C/C++ Internal Representation: Trees. (line 6)
-* C99 math functions, implicit usage: Library Calls. (line 76)
-* C_COMMON_OVERRIDE_OPTIONS: Run-time Target. (line 114)
-* c_register_pragma: Misc. (line 404)
-* c_register_pragma_with_expansion: Misc. (line 406)
-* call <1>: Side Effects. (line 86)
-* call: Flags. (line 234)
-* call instruction pattern: Standard Names. (line 974)
-* call usage: Calls. (line 10)
-* call, in call_insn: Flags. (line 33)
-* call, in mem: Flags. (line 99)
-* call-clobbered register: Register Basics. (line 35)
-* call-saved register: Register Basics. (line 35)
-* call-used register: Register Basics. (line 35)
-* CALL_EXPR: Expression trees. (line 6)
-* call_insn: Insns. (line 95)
-* call_insn and /c: Flags. (line 33)
-* call_insn and /f: Flags. (line 125)
-* call_insn and /i: Flags. (line 24)
-* call_insn and /j: Flags. (line 179)
-* call_insn and /s: Flags. (line 49)
-* call_insn and /u: Flags. (line 19)
-* call_insn and /u or /i: Flags. (line 29)
-* call_insn and /v: Flags. (line 44)
-* CALL_INSN_FUNCTION_USAGE: Insns. (line 101)
-* call_pop instruction pattern: Standard Names. (line 1002)
-* CALL_POPS_ARGS: Stack Arguments. (line 130)
-* CALL_REALLY_USED_REGISTERS: Register Basics. (line 46)
-* CALL_USED_REGISTERS: Register Basics. (line 35)
-* call_used_regs: Register Basics. (line 59)
-* call_value instruction pattern: Standard Names. (line 994)
-* call_value_pop instruction pattern: Standard Names. (line 1002)
-* CALLER_SAVE_PROFITABLE: Caller Saves. (line 11)
-* calling conventions: Stack and Calling. (line 6)
-* calling functions in RTL: Calls. (line 6)
-* can_create_pseudo_p: Standard Names. (line 75)
-* CAN_DEBUG_WITHOUT_FP: Run-time Target. (line 146)
-* CAN_ELIMINATE: Elimination. (line 71)
-* can_fallthru: Basic Blocks. (line 57)
-* canadian: Configure Terms. (line 6)
-* CANNOT_CHANGE_MODE_CLASS: Register Classes. (line 481)
-* CANNOT_CHANGE_MODE_CLASS and subreg semantics: Regs and Memory.
- (line 280)
-* canonicalization of instructions: Insn Canonicalizations.
- (line 6)
-* CANONICALIZE_COMPARISON: Condition Code. (line 84)
-* canonicalize_funcptr_for_compare instruction pattern: Standard Names.
- (line 1158)
-* CASE_USE_BIT_TESTS: Misc. (line 54)
-* CASE_VALUES_THRESHOLD: Misc. (line 47)
-* CASE_VECTOR_MODE: Misc. (line 27)
-* CASE_VECTOR_PC_RELATIVE: Misc. (line 40)
-* CASE_VECTOR_SHORTEN_MODE: Misc. (line 31)
-* casesi instruction pattern: Standard Names. (line 1082)
-* cbranchMODE4 instruction pattern: Standard Names. (line 963)
-* cc0: Regs and Memory. (line 307)
-* cc0, RTL sharing: Sharing. (line 27)
-* cc0_rtx: Regs and Memory. (line 333)
-* CC1_SPEC: Driver. (line 118)
-* CC1PLUS_SPEC: Driver. (line 126)
-* cc_status: Condition Code. (line 8)
-* CC_STATUS_MDEP: Condition Code. (line 19)
-* CC_STATUS_MDEP_INIT: Condition Code. (line 25)
-* CCmode: Machine Modes. (line 176)
-* CDImode: Machine Modes. (line 202)
-* CEIL_DIV_EXPR: Expression trees. (line 6)
-* CEIL_MOD_EXPR: Expression trees. (line 6)
-* ceilM2 instruction pattern: Standard Names. (line 556)
-* CFA_FRAME_BASE_OFFSET: Frame Layout. (line 226)
-* CFG, Control Flow Graph: Control Flow. (line 6)
-* cfghooks.h: Maintaining the CFG.
- (line 6)
-* cgraph_finalize_function: Parsing pass. (line 52)
-* chain_circular: GTY Options. (line 195)
-* chain_next: GTY Options. (line 195)
-* chain_prev: GTY Options. (line 195)
-* change_address: Standard Names. (line 47)
-* CHANGE_DYNAMIC_TYPE_EXPR: Expression trees. (line 6)
-* char <1>: Misc. (line 685)
-* char <2>: PCH Target. (line 12)
-* char <3>: Sections. (line 272)
-* char: GIMPLE_ASM. (line 53)
-* CHAR_TYPE_SIZE: Type Layout. (line 39)
-* check_stack instruction pattern: Standard Names. (line 1245)
-* CHImode: Machine Modes. (line 202)
-* class: Classes. (line 6)
-* class definitions, register: Register Classes. (line 6)
-* class preference constraints: Class Preferences. (line 6)
-* CLASS_LIKELY_SPILLED_P: Register Classes. (line 452)
-* CLASS_MAX_NREGS: Register Classes. (line 469)
-* CLASS_TYPE_P: Types. (line 80)
-* classes of RTX codes: RTL Classes. (line 6)
-* CLASSTYPE_DECLARED_CLASS: Classes. (line 6)
-* CLASSTYPE_HAS_MUTABLE: Classes. (line 80)
-* CLASSTYPE_NON_POD_P: Classes. (line 85)
-* CLEANUP_DECL: Function Bodies. (line 6)
-* CLEANUP_EXPR: Function Bodies. (line 6)
-* CLEANUP_POINT_EXPR: Expression trees. (line 6)
-* CLEANUP_STMT: Function Bodies. (line 6)
-* Cleanups: Cleanups. (line 6)
-* CLEAR_BY_PIECES_P: Costs. (line 130)
-* clear_cache instruction pattern: Standard Names. (line 1553)
-* CLEAR_INSN_CACHE: Trampolines. (line 100)
-* CLEAR_RATIO: Costs. (line 121)
-* clobber: Side Effects. (line 100)
-* clz: Arithmetic. (line 208)
-* CLZ_DEFINED_VALUE_AT_ZERO: Misc. (line 319)
-* clzM2 instruction pattern: Standard Names. (line 621)
-* cmpM instruction pattern: Standard Names. (line 654)
-* cmpmemM instruction pattern: Standard Names. (line 769)
-* cmpstrM instruction pattern: Standard Names. (line 750)
-* cmpstrnM instruction pattern: Standard Names. (line 738)
-* code generation RTL sequences: Expander Definitions.
- (line 6)
-* code iterators in .md files: Code Iterators. (line 6)
-* code_label: Insns. (line 119)
-* code_label and /i: Flags. (line 59)
-* code_label and /v: Flags. (line 44)
-* CODE_LABEL_NUMBER: Insns. (line 119)
-* codes, RTL expression: RTL Objects. (line 47)
-* COImode: Machine Modes. (line 202)
-* COLLECT2_HOST_INITIALIZATION: Host Misc. (line 32)
-* COLLECT_EXPORT_LIST: Misc. (line 767)
-* COLLECT_SHARED_FINI_FUNC: Macros for Initialization.
- (line 44)
-* COLLECT_SHARED_INIT_FUNC: Macros for Initialization.
- (line 33)
-* commit_edge_insertions: Maintaining the CFG.
- (line 118)
-* compare: Arithmetic. (line 43)
-* compare, canonicalization of: Insn Canonicalizations.
- (line 37)
-* comparison_operator: Machine-Independent Predicates.
- (line 111)
-* compiler passes and files: Passes. (line 6)
-* complement, bitwise: Arithmetic. (line 149)
-* COMPLEX_CST: Expression trees. (line 6)
-* COMPLEX_EXPR: Expression trees. (line 6)
-* COMPLEX_TYPE: Types. (line 6)
-* COMPONENT_REF: Expression trees. (line 6)
-* Compound Expressions: Compound Expressions.
- (line 6)
-* Compound Lvalues: Compound Lvalues. (line 6)
-* COMPOUND_EXPR: Expression trees. (line 6)
-* COMPOUND_LITERAL_EXPR: Expression trees. (line 6)
-* COMPOUND_LITERAL_EXPR_DECL: Expression trees. (line 608)
-* COMPOUND_LITERAL_EXPR_DECL_STMT: Expression trees. (line 608)
-* computed jump: Edges. (line 128)
-* computing the length of an insn: Insn Lengths. (line 6)
-* concat: Regs and Memory. (line 385)
-* concatn: Regs and Memory. (line 391)
-* cond: Comparisons. (line 90)
-* cond and attributes: Expressions. (line 37)
-* cond_exec: Side Effects. (line 248)
-* COND_EXPR: Expression trees. (line 6)
-* condition code register: Regs and Memory. (line 307)
-* condition code status: Condition Code. (line 6)
-* condition codes: Comparisons. (line 20)
-* conditional execution: Conditional Execution.
- (line 6)
-* Conditional Expressions: Conditional Expressions.
- (line 6)
-* CONDITIONAL_REGISTER_USAGE: Register Basics. (line 60)
-* conditional_trap instruction pattern: Standard Names. (line 1379)
-* conditions, in patterns: Patterns. (line 43)
-* configuration file <1>: Host Misc. (line 6)
-* configuration file: Filesystem. (line 6)
-* configure terms: Configure Terms. (line 6)
-* CONJ_EXPR: Expression trees. (line 6)
-* const: Constants. (line 99)
-* CONST0_RTX: Constants. (line 119)
-* const0_rtx: Constants. (line 16)
-* CONST1_RTX: Constants. (line 119)
-* const1_rtx: Constants. (line 16)
-* CONST2_RTX: Constants. (line 119)
-* const2_rtx: Constants. (line 16)
-* CONST_DECL: Declarations. (line 6)
-* const_double: Constants. (line 32)
-* const_double, RTL sharing: Sharing. (line 29)
-* CONST_DOUBLE_LOW: Constants. (line 39)
-* CONST_DOUBLE_OK_FOR_CONSTRAINT_P: Old Constraints. (line 69)
-* CONST_DOUBLE_OK_FOR_LETTER_P: Old Constraints. (line 54)
-* const_double_operand: Machine-Independent Predicates.
- (line 21)
-* const_fixed: Constants. (line 52)
-* const_int: Constants. (line 8)
-* const_int and attribute tests: Expressions. (line 47)
-* const_int and attributes: Expressions. (line 10)
-* const_int, RTL sharing: Sharing. (line 23)
-* const_int_operand: Machine-Independent Predicates.
- (line 16)
-* CONST_OK_FOR_CONSTRAINT_P: Old Constraints. (line 49)
-* CONST_OK_FOR_LETTER_P: Old Constraints. (line 40)
-* const_string: Constants. (line 71)
-* const_string and attributes: Expressions. (line 20)
-* const_true_rtx: Constants. (line 26)
-* const_vector: Constants. (line 59)
-* const_vector, RTL sharing: Sharing. (line 32)
-* constant attributes: Constant Attributes.
- (line 6)
-* constant definitions: Constant Definitions.
- (line 6)
-* CONSTANT_ADDRESS_P: Addressing Modes. (line 29)
-* CONSTANT_ALIGNMENT: Storage Layout. (line 241)
-* CONSTANT_P: Addressing Modes. (line 35)
-* CONSTANT_POOL_ADDRESS_P: Flags. (line 10)
-* CONSTANT_POOL_BEFORE_FUNCTION: Data Output. (line 64)
-* constants in constraints: Simple Constraints. (line 60)
-* constm1_rtx: Constants. (line 16)
-* constraint modifier characters: Modifiers. (line 6)
-* constraint, matching: Simple Constraints. (line 132)
-* CONSTRAINT_LEN: Old Constraints. (line 12)
-* constraint_num: C Constraint Interface.
- (line 38)
-* constraint_satisfied_p: C Constraint Interface.
- (line 54)
-* constraints: Constraints. (line 6)
-* constraints, defining: Define Constraints. (line 6)
-* constraints, defining, obsolete method: Old Constraints. (line 6)
-* constraints, machine specific: Machine Constraints.
- (line 6)
-* constraints, testing: C Constraint Interface.
- (line 6)
-* CONSTRUCTOR: Expression trees. (line 6)
-* constructor: Function Basics. (line 6)
-* constructors, automatic calls: Collect2. (line 15)
-* constructors, output of: Initialization. (line 6)
-* container: Containers. (line 6)
-* CONTINUE_STMT: Function Bodies. (line 6)
-* contributors: Contributors. (line 6)
-* controlling register usage: Register Basics. (line 76)
-* controlling the compilation driver: Driver. (line 6)
-* conventions, run-time: Interface. (line 6)
-* conversions: Conversions. (line 6)
-* CONVERT_EXPR: Expression trees. (line 6)
-* copy constructor: Function Basics. (line 6)
-* copy_rtx: Addressing Modes. (line 182)
-* copy_rtx_if_shared: Sharing. (line 64)
-* copysignM3 instruction pattern: Standard Names. (line 602)
-* cosM2 instruction pattern: Standard Names. (line 481)
-* costs of instructions: Costs. (line 6)
-* CP_INTEGRAL_TYPE: Types. (line 72)
-* cp_namespace_decls: Namespaces. (line 44)
-* CP_TYPE_CONST_NON_VOLATILE_P: Types. (line 45)
-* CP_TYPE_CONST_P: Types. (line 36)
-* CP_TYPE_QUALS: Types. (line 6)
-* CP_TYPE_RESTRICT_P: Types. (line 42)
-* CP_TYPE_VOLATILE_P: Types. (line 39)
-* CPLUSPLUS_CPP_SPEC: Driver. (line 113)
-* CPP_SPEC: Driver. (line 106)
-* CQImode: Machine Modes. (line 202)
-* cross compilation and floating point: Floating Point. (line 6)
-* CRT_CALL_STATIC_FUNCTION: Sections. (line 112)
-* CRTSTUFF_T_CFLAGS: Target Fragment. (line 35)
-* CRTSTUFF_T_CFLAGS_S: Target Fragment. (line 39)
-* CSImode: Machine Modes. (line 202)
-* CTImode: Machine Modes. (line 202)
-* ctz: Arithmetic. (line 216)
-* CTZ_DEFINED_VALUE_AT_ZERO: Misc. (line 320)
-* ctzM2 instruction pattern: Standard Names. (line 630)
-* CUMULATIVE_ARGS: Register Arguments. (line 127)
-* current_function_epilogue_delay_list: Function Entry. (line 181)
-* current_function_is_leaf: Leaf Functions. (line 51)
-* current_function_outgoing_args_size: Stack Arguments. (line 45)
-* current_function_pops_args: Function Entry. (line 106)
-* current_function_pretend_args_size: Function Entry. (line 112)
-* current_function_uses_only_leaf_regs: Leaf Functions. (line 51)
-* current_insn_predicate: Conditional Execution.
- (line 26)
-* DAmode: Machine Modes. (line 152)
-* data bypass: Processor pipeline description.
- (line 106)
-* data dependence delays: Processor pipeline description.
- (line 6)
-* Data Dependency Analysis: Dependency analysis.
- (line 6)
-* data structures: Per-Function Data. (line 6)
-* DATA_ALIGNMENT: Storage Layout. (line 228)
-* DATA_SECTION_ASM_OP: Sections. (line 53)
-* DBR_OUTPUT_SEQEND: Instruction Output. (line 107)
-* dbr_sequence_length: Instruction Output. (line 106)
-* DBX_BLOCKS_FUNCTION_RELATIVE: DBX Options. (line 103)
-* DBX_CONTIN_CHAR: DBX Options. (line 66)
-* DBX_CONTIN_LENGTH: DBX Options. (line 56)
-* DBX_DEBUGGING_INFO: DBX Options. (line 9)
-* DBX_FUNCTION_FIRST: DBX Options. (line 97)
-* DBX_LINES_FUNCTION_RELATIVE: DBX Options. (line 109)
-* DBX_NO_XREFS: DBX Options. (line 50)
-* DBX_OUTPUT_LBRAC: DBX Hooks. (line 9)
-* DBX_OUTPUT_MAIN_SOURCE_FILE_END: File Names and DBX. (line 34)
-* DBX_OUTPUT_MAIN_SOURCE_FILENAME: File Names and DBX. (line 9)
-* DBX_OUTPUT_NFUN: DBX Hooks. (line 18)
-* DBX_OUTPUT_NULL_N_SO_AT_MAIN_SOURCE_FILE_END: File Names and DBX.
- (line 42)
-* DBX_OUTPUT_RBRAC: DBX Hooks. (line 15)
-* DBX_OUTPUT_SOURCE_LINE: DBX Hooks. (line 22)
-* DBX_REGISTER_NUMBER: All Debuggers. (line 9)
-* DBX_REGPARM_STABS_CODE: DBX Options. (line 87)
-* DBX_REGPARM_STABS_LETTER: DBX Options. (line 92)
-* DBX_STATIC_CONST_VAR_CODE: DBX Options. (line 82)
-* DBX_STATIC_STAB_DATA_SECTION: DBX Options. (line 73)
-* DBX_TYPE_DECL_STABS_CODE: DBX Options. (line 78)
-* DBX_USE_BINCL: DBX Options. (line 115)
-* DCmode: Machine Modes. (line 197)
-* DDmode: Machine Modes. (line 90)
-* De Morgan's law: Insn Canonicalizations.
- (line 57)
-* dead_or_set_p: define_peephole. (line 65)
-* DEBUG_SYMS_TEXT: DBX Options. (line 25)
-* DEBUGGER_ARG_OFFSET: All Debuggers. (line 37)
-* DEBUGGER_AUTO_OFFSET: All Debuggers. (line 28)
-* decimal float library: Decimal float library routines.
- (line 6)
-* DECL_ALIGN: Declarations. (line 6)
-* DECL_ANTICIPATED: Function Basics. (line 48)
-* DECL_ARGUMENTS: Function Basics. (line 163)
-* DECL_ARRAY_DELETE_OPERATOR_P: Function Basics. (line 184)
-* DECL_ARTIFICIAL <1>: Function Basics. (line 6)
-* DECL_ARTIFICIAL: Working with declarations.
- (line 24)
-* DECL_ASSEMBLER_NAME: Function Basics. (line 6)
-* DECL_ATTRIBUTES: Attributes. (line 22)
-* DECL_BASE_CONSTRUCTOR_P: Function Basics. (line 94)
-* DECL_CLASS_SCOPE_P: Working with declarations.
- (line 41)
-* DECL_COMPLETE_CONSTRUCTOR_P: Function Basics. (line 90)
-* DECL_COMPLETE_DESTRUCTOR_P: Function Basics. (line 104)
-* DECL_CONST_MEMFUNC_P: Function Basics. (line 77)
-* DECL_CONSTRUCTOR_P: Function Basics. (line 6)
-* DECL_CONTEXT: Namespaces. (line 26)
-* DECL_CONV_FN_P: Function Basics. (line 6)
-* DECL_COPY_CONSTRUCTOR_P: Function Basics. (line 98)
-* DECL_DESTRUCTOR_P: Function Basics. (line 6)
-* DECL_EXTERN_C_FUNCTION_P: Function Basics. (line 52)
-* DECL_EXTERNAL <1>: Function Basics. (line 38)
-* DECL_EXTERNAL: Declarations. (line 6)
-* DECL_FUNCTION_MEMBER_P: Function Basics. (line 6)
-* DECL_FUNCTION_SCOPE_P: Working with declarations.
- (line 44)
-* DECL_FUNCTION_SPECIFIC_OPTIMIZATION: Function Basics. (line 6)
-* DECL_FUNCTION_SPECIFIC_TARGET: Function Basics. (line 6)
-* DECL_GLOBAL_CTOR_P: Function Basics. (line 6)
-* DECL_GLOBAL_DTOR_P: Function Basics. (line 6)
-* DECL_INITIAL: Declarations. (line 6)
-* DECL_LINKONCE_P: Function Basics. (line 6)
-* DECL_LOCAL_FUNCTION_P: Function Basics. (line 44)
-* DECL_MAIN_P: Function Basics. (line 7)
-* DECL_NAME <1>: Function Basics. (line 6)
-* DECL_NAME <2>: Working with declarations.
- (line 7)
-* DECL_NAME: Namespaces. (line 15)
-* DECL_NAMESPACE_ALIAS: Namespaces. (line 30)
-* DECL_NAMESPACE_SCOPE_P: Working with declarations.
- (line 37)
-* DECL_NAMESPACE_STD_P: Namespaces. (line 40)
-* DECL_NON_THUNK_FUNCTION_P: Function Basics. (line 144)
-* DECL_NONCONVERTING_P: Function Basics. (line 86)
-* DECL_NONSTATIC_MEMBER_FUNCTION_P: Function Basics. (line 74)
-* DECL_OVERLOADED_OPERATOR_P: Function Basics. (line 6)
-* DECL_RESULT: Function Basics. (line 168)
-* DECL_SIZE: Declarations. (line 6)
-* DECL_STATIC_FUNCTION_P: Function Basics. (line 71)
-* DECL_STMT: Function Bodies. (line 6)
-* DECL_STMT_DECL: Function Bodies. (line 6)
-* DECL_THUNK_P: Function Basics. (line 122)
-* DECL_VOLATILE_MEMFUNC_P: Function Basics. (line 80)
-* declaration: Declarations. (line 6)
-* declarations, RTL: RTL Declarations. (line 6)
-* DECLARE_LIBRARY_RENAMES: Library Calls. (line 9)
-* decrement_and_branch_until_zero instruction pattern: Standard Names.
- (line 1120)
-* def_optype_d: Manipulating GIMPLE statements.
- (line 94)
-* default: GTY Options. (line 81)
-* default_file_start: File Framework. (line 9)
-* DEFAULT_GDB_EXTENSIONS: DBX Options. (line 18)
-* DEFAULT_PCC_STRUCT_RETURN: Aggregate Return. (line 34)
-* DEFAULT_SIGNED_CHAR: Type Layout. (line 154)
-* define_address_constraint: Define Constraints. (line 107)
-* define_asm_attributes: Tagging Insns. (line 73)
-* define_attr: Defining Attributes.
- (line 6)
-* define_automaton: Processor pipeline description.
- (line 53)
-* define_bypass: Processor pipeline description.
- (line 197)
-* define_code_attr: Code Iterators. (line 6)
-* define_code_iterator: Code Iterators. (line 6)
-* define_cond_exec: Conditional Execution.
- (line 13)
-* define_constants: Constant Definitions.
- (line 6)
-* define_constraint: Define Constraints. (line 48)
-* define_cpu_unit: Processor pipeline description.
- (line 68)
-* define_delay: Delay Slots. (line 25)
-* define_expand: Expander Definitions.
- (line 11)
-* define_insn: Patterns. (line 6)
-* define_insn example: Example. (line 6)
-* define_insn_and_split: Insn Splitting. (line 170)
-* define_insn_reservation: Processor pipeline description.
- (line 106)
-* define_memory_constraint: Define Constraints. (line 88)
-* define_mode_attr: Substitutions. (line 6)
-* define_mode_iterator: Defining Mode Iterators.
- (line 6)
-* define_peephole: define_peephole. (line 6)
-* define_peephole2: define_peephole2. (line 6)
-* define_predicate: Defining Predicates.
- (line 6)
-* define_query_cpu_unit: Processor pipeline description.
- (line 90)
-* define_register_constraint: Define Constraints. (line 28)
-* define_reservation: Processor pipeline description.
- (line 186)
-* define_special_predicate: Defining Predicates.
- (line 6)
-* define_split: Insn Splitting. (line 32)
-* defining attributes and their values: Defining Attributes.
- (line 6)
-* defining constraints: Define Constraints. (line 6)
-* defining constraints, obsolete method: Old Constraints. (line 6)
-* defining jump instruction patterns: Jump Patterns. (line 6)
-* defining looping instruction patterns: Looping Patterns. (line 6)
-* defining peephole optimizers: Peephole Definitions.
- (line 6)
-* defining predicates: Defining Predicates.
- (line 6)
-* defining RTL sequences for code generation: Expander Definitions.
- (line 6)
-* delay slots, defining: Delay Slots. (line 6)
-* DELAY_SLOTS_FOR_EPILOGUE: Function Entry. (line 163)
-* deletable: GTY Options. (line 149)
-* DELETE_IF_ORDINARY: Filesystem. (line 79)
-* Dependent Patterns: Dependent Patterns. (line 6)
-* desc: GTY Options. (line 81)
-* destructor: Function Basics. (line 6)
-* destructors, output of: Initialization. (line 6)
-* deterministic finite state automaton: Processor pipeline description.
- (line 6)
-* DF_SIZE: Type Layout. (line 130)
-* DFmode: Machine Modes. (line 73)
-* digits in constraint: Simple Constraints. (line 120)
-* DImode: Machine Modes. (line 45)
-* DIR_SEPARATOR: Filesystem. (line 18)
-* DIR_SEPARATOR_2: Filesystem. (line 19)
-* directory options .md: Including Patterns. (line 44)
-* disabling certain registers: Register Basics. (line 76)
-* dispatch table: Dispatch Tables. (line 8)
-* div: Arithmetic. (line 111)
-* div and attributes: Expressions. (line 64)
-* division: Arithmetic. (line 111)
-* divM3 instruction pattern: Standard Names. (line 222)
-* divmodM4 instruction pattern: Standard Names. (line 411)
-* DO_BODY: Function Bodies. (line 6)
-* DO_COND: Function Bodies. (line 6)
-* DO_STMT: Function Bodies. (line 6)
-* DOLLARS_IN_IDENTIFIERS: Misc. (line 488)
-* doloop_begin instruction pattern: Standard Names. (line 1151)
-* doloop_end instruction pattern: Standard Names. (line 1130)
-* DONE: Expander Definitions.
- (line 74)
-* DONT_USE_BUILTIN_SETJMP: Exception Region Output.
- (line 70)
-* DOUBLE_TYPE_SIZE: Type Layout. (line 53)
-* DQmode: Machine Modes. (line 115)
-* driver: Driver. (line 6)
-* DRIVER_SELF_SPECS: Driver. (line 71)
-* DUMPFILE_FORMAT: Filesystem. (line 67)
-* DWARF2_ASM_LINE_DEBUG_INFO: SDB and DWARF. (line 36)
-* DWARF2_DEBUGGING_INFO: SDB and DWARF. (line 13)
-* DWARF2_FRAME_INFO: SDB and DWARF. (line 30)
-* DWARF2_FRAME_REG_OUT: Frame Registers. (line 133)
-* DWARF2_UNWIND_INFO: Exception Region Output.
- (line 40)
-* DWARF_ALT_FRAME_RETURN_COLUMN: Frame Layout. (line 152)
-* DWARF_CIE_DATA_ALIGNMENT: Exception Region Output.
- (line 75)
-* DWARF_FRAME_REGISTERS: Frame Registers. (line 93)
-* DWARF_FRAME_REGNUM: Frame Registers. (line 125)
-* DWARF_REG_TO_UNWIND_COLUMN: Frame Registers. (line 117)
-* DWARF_ZERO_REG: Frame Layout. (line 163)
-* DYNAMIC_CHAIN_ADDRESS: Frame Layout. (line 92)
-* E in constraint: Simple Constraints. (line 79)
-* earlyclobber operand: Modifiers. (line 25)
-* edge: Edges. (line 6)
-* edge in the flow graph: Edges. (line 6)
-* edge iterators: Edges. (line 15)
-* edge splitting: Maintaining the CFG.
- (line 118)
-* EDGE_ABNORMAL: Edges. (line 128)
-* EDGE_ABNORMAL, EDGE_ABNORMAL_CALL: Edges. (line 171)
-* EDGE_ABNORMAL, EDGE_EH: Edges. (line 96)
-* EDGE_ABNORMAL, EDGE_SIBCALL: Edges. (line 122)
-* EDGE_FALLTHRU, force_nonfallthru: Edges. (line 86)
-* EDOM, implicit usage: Library Calls. (line 58)
-* EH_FRAME_IN_DATA_SECTION: Exception Region Output.
- (line 20)
-* EH_FRAME_SECTION_NAME: Exception Region Output.
- (line 10)
-* eh_return instruction pattern: Standard Names. (line 1319)
-* EH_RETURN_DATA_REGNO: Exception Handling. (line 7)
-* EH_RETURN_HANDLER_RTX: Exception Handling. (line 39)
-* EH_RETURN_STACKADJ_RTX: Exception Handling. (line 22)
-* EH_TABLES_CAN_BE_READ_ONLY: Exception Region Output.
- (line 29)
-* EH_USES: Function Entry. (line 158)
-* ei_edge: Edges. (line 43)
-* ei_end_p: Edges. (line 27)
-* ei_last: Edges. (line 23)
-* ei_next: Edges. (line 35)
-* ei_one_before_end_p: Edges. (line 31)
-* ei_prev: Edges. (line 39)
-* ei_safe_safe: Edges. (line 47)
-* ei_start: Edges. (line 19)
-* ELIGIBLE_FOR_EPILOGUE_DELAY: Function Entry. (line 169)
-* ELIMINABLE_REGS: Elimination. (line 44)
-* ELSE_CLAUSE: Function Bodies. (line 6)
-* Embedded C: Fixed-point fractional library routines.
- (line 6)
-* EMIT_MODE_SET: Mode Switching. (line 74)
-* Empty Statements: Empty Statements. (line 6)
-* EMPTY_CLASS_EXPR: Function Bodies. (line 6)
-* EMPTY_FIELD_BOUNDARY: Storage Layout. (line 295)
-* Emulated TLS: Emulated TLS. (line 6)
-* ENABLE_EXECUTE_STACK: Trampolines. (line 110)
-* enabled: Disable Insn Alternatives.
- (line 6)
-* ENDFILE_SPEC: Driver. (line 218)
-* endianness: Portability. (line 21)
-* ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR: Basic Blocks. (line 28)
-* enum machine_mode: Machine Modes. (line 6)
-* enum reg_class: Register Classes. (line 65)
-* ENUMERAL_TYPE: Types. (line 6)
-* epilogue: Function Entry. (line 6)
-* epilogue instruction pattern: Standard Names. (line 1351)
-* EPILOGUE_USES: Function Entry. (line 152)
-* eq: Comparisons. (line 52)
-* eq and attributes: Expressions. (line 64)
-* eq_attr: Expressions. (line 85)
-* EQ_EXPR: Expression trees. (line 6)
-* equal: Comparisons. (line 52)
-* errno, implicit usage: Library Calls. (line 70)
-* EXACT_DIV_EXPR: Expression trees. (line 6)
-* examining SSA_NAMEs: SSA. (line 218)
-* exception handling <1>: Exception Handling. (line 6)
-* exception handling: Edges. (line 96)
-* exception_receiver instruction pattern: Standard Names. (line 1283)
-* exclamation point: Multi-Alternative. (line 47)
-* exclusion_set: Processor pipeline description.
- (line 215)
-* exclusive-or, bitwise: Arithmetic. (line 163)
-* EXIT_EXPR: Expression trees. (line 6)
-* EXIT_IGNORE_STACK: Function Entry. (line 140)
-* expander definitions: Expander Definitions.
- (line 6)
-* expM2 instruction pattern: Standard Names. (line 497)
-* expr_list: Insns. (line 505)
-* EXPR_STMT: Function Bodies. (line 6)
-* EXPR_STMT_EXPR: Function Bodies. (line 6)
-* expression: Expression trees. (line 6)
-* expression codes: RTL Objects. (line 47)
-* extendMN2 instruction pattern: Standard Names. (line 826)
-* extensible constraints: Simple Constraints. (line 163)
-* EXTRA_ADDRESS_CONSTRAINT: Old Constraints. (line 123)
-* EXTRA_CONSTRAINT: Old Constraints. (line 74)
-* EXTRA_CONSTRAINT_STR: Old Constraints. (line 95)
-* EXTRA_MEMORY_CONSTRAINT: Old Constraints. (line 100)
-* EXTRA_SPECS: Driver. (line 245)
-* extv instruction pattern: Standard Names. (line 862)
-* extzv instruction pattern: Standard Names. (line 877)
-* F in constraint: Simple Constraints. (line 84)
-* FAIL: Expander Definitions.
- (line 80)
-* fall-thru: Edges. (line 69)
-* FATAL_EXIT_CODE: Host Misc. (line 6)
-* FDL, GNU Free Documentation License: GNU Free Documentation License.
- (line 6)
-* features, optional, in system conventions: Run-time Target.
- (line 59)
-* ffs: Arithmetic. (line 202)
-* ffsM2 instruction pattern: Standard Names. (line 611)
-* FIELD_DECL: Declarations. (line 6)
-* file_end_indicate_exec_stack: File Framework. (line 41)
-* files and passes of the compiler: Passes. (line 6)
-* files, generated: Files. (line 6)
-* final_absence_set: Processor pipeline description.
- (line 215)
-* FINAL_PRESCAN_INSN: Instruction Output. (line 46)
-* final_presence_set: Processor pipeline description.
- (line 215)
-* final_scan_insn: Function Entry. (line 181)
-* final_sequence: Instruction Output. (line 117)
-* FIND_BASE_TERM: Addressing Modes. (line 110)
-* FINI_ARRAY_SECTION_ASM_OP: Sections. (line 105)
-* FINI_SECTION_ASM_OP: Sections. (line 90)
-* finite state automaton minimization: Processor pipeline description.
- (line 296)
-* FIRST_PARM_OFFSET: Frame Layout. (line 67)
-* FIRST_PARM_OFFSET and virtual registers: Regs and Memory. (line 65)
-* FIRST_PSEUDO_REGISTER: Register Basics. (line 9)
-* FIRST_STACK_REG: Stack Registers. (line 23)
-* FIRST_VIRTUAL_REGISTER: Regs and Memory. (line 51)
-* fix: Conversions. (line 66)
-* FIX_TRUNC_EXPR: Expression trees. (line 6)
-* fix_truncMN2 instruction pattern: Standard Names. (line 813)
-* fixed register: Register Basics. (line 15)
-* fixed-point fractional library: Fixed-point fractional library routines.
- (line 6)
-* FIXED_CONVERT_EXPR: Expression trees. (line 6)
-* FIXED_CST: Expression trees. (line 6)
-* FIXED_POINT_TYPE: Types. (line 6)
-* FIXED_REGISTERS: Register Basics. (line 15)
-* fixed_regs: Register Basics. (line 59)
-* fixMN2 instruction pattern: Standard Names. (line 793)
-* FIXUNS_TRUNC_LIKE_FIX_TRUNC: Misc. (line 100)
-* fixuns_truncMN2 instruction pattern: Standard Names. (line 817)
-* fixunsMN2 instruction pattern: Standard Names. (line 802)
-* flags in RTL expression: Flags. (line 6)
-* float: Conversions. (line 58)
-* FLOAT_EXPR: Expression trees. (line 6)
-* float_extend: Conversions. (line 33)
-* FLOAT_LIB_COMPARE_RETURNS_BOOL: Library Calls. (line 25)
-* FLOAT_STORE_FLAG_VALUE: Misc. (line 301)
-* float_truncate: Conversions. (line 53)
-* FLOAT_TYPE_SIZE: Type Layout. (line 49)
-* FLOAT_WORDS_BIG_ENDIAN: Storage Layout. (line 43)
-* FLOAT_WORDS_BIG_ENDIAN, (lack of) effect on subreg: Regs and Memory.
- (line 226)
-* floating point and cross compilation: Floating Point. (line 6)
-* Floating Point Emulation: Target Fragment. (line 15)
-* floating point emulation library, US Software GOFAST: Library Calls.
- (line 44)
-* floatMN2 instruction pattern: Standard Names. (line 785)
-* floatunsMN2 instruction pattern: Standard Names. (line 789)
-* FLOOR_DIV_EXPR: Expression trees. (line 6)
-* FLOOR_MOD_EXPR: Expression trees. (line 6)
-* floorM2 instruction pattern: Standard Names. (line 532)
-* flow-insensitive alias analysis: Alias analysis. (line 6)
-* flow-sensitive alias analysis: Alias analysis. (line 6)
-* fmodM3 instruction pattern: Standard Names. (line 463)
-* FOR_BODY: Function Bodies. (line 6)
-* FOR_COND: Function Bodies. (line 6)
-* FOR_EXPR: Function Bodies. (line 6)
-* FOR_INIT_STMT: Function Bodies. (line 6)
-* FOR_STMT: Function Bodies. (line 6)
-* FORCE_CODE_SECTION_ALIGN: Sections. (line 136)
-* force_reg: Standard Names. (line 36)
-* fract_convert: Conversions. (line 82)
-* FRACT_TYPE_SIZE: Type Layout. (line 68)
-* fractional types: Fixed-point fractional library routines.
- (line 6)
-* fractMN2 instruction pattern: Standard Names. (line 835)
-* fractunsMN2 instruction pattern: Standard Names. (line 850)
-* frame layout: Frame Layout. (line 6)
-* FRAME_ADDR_RTX: Frame Layout. (line 116)
-* FRAME_GROWS_DOWNWARD: Frame Layout. (line 31)
-* FRAME_GROWS_DOWNWARD and virtual registers: Regs and Memory.
- (line 69)
-* FRAME_POINTER_CFA_OFFSET: Frame Layout. (line 212)
-* frame_pointer_needed: Function Entry. (line 34)
-* FRAME_POINTER_REGNUM: Frame Registers. (line 14)
-* FRAME_POINTER_REGNUM and virtual registers: Regs and Memory.
- (line 74)
-* FRAME_POINTER_REQUIRED: Elimination. (line 9)
-* frame_pointer_rtx: Frame Registers. (line 85)
-* frame_related: Flags. (line 242)
-* frame_related, in insn, call_insn, jump_insn, barrier, and set: Flags.
- (line 125)
-* frame_related, in mem: Flags. (line 103)
-* frame_related, in reg: Flags. (line 112)
-* frame_related, in symbol_ref: Flags. (line 183)
-* frequency, count, BB_FREQ_BASE: Profile information.
- (line 30)
-* ftruncM2 instruction pattern: Standard Names. (line 808)
-* function: Functions. (line 6)
-* function body: Function Bodies. (line 6)
-* function call conventions: Interface. (line 6)
-* function entry and exit: Function Entry. (line 6)
-* function entry point, alternate function entry point: Edges.
- (line 180)
-* function-call insns: Calls. (line 6)
-* FUNCTION_ARG: Register Arguments. (line 11)
-* FUNCTION_ARG_ADVANCE: Register Arguments. (line 185)
-* FUNCTION_ARG_BOUNDARY: Register Arguments. (line 238)
-* FUNCTION_ARG_OFFSET: Register Arguments. (line 196)
-* FUNCTION_ARG_PADDING: Register Arguments. (line 203)
-* FUNCTION_ARG_REGNO_P: Register Arguments. (line 243)
-* FUNCTION_BOUNDARY: Storage Layout. (line 170)
-* FUNCTION_DECL: Functions. (line 6)
-* FUNCTION_INCOMING_ARG: Register Arguments. (line 68)
-* FUNCTION_MODE: Misc. (line 356)
-* FUNCTION_OUTGOING_VALUE: Scalar Return. (line 56)
-* FUNCTION_PROFILER: Profiling. (line 9)
-* FUNCTION_TYPE: Types. (line 6)
-* FUNCTION_VALUE: Scalar Return. (line 52)
-* FUNCTION_VALUE_REGNO_P: Scalar Return. (line 69)
-* functions, leaf: Leaf Functions. (line 6)
-* fundamental type: Types. (line 6)
-* g in constraint: Simple Constraints. (line 110)
-* G in constraint: Simple Constraints. (line 88)
-* garbage collector, invocation: Invoking the garbage collector.
- (line 6)
-* GCC and portability: Portability. (line 6)
-* GCC_DRIVER_HOST_INITIALIZATION: Host Misc. (line 36)
-* gcov_type: Profile information.
- (line 41)
-* ge: Comparisons. (line 72)
-* ge and attributes: Expressions. (line 64)
-* GE_EXPR: Expression trees. (line 6)
-* GEN_ERRNO_RTX: Library Calls. (line 71)
-* gencodes: RTL passes. (line 18)
-* general_operand: Machine-Independent Predicates.
- (line 105)
-* GENERAL_REGS: Register Classes. (line 23)
-* generated files: Files. (line 6)
-* generating assembler output: Output Statement. (line 6)
-* generating insns: RTL Template. (line 6)
-* GENERIC <1>: GENERIC. (line 6)
-* GENERIC <2>: Gimplification pass.
- (line 12)
-* GENERIC: Parsing pass. (line 6)
-* generic predicates: Machine-Independent Predicates.
- (line 6)
-* genflags: RTL passes. (line 18)
-* get_attr: Expressions. (line 80)
-* get_attr_length: Insn Lengths. (line 46)
-* GET_CLASS_NARROWEST_MODE: Machine Modes. (line 333)
-* GET_CODE: RTL Objects. (line 47)
-* get_frame_size: Elimination. (line 31)
-* get_insns: Insns. (line 34)
-* get_last_insn: Insns. (line 34)
-* GET_MODE: Machine Modes. (line 280)
-* GET_MODE_ALIGNMENT: Machine Modes. (line 320)
-* GET_MODE_BITSIZE: Machine Modes. (line 304)
-* GET_MODE_CLASS: Machine Modes. (line 294)
-* GET_MODE_FBIT: Machine Modes. (line 311)
-* GET_MODE_IBIT: Machine Modes. (line 307)
-* GET_MODE_MASK: Machine Modes. (line 315)
-* GET_MODE_NAME: Machine Modes. (line 291)
-* GET_MODE_NUNITS: Machine Modes. (line 329)
-* GET_MODE_SIZE: Machine Modes. (line 301)
-* GET_MODE_UNIT_SIZE: Machine Modes. (line 323)
-* GET_MODE_WIDER_MODE: Machine Modes. (line 297)
-* GET_RTX_CLASS: RTL Classes. (line 6)
-* GET_RTX_FORMAT: RTL Classes. (line 130)
-* GET_RTX_LENGTH: RTL Classes. (line 127)
-* geu: Comparisons. (line 72)
-* geu and attributes: Expressions. (line 64)
-* GGC: Type Information. (line 6)
-* ggc_collect: Invoking the garbage collector.
- (line 6)
-* GIMPLE <1>: GIMPLE. (line 6)
-* GIMPLE <2>: Gimplification pass.
- (line 6)
-* GIMPLE: Parsing pass. (line 14)
-* GIMPLE Exception Handling: GIMPLE Exception Handling.
- (line 6)
-* GIMPLE instruction set: GIMPLE instruction set.
- (line 6)
-* GIMPLE sequences: GIMPLE sequences. (line 6)
-* gimple_addresses_taken: Manipulating GIMPLE statements.
- (line 90)
-* GIMPLE_ASM: GIMPLE_ASM. (line 6)
-* gimple_asm_clear_volatile: GIMPLE_ASM. (line 63)
-* gimple_asm_clobber_op: GIMPLE_ASM. (line 46)
-* gimple_asm_input_op: GIMPLE_ASM. (line 30)
-* gimple_asm_output_op: GIMPLE_ASM. (line 38)
-* gimple_asm_set_clobber_op: GIMPLE_ASM. (line 50)
-* gimple_asm_set_input_op: GIMPLE_ASM. (line 34)
-* gimple_asm_set_output_op: GIMPLE_ASM. (line 42)
-* gimple_asm_set_volatile: GIMPLE_ASM. (line 60)
-* gimple_asm_volatile_p: GIMPLE_ASM. (line 57)
-* GIMPLE_ASSIGN: GIMPLE_ASSIGN. (line 6)
-* gimple_assign_cast_p: GIMPLE_ASSIGN. (line 89)
-* gimple_assign_lhs: GIMPLE_ASSIGN. (line 51)
-* gimple_assign_rhs1: GIMPLE_ASSIGN. (line 57)
-* gimple_assign_rhs2: GIMPLE_ASSIGN. (line 64)
-* gimple_assign_set_lhs: GIMPLE_ASSIGN. (line 71)
-* gimple_assign_set_rhs1: GIMPLE_ASSIGN. (line 74)
-* gimple_assign_set_rhs2: GIMPLE_ASSIGN. (line 85)
-* gimple_bb: Manipulating GIMPLE statements.
- (line 18)
-* GIMPLE_BIND: GIMPLE_BIND. (line 6)
-* gimple_bind_add_seq: GIMPLE_BIND. (line 36)
-* gimple_bind_add_stmt: GIMPLE_BIND. (line 32)
-* gimple_bind_append_vars: GIMPLE_BIND. (line 19)
-* gimple_bind_block: GIMPLE_BIND. (line 40)
-* gimple_bind_body: GIMPLE_BIND. (line 23)
-* gimple_bind_set_block: GIMPLE_BIND. (line 45)
-* gimple_bind_set_body: GIMPLE_BIND. (line 28)
-* gimple_bind_set_vars: GIMPLE_BIND. (line 15)
-* gimple_bind_vars: GIMPLE_BIND. (line 12)
-* gimple_block: Manipulating GIMPLE statements.
- (line 21)
-* gimple_build_asm: GIMPLE_ASM. (line 8)
-* gimple_build_asm_vec: GIMPLE_ASM. (line 17)
-* gimple_build_assign: GIMPLE_ASSIGN. (line 7)
-* gimple_build_assign_with_ops: GIMPLE_ASSIGN. (line 30)
-* gimple_build_bind: GIMPLE_BIND. (line 8)
-* gimple_build_call: GIMPLE_CALL. (line 8)
-* gimple_build_call_from_tree: GIMPLE_CALL. (line 16)
-* gimple_build_call_vec: GIMPLE_CALL. (line 25)
-* gimple_build_catch: GIMPLE_CATCH. (line 8)
-* gimple_build_cdt: GIMPLE_CHANGE_DYNAMIC_TYPE.
- (line 7)
-* gimple_build_cond: GIMPLE_COND. (line 8)
-* gimple_build_cond_from_tree: GIMPLE_COND. (line 16)
-* gimple_build_eh_filter: GIMPLE_EH_FILTER. (line 8)
-* gimple_build_goto: GIMPLE_LABEL. (line 18)
-* gimple_build_label: GIMPLE_LABEL. (line 7)
-* gimple_build_nop: GIMPLE_NOP. (line 7)
-* gimple_build_omp_atomic_load: GIMPLE_OMP_ATOMIC_LOAD.
- (line 8)
-* gimple_build_omp_atomic_store: GIMPLE_OMP_ATOMIC_STORE.
- (line 7)
-* gimple_build_omp_continue: GIMPLE_OMP_CONTINUE.
- (line 8)
-* gimple_build_omp_critical: GIMPLE_OMP_CRITICAL.
- (line 8)
-* gimple_build_omp_for: GIMPLE_OMP_FOR. (line 9)
-* gimple_build_omp_master: GIMPLE_OMP_MASTER. (line 7)
-* gimple_build_omp_ordered: GIMPLE_OMP_ORDERED. (line 7)
-* gimple_build_omp_parallel: GIMPLE_OMP_PARALLEL.
- (line 8)
-* gimple_build_omp_return: GIMPLE_OMP_RETURN. (line 7)
-* gimple_build_omp_section: GIMPLE_OMP_SECTION. (line 7)
-* gimple_build_omp_sections: GIMPLE_OMP_SECTIONS.
- (line 8)
-* gimple_build_omp_sections_switch: GIMPLE_OMP_SECTIONS.
- (line 14)
-* gimple_build_omp_single: GIMPLE_OMP_SINGLE. (line 8)
-* gimple_build_resx: GIMPLE_RESX. (line 7)
-* gimple_build_return: GIMPLE_RETURN. (line 7)
-* gimple_build_switch: GIMPLE_SWITCH. (line 8)
-* gimple_build_switch_vec: GIMPLE_SWITCH. (line 16)
-* gimple_build_try: GIMPLE_TRY. (line 8)
-* gimple_build_wce: GIMPLE_WITH_CLEANUP_EXPR.
- (line 7)
-* GIMPLE_CALL: GIMPLE_CALL. (line 6)
-* gimple_call_arg: GIMPLE_CALL. (line 66)
-* gimple_call_cannot_inline_p: GIMPLE_CALL. (line 91)
-* gimple_call_chain: GIMPLE_CALL. (line 57)
-* gimple_call_copy_skip_args: GIMPLE_CALL. (line 98)
-* gimple_call_fn: GIMPLE_CALL. (line 38)
-* gimple_call_fndecl: GIMPLE_CALL. (line 46)
-* gimple_call_lhs: GIMPLE_CALL. (line 29)
-* gimple_call_mark_uninlinable: GIMPLE_CALL. (line 88)
-* gimple_call_noreturn_p: GIMPLE_CALL. (line 94)
-* gimple_call_return_type: GIMPLE_CALL. (line 54)
-* gimple_call_set_arg: GIMPLE_CALL. (line 76)
-* gimple_call_set_chain: GIMPLE_CALL. (line 60)
-* gimple_call_set_fn: GIMPLE_CALL. (line 42)
-* gimple_call_set_fndecl: GIMPLE_CALL. (line 51)
-* gimple_call_set_lhs: GIMPLE_CALL. (line 35)
-* gimple_call_set_tail: GIMPLE_CALL. (line 80)
-* gimple_call_tail_p: GIMPLE_CALL. (line 85)
-* GIMPLE_CATCH: GIMPLE_CATCH. (line 6)
-* gimple_catch_handler: GIMPLE_CATCH. (line 20)
-* gimple_catch_set_handler: GIMPLE_CATCH. (line 28)
-* gimple_catch_set_types: GIMPLE_CATCH. (line 24)
-* gimple_catch_types: GIMPLE_CATCH. (line 13)
-* gimple_cdt_location: GIMPLE_CHANGE_DYNAMIC_TYPE.
- (line 24)
-* gimple_cdt_new_type: GIMPLE_CHANGE_DYNAMIC_TYPE.
- (line 11)
-* gimple_cdt_set_location: GIMPLE_CHANGE_DYNAMIC_TYPE.
- (line 32)
-* gimple_cdt_set_new_type: GIMPLE_CHANGE_DYNAMIC_TYPE.
- (line 20)
-* GIMPLE_CHANGE_DYNAMIC_TYPE: GIMPLE_CHANGE_DYNAMIC_TYPE.
- (line 6)
-* gimple_code: Manipulating GIMPLE statements.
- (line 15)
-* GIMPLE_COND: GIMPLE_COND. (line 6)
-* gimple_cond_false_label: GIMPLE_COND. (line 60)
-* gimple_cond_lhs: GIMPLE_COND. (line 30)
-* gimple_cond_make_false: GIMPLE_COND. (line 64)
-* gimple_cond_make_true: GIMPLE_COND. (line 67)
-* gimple_cond_rhs: GIMPLE_COND. (line 38)
-* gimple_cond_set_code: GIMPLE_COND. (line 26)
-* gimple_cond_set_false_label: GIMPLE_COND. (line 56)
-* gimple_cond_set_lhs: GIMPLE_COND. (line 34)
-* gimple_cond_set_rhs: GIMPLE_COND. (line 42)
-* gimple_cond_set_true_label: GIMPLE_COND. (line 51)
-* gimple_cond_true_label: GIMPLE_COND. (line 46)
-* gimple_copy: Manipulating GIMPLE statements.
- (line 147)
-* GIMPLE_EH_FILTER: GIMPLE_EH_FILTER. (line 6)
-* gimple_eh_filter_failure: GIMPLE_EH_FILTER. (line 19)
-* gimple_eh_filter_must_not_throw: GIMPLE_EH_FILTER. (line 33)
-* gimple_eh_filter_set_failure: GIMPLE_EH_FILTER. (line 29)
-* gimple_eh_filter_set_must_not_throw: GIMPLE_EH_FILTER. (line 37)
-* gimple_eh_filter_set_types: GIMPLE_EH_FILTER. (line 24)
-* gimple_eh_filter_types: GIMPLE_EH_FILTER. (line 12)
-* gimple_expr_type: Manipulating GIMPLE statements.
- (line 24)
-* gimple_goto_dest: GIMPLE_LABEL. (line 21)
-* gimple_goto_set_dest: GIMPLE_LABEL. (line 24)
-* gimple_has_mem_ops: Manipulating GIMPLE statements.
- (line 72)
-* gimple_has_ops: Manipulating GIMPLE statements.
- (line 69)
-* gimple_has_volatile_ops: Manipulating GIMPLE statements.
- (line 134)
-* GIMPLE_LABEL: GIMPLE_LABEL. (line 6)
-* gimple_label_label: GIMPLE_LABEL. (line 11)
-* gimple_label_set_label: GIMPLE_LABEL. (line 14)
-* gimple_loaded_syms: Manipulating GIMPLE statements.
- (line 122)
-* gimple_locus: Manipulating GIMPLE statements.
- (line 42)
-* gimple_locus_empty_p: Manipulating GIMPLE statements.
- (line 48)
-* gimple_modified_p: Manipulating GIMPLE statements.
- (line 130)
-* gimple_no_warning_p: Manipulating GIMPLE statements.
- (line 51)
-* GIMPLE_NOP: GIMPLE_NOP. (line 6)
-* gimple_nop_p: GIMPLE_NOP. (line 10)
-* gimple_num_ops <1>: Manipulating GIMPLE statements.
- (line 75)
-* gimple_num_ops: Logical Operators. (line 76)
-* GIMPLE_OMP_ATOMIC_LOAD: GIMPLE_OMP_ATOMIC_LOAD.
- (line 6)
-* gimple_omp_atomic_load_lhs: GIMPLE_OMP_ATOMIC_LOAD.
- (line 17)
-* gimple_omp_atomic_load_rhs: GIMPLE_OMP_ATOMIC_LOAD.
- (line 24)
-* gimple_omp_atomic_load_set_lhs: GIMPLE_OMP_ATOMIC_LOAD.
- (line 14)
-* gimple_omp_atomic_load_set_rhs: GIMPLE_OMP_ATOMIC_LOAD.
- (line 21)
-* GIMPLE_OMP_ATOMIC_STORE: GIMPLE_OMP_ATOMIC_STORE.
- (line 6)
-* gimple_omp_atomic_store_set_val: GIMPLE_OMP_ATOMIC_STORE.
- (line 12)
-* gimple_omp_atomic_store_val: GIMPLE_OMP_ATOMIC_STORE.
- (line 15)
-* gimple_omp_body: GIMPLE_OMP_PARALLEL.
- (line 24)
-* GIMPLE_OMP_CONTINUE: GIMPLE_OMP_CONTINUE.
- (line 6)
-* gimple_omp_continue_control_def: GIMPLE_OMP_CONTINUE.
- (line 13)
-* gimple_omp_continue_control_def_ptr: GIMPLE_OMP_CONTINUE.
- (line 17)
-* gimple_omp_continue_control_use: GIMPLE_OMP_CONTINUE.
- (line 24)
-* gimple_omp_continue_control_use_ptr: GIMPLE_OMP_CONTINUE.
- (line 28)
-* gimple_omp_continue_set_control_def: GIMPLE_OMP_CONTINUE.
- (line 20)
-* gimple_omp_continue_set_control_use: GIMPLE_OMP_CONTINUE.
- (line 31)
-* GIMPLE_OMP_CRITICAL: GIMPLE_OMP_CRITICAL.
- (line 6)
-* gimple_omp_critical_name: GIMPLE_OMP_CRITICAL.
- (line 13)
-* gimple_omp_critical_set_name: GIMPLE_OMP_CRITICAL.
- (line 21)
-* GIMPLE_OMP_FOR: GIMPLE_OMP_FOR. (line 6)
-* gimple_omp_for_clauses: GIMPLE_OMP_FOR. (line 20)
-* gimple_omp_for_final: GIMPLE_OMP_FOR. (line 51)
-* gimple_omp_for_incr: GIMPLE_OMP_FOR. (line 61)
-* gimple_omp_for_index: GIMPLE_OMP_FOR. (line 31)
-* gimple_omp_for_initial: GIMPLE_OMP_FOR. (line 41)
-* gimple_omp_for_pre_body: GIMPLE_OMP_FOR. (line 70)
-* gimple_omp_for_set_clauses: GIMPLE_OMP_FOR. (line 27)
-* gimple_omp_for_set_cond: GIMPLE_OMP_FOR. (line 80)
-* gimple_omp_for_set_final: GIMPLE_OMP_FOR. (line 58)
-* gimple_omp_for_set_incr: GIMPLE_OMP_FOR. (line 67)
-* gimple_omp_for_set_index: GIMPLE_OMP_FOR. (line 38)
-* gimple_omp_for_set_initial: GIMPLE_OMP_FOR. (line 48)
-* gimple_omp_for_set_pre_body: GIMPLE_OMP_FOR. (line 75)
-* GIMPLE_OMP_MASTER: GIMPLE_OMP_MASTER. (line 6)
-* GIMPLE_OMP_ORDERED: GIMPLE_OMP_ORDERED. (line 6)
-* GIMPLE_OMP_PARALLEL: GIMPLE_OMP_PARALLEL.
- (line 6)
-* gimple_omp_parallel_child_fn: GIMPLE_OMP_PARALLEL.
- (line 42)
-* gimple_omp_parallel_clauses: GIMPLE_OMP_PARALLEL.
- (line 31)
-* gimple_omp_parallel_combined_p: GIMPLE_OMP_PARALLEL.
- (line 16)
-* gimple_omp_parallel_data_arg: GIMPLE_OMP_PARALLEL.
- (line 54)
-* gimple_omp_parallel_set_child_fn: GIMPLE_OMP_PARALLEL.
- (line 51)
-* gimple_omp_parallel_set_clauses: GIMPLE_OMP_PARALLEL.
- (line 38)
-* gimple_omp_parallel_set_combined_p: GIMPLE_OMP_PARALLEL.
- (line 20)
-* gimple_omp_parallel_set_data_arg: GIMPLE_OMP_PARALLEL.
- (line 62)
-* GIMPLE_OMP_RETURN: GIMPLE_OMP_RETURN. (line 6)
-* gimple_omp_return_nowait_p: GIMPLE_OMP_RETURN. (line 14)
-* gimple_omp_return_set_nowait: GIMPLE_OMP_RETURN. (line 11)
-* GIMPLE_OMP_SECTION: GIMPLE_OMP_SECTION. (line 6)
-* gimple_omp_section_last_p: GIMPLE_OMP_SECTION. (line 12)
-* gimple_omp_section_set_last: GIMPLE_OMP_SECTION. (line 16)
-* GIMPLE_OMP_SECTIONS: GIMPLE_OMP_SECTIONS.
- (line 6)
-* gimple_omp_sections_clauses: GIMPLE_OMP_SECTIONS.
- (line 30)
-* gimple_omp_sections_control: GIMPLE_OMP_SECTIONS.
- (line 17)
-* gimple_omp_sections_set_clauses: GIMPLE_OMP_SECTIONS.
- (line 37)
-* gimple_omp_sections_set_control: GIMPLE_OMP_SECTIONS.
- (line 26)
-* gimple_omp_set_body: GIMPLE_OMP_PARALLEL.
- (line 28)
-* GIMPLE_OMP_SINGLE: GIMPLE_OMP_SINGLE. (line 6)
-* gimple_omp_single_clauses: GIMPLE_OMP_SINGLE. (line 14)
-* gimple_omp_single_set_clauses: GIMPLE_OMP_SINGLE. (line 21)
-* gimple_op <1>: Manipulating GIMPLE statements.
- (line 81)
-* gimple_op: Logical Operators. (line 79)
-* GIMPLE_PHI: GIMPLE_PHI. (line 6)
-* gimple_phi_capacity: GIMPLE_PHI. (line 10)
-* gimple_phi_num_args: GIMPLE_PHI. (line 14)
-* gimple_phi_result: GIMPLE_PHI. (line 19)
-* gimple_phi_set_arg: GIMPLE_PHI. (line 33)
-* gimple_phi_set_result: GIMPLE_PHI. (line 25)
-* GIMPLE_RESX: GIMPLE_RESX. (line 6)
-* gimple_resx_region: GIMPLE_RESX. (line 13)
-* gimple_resx_set_region: GIMPLE_RESX. (line 16)
-* GIMPLE_RETURN: GIMPLE_RETURN. (line 6)
-* gimple_return_retval: GIMPLE_RETURN. (line 10)
-* gimple_return_set_retval: GIMPLE_RETURN. (line 14)
-* gimple_rhs_class: GIMPLE_ASSIGN. (line 46)
-* gimple_seq_add_seq: GIMPLE sequences. (line 32)
-* gimple_seq_add_stmt: GIMPLE sequences. (line 26)
-* gimple_seq_alloc: GIMPLE sequences. (line 62)
-* gimple_seq_copy: GIMPLE sequences. (line 67)
-* gimple_seq_deep_copy: GIMPLE sequences. (line 37)
-* gimple_seq_empty_p: GIMPLE sequences. (line 70)
-* gimple_seq_first: GIMPLE sequences. (line 44)
-* gimple_seq_init: GIMPLE sequences. (line 59)
-* gimple_seq_last: GIMPLE sequences. (line 47)
-* gimple_seq_reverse: GIMPLE sequences. (line 40)
-* gimple_seq_set_first: GIMPLE sequences. (line 55)
-* gimple_seq_set_last: GIMPLE sequences. (line 51)
-* gimple_seq_singleton_p: GIMPLE sequences. (line 79)
-* gimple_set_block: Manipulating GIMPLE statements.
- (line 39)
-* gimple_set_def_ops: Manipulating GIMPLE statements.
- (line 98)
-* gimple_set_has_volatile_ops: Manipulating GIMPLE statements.
- (line 138)
-* gimple_set_locus: Manipulating GIMPLE statements.
- (line 45)
-* gimple_set_op: Manipulating GIMPLE statements.
- (line 87)
-* gimple_set_plf: Manipulating GIMPLE statements.
- (line 62)
-* gimple_set_use_ops: Manipulating GIMPLE statements.
- (line 105)
-* gimple_set_vdef_ops: Manipulating GIMPLE statements.
- (line 119)
-* gimple_set_visited: Manipulating GIMPLE statements.
- (line 55)
-* gimple_set_vuse_ops: Manipulating GIMPLE statements.
- (line 112)
-* gimple_statement_base: Tuple representation.
- (line 14)
-* gimple_statement_with_ops: Tuple representation.
- (line 96)
-* gimple_stored_syms: Manipulating GIMPLE statements.
- (line 126)
-* GIMPLE_SWITCH: GIMPLE_SWITCH. (line 6)
-* gimple_switch_default_label: GIMPLE_SWITCH. (line 46)
-* gimple_switch_index: GIMPLE_SWITCH. (line 31)
-* gimple_switch_label: GIMPLE_SWITCH. (line 37)
-* gimple_switch_num_labels: GIMPLE_SWITCH. (line 22)
-* gimple_switch_set_default_label: GIMPLE_SWITCH. (line 50)
-* gimple_switch_set_index: GIMPLE_SWITCH. (line 34)
-* gimple_switch_set_label: GIMPLE_SWITCH. (line 42)
-* gimple_switch_set_num_labels: GIMPLE_SWITCH. (line 27)
-* GIMPLE_TRY: GIMPLE_TRY. (line 6)
-* gimple_try_catch_is_cleanup: GIMPLE_TRY. (line 20)
-* gimple_try_cleanup: GIMPLE_TRY. (line 27)
-* gimple_try_eval: GIMPLE_TRY. (line 23)
-* gimple_try_flags: GIMPLE_TRY. (line 16)
-* gimple_try_set_catch_is_cleanup: GIMPLE_TRY. (line 32)
-* gimple_try_set_cleanup: GIMPLE_TRY. (line 41)
-* gimple_try_set_eval: GIMPLE_TRY. (line 36)
-* gimple_visited_p: Manipulating GIMPLE statements.
- (line 58)
-* gimple_wce_cleanup: GIMPLE_WITH_CLEANUP_EXPR.
- (line 11)
-* gimple_wce_cleanup_eh_only: GIMPLE_WITH_CLEANUP_EXPR.
- (line 18)
-* gimple_wce_set_cleanup: GIMPLE_WITH_CLEANUP_EXPR.
- (line 15)
-* gimple_wce_set_cleanup_eh_only: GIMPLE_WITH_CLEANUP_EXPR.
- (line 22)
-* GIMPLE_WITH_CLEANUP_EXPR: GIMPLE_WITH_CLEANUP_EXPR.
- (line 6)
-* gimplification <1>: Gimplification pass.
- (line 6)
-* gimplification: Parsing pass. (line 14)
-* gimplifier: Parsing pass. (line 14)
-* gimplify_assign: GIMPLE_ASSIGN. (line 19)
-* gimplify_expr: Gimplification pass.
- (line 18)
-* gimplify_function_tree: Gimplification pass.
- (line 18)
-* GLOBAL_INIT_PRIORITY: Function Basics. (line 6)
-* global_regs: Register Basics. (line 59)
-* GO_IF_LEGITIMATE_ADDRESS: Addressing Modes. (line 48)
-* GO_IF_MODE_DEPENDENT_ADDRESS: Addressing Modes. (line 190)
-* GOFAST, floating point emulation library: Library Calls. (line 44)
-* gofast_maybe_init_libfuncs: Library Calls. (line 44)
-* greater than: Comparisons. (line 60)
-* gsi_after_labels: Sequence iterators. (line 76)
-* gsi_bb: Sequence iterators. (line 83)
-* gsi_commit_edge_inserts: Sequence iterators. (line 194)
-* gsi_commit_one_edge_insert: Sequence iterators. (line 190)
-* gsi_end_p: Sequence iterators. (line 60)
-* gsi_for_stmt: Sequence iterators. (line 157)
-* gsi_insert_after: Sequence iterators. (line 147)
-* gsi_insert_before: Sequence iterators. (line 136)
-* gsi_insert_on_edge: Sequence iterators. (line 174)
-* gsi_insert_on_edge_immediate: Sequence iterators. (line 185)
-* gsi_insert_seq_after: Sequence iterators. (line 154)
-* gsi_insert_seq_before: Sequence iterators. (line 143)
-* gsi_insert_seq_on_edge: Sequence iterators. (line 179)
-* gsi_last: Sequence iterators. (line 50)
-* gsi_last_bb: Sequence iterators. (line 56)
-* gsi_link_after: Sequence iterators. (line 115)
-* gsi_link_before: Sequence iterators. (line 105)
-* gsi_link_seq_after: Sequence iterators. (line 110)
-* gsi_link_seq_before: Sequence iterators. (line 99)
-* gsi_move_after: Sequence iterators. (line 161)
-* gsi_move_before: Sequence iterators. (line 166)
-* gsi_move_to_bb_end: Sequence iterators. (line 171)
-* gsi_next: Sequence iterators. (line 66)
-* gsi_one_before_end_p: Sequence iterators. (line 63)
-* gsi_prev: Sequence iterators. (line 69)
-* gsi_remove: Sequence iterators. (line 90)
-* gsi_replace: Sequence iterators. (line 130)
-* gsi_seq: Sequence iterators. (line 86)
-* gsi_split_seq_after: Sequence iterators. (line 120)
-* gsi_split_seq_before: Sequence iterators. (line 125)
-* gsi_start: Sequence iterators. (line 40)
-* gsi_start_bb: Sequence iterators. (line 46)
-* gsi_stmt: Sequence iterators. (line 72)
-* gt: Comparisons. (line 60)
-* gt and attributes: Expressions. (line 64)
-* GT_EXPR: Expression trees. (line 6)
-* gtu: Comparisons. (line 64)
-* gtu and attributes: Expressions. (line 64)
-* GTY: Type Information. (line 6)
-* H in constraint: Simple Constraints. (line 88)
-* HAmode: Machine Modes. (line 144)
-* HANDLE_PRAGMA_PACK_PUSH_POP: Misc. (line 467)
-* HANDLE_PRAGMA_PACK_WITH_EXPANSION: Misc. (line 478)
-* HANDLE_SYSV_PRAGMA: Misc. (line 438)
-* HANDLER: Function Bodies. (line 6)
-* HANDLER_BODY: Function Bodies. (line 6)
-* HANDLER_PARMS: Function Bodies. (line 6)
-* hard registers: Regs and Memory. (line 9)
-* HARD_FRAME_POINTER_REGNUM: Frame Registers. (line 20)
-* HARD_REGNO_CALL_PART_CLOBBERED: Register Basics. (line 53)
-* HARD_REGNO_CALLER_SAVE_MODE: Caller Saves. (line 20)
-* HARD_REGNO_MODE_OK: Values in Registers.
- (line 58)
-* HARD_REGNO_NREGS: Values in Registers.
- (line 11)
-* HARD_REGNO_NREGS_HAS_PADDING: Values in Registers.
- (line 25)
-* HARD_REGNO_NREGS_WITH_PADDING: Values in Registers.
- (line 43)
-* HARD_REGNO_RENAME_OK: Values in Registers.
- (line 119)
-* HAS_INIT_SECTION: Macros for Initialization.
- (line 19)
-* HAS_LONG_COND_BRANCH: Misc. (line 9)
-* HAS_LONG_UNCOND_BRANCH: Misc. (line 18)
-* HAVE_DOS_BASED_FILE_SYSTEM: Filesystem. (line 11)
-* HAVE_POST_DECREMENT: Addressing Modes. (line 12)
-* HAVE_POST_INCREMENT: Addressing Modes. (line 11)
-* HAVE_POST_MODIFY_DISP: Addressing Modes. (line 18)
-* HAVE_POST_MODIFY_REG: Addressing Modes. (line 24)
-* HAVE_PRE_DECREMENT: Addressing Modes. (line 10)
-* HAVE_PRE_INCREMENT: Addressing Modes. (line 9)
-* HAVE_PRE_MODIFY_DISP: Addressing Modes. (line 17)
-* HAVE_PRE_MODIFY_REG: Addressing Modes. (line 23)
-* HCmode: Machine Modes. (line 197)
-* HFmode: Machine Modes. (line 58)
-* high: Constants. (line 109)
-* HImode: Machine Modes. (line 29)
-* HImode, in insn: Insns. (line 231)
-* HONOR_REG_ALLOC_ORDER: Allocation Order. (line 37)
-* host configuration: Host Config. (line 6)
-* host functions: Host Common. (line 6)
-* host hooks: Host Common. (line 6)
-* host makefile fragment: Host Fragment. (line 6)
-* HOST_BIT_BUCKET: Filesystem. (line 51)
-* HOST_EXECUTABLE_SUFFIX: Filesystem. (line 45)
-* HOST_HOOKS_EXTRA_SIGNALS: Host Common. (line 12)
-* HOST_HOOKS_GT_PCH_ALLOC_GRANULARITY: Host Common. (line 45)
-* HOST_HOOKS_GT_PCH_USE_ADDRESS: Host Common. (line 26)
-* HOST_LACKS_INODE_NUMBERS: Filesystem. (line 89)
-* HOST_LONG_LONG_FORMAT: Host Misc. (line 41)
-* HOST_OBJECT_SUFFIX: Filesystem. (line 40)
-* HOST_WIDE_INT: Anchored Addresses. (line 33)
-* HOT_TEXT_SECTION_NAME: Sections. (line 43)
-* HQmode: Machine Modes. (line 107)
-* I in constraint: Simple Constraints. (line 71)
-* i in constraint: Simple Constraints. (line 60)
-* identifier: Identifiers. (line 6)
-* IDENTIFIER_LENGTH: Identifiers. (line 20)
-* IDENTIFIER_NODE: Identifiers. (line 6)
-* IDENTIFIER_OPNAME_P: Identifiers. (line 25)
-* IDENTIFIER_POINTER: Identifiers. (line 15)
-* IDENTIFIER_TYPENAME_P: Identifiers. (line 31)
-* IEEE 754-2008: Decimal float library routines.
- (line 6)
-* IF_COND: Function Bodies. (line 6)
-* if_marked: GTY Options. (line 155)
-* IF_STMT: Function Bodies. (line 6)
-* if_then_else: Comparisons. (line 80)
-* if_then_else and attributes: Expressions. (line 32)
-* if_then_else usage: Side Effects. (line 56)
-* IFCVT_EXTRA_FIELDS: Misc. (line 619)
-* IFCVT_INIT_EXTRA_FIELDS: Misc. (line 614)
-* IFCVT_MODIFY_CANCEL: Misc. (line 608)
-* IFCVT_MODIFY_FINAL: Misc. (line 602)
-* IFCVT_MODIFY_INSN: Misc. (line 596)
-* IFCVT_MODIFY_MULTIPLE_TESTS: Misc. (line 589)
-* IFCVT_MODIFY_TESTS: Misc. (line 578)
-* IMAGPART_EXPR: Expression trees. (line 6)
-* Immediate Uses: SSA Operands. (line 274)
-* immediate_operand: Machine-Independent Predicates.
- (line 11)
-* IMMEDIATE_PREFIX: Instruction Output. (line 127)
-* in_struct: Flags. (line 258)
-* in_struct, in code_label and note: Flags. (line 59)
-* in_struct, in insn and jump_insn and call_insn: Flags. (line 49)
-* in_struct, in insn, jump_insn and call_insn: Flags. (line 166)
-* in_struct, in mem: Flags. (line 70)
-* in_struct, in subreg: Flags. (line 205)
-* include: Including Patterns. (line 6)
-* INCLUDE_DEFAULTS: Driver. (line 430)
-* inclusive-or, bitwise: Arithmetic. (line 158)
-* INCOMING_FRAME_SP_OFFSET: Frame Layout. (line 183)
-* INCOMING_REGNO: Register Basics. (line 91)
-* INCOMING_RETURN_ADDR_RTX: Frame Layout. (line 139)
-* INCOMING_STACK_BOUNDARY: Storage Layout. (line 165)
-* INDEX_REG_CLASS: Register Classes. (line 134)
-* indirect_jump instruction pattern: Standard Names. (line 1078)
-* indirect_operand: Machine-Independent Predicates.
- (line 71)
-* INDIRECT_REF: Expression trees. (line 6)
-* INIT_ARRAY_SECTION_ASM_OP: Sections. (line 98)
-* INIT_CUMULATIVE_ARGS: Register Arguments. (line 149)
-* INIT_CUMULATIVE_INCOMING_ARGS: Register Arguments. (line 176)
-* INIT_CUMULATIVE_LIBCALL_ARGS: Register Arguments. (line 170)
-* INIT_ENVIRONMENT: Driver. (line 369)
-* INIT_EXPANDERS: Per-Function Data. (line 39)
-* INIT_EXPR: Expression trees. (line 6)
-* init_machine_status: Per-Function Data. (line 45)
-* init_one_libfunc: Library Calls. (line 15)
-* INIT_SECTION_ASM_OP <1>: Macros for Initialization.
- (line 10)
-* INIT_SECTION_ASM_OP: Sections. (line 82)
-* INITIAL_ELIMINATION_OFFSET: Elimination. (line 79)
-* INITIAL_FRAME_ADDRESS_RTX: Frame Layout. (line 83)
-* INITIAL_FRAME_POINTER_OFFSET: Elimination. (line 32)
-* initialization routines: Initialization. (line 6)
-* INITIALIZE_TRAMPOLINE: Trampolines. (line 55)
-* inlining: Target Attributes. (line 86)
-* insert_insn_on_edge: Maintaining the CFG.
- (line 118)
-* insn: Insns. (line 63)
-* insn and /f: Flags. (line 125)
-* insn and /j: Flags. (line 175)
-* insn and /s: Flags. (line 49)
-* insn and /u: Flags. (line 39)
-* insn and /v: Flags. (line 44)
-* insn attributes: Insn Attributes. (line 6)
-* insn canonicalization: Insn Canonicalizations.
- (line 6)
-* insn includes: Including Patterns. (line 6)
-* insn lengths, computing: Insn Lengths. (line 6)
-* insn splitting: Insn Splitting. (line 6)
-* insn-attr.h: Defining Attributes.
- (line 24)
-* INSN_ANNULLED_BRANCH_P: Flags. (line 39)
-* INSN_CODE: Insns. (line 257)
-* INSN_DELETED_P: Flags. (line 44)
-* INSN_FROM_TARGET_P: Flags. (line 49)
-* insn_list: Insns. (line 505)
-* INSN_REFERENCES_ARE_DELAYED: Misc. (line 517)
-* INSN_SETS_ARE_DELAYED: Misc. (line 506)
-* INSN_UID: Insns. (line 23)
-* insns: Insns. (line 6)
-* insns, generating: RTL Template. (line 6)
-* insns, recognizing: RTL Template. (line 6)
-* instruction attributes: Insn Attributes. (line 6)
-* instruction latency time: Processor pipeline description.
- (line 6)
-* instruction patterns: Patterns. (line 6)
-* instruction splitting: Insn Splitting. (line 6)
-* insv instruction pattern: Standard Names. (line 880)
-* int <1>: Run-time Target. (line 56)
-* int: Manipulating GIMPLE statements.
- (line 66)
-* INT_TYPE_SIZE: Type Layout. (line 12)
-* INTEGER_CST: Expression trees. (line 6)
-* INTEGER_TYPE: Types. (line 6)
-* Interdependence of Patterns: Dependent Patterns. (line 6)
-* interfacing to GCC output: Interface. (line 6)
-* interlock delays: Processor pipeline description.
- (line 6)
-* intermediate representation lowering: Parsing pass. (line 14)
-* INTMAX_TYPE: Type Layout. (line 213)
-* introduction: Top. (line 6)
-* INVOKE__main: Macros for Initialization.
- (line 51)
-* ior: Arithmetic. (line 158)
-* ior and attributes: Expressions. (line 50)
-* ior, canonicalization of: Insn Canonicalizations.
- (line 57)
-* iorM3 instruction pattern: Standard Names. (line 222)
-* IRA_COVER_CLASSES: Register Classes. (line 516)
-* IRA_HARD_REGNO_ADD_COST_MULTIPLIER: Allocation Order. (line 45)
-* IS_ASM_LOGICAL_LINE_SEPARATOR: Data Output. (line 120)
-* is_gimple_omp: GIMPLE_OMP_PARALLEL.
- (line 65)
-* iterators in .md files: Iterators. (line 6)
-* IV analysis on GIMPLE: Scalar evolutions. (line 6)
-* IV analysis on RTL: loop-iv. (line 6)
-* jump: Flags. (line 309)
-* jump instruction pattern: Standard Names. (line 969)
-* jump instruction patterns: Jump Patterns. (line 6)
-* jump instructions and set: Side Effects. (line 56)
-* jump, in call_insn: Flags. (line 179)
-* jump, in insn: Flags. (line 175)
-* jump, in mem: Flags. (line 79)
-* JUMP_ALIGN: Alignment Output. (line 9)
-* jump_insn: Insns. (line 73)
-* jump_insn and /f: Flags. (line 125)
-* jump_insn and /s: Flags. (line 49)
-* jump_insn and /u: Flags. (line 39)
-* jump_insn and /v: Flags. (line 44)
-* JUMP_LABEL: Insns. (line 80)
-* JUMP_TABLES_IN_TEXT_SECTION: Sections. (line 142)
-* Jumps: Jumps. (line 6)
-* LABEL_ALIGN: Alignment Output. (line 52)
-* LABEL_ALIGN_AFTER_BARRIER: Alignment Output. (line 22)
-* LABEL_ALIGN_AFTER_BARRIER_MAX_SKIP: Alignment Output. (line 30)
-* LABEL_ALIGN_MAX_SKIP: Alignment Output. (line 62)
-* LABEL_ALT_ENTRY_P: Insns. (line 140)
-* LABEL_ALTERNATE_NAME: Edges. (line 180)
-* LABEL_DECL: Declarations. (line 6)
-* LABEL_KIND: Insns. (line 140)
-* LABEL_NUSES: Insns. (line 136)
-* LABEL_PRESERVE_P: Flags. (line 59)
-* label_ref: Constants. (line 86)
-* label_ref and /v: Flags. (line 65)
-* label_ref, RTL sharing: Sharing. (line 35)
-* LABEL_REF_NONLOCAL_P: Flags. (line 65)
-* lang_hooks.gimplify_expr: Gimplification pass.
- (line 18)
-* lang_hooks.parse_file: Parsing pass. (line 6)
-* language-independent intermediate representation: Parsing pass.
- (line 14)
-* large return values: Aggregate Return. (line 6)
-* LARGEST_EXPONENT_IS_NORMAL: Storage Layout. (line 469)
-* LAST_STACK_REG: Stack Registers. (line 27)
-* LAST_VIRTUAL_REGISTER: Regs and Memory. (line 51)
-* lceilMN2: Standard Names. (line 597)
-* LCSSA: LCSSA. (line 6)
-* LD_FINI_SWITCH: Macros for Initialization.
- (line 29)
-* LD_INIT_SWITCH: Macros for Initialization.
- (line 25)
-* LDD_SUFFIX: Macros for Initialization.
- (line 116)
-* le: Comparisons. (line 76)
-* le and attributes: Expressions. (line 64)
-* LE_EXPR: Expression trees. (line 6)
-* leaf functions: Leaf Functions. (line 6)
-* leaf_function_p: Standard Names. (line 1040)
-* LEAF_REG_REMAP: Leaf Functions. (line 39)
-* LEAF_REGISTERS: Leaf Functions. (line 25)
-* left rotate: Arithmetic. (line 190)
-* left shift: Arithmetic. (line 168)
-* LEGITIMATE_CONSTANT_P: Addressing Modes. (line 205)
-* LEGITIMATE_PIC_OPERAND_P: PIC. (line 31)
-* LEGITIMIZE_ADDRESS: Addressing Modes. (line 122)
-* LEGITIMIZE_RELOAD_ADDRESS: Addressing Modes. (line 145)
-* length: GTY Options. (line 50)
-* less than: Comparisons. (line 68)
-* less than or equal: Comparisons. (line 76)
-* leu: Comparisons. (line 76)
-* leu and attributes: Expressions. (line 64)
-* lfloorMN2: Standard Names. (line 592)
-* LIB2FUNCS_EXTRA: Target Fragment. (line 11)
-* LIB_SPEC: Driver. (line 170)
-* LIBCALL_VALUE: Scalar Return. (line 60)
-* libgcc.a: Library Calls. (line 6)
-* LIBGCC2_CFLAGS: Target Fragment. (line 8)
-* LIBGCC2_HAS_DF_MODE: Type Layout. (line 109)
-* LIBGCC2_HAS_TF_MODE: Type Layout. (line 123)
-* LIBGCC2_HAS_XF_MODE: Type Layout. (line 117)
-* LIBGCC2_LONG_DOUBLE_TYPE_SIZE: Type Layout. (line 103)
-* LIBGCC2_UNWIND_ATTRIBUTE: Misc. (line 935)
-* LIBGCC2_WORDS_BIG_ENDIAN: Storage Layout. (line 36)
-* LIBGCC_SPEC: Driver. (line 178)
-* library subroutine names: Library Calls. (line 6)
-* LIBRARY_PATH_ENV: Misc. (line 557)
-* LIMIT_RELOAD_CLASS: Register Classes. (line 239)
-* Linear loop transformations framework: Lambda. (line 6)
-* LINK_COMMAND_SPEC: Driver. (line 299)
-* LINK_EH_SPEC: Driver. (line 205)
-* LINK_ELIMINATE_DUPLICATE_LDIRECTORIES: Driver. (line 309)
-* LINK_GCC_C_SEQUENCE_SPEC: Driver. (line 295)
-* LINK_LIBGCC_SPECIAL_1: Driver. (line 290)
-* LINK_SPEC: Driver. (line 163)
-* linkage: Function Basics. (line 6)
-* list: Containers. (line 6)
-* Liveness representation: Liveness information.
- (line 6)
-* lo_sum: Arithmetic. (line 24)
-* load address instruction: Simple Constraints. (line 154)
-* LOAD_EXTEND_OP: Misc. (line 69)
-* load_multiple instruction pattern: Standard Names. (line 137)
-* LOCAL_ALIGNMENT: Storage Layout. (line 254)
-* LOCAL_CLASS_P: Classes. (line 68)
-* LOCAL_DECL_ALIGNMENT: Storage Layout. (line 278)
-* LOCAL_INCLUDE_DIR: Driver. (line 376)
-* LOCAL_LABEL_PREFIX: Instruction Output. (line 125)
-* LOCAL_REGNO: Register Basics. (line 105)
-* LOG_LINKS: Insns. (line 276)
-* Logical Operators: Logical Operators. (line 6)
-* logical-and, bitwise: Arithmetic. (line 153)
-* logM2 instruction pattern: Standard Names. (line 505)
-* LONG_ACCUM_TYPE_SIZE: Type Layout. (line 93)
-* LONG_DOUBLE_TYPE_SIZE: Type Layout. (line 58)
-* LONG_FRACT_TYPE_SIZE: Type Layout. (line 73)
-* LONG_LONG_ACCUM_TYPE_SIZE: Type Layout. (line 98)
-* LONG_LONG_FRACT_TYPE_SIZE: Type Layout. (line 78)
-* LONG_LONG_TYPE_SIZE: Type Layout. (line 33)
-* LONG_TYPE_SIZE: Type Layout. (line 22)
-* longjmp and automatic variables: Interface. (line 52)
-* Loop analysis: Loop representation.
- (line 6)
-* Loop manipulation: Loop manipulation. (line 6)
-* Loop querying: Loop querying. (line 6)
-* Loop representation: Loop representation.
- (line 6)
-* Loop-closed SSA form: LCSSA. (line 6)
-* LOOP_ALIGN: Alignment Output. (line 35)
-* LOOP_ALIGN_MAX_SKIP: Alignment Output. (line 48)
-* LOOP_EXPR: Expression trees. (line 6)
-* looping instruction patterns: Looping Patterns. (line 6)
-* lowering, language-dependent intermediate representation: Parsing pass.
- (line 14)
-* lrintMN2: Standard Names. (line 582)
-* lroundMN2: Standard Names. (line 587)
-* LSHIFT_EXPR: Expression trees. (line 6)
-* lshiftrt: Arithmetic. (line 185)
-* lshiftrt and attributes: Expressions. (line 64)
-* lshrM3 instruction pattern: Standard Names. (line 441)
-* lt: Comparisons. (line 68)
-* lt and attributes: Expressions. (line 64)
-* LT_EXPR: Expression trees. (line 6)
-* LTGT_EXPR: Expression trees. (line 6)
-* ltu: Comparisons. (line 68)
-* m in constraint: Simple Constraints. (line 17)
-* machine attributes: Target Attributes. (line 6)
-* machine description macros: Target Macros. (line 6)
-* machine descriptions: Machine Desc. (line 6)
-* machine mode conversions: Conversions. (line 6)
-* machine modes: Machine Modes. (line 6)
-* machine specific constraints: Machine Constraints.
- (line 6)
-* machine-independent predicates: Machine-Independent Predicates.
- (line 6)
-* machine_mode: Condition Code. (line 157)
-* macros, target description: Target Macros. (line 6)
-* maddMN4 instruction pattern: Standard Names. (line 364)
-* MAKE_DECL_ONE_ONLY: Label Output. (line 218)
-* make_phi_node: GIMPLE_PHI. (line 7)
-* make_safe_from: Expander Definitions.
- (line 148)
-* makefile fragment: Fragments. (line 6)
-* makefile targets: Makefile. (line 6)
-* MALLOC_ABI_ALIGNMENT: Storage Layout. (line 179)
-* Manipulating GIMPLE statements: Manipulating GIMPLE statements.
- (line 6)
-* mark_hook: GTY Options. (line 170)
-* marking roots: GGC Roots. (line 6)
-* MASK_RETURN_ADDR: Exception Region Output.
- (line 35)
-* match_dup <1>: define_peephole2. (line 28)
-* match_dup: RTL Template. (line 73)
-* match_dup and attributes: Insn Lengths. (line 16)
-* match_op_dup: RTL Template. (line 163)
-* match_operand: RTL Template. (line 16)
-* match_operand and attributes: Expressions. (line 55)
-* match_operator: RTL Template. (line 95)
-* match_par_dup: RTL Template. (line 219)
-* match_parallel: RTL Template. (line 172)
-* match_scratch <1>: define_peephole2. (line 28)
-* match_scratch: RTL Template. (line 58)
-* matching constraint: Simple Constraints. (line 132)
-* matching operands: Output Template. (line 49)
-* math library: Soft float library routines.
- (line 6)
-* math, in RTL: Arithmetic. (line 6)
-* MATH_LIBRARY: Misc. (line 550)
-* matherr: Library Calls. (line 58)
-* MAX_BITS_PER_WORD: Storage Layout. (line 61)
-* MAX_CONDITIONAL_EXECUTE: Misc. (line 572)
-* MAX_FIXED_MODE_SIZE: Storage Layout. (line 420)
-* MAX_MOVE_MAX: Misc. (line 120)
-* MAX_OFILE_ALIGNMENT: Storage Layout. (line 216)
-* MAX_REGS_PER_ADDRESS: Addressing Modes. (line 42)
-* MAX_STACK_ALIGNMENT: Storage Layout. (line 209)
-* maxM3 instruction pattern: Standard Names. (line 234)
-* may_trap_p, tree_could_trap_p: Edges. (line 115)
-* maybe_undef: GTY Options. (line 178)
-* mcount: Profiling. (line 12)
-* MD_CAN_REDIRECT_BRANCH: Misc. (line 697)
-* MD_EXEC_PREFIX: Driver. (line 330)
-* MD_FALLBACK_FRAME_STATE_FOR: Exception Handling. (line 98)
-* MD_HANDLE_UNWABI: Exception Handling. (line 118)
-* MD_STARTFILE_PREFIX: Driver. (line 358)
-* MD_STARTFILE_PREFIX_1: Driver. (line 364)
-* MD_UNWIND_SUPPORT: Exception Handling. (line 94)
-* mem: Regs and Memory. (line 374)
-* mem and /c: Flags. (line 99)
-* mem and /f: Flags. (line 103)
-* mem and /i: Flags. (line 85)
-* mem and /j: Flags. (line 79)
-* mem and /s: Flags. (line 70)
-* mem and /u: Flags. (line 152)
-* mem and /v: Flags. (line 94)
-* mem, RTL sharing: Sharing. (line 40)
-* MEM_ALIAS_SET: Special Accessors. (line 9)
-* MEM_ALIGN: Special Accessors. (line 36)
-* MEM_EXPR: Special Accessors. (line 20)
-* MEM_IN_STRUCT_P: Flags. (line 70)
-* MEM_KEEP_ALIAS_SET_P: Flags. (line 79)
-* MEM_NOTRAP_P: Flags. (line 99)
-* MEM_OFFSET: Special Accessors. (line 28)
-* MEM_POINTER: Flags. (line 103)
-* MEM_READONLY_P: Flags. (line 152)
-* MEM_SCALAR_P: Flags. (line 85)
-* MEM_SIZE: Special Accessors. (line 31)
-* MEM_VOLATILE_P: Flags. (line 94)
-* MEMBER_TYPE_FORCES_BLK: Storage Layout. (line 400)
-* memory reference, nonoffsettable: Simple Constraints. (line 246)
-* memory references in constraints: Simple Constraints. (line 17)
-* memory_barrier instruction pattern: Standard Names. (line 1413)
-* MEMORY_MOVE_COST: Costs. (line 29)
-* memory_operand: Machine-Independent Predicates.
- (line 58)
-* METHOD_TYPE: Types. (line 6)
-* MIN_UNITS_PER_WORD: Storage Layout. (line 71)
-* MINIMUM_ALIGNMENT: Storage Layout. (line 288)
-* MINIMUM_ATOMIC_ALIGNMENT: Storage Layout. (line 187)
-* minM3 instruction pattern: Standard Names. (line 234)
-* minus: Arithmetic. (line 36)
-* minus and attributes: Expressions. (line 64)
-* minus, canonicalization of: Insn Canonicalizations.
- (line 27)
-* MINUS_EXPR: Expression trees. (line 6)
-* MIPS coprocessor-definition macros: MIPS Coprocessors. (line 6)
-* mod: Arithmetic. (line 131)
-* mod and attributes: Expressions. (line 64)
-* mode classes: Machine Modes. (line 219)
-* mode iterators in .md files: Mode Iterators. (line 6)
-* mode switching: Mode Switching. (line 6)
-* MODE_ACCUM: Machine Modes. (line 249)
-* MODE_AFTER: Mode Switching. (line 49)
-* MODE_BASE_REG_CLASS: Register Classes. (line 112)
-* MODE_BASE_REG_REG_CLASS: Register Classes. (line 118)
-* MODE_CC: Machine Modes. (line 268)
-* MODE_CODE_BASE_REG_CLASS: Register Classes. (line 125)
-* MODE_COMPLEX_FLOAT: Machine Modes. (line 260)
-* MODE_COMPLEX_INT: Machine Modes. (line 257)
-* MODE_DECIMAL_FLOAT: Machine Modes. (line 237)
-* MODE_ENTRY: Mode Switching. (line 54)
-* MODE_EXIT: Mode Switching. (line 60)
-* MODE_FLOAT: Machine Modes. (line 233)
-* MODE_FRACT: Machine Modes. (line 241)
-* MODE_FUNCTION: Machine Modes. (line 264)
-* MODE_INT: Machine Modes. (line 225)
-* MODE_NEEDED: Mode Switching. (line 42)
-* MODE_PARTIAL_INT: Machine Modes. (line 229)
-* MODE_PRIORITY_TO_MODE: Mode Switching. (line 66)
-* MODE_RANDOM: Machine Modes. (line 273)
-* MODE_UACCUM: Machine Modes. (line 253)
-* MODE_UFRACT: Machine Modes. (line 245)
-* MODES_TIEABLE_P: Values in Registers.
- (line 129)
-* modifiers in constraints: Modifiers. (line 6)
-* MODIFY_EXPR: Expression trees. (line 6)
-* MODIFY_JNI_METHOD_CALL: Misc. (line 774)
-* MODIFY_TARGET_NAME: Driver. (line 385)
-* modM3 instruction pattern: Standard Names. (line 222)
-* modulo scheduling: RTL passes. (line 131)
-* MOVE_BY_PIECES_P: Costs. (line 110)
-* MOVE_MAX: Misc. (line 115)
-* MOVE_MAX_PIECES: Costs. (line 116)
-* MOVE_RATIO: Costs. (line 97)
-* movM instruction pattern: Standard Names. (line 11)
-* movmemM instruction pattern: Standard Names. (line 672)
-* movmisalignM instruction pattern: Standard Names. (line 126)
-* movMODEcc instruction pattern: Standard Names. (line 891)
-* movstr instruction pattern: Standard Names. (line 707)
-* movstrictM instruction pattern: Standard Names. (line 120)
-* msubMN4 instruction pattern: Standard Names. (line 387)
-* mulhisi3 instruction pattern: Standard Names. (line 340)
-* mulM3 instruction pattern: Standard Names. (line 222)
-* mulqihi3 instruction pattern: Standard Names. (line 344)
-* mulsidi3 instruction pattern: Standard Names. (line 344)
-* mult: Arithmetic. (line 92)
-* mult and attributes: Expressions. (line 64)
-* mult, canonicalization of: Insn Canonicalizations.
- (line 27)
-* MULT_EXPR: Expression trees. (line 6)
-* MULTILIB_DEFAULTS: Driver. (line 315)
-* MULTILIB_DIRNAMES: Target Fragment. (line 64)
-* MULTILIB_EXCEPTIONS: Target Fragment. (line 84)
-* MULTILIB_EXTRA_OPTS: Target Fragment. (line 96)
-* MULTILIB_MATCHES: Target Fragment. (line 77)
-* MULTILIB_OPTIONS: Target Fragment. (line 44)
-* multiple alternative constraints: Multi-Alternative. (line 6)
-* MULTIPLE_SYMBOL_SPACES: Misc. (line 530)
-* multiplication: Arithmetic. (line 92)
-* multiplication with signed saturation: Arithmetic. (line 92)
-* multiplication with unsigned saturation: Arithmetic. (line 92)
-* MUST_USE_SJLJ_EXCEPTIONS: Exception Region Output.
- (line 64)
-* n in constraint: Simple Constraints. (line 65)
-* N_REG_CLASSES: Register Classes. (line 76)
-* name: Identifiers. (line 6)
-* named patterns and conditions: Patterns. (line 47)
-* names, pattern: Standard Names. (line 6)
-* namespace: Namespaces. (line 6)
-* namespace, class, scope: Scopes. (line 6)
-* NAMESPACE_DECL <1>: Declarations. (line 6)
-* NAMESPACE_DECL: Namespaces. (line 6)
-* NATIVE_SYSTEM_HEADER_DIR: Target Fragment. (line 103)
-* ne: Comparisons. (line 56)
-* ne and attributes: Expressions. (line 64)
-* NE_EXPR: Expression trees. (line 6)
-* nearbyintM2 instruction pattern: Standard Names. (line 564)
-* neg: Arithmetic. (line 81)
-* neg and attributes: Expressions. (line 64)
-* neg, canonicalization of: Insn Canonicalizations.
- (line 27)
-* NEGATE_EXPR: Expression trees. (line 6)
-* negation: Arithmetic. (line 81)
-* negation with signed saturation: Arithmetic. (line 81)
-* negation with unsigned saturation: Arithmetic. (line 81)
-* negM2 instruction pattern: Standard Names. (line 449)
-* nested functions, trampolines for: Trampolines. (line 6)
-* nested_ptr: GTY Options. (line 185)
-* next_bb, prev_bb, FOR_EACH_BB: Basic Blocks. (line 10)
-* next_cc0_user: Jump Patterns. (line 64)
-* NEXT_INSN: Insns. (line 30)
-* NEXT_OBJC_RUNTIME: Library Calls. (line 94)
-* nil: RTL Objects. (line 73)
-* NO_DBX_BNSYM_ENSYM: DBX Hooks. (line 39)
-* NO_DBX_FUNCTION_END: DBX Hooks. (line 33)
-* NO_DBX_GCC_MARKER: File Names and DBX. (line 28)
-* NO_DBX_MAIN_SOURCE_DIRECTORY: File Names and DBX. (line 23)
-* NO_DOLLAR_IN_LABEL: Misc. (line 494)
-* NO_DOT_IN_LABEL: Misc. (line 500)
-* NO_FUNCTION_CSE: Costs. (line 200)
-* NO_IMPLICIT_EXTERN_C: Misc. (line 376)
-* NO_PROFILE_COUNTERS: Profiling. (line 28)
-* NO_REGS: Register Classes. (line 17)
-* NON_LVALUE_EXPR: Expression trees. (line 6)
-* nondeterministic finite state automaton: Processor pipeline description.
- (line 296)
-* nonimmediate_operand: Machine-Independent Predicates.
- (line 101)
-* nonlocal goto handler: Edges. (line 171)
-* nonlocal_goto instruction pattern: Standard Names. (line 1255)
-* nonlocal_goto_receiver instruction pattern: Standard Names.
- (line 1272)
-* nonmemory_operand: Machine-Independent Predicates.
- (line 97)
-* nonoffsettable memory reference: Simple Constraints. (line 246)
-* nop instruction pattern: Standard Names. (line 1073)
-* NOP_EXPR: Expression trees. (line 6)
-* normal predicates: Predicates. (line 31)
-* not: Arithmetic. (line 149)
-* not and attributes: Expressions. (line 50)
-* not equal: Comparisons. (line 56)
-* not, canonicalization of: Insn Canonicalizations.
- (line 27)
-* note: Insns. (line 168)
-* note and /i: Flags. (line 59)
-* note and /v: Flags. (line 44)
-* NOTE_INSN_BASIC_BLOCK, CODE_LABEL, notes: Basic Blocks. (line 41)
-* NOTE_INSN_BLOCK_BEG: Insns. (line 193)
-* NOTE_INSN_BLOCK_END: Insns. (line 193)
-* NOTE_INSN_DELETED: Insns. (line 183)
-* NOTE_INSN_DELETED_LABEL: Insns. (line 188)
-* NOTE_INSN_EH_REGION_BEG: Insns. (line 199)
-* NOTE_INSN_EH_REGION_END: Insns. (line 199)
-* NOTE_INSN_FUNCTION_BEG: Insns. (line 223)
-* NOTE_INSN_LOOP_BEG: Insns. (line 207)
-* NOTE_INSN_LOOP_CONT: Insns. (line 213)
-* NOTE_INSN_LOOP_END: Insns. (line 207)
-* NOTE_INSN_LOOP_VTOP: Insns. (line 217)
-* NOTE_LINE_NUMBER: Insns. (line 168)
-* NOTE_SOURCE_FILE: Insns. (line 168)
-* NOTICE_UPDATE_CC: Condition Code. (line 33)
-* NUM_MACHINE_MODES: Machine Modes. (line 286)
-* NUM_MODES_FOR_MODE_SWITCHING: Mode Switching. (line 30)
-* Number of iterations analysis: Number of iterations.
- (line 6)
-* o in constraint: Simple Constraints. (line 23)
-* OBJC_GEN_METHOD_LABEL: Label Output. (line 411)
-* OBJC_JBLEN: Misc. (line 930)
-* OBJECT_FORMAT_COFF: Macros for Initialization.
- (line 97)
-* OFFSET_TYPE: Types. (line 6)
-* offsettable address: Simple Constraints. (line 23)
-* OImode: Machine Modes. (line 51)
-* Omega a solver for linear programming problems: Omega. (line 6)
-* OMP_ATOMIC: Expression trees. (line 6)
-* OMP_CLAUSE: Expression trees. (line 6)
-* OMP_CONTINUE: Expression trees. (line 6)
-* OMP_CRITICAL: Expression trees. (line 6)
-* OMP_FOR: Expression trees. (line 6)
-* OMP_MASTER: Expression trees. (line 6)
-* OMP_ORDERED: Expression trees. (line 6)
-* OMP_PARALLEL: Expression trees. (line 6)
-* OMP_RETURN: Expression trees. (line 6)
-* OMP_SECTION: Expression trees. (line 6)
-* OMP_SECTIONS: Expression trees. (line 6)
-* OMP_SINGLE: Expression trees. (line 6)
-* one_cmplM2 instruction pattern: Standard Names. (line 651)
-* operand access: Accessors. (line 6)
-* Operand Access Routines: SSA Operands. (line 119)
-* operand constraints: Constraints. (line 6)
-* Operand Iterators: SSA Operands. (line 119)
-* operand predicates: Predicates. (line 6)
-* operand substitution: Output Template. (line 6)
-* operands <1>: Patterns. (line 53)
-* operands: SSA Operands. (line 6)
-* Operands: Operands. (line 6)
-* operator predicates: Predicates. (line 6)
-* optc-gen.awk: Options. (line 6)
-* Optimization infrastructure for GIMPLE: Tree SSA. (line 6)
-* OPTIMIZATION_OPTIONS: Run-time Target. (line 120)
-* OPTIMIZE_MODE_SWITCHING: Mode Switching. (line 9)
-* option specification files: Options. (line 6)
-* OPTION_DEFAULT_SPECS: Driver. (line 88)
-* optional hardware or system features: Run-time Target. (line 59)
-* options, directory search: Including Patterns. (line 44)
-* order of register allocation: Allocation Order. (line 6)
-* ORDERED_EXPR: Expression trees. (line 6)
-* Ordering of Patterns: Pattern Ordering. (line 6)
-* ORIGINAL_REGNO: Special Accessors. (line 40)
-* other register constraints: Simple Constraints. (line 163)
-* OUTGOING_REG_PARM_STACK_SPACE: Stack Arguments. (line 71)
-* OUTGOING_REGNO: Register Basics. (line 98)
-* output of assembler code: File Framework. (line 6)
-* output statements: Output Statement. (line 6)
-* output templates: Output Template. (line 6)
-* OUTPUT_ADDR_CONST_EXTRA: Data Output. (line 39)
-* output_asm_insn: Output Statement. (line 53)
-* OUTPUT_QUOTED_STRING: File Framework. (line 76)
-* OVERLOAD: Functions. (line 6)
-* OVERRIDE_ABI_FORMAT: Register Arguments. (line 140)
-* OVERRIDE_OPTIONS: Run-time Target. (line 104)
-* OVL_CURRENT: Functions. (line 6)
-* OVL_NEXT: Functions. (line 6)
-* p in constraint: Simple Constraints. (line 154)
-* PAD_VARARGS_DOWN: Register Arguments. (line 220)
-* parallel: Side Effects. (line 204)
-* param_is: GTY Options. (line 113)
-* parameters, c++ abi: C++ ABI. (line 6)
-* parameters, miscellaneous: Misc. (line 6)
-* parameters, precompiled headers: PCH Target. (line 6)
-* paramN_is: GTY Options. (line 131)
-* parity: Arithmetic. (line 228)
-* parityM2 instruction pattern: Standard Names. (line 645)
-* PARM_BOUNDARY: Storage Layout. (line 144)
-* PARM_DECL: Declarations. (line 6)
-* PARSE_LDD_OUTPUT: Macros for Initialization.
- (line 121)
-* passes and files of the compiler: Passes. (line 6)
-* passing arguments: Interface. (line 36)
-* PATH_SEPARATOR: Filesystem. (line 31)
-* PATTERN: Insns. (line 247)
-* pattern conditions: Patterns. (line 43)
-* pattern names: Standard Names. (line 6)
-* Pattern Ordering: Pattern Ordering. (line 6)
-* patterns: Patterns. (line 6)
-* pc: Regs and Memory. (line 361)
-* pc and attributes: Insn Lengths. (line 20)
-* pc, RTL sharing: Sharing. (line 25)
-* PC_REGNUM: Register Basics. (line 112)
-* pc_rtx: Regs and Memory. (line 366)
-* PCC_BITFIELD_TYPE_MATTERS: Storage Layout. (line 314)
-* PCC_STATIC_STRUCT_RETURN: Aggregate Return. (line 64)
-* PDImode: Machine Modes. (line 40)
-* peephole optimization, RTL representation: Side Effects. (line 238)
-* peephole optimizer definitions: Peephole Definitions.
- (line 6)
-* per-function data: Per-Function Data. (line 6)
-* percent sign: Output Template. (line 6)
-* PHI nodes: SSA. (line 31)
-* phi_arg_d: GIMPLE_PHI. (line 28)
-* PHI_ARG_DEF: SSA. (line 71)
-* PHI_ARG_EDGE: SSA. (line 68)
-* PHI_ARG_ELT: SSA. (line 63)
-* PHI_NUM_ARGS: SSA. (line 59)
-* PHI_RESULT: SSA. (line 56)
-* PIC: PIC. (line 6)
-* PIC_OFFSET_TABLE_REG_CALL_CLOBBERED: PIC. (line 26)
-* PIC_OFFSET_TABLE_REGNUM: PIC. (line 16)
-* pipeline hazard recognizer: Processor pipeline description.
- (line 6)
-* Plugins: Plugins. (line 6)
-* plus: Arithmetic. (line 14)
-* plus and attributes: Expressions. (line 64)
-* plus, canonicalization of: Insn Canonicalizations.
- (line 27)
-* PLUS_EXPR: Expression trees. (line 6)
-* Pmode: Misc. (line 344)
-* pmode_register_operand: Machine-Independent Predicates.
- (line 35)
-* pointer: Types. (line 6)
-* POINTER_PLUS_EXPR: Expression trees. (line 6)
-* POINTER_SIZE: Storage Layout. (line 83)
-* POINTER_TYPE: Types. (line 6)
-* POINTERS_EXTEND_UNSIGNED: Storage Layout. (line 89)
-* pop_operand: Machine-Independent Predicates.
- (line 88)
-* popcount: Arithmetic. (line 224)
-* popcountM2 instruction pattern: Standard Names. (line 639)
-* portability: Portability. (line 6)
-* position independent code: PIC. (line 6)
-* post_dec: Incdec. (line 25)
-* post_inc: Incdec. (line 30)
-* post_modify: Incdec. (line 33)
-* POSTDECREMENT_EXPR: Expression trees. (line 6)
-* POSTINCREMENT_EXPR: Expression trees. (line 6)
-* POWI_MAX_MULTS: Misc. (line 828)
-* powM3 instruction pattern: Standard Names. (line 513)
-* pragma: Misc. (line 381)
-* pre_dec: Incdec. (line 8)
-* PRE_GCC3_DWARF_FRAME_REGISTERS: Frame Registers. (line 110)
-* pre_inc: Incdec. (line 22)
-* pre_modify: Incdec. (line 51)
-* PREDECREMENT_EXPR: Expression trees. (line 6)
-* predefined macros: Run-time Target. (line 6)
-* predicates: Predicates. (line 6)
-* predicates and machine modes: Predicates. (line 31)
-* predication: Conditional Execution.
- (line 6)
-* predict.def: Profile information.
- (line 24)
-* PREFERRED_DEBUGGING_TYPE: All Debuggers. (line 42)
-* PREFERRED_OUTPUT_RELOAD_CLASS: Register Classes. (line 231)
-* PREFERRED_RELOAD_CLASS: Register Classes. (line 196)
-* PREFERRED_STACK_BOUNDARY: Storage Layout. (line 158)
-* prefetch: Side Effects. (line 312)
-* prefetch instruction pattern: Standard Names. (line 1392)
-* PREINCREMENT_EXPR: Expression trees. (line 6)
-* presence_set: Processor pipeline description.
- (line 215)
-* preserving SSA form: SSA. (line 76)
-* preserving virtual SSA form: SSA. (line 186)
-* prev_active_insn: define_peephole. (line 60)
-* prev_cc0_setter: Jump Patterns. (line 64)
-* PREV_INSN: Insns. (line 26)
-* PRINT_OPERAND: Instruction Output. (line 68)
-* PRINT_OPERAND_ADDRESS: Instruction Output. (line 96)
-* PRINT_OPERAND_PUNCT_VALID_P: Instruction Output. (line 89)
-* processor functional units: Processor pipeline description.
- (line 6)
-* processor pipeline description: Processor pipeline description.
- (line 6)
-* product: Arithmetic. (line 92)
-* profile feedback: Profile information.
- (line 14)
-* profile representation: Profile information.
- (line 6)
-* PROFILE_BEFORE_PROLOGUE: Profiling. (line 35)
-* PROFILE_HOOK: Profiling. (line 23)
-* profiling, code generation: Profiling. (line 6)
-* program counter: Regs and Memory. (line 362)
-* prologue: Function Entry. (line 6)
-* prologue instruction pattern: Standard Names. (line 1338)
-* PROMOTE_FUNCTION_MODE: Storage Layout. (line 123)
-* PROMOTE_MODE: Storage Layout. (line 100)
-* pseudo registers: Regs and Memory. (line 9)
-* PSImode: Machine Modes. (line 32)
-* PTRDIFF_TYPE: Type Layout. (line 184)
-* PTRMEM_CST: Expression trees. (line 6)
-* PTRMEM_CST_CLASS: Expression trees. (line 6)
-* PTRMEM_CST_MEMBER: Expression trees. (line 6)
-* purge_dead_edges <1>: Maintaining the CFG.
- (line 93)
-* purge_dead_edges: Edges. (line 104)
-* push address instruction: Simple Constraints. (line 154)
-* PUSH_ARGS: Stack Arguments. (line 18)
-* PUSH_ARGS_REVERSED: Stack Arguments. (line 26)
-* push_operand: Machine-Independent Predicates.
- (line 81)
-* push_reload: Addressing Modes. (line 169)
-* PUSH_ROUNDING: Stack Arguments. (line 32)
-* pushM1 instruction pattern: Standard Names. (line 209)
-* PUT_CODE: RTL Objects. (line 47)
-* PUT_MODE: Machine Modes. (line 283)
-* PUT_REG_NOTE_KIND: Insns. (line 309)
-* PUT_SDB_: SDB and DWARF. (line 63)
-* QCmode: Machine Modes. (line 197)
-* QFmode: Machine Modes. (line 54)
-* QImode: Machine Modes. (line 25)
-* QImode, in insn: Insns. (line 231)
-* QQmode: Machine Modes. (line 103)
-* qualified type: Types. (line 6)
-* querying function unit reservations: Processor pipeline description.
- (line 90)
-* question mark: Multi-Alternative. (line 41)
-* quotient: Arithmetic. (line 111)
-* r in constraint: Simple Constraints. (line 56)
-* RANGE_TEST_NON_SHORT_CIRCUIT: Costs. (line 204)
-* RDIV_EXPR: Expression trees. (line 6)
-* READONLY_DATA_SECTION_ASM_OP: Sections. (line 63)
-* real operands: SSA Operands. (line 6)
-* REAL_ARITHMETIC: Floating Point. (line 66)
-* REAL_CST: Expression trees. (line 6)
-* REAL_LIBGCC_SPEC: Driver. (line 187)
-* REAL_NM_FILE_NAME: Macros for Initialization.
- (line 106)
-* REAL_TYPE: Types. (line 6)
-* REAL_VALUE_ABS: Floating Point. (line 82)
-* REAL_VALUE_ATOF: Floating Point. (line 50)
-* REAL_VALUE_FIX: Floating Point. (line 41)
-* REAL_VALUE_FROM_INT: Floating Point. (line 99)
-* REAL_VALUE_ISINF: Floating Point. (line 59)
-* REAL_VALUE_ISNAN: Floating Point. (line 62)
-* REAL_VALUE_NEGATE: Floating Point. (line 79)
-* REAL_VALUE_NEGATIVE: Floating Point. (line 56)
-* REAL_VALUE_TO_INT: Floating Point. (line 93)
-* REAL_VALUE_TO_TARGET_DECIMAL128: Data Output. (line 144)
-* REAL_VALUE_TO_TARGET_DECIMAL32: Data Output. (line 142)
-* REAL_VALUE_TO_TARGET_DECIMAL64: Data Output. (line 143)
-* REAL_VALUE_TO_TARGET_DOUBLE: Data Output. (line 140)
-* REAL_VALUE_TO_TARGET_LONG_DOUBLE: Data Output. (line 141)
-* REAL_VALUE_TO_TARGET_SINGLE: Data Output. (line 139)
-* REAL_VALUE_TRUNCATE: Floating Point. (line 86)
-* REAL_VALUE_TYPE: Floating Point. (line 26)
-* REAL_VALUE_UNSIGNED_FIX: Floating Point. (line 45)
-* REAL_VALUES_EQUAL: Floating Point. (line 32)
-* REAL_VALUES_LESS: Floating Point. (line 38)
-* REALPART_EXPR: Expression trees. (line 6)
-* recog_data.operand: Instruction Output. (line 39)
-* recognizing insns: RTL Template. (line 6)
-* RECORD_TYPE <1>: Classes. (line 6)
-* RECORD_TYPE: Types. (line 6)
-* redirect_edge_and_branch: Profile information.
- (line 71)
-* redirect_edge_and_branch, redirect_jump: Maintaining the CFG.
- (line 103)
-* reduc_smax_M instruction pattern: Standard Names. (line 240)
-* reduc_smin_M instruction pattern: Standard Names. (line 240)
-* reduc_splus_M instruction pattern: Standard Names. (line 252)
-* reduc_umax_M instruction pattern: Standard Names. (line 246)
-* reduc_umin_M instruction pattern: Standard Names. (line 246)
-* reduc_uplus_M instruction pattern: Standard Names. (line 258)
-* reference: Types. (line 6)
-* REFERENCE_TYPE: Types. (line 6)
-* reg: Regs and Memory. (line 9)
-* reg and /f: Flags. (line 112)
-* reg and /i: Flags. (line 107)
-* reg and /v: Flags. (line 116)
-* reg, RTL sharing: Sharing. (line 17)
-* REG_ALLOC_ORDER: Allocation Order. (line 9)
-* REG_BR_PRED: Insns. (line 491)
-* REG_BR_PROB: Insns. (line 485)
-* REG_BR_PROB_BASE, BB_FREQ_BASE, count: Profile information.
- (line 82)
-* REG_BR_PROB_BASE, EDGE_FREQUENCY: Profile information.
- (line 52)
-* REG_CC_SETTER: Insns. (line 456)
-* REG_CC_USER: Insns. (line 456)
-* REG_CLASS_CONTENTS: Register Classes. (line 86)
-* reg_class_contents: Register Basics. (line 59)
-* REG_CLASS_FROM_CONSTRAINT: Old Constraints. (line 35)
-* REG_CLASS_FROM_LETTER: Old Constraints. (line 27)
-* REG_CLASS_NAMES: Register Classes. (line 81)
-* REG_CROSSING_JUMP: Insns. (line 368)
-* REG_DEAD: Insns. (line 320)
-* REG_DEAD, REG_UNUSED: Liveness information.
- (line 32)
-* REG_DEP_ANTI: Insns. (line 478)
-* REG_DEP_OUTPUT: Insns. (line 474)
-* REG_DEP_TRUE: Insns. (line 471)
-* REG_EH_REGION, EDGE_ABNORMAL_CALL: Edges. (line 110)
-* REG_EQUAL: Insns. (line 384)
-* REG_EQUIV: Insns. (line 384)
-* REG_EXPR: Special Accessors. (line 46)
-* REG_FRAME_RELATED_EXPR: Insns. (line 497)
-* REG_FUNCTION_VALUE_P: Flags. (line 107)
-* REG_INC: Insns. (line 336)
-* reg_label and /v: Flags. (line 65)
-* REG_LABEL_OPERAND: Insns. (line 350)
-* REG_LABEL_TARGET: Insns. (line 359)
-* reg_names <1>: Instruction Output. (line 80)
-* reg_names: Register Basics. (line 59)
-* REG_NONNEG: Insns. (line 342)
-* REG_NOTE_KIND: Insns. (line 309)
-* REG_NOTES: Insns. (line 283)
-* REG_OFFSET: Special Accessors. (line 50)
-* REG_OK_STRICT: Addressing Modes. (line 67)
-* REG_PARM_STACK_SPACE: Stack Arguments. (line 56)
-* REG_PARM_STACK_SPACE, and FUNCTION_ARG: Register Arguments.
- (line 52)
-* REG_POINTER: Flags. (line 112)
-* REG_SETJMP: Insns. (line 378)
-* REG_UNUSED: Insns. (line 329)
-* REG_USERVAR_P: Flags. (line 116)
-* regclass_for_constraint: C Constraint Interface.
- (line 60)
-* register allocation order: Allocation Order. (line 6)
-* register class definitions: Register Classes. (line 6)
-* register class preference constraints: Class Preferences. (line 6)
-* register pairs: Values in Registers.
- (line 69)
-* Register Transfer Language (RTL): RTL. (line 6)
-* register usage: Registers. (line 6)
-* REGISTER_MOVE_COST: Costs. (line 10)
-* REGISTER_NAMES: Instruction Output. (line 9)
-* register_operand: Machine-Independent Predicates.
- (line 30)
-* REGISTER_PREFIX: Instruction Output. (line 124)
-* REGISTER_TARGET_PRAGMAS: Misc. (line 382)
-* registers arguments: Register Arguments. (line 6)
-* registers in constraints: Simple Constraints. (line 56)
-* REGMODE_NATURAL_SIZE: Values in Registers.
- (line 50)
-* REGNO_MODE_CODE_OK_FOR_BASE_P: Register Classes. (line 170)
-* REGNO_MODE_OK_FOR_BASE_P: Register Classes. (line 146)
-* REGNO_MODE_OK_FOR_REG_BASE_P: Register Classes. (line 157)
-* REGNO_OK_FOR_BASE_P: Register Classes. (line 140)
-* REGNO_OK_FOR_INDEX_P: Register Classes. (line 181)
-* REGNO_REG_CLASS: Register Classes. (line 101)
-* regs_ever_live: Function Entry. (line 21)
-* regular expressions: Processor pipeline description.
- (line 6)
-* relative costs: Costs. (line 6)
-* RELATIVE_PREFIX_NOT_LINKDIR: Driver. (line 325)
-* reload_completed: Standard Names. (line 1040)
-* reload_in instruction pattern: Standard Names. (line 99)
-* reload_in_progress: Standard Names. (line 57)
-* reload_out instruction pattern: Standard Names. (line 99)
-* reloading: RTL passes. (line 182)
-* remainder: Arithmetic. (line 131)
-* remainderM3 instruction pattern: Standard Names. (line 472)
-* reorder: GTY Options. (line 209)
-* representation of RTL: RTL. (line 6)
-* reservation delays: Processor pipeline description.
- (line 6)
-* rest_of_decl_compilation: Parsing pass. (line 52)
-* rest_of_type_compilation: Parsing pass. (line 52)
-* restore_stack_block instruction pattern: Standard Names. (line 1174)
-* restore_stack_function instruction pattern: Standard Names.
- (line 1174)
-* restore_stack_nonlocal instruction pattern: Standard Names.
- (line 1174)
-* RESULT_DECL: Declarations. (line 6)
-* return: Side Effects. (line 72)
-* return instruction pattern: Standard Names. (line 1027)
-* return values in registers: Scalar Return. (line 6)
-* RETURN_ADDR_IN_PREVIOUS_FRAME: Frame Layout. (line 135)
-* RETURN_ADDR_OFFSET: Exception Handling. (line 60)
-* RETURN_ADDR_RTX: Frame Layout. (line 124)
-* RETURN_ADDRESS_POINTER_REGNUM: Frame Registers. (line 51)
-* RETURN_EXPR: Function Bodies. (line 6)
-* RETURN_POPS_ARGS: Stack Arguments. (line 90)
-* RETURN_STMT: Function Bodies. (line 6)
-* return_val: Flags. (line 294)
-* return_val, in call_insn: Flags. (line 24)
-* return_val, in mem: Flags. (line 85)
-* return_val, in reg: Flags. (line 107)
-* return_val, in symbol_ref: Flags. (line 220)
-* returning aggregate values: Aggregate Return. (line 6)
-* returning structures and unions: Interface. (line 10)
-* reverse probability: Profile information.
- (line 66)
-* REVERSE_CONDEXEC_PREDICATES_P: Condition Code. (line 129)
-* REVERSE_CONDITION: Condition Code. (line 116)
-* REVERSIBLE_CC_MODE: Condition Code. (line 102)
-* right rotate: Arithmetic. (line 190)
-* right shift: Arithmetic. (line 185)
-* rintM2 instruction pattern: Standard Names. (line 572)
-* RISC: Processor pipeline description.
- (line 6)
-* roots, marking: GGC Roots. (line 6)
-* rotate: Arithmetic. (line 190)
-* rotatert: Arithmetic. (line 190)
-* rotlM3 instruction pattern: Standard Names. (line 441)
-* rotrM3 instruction pattern: Standard Names. (line 441)
-* ROUND_DIV_EXPR: Expression trees. (line 6)
-* ROUND_MOD_EXPR: Expression trees. (line 6)
-* ROUND_TOWARDS_ZERO: Storage Layout. (line 460)
-* ROUND_TYPE_ALIGN: Storage Layout. (line 411)
-* roundM2 instruction pattern: Standard Names. (line 548)
-* RSHIFT_EXPR: Expression trees. (line 6)
-* RTL addition: Arithmetic. (line 14)
-* RTL addition with signed saturation: Arithmetic. (line 14)
-* RTL addition with unsigned saturation: Arithmetic. (line 14)
-* RTL classes: RTL Classes. (line 6)
-* RTL comparison: Arithmetic. (line 43)
-* RTL comparison operations: Comparisons. (line 6)
-* RTL constant expression types: Constants. (line 6)
-* RTL constants: Constants. (line 6)
-* RTL declarations: RTL Declarations. (line 6)
-* RTL difference: Arithmetic. (line 36)
-* RTL expression: RTL Objects. (line 6)
-* RTL expressions for arithmetic: Arithmetic. (line 6)
-* RTL format: RTL Classes. (line 71)
-* RTL format characters: RTL Classes. (line 76)
-* RTL function-call insns: Calls. (line 6)
-* RTL insn template: RTL Template. (line 6)
-* RTL integers: RTL Objects. (line 6)
-* RTL memory expressions: Regs and Memory. (line 6)
-* RTL object types: RTL Objects. (line 6)
-* RTL postdecrement: Incdec. (line 6)
-* RTL postincrement: Incdec. (line 6)
-* RTL predecrement: Incdec. (line 6)
-* RTL preincrement: Incdec. (line 6)
-* RTL register expressions: Regs and Memory. (line 6)
-* RTL representation: RTL. (line 6)
-* RTL side effect expressions: Side Effects. (line 6)
-* RTL strings: RTL Objects. (line 6)
-* RTL structure sharing assumptions: Sharing. (line 6)
-* RTL subtraction: Arithmetic. (line 36)
-* RTL subtraction with signed saturation: Arithmetic. (line 36)
-* RTL subtraction with unsigned saturation: Arithmetic. (line 36)
-* RTL sum: Arithmetic. (line 14)
-* RTL vectors: RTL Objects. (line 6)
-* RTL_CONST_CALL_P: Flags. (line 19)
-* RTL_CONST_OR_PURE_CALL_P: Flags. (line 29)
-* RTL_LOOPING_CONST_OR_PURE_CALL_P: Flags. (line 33)
-* RTL_PURE_CALL_P: Flags. (line 24)
-* RTX (See RTL): RTL Objects. (line 6)
-* RTX codes, classes of: RTL Classes. (line 6)
-* RTX_FRAME_RELATED_P: Flags. (line 125)
-* run-time conventions: Interface. (line 6)
-* run-time target specification: Run-time Target. (line 6)
-* s in constraint: Simple Constraints. (line 92)
-* same_type_p: Types. (line 148)
-* SAmode: Machine Modes. (line 148)
-* sat_fract: Conversions. (line 90)
-* satfractMN2 instruction pattern: Standard Names. (line 843)
-* satfractunsMN2 instruction pattern: Standard Names. (line 856)
-* satisfies_constraint_: C Constraint Interface.
- (line 47)
-* SAVE_EXPR: Expression trees. (line 6)
-* save_stack_block instruction pattern: Standard Names. (line 1174)
-* save_stack_function instruction pattern: Standard Names. (line 1174)
-* save_stack_nonlocal instruction pattern: Standard Names. (line 1174)
-* SBSS_SECTION_ASM_OP: Sections. (line 77)
-* Scalar evolutions: Scalar evolutions. (line 6)
-* scalars, returned as values: Scalar Return. (line 6)
-* SCHED_GROUP_P: Flags. (line 166)
-* SCmode: Machine Modes. (line 197)
-* sCOND instruction pattern: Standard Names. (line 911)
-* scratch: Regs and Memory. (line 298)
-* scratch operands: Regs and Memory. (line 298)
-* scratch, RTL sharing: Sharing. (line 35)
-* scratch_operand: Machine-Independent Predicates.
- (line 50)
-* SDATA_SECTION_ASM_OP: Sections. (line 58)
-* SDB_ALLOW_FORWARD_REFERENCES: SDB and DWARF. (line 81)
-* SDB_ALLOW_UNKNOWN_REFERENCES: SDB and DWARF. (line 76)
-* SDB_DEBUGGING_INFO: SDB and DWARF. (line 9)
-* SDB_DELIM: SDB and DWARF. (line 69)
-* SDB_OUTPUT_SOURCE_LINE: SDB and DWARF. (line 86)
-* SDmode: Machine Modes. (line 85)
-* sdot_prodM instruction pattern: Standard Names. (line 264)
-* search options: Including Patterns. (line 44)
-* SECONDARY_INPUT_RELOAD_CLASS: Register Classes. (line 335)
-* SECONDARY_MEMORY_NEEDED: Register Classes. (line 391)
-* SECONDARY_MEMORY_NEEDED_MODE: Register Classes. (line 410)
-* SECONDARY_MEMORY_NEEDED_RTX: Register Classes. (line 401)
-* SECONDARY_OUTPUT_RELOAD_CLASS: Register Classes. (line 336)
-* SECONDARY_RELOAD_CLASS: Register Classes. (line 334)
-* SELECT_CC_MODE: Condition Code. (line 68)
-* sequence: Side Effects. (line 254)
-* Sequence iterators: Sequence iterators. (line 6)
-* set: Side Effects. (line 15)
-* set and /f: Flags. (line 125)
-* SET_ASM_OP: Label Output. (line 378)
-* set_attr: Tagging Insns. (line 31)
-* set_attr_alternative: Tagging Insns. (line 49)
-* set_bb_seq: GIMPLE sequences. (line 76)
-* SET_BY_PIECES_P: Costs. (line 145)
-* SET_DEST: Side Effects. (line 69)
-* SET_IS_RETURN_P: Flags. (line 175)
-* SET_LABEL_KIND: Insns. (line 140)
-* set_optab_libfunc: Library Calls. (line 15)
-* SET_RATIO: Costs. (line 136)
-* SET_SRC: Side Effects. (line 69)
-* SET_TYPE_STRUCTURAL_EQUALITY: Types. (line 6)
-* setmemM instruction pattern: Standard Names. (line 715)
-* SETUP_FRAME_ADDRESSES: Frame Layout. (line 102)
-* SF_SIZE: Type Layout. (line 129)
-* SFmode: Machine Modes. (line 66)
-* sharing of RTL components: Sharing. (line 6)
-* shift: Arithmetic. (line 168)
-* SHIFT_COUNT_TRUNCATED: Misc. (line 127)
-* SHLIB_SUFFIX: Macros for Initialization.
- (line 129)
-* SHORT_ACCUM_TYPE_SIZE: Type Layout. (line 83)
-* SHORT_FRACT_TYPE_SIZE: Type Layout. (line 63)
-* SHORT_IMMEDIATES_SIGN_EXTEND: Misc. (line 96)
-* SHORT_TYPE_SIZE: Type Layout. (line 16)
-* sibcall_epilogue instruction pattern: Standard Names. (line 1364)
-* sibling call: Edges. (line 122)
-* SIBLING_CALL_P: Flags. (line 179)
-* sign_extend: Conversions. (line 23)
-* sign_extract: Bit-Fields. (line 8)
-* sign_extract, canonicalization of: Insn Canonicalizations.
- (line 96)
-* signed division: Arithmetic. (line 111)
-* signed division with signed saturation: Arithmetic. (line 111)
-* signed maximum: Arithmetic. (line 136)
-* signed minimum: Arithmetic. (line 136)
-* SImode: Machine Modes. (line 37)
-* simple constraints: Simple Constraints. (line 6)
-* sincos math function, implicit usage: Library Calls. (line 84)
-* sinM2 instruction pattern: Standard Names. (line 489)
-* SIZE_ASM_OP: Label Output. (line 23)
-* SIZE_TYPE: Type Layout. (line 168)
-* skip: GTY Options. (line 76)
-* SLOW_BYTE_ACCESS: Costs. (line 66)
-* SLOW_UNALIGNED_ACCESS: Costs. (line 81)
-* SMALL_REGISTER_CLASSES: Register Classes. (line 433)
-* smax: Arithmetic. (line 136)
-* smin: Arithmetic. (line 136)
-* sms, swing, software pipelining: RTL passes. (line 131)
-* smulM3_highpart instruction pattern: Standard Names. (line 356)
-* soft float library: Soft float library routines.
- (line 6)
-* special: GTY Options. (line 229)
-* special predicates: Predicates. (line 31)
-* SPECS: Target Fragment. (line 108)
-* speed of instructions: Costs. (line 6)
-* split_block: Maintaining the CFG.
- (line 110)
-* splitting instructions: Insn Splitting. (line 6)
-* SQmode: Machine Modes. (line 111)
-* sqrt: Arithmetic. (line 198)
-* sqrtM2 instruction pattern: Standard Names. (line 455)
-* square root: Arithmetic. (line 198)
-* ss_ashift: Arithmetic. (line 168)
-* ss_div: Arithmetic. (line 111)
-* ss_minus: Arithmetic. (line 36)
-* ss_mult: Arithmetic. (line 92)
-* ss_neg: Arithmetic. (line 81)
-* ss_plus: Arithmetic. (line 14)
-* ss_truncate: Conversions. (line 43)
-* SSA: SSA. (line 6)
-* SSA_NAME_DEF_STMT: SSA. (line 221)
-* SSA_NAME_VERSION: SSA. (line 226)
-* ssaddM3 instruction pattern: Standard Names. (line 222)
-* ssashlM3 instruction pattern: Standard Names. (line 431)
-* ssdivM3 instruction pattern: Standard Names. (line 222)
-* ssmaddMN4 instruction pattern: Standard Names. (line 379)
-* ssmsubMN4 instruction pattern: Standard Names. (line 403)
-* ssmulM3 instruction pattern: Standard Names. (line 222)
-* ssnegM2 instruction pattern: Standard Names. (line 449)
-* sssubM3 instruction pattern: Standard Names. (line 222)
-* ssum_widenM3 instruction pattern: Standard Names. (line 274)
-* stack arguments: Stack Arguments. (line 6)
-* stack frame layout: Frame Layout. (line 6)
-* stack smashing protection: Stack Smashing Protection.
- (line 6)
-* STACK_ALIGNMENT_NEEDED: Frame Layout. (line 48)
-* STACK_BOUNDARY: Storage Layout. (line 150)
-* STACK_CHECK_BUILTIN: Stack Checking. (line 32)
-* STACK_CHECK_FIXED_FRAME_SIZE: Stack Checking. (line 77)
-* STACK_CHECK_MAX_FRAME_SIZE: Stack Checking. (line 68)
-* STACK_CHECK_MAX_VAR_SIZE: Stack Checking. (line 84)
-* STACK_CHECK_PROBE_INTERVAL: Stack Checking. (line 46)
-* STACK_CHECK_PROBE_LOAD: Stack Checking. (line 53)
-* STACK_CHECK_PROTECT: Stack Checking. (line 59)
-* STACK_CHECK_STATIC_BUILTIN: Stack Checking. (line 39)
-* STACK_DYNAMIC_OFFSET: Frame Layout. (line 75)
-* STACK_DYNAMIC_OFFSET and virtual registers: Regs and Memory.
- (line 83)
-* STACK_GROWS_DOWNWARD: Frame Layout. (line 9)
-* STACK_PARMS_IN_REG_PARM_AREA: Stack Arguments. (line 81)
-* STACK_POINTER_OFFSET: Frame Layout. (line 58)
-* STACK_POINTER_OFFSET and virtual registers: Regs and Memory.
- (line 93)
-* STACK_POINTER_REGNUM: Frame Registers. (line 9)
-* STACK_POINTER_REGNUM and virtual registers: Regs and Memory.
- (line 83)
-* stack_pointer_rtx: Frame Registers. (line 85)
-* stack_protect_set instruction pattern: Standard Names. (line 1534)
-* stack_protect_test instruction pattern: Standard Names. (line 1544)
-* STACK_PUSH_CODE: Frame Layout. (line 17)
-* STACK_REGS: Stack Registers. (line 20)
-* STACK_SAVEAREA_MODE: Storage Layout. (line 427)
-* STACK_SIZE_MODE: Storage Layout. (line 439)
-* STACK_SLOT_ALIGNMENT: Storage Layout. (line 265)
-* standard pattern names: Standard Names. (line 6)
-* STANDARD_INCLUDE_COMPONENT: Driver. (line 425)
-* STANDARD_INCLUDE_DIR: Driver. (line 417)
-* STANDARD_STARTFILE_PREFIX: Driver. (line 337)
-* STANDARD_STARTFILE_PREFIX_1: Driver. (line 344)
-* STANDARD_STARTFILE_PREFIX_2: Driver. (line 351)
-* STARTFILE_SPEC: Driver. (line 210)
-* STARTING_FRAME_OFFSET: Frame Layout. (line 39)
-* STARTING_FRAME_OFFSET and virtual registers: Regs and Memory.
- (line 74)
-* Statement and operand traversals: Statement and operand traversals.
- (line 6)
-* Statement Sequences: Statement Sequences.
- (line 6)
-* Statements: Statements. (line 6)
-* statements: Function Bodies. (line 6)
-* Static profile estimation: Profile information.
- (line 24)
-* static single assignment: SSA. (line 6)
-* STATIC_CHAIN: Frame Registers. (line 77)
-* STATIC_CHAIN_INCOMING: Frame Registers. (line 78)
-* STATIC_CHAIN_INCOMING_REGNUM: Frame Registers. (line 64)
-* STATIC_CHAIN_REGNUM: Frame Registers. (line 63)
-* stdarg.h and register arguments: Register Arguments. (line 47)
-* STDC_0_IN_SYSTEM_HEADERS: Misc. (line 365)
-* STMT_EXPR: Expression trees. (line 6)
-* STMT_IS_FULL_EXPR_P: Function Bodies. (line 22)
-* storage layout: Storage Layout. (line 6)
-* STORE_BY_PIECES_P: Costs. (line 152)
-* STORE_FLAG_VALUE: Misc. (line 216)
-* store_multiple instruction pattern: Standard Names. (line 160)
-* strcpy: Storage Layout. (line 235)
-* STRICT_ALIGNMENT: Storage Layout. (line 309)
-* strict_low_part: RTL Declarations. (line 9)
-* strict_memory_address_p: Addressing Modes. (line 179)
-* STRING_CST: Expression trees. (line 6)
-* STRING_POOL_ADDRESS_P: Flags. (line 183)
-* strlenM instruction pattern: Standard Names. (line 778)
-* structure value address: Aggregate Return. (line 6)
-* STRUCTURE_SIZE_BOUNDARY: Storage Layout. (line 301)
-* structures, returning: Interface. (line 10)
-* subM3 instruction pattern: Standard Names. (line 222)
-* SUBOBJECT: Function Bodies. (line 6)
-* SUBOBJECT_CLEANUP: Function Bodies. (line 6)
-* subreg: Regs and Memory. (line 97)
-* subreg and /s: Flags. (line 205)
-* subreg and /u: Flags. (line 198)
-* subreg and /u and /v: Flags. (line 188)
-* subreg, in strict_low_part: RTL Declarations. (line 9)
-* SUBREG_BYTE: Regs and Memory. (line 289)
-* SUBREG_PROMOTED_UNSIGNED_P: Flags. (line 188)
-* SUBREG_PROMOTED_UNSIGNED_SET: Flags. (line 198)
-* SUBREG_PROMOTED_VAR_P: Flags. (line 205)
-* SUBREG_REG: Regs and Memory. (line 289)
-* SUCCESS_EXIT_CODE: Host Misc. (line 12)
-* SUPPORTS_INIT_PRIORITY: Macros for Initialization.
- (line 58)
-* SUPPORTS_ONE_ONLY: Label Output. (line 227)
-* SUPPORTS_WEAK: Label Output. (line 208)
-* SWITCH_BODY: Function Bodies. (line 6)
-* SWITCH_COND: Function Bodies. (line 6)
-* SWITCH_CURTAILS_COMPILATION: Driver. (line 33)
-* SWITCH_STMT: Function Bodies. (line 6)
-* SWITCH_TAKES_ARG: Driver. (line 9)
-* SWITCHES_NEED_SPACES: Driver. (line 47)
-* SYMBOL_FLAG_ANCHOR: Special Accessors. (line 106)
-* SYMBOL_FLAG_EXTERNAL: Special Accessors. (line 88)
-* SYMBOL_FLAG_FUNCTION: Special Accessors. (line 81)
-* SYMBOL_FLAG_HAS_BLOCK_INFO: Special Accessors. (line 102)
-* SYMBOL_FLAG_LOCAL: Special Accessors. (line 84)
-* SYMBOL_FLAG_SMALL: Special Accessors. (line 93)
-* SYMBOL_FLAG_TLS_SHIFT: Special Accessors. (line 97)
-* symbol_ref: Constants. (line 76)
-* symbol_ref and /f: Flags. (line 183)
-* symbol_ref and /i: Flags. (line 220)
-* symbol_ref and /u: Flags. (line 10)
-* symbol_ref and /v: Flags. (line 224)
-* symbol_ref, RTL sharing: Sharing. (line 20)
-* SYMBOL_REF_ANCHOR_P: Special Accessors. (line 106)
-* SYMBOL_REF_BLOCK: Special Accessors. (line 119)
-* SYMBOL_REF_BLOCK_OFFSET: Special Accessors. (line 124)
-* SYMBOL_REF_CONSTANT: Special Accessors. (line 67)
-* SYMBOL_REF_DATA: Special Accessors. (line 71)
-* SYMBOL_REF_DECL: Special Accessors. (line 55)
-* SYMBOL_REF_EXTERNAL_P: Special Accessors. (line 88)
-* SYMBOL_REF_FLAG: Flags. (line 224)
-* SYMBOL_REF_FLAG, in TARGET_ENCODE_SECTION_INFO: Sections. (line 259)
-* SYMBOL_REF_FLAGS: Special Accessors. (line 75)
-* SYMBOL_REF_FUNCTION_P: Special Accessors. (line 81)
-* SYMBOL_REF_HAS_BLOCK_INFO_P: Special Accessors. (line 102)
-* SYMBOL_REF_LOCAL_P: Special Accessors. (line 84)
-* SYMBOL_REF_SMALL_P: Special Accessors. (line 93)
-* SYMBOL_REF_TLS_MODEL: Special Accessors. (line 97)
-* SYMBOL_REF_USED: Flags. (line 215)
-* SYMBOL_REF_WEAK: Flags. (line 220)
-* symbolic label: Sharing. (line 20)
-* sync_addMODE instruction pattern: Standard Names. (line 1450)
-* sync_andMODE instruction pattern: Standard Names. (line 1450)
-* sync_compare_and_swap_ccMODE instruction pattern: Standard Names.
- (line 1437)
-* sync_compare_and_swapMODE instruction pattern: Standard Names.
- (line 1419)
-* sync_iorMODE instruction pattern: Standard Names. (line 1450)
-* sync_lock_releaseMODE instruction pattern: Standard Names. (line 1515)
-* sync_lock_test_and_setMODE instruction pattern: Standard Names.
- (line 1489)
-* sync_nandMODE instruction pattern: Standard Names. (line 1450)
-* sync_new_addMODE instruction pattern: Standard Names. (line 1482)
-* sync_new_andMODE instruction pattern: Standard Names. (line 1482)
-* sync_new_iorMODE instruction pattern: Standard Names. (line 1482)
-* sync_new_nandMODE instruction pattern: Standard Names. (line 1482)
-* sync_new_subMODE instruction pattern: Standard Names. (line 1482)
-* sync_new_xorMODE instruction pattern: Standard Names. (line 1482)
-* sync_old_addMODE instruction pattern: Standard Names. (line 1465)
-* sync_old_andMODE instruction pattern: Standard Names. (line 1465)
-* sync_old_iorMODE instruction pattern: Standard Names. (line 1465)
-* sync_old_nandMODE instruction pattern: Standard Names. (line 1465)
-* sync_old_subMODE instruction pattern: Standard Names. (line 1465)
-* sync_old_xorMODE instruction pattern: Standard Names. (line 1465)
-* sync_subMODE instruction pattern: Standard Names. (line 1450)
-* sync_xorMODE instruction pattern: Standard Names. (line 1450)
-* SYSROOT_HEADERS_SUFFIX_SPEC: Driver. (line 239)
-* SYSROOT_SUFFIX_SPEC: Driver. (line 234)
-* SYSTEM_INCLUDE_DIR: Driver. (line 408)
-* t-TARGET: Target Fragment. (line 6)
-* table jump: Basic Blocks. (line 57)
-* tablejump instruction pattern: Standard Names. (line 1102)
-* tag: GTY Options. (line 81)
-* tagging insns: Tagging Insns. (line 6)
-* tail calls: Tail Calls. (line 6)
-* TAmode: Machine Modes. (line 156)
-* target attributes: Target Attributes. (line 6)
-* target description macros: Target Macros. (line 6)
-* target functions: Target Structure. (line 6)
-* target hooks: Target Structure. (line 6)
-* target makefile fragment: Target Fragment. (line 6)
-* target specifications: Run-time Target. (line 6)
-* TARGET_ADDRESS_COST: Costs. (line 236)
-* TARGET_ALIGN_ANON_BITFIELD: Storage Layout. (line 386)
-* TARGET_ALLOCATE_INITIAL_VALUE: Misc. (line 712)
-* TARGET_ALLOCATE_STACK_SLOTS_FOR_ARGS: Misc. (line 951)
-* TARGET_ARG_PARTIAL_BYTES: Register Arguments. (line 83)
-* TARGET_ARM_EABI_UNWINDER: Exception Region Output.
- (line 113)
-* TARGET_ASM_ALIGNED_DI_OP: Data Output. (line 10)
-* TARGET_ASM_ALIGNED_HI_OP: Data Output. (line 8)
-* TARGET_ASM_ALIGNED_SI_OP: Data Output. (line 9)
-* TARGET_ASM_ALIGNED_TI_OP: Data Output. (line 11)
-* TARGET_ASM_ASSEMBLE_VISIBILITY: Label Output. (line 239)
-* TARGET_ASM_BYTE_OP: Data Output. (line 7)
-* TARGET_ASM_CAN_OUTPUT_MI_THUNK: Function Entry. (line 237)
-* TARGET_ASM_CLOSE_PAREN: Data Output. (line 130)
-* TARGET_ASM_CONSTRUCTOR: Macros for Initialization.
- (line 69)
-* TARGET_ASM_DESTRUCTOR: Macros for Initialization.
- (line 83)
-* TARGET_ASM_EMIT_EXCEPT_TABLE_LABEL: Dispatch Tables. (line 74)
-* TARGET_ASM_EMIT_UNWIND_LABEL: Dispatch Tables. (line 63)
-* TARGET_ASM_EXTERNAL_LIBCALL: Label Output. (line 274)
-* TARGET_ASM_FILE_END: File Framework. (line 37)
-* TARGET_ASM_FILE_START: File Framework. (line 9)
-* TARGET_ASM_FILE_START_APP_OFF: File Framework. (line 17)
-* TARGET_ASM_FILE_START_FILE_DIRECTIVE: File Framework. (line 31)
-* TARGET_ASM_FUNCTION_BEGIN_EPILOGUE: Function Entry. (line 61)
-* TARGET_ASM_FUNCTION_END_PROLOGUE: Function Entry. (line 55)
-* TARGET_ASM_FUNCTION_EPILOGUE: Function Entry. (line 68)
-* TARGET_ASM_FUNCTION_EPILOGUE and trampolines: Trampolines. (line 70)
-* TARGET_ASM_FUNCTION_PROLOGUE: Function Entry. (line 11)
-* TARGET_ASM_FUNCTION_PROLOGUE and trampolines: Trampolines. (line 70)
-* TARGET_ASM_FUNCTION_RODATA_SECTION: Sections. (line 206)
-* TARGET_ASM_GLOBALIZE_DECL_NAME: Label Output. (line 174)
-* TARGET_ASM_GLOBALIZE_LABEL: Label Output. (line 165)
-* TARGET_ASM_INIT_SECTIONS: Sections. (line 151)
-* TARGET_ASM_INTEGER: Data Output. (line 27)
-* TARGET_ASM_INTERNAL_LABEL: Label Output. (line 309)
-* TARGET_ASM_MARK_DECL_PRESERVED: Label Output. (line 280)
-* TARGET_ASM_NAMED_SECTION: File Framework. (line 89)
-* TARGET_ASM_OPEN_PAREN: Data Output. (line 129)
-* TARGET_ASM_OUTPUT_ANCHOR: Anchored Addresses. (line 44)
-* TARGET_ASM_OUTPUT_DWARF_DTPREL: SDB and DWARF. (line 58)
-* TARGET_ASM_OUTPUT_MI_THUNK: Function Entry. (line 195)
-* TARGET_ASM_RECORD_GCC_SWITCHES: File Framework. (line 122)
-* TARGET_ASM_RECORD_GCC_SWITCHES_SECTION: File Framework. (line 166)
-* TARGET_ASM_SELECT_RTX_SECTION: Sections. (line 214)
-* TARGET_ASM_SELECT_SECTION: Sections. (line 172)
-* TARGET_ASM_TTYPE: Exception Region Output.
- (line 107)
-* TARGET_ASM_UNALIGNED_DI_OP: Data Output. (line 14)
-* TARGET_ASM_UNALIGNED_HI_OP: Data Output. (line 12)
-* TARGET_ASM_UNALIGNED_SI_OP: Data Output. (line 13)
-* TARGET_ASM_UNALIGNED_TI_OP: Data Output. (line 15)
-* TARGET_ASM_UNIQUE_SECTION: Sections. (line 193)
-* TARGET_ATTRIBUTE_TABLE: Target Attributes. (line 11)
-* TARGET_BINDS_LOCAL_P: Sections. (line 284)
-* TARGET_BRANCH_TARGET_REGISTER_CALLEE_SAVED: Misc. (line 808)
-* TARGET_BRANCH_TARGET_REGISTER_CLASS: Misc. (line 800)
-* TARGET_BUILD_BUILTIN_VA_LIST: Register Arguments. (line 263)
-* TARGET_BUILTIN_RECIPROCAL: Addressing Modes. (line 240)
-* TARGET_BUILTIN_SETJMP_FRAME_VALUE: Frame Layout. (line 109)
-* TARGET_C99_FUNCTIONS: Library Calls. (line 77)
-* TARGET_CALLEE_COPIES: Register Arguments. (line 115)
-* TARGET_CAN_INLINE_P: Target Attributes. (line 126)
-* TARGET_CAN_SIMPLIFY_GOT_ACCESS: Misc. (line 982)
-* TARGET_CANNOT_FORCE_CONST_MEM: Addressing Modes. (line 221)
-* TARGET_CANNOT_MODIFY_JUMPS_P: Misc. (line 787)
-* TARGET_CANONICAL_VA_LIST_TYPE: Register Arguments. (line 272)
-* TARGET_CLEAR_PIC_REG: Misc. (line 966)
-* TARGET_COMMUTATIVE_P: Misc. (line 705)
-* TARGET_COMP_TYPE_ATTRIBUTES: Target Attributes. (line 19)
-* TARGET_CPU_CPP_BUILTINS: Run-time Target. (line 9)
-* TARGET_CXX_ADJUST_CLASS_AT_DEFINITION: C++ ABI. (line 87)
-* TARGET_CXX_CDTOR_RETURNS_THIS: C++ ABI. (line 38)
-* TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT: C++ ABI. (line 62)
-* TARGET_CXX_COOKIE_HAS_SIZE: C++ ABI. (line 25)
-* TARGET_CXX_DETERMINE_CLASS_DATA_VISIBILITY: C++ ABI. (line 54)
-* TARGET_CXX_GET_COOKIE_SIZE: C++ ABI. (line 18)
-* TARGET_CXX_GUARD_MASK_BIT: C++ ABI. (line 12)
-* TARGET_CXX_GUARD_TYPE: C++ ABI. (line 7)
-* TARGET_CXX_IMPORT_EXPORT_CLASS: C++ ABI. (line 30)
-* TARGET_CXX_KEY_METHOD_MAY_BE_INLINE: C++ ABI. (line 43)
-* TARGET_CXX_LIBRARY_RTTI_COMDAT: C++ ABI. (line 69)
-* TARGET_CXX_USE_AEABI_ATEXIT: C++ ABI. (line 74)
-* TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT: C++ ABI. (line 80)
-* TARGET_DECIMAL_FLOAT_SUPPORTED_P: Storage Layout. (line 513)
-* TARGET_DECLSPEC: Target Attributes. (line 64)
-* TARGET_DEFAULT_PACK_STRUCT: Misc. (line 482)
-* TARGET_DEFAULT_SHORT_ENUMS: Type Layout. (line 160)
-* TARGET_DEFERRED_OUTPUT_DEFS: Label Output. (line 393)
-* TARGET_DELEGITIMIZE_ADDRESS: Addressing Modes. (line 212)
-* TARGET_DLLIMPORT_DECL_ATTRIBUTES: Target Attributes. (line 47)
-* TARGET_DWARF_CALLING_CONVENTION: SDB and DWARF. (line 18)
-* TARGET_DWARF_HANDLE_FRAME_UNSPEC: Frame Layout. (line 172)
-* TARGET_DWARF_REGISTER_SPAN: Exception Region Output.
- (line 90)
-* TARGET_EDOM: Library Calls. (line 59)
-* TARGET_EMUTLS_DEBUG_FORM_TLS_ADDRESS: Emulated TLS. (line 68)
-* TARGET_EMUTLS_GET_ADDRESS: Emulated TLS. (line 19)
-* TARGET_EMUTLS_REGISTER_COMMON: Emulated TLS. (line 24)
-* TARGET_EMUTLS_TMPL_PREFIX: Emulated TLS. (line 45)
-* TARGET_EMUTLS_TMPL_SECTION: Emulated TLS. (line 36)
-* TARGET_EMUTLS_VAR_ALIGN_FIXED: Emulated TLS. (line 63)
-* TARGET_EMUTLS_VAR_FIELDS: Emulated TLS. (line 49)
-* TARGET_EMUTLS_VAR_INIT: Emulated TLS. (line 57)
-* TARGET_EMUTLS_VAR_PREFIX: Emulated TLS. (line 41)
-* TARGET_EMUTLS_VAR_SECTION: Emulated TLS. (line 31)
-* TARGET_ENCODE_SECTION_INFO: Sections. (line 235)
-* TARGET_ENCODE_SECTION_INFO and address validation: Addressing Modes.
- (line 91)
-* TARGET_ENCODE_SECTION_INFO usage: Instruction Output. (line 100)
-* TARGET_ENUM_VA_LIST: Scalar Return. (line 84)
-* TARGET_EXECUTABLE_SUFFIX: Misc. (line 761)
-* TARGET_EXPAND_BUILTIN: Misc. (line 657)
-* TARGET_EXPAND_BUILTIN_SAVEREGS: Varargs. (line 92)
-* TARGET_EXPAND_TO_RTL_HOOK: Storage Layout. (line 519)
-* TARGET_EXPR: Expression trees. (line 6)
-* TARGET_EXTRA_INCLUDES: Misc. (line 839)
-* TARGET_EXTRA_LIVE_ON_ENTRY: Tail Calls. (line 21)
-* TARGET_EXTRA_PRE_INCLUDES: Misc. (line 846)
-* TARGET_FIXED_CONDITION_CODE_REGS: Condition Code. (line 142)
-* TARGET_FIXED_POINT_SUPPORTED_P: Storage Layout. (line 516)
-* target_flags: Run-time Target. (line 52)
-* TARGET_FLT_EVAL_METHOD: Type Layout. (line 141)
-* TARGET_FN_ABI_VA_LIST: Register Arguments. (line 267)
-* TARGET_FOLD_BUILTIN: Misc. (line 677)
-* TARGET_FORMAT_TYPES: Misc. (line 866)
-* TARGET_FUNCTION_ATTRIBUTE_INLINABLE_P: Target Attributes. (line 86)
-* TARGET_FUNCTION_OK_FOR_SIBCALL: Tail Calls. (line 8)
-* TARGET_FUNCTION_VALUE: Scalar Return. (line 11)
-* TARGET_GET_DRAP_RTX: Misc. (line 946)
-* TARGET_GET_PIC_REG: Misc. (line 962)
-* TARGET_GIMPLIFY_VA_ARG_EXPR: Register Arguments. (line 278)
-* TARGET_HANDLE_C_OPTION: Run-time Target. (line 78)
-* TARGET_HANDLE_OPTION: Run-time Target. (line 61)
-* TARGET_HARD_REGNO_SCRATCH_OK: Values in Registers.
- (line 144)
-* TARGET_HAS_SINCOS: Library Calls. (line 85)
-* TARGET_HAVE_CONDITIONAL_EXECUTION: Misc. (line 822)
-* TARGET_HAVE_CTORS_DTORS: Macros for Initialization.
- (line 64)
-* TARGET_HAVE_NAMED_SECTIONS: File Framework. (line 99)
-* TARGET_HAVE_SWITCHABLE_BSS_SECTIONS: File Framework. (line 103)
-* TARGET_HELP: Run-time Target. (line 140)
-* TARGET_IN_SMALL_DATA_P: Sections. (line 276)
-* TARGET_INIT_BUILTINS: Misc. (line 639)
-* TARGET_INIT_DWARF_REG_SIZES_EXTRA: Exception Region Output.
- (line 99)
-* TARGET_INIT_LIBFUNCS: Library Calls. (line 16)
-* TARGET_INSERT_ATTRIBUTES: Target Attributes. (line 73)
-* TARGET_INSTANTIATE_DECLS: Storage Layout. (line 527)
-* TARGET_INVALID_BINARY_OP: Misc. (line 919)
-* TARGET_INVALID_CONVERSION: Misc. (line 906)
-* TARGET_INVALID_UNARY_OP: Misc. (line 912)
-* TARGET_IRA_COVER_CLASSES: Register Classes. (line 496)
-* TARGET_LIB_INT_CMP_BIASED: Library Calls. (line 35)
-* TARGET_LIBGCC_CMP_RETURN_MODE: Storage Layout. (line 448)
-* TARGET_LIBGCC_SDATA_SECTION: Sections. (line 123)
-* TARGET_LIBGCC_SHIFT_COUNT_MODE: Storage Layout. (line 454)
-* TARGET_LOAD_GLOBAL_ADDRESS: Misc. (line 990)
-* TARGET_LOADED_GLOBAL_VAR: Misc. (line 971)
-* TARGET_MACHINE_DEPENDENT_REORG: Misc. (line 624)
-* TARGET_MANGLE_DECL_ASSEMBLER_NAME: Sections. (line 225)
-* TARGET_MANGLE_TYPE: Storage Layout. (line 531)
-* TARGET_MD_ASM_CLOBBERS: Misc. (line 540)
-* TARGET_MEM_CONSTRAINT: Addressing Modes. (line 100)
-* TARGET_MEM_REF: Expression trees. (line 6)
-* TARGET_MERGE_DECL_ATTRIBUTES: Target Attributes. (line 39)
-* TARGET_MERGE_TYPE_ATTRIBUTES: Target Attributes. (line 31)
-* TARGET_MIN_DIVISIONS_FOR_RECIP_MUL: Misc. (line 106)
-* TARGET_MODE_REP_EXTENDED: Misc. (line 191)
-* TARGET_MS_BITFIELD_LAYOUT_P: Storage Layout. (line 486)
-* TARGET_MUST_PASS_IN_STACK: Register Arguments. (line 62)
-* TARGET_MUST_PASS_IN_STACK, and FUNCTION_ARG: Register Arguments.
- (line 52)
-* TARGET_N_FORMAT_TYPES: Misc. (line 871)
-* TARGET_NARROW_VOLATILE_BITFIELD: Storage Layout. (line 392)
-* TARGET_OBJECT_SUFFIX: Misc. (line 756)
-* TARGET_OBJFMT_CPP_BUILTINS: Run-time Target. (line 46)
-* TARGET_OPTF: Misc. (line 853)
-* TARGET_OPTION_PRAGMA_PARSE: Target Attributes. (line 120)
-* TARGET_OPTION_PRINT: Target Attributes. (line 115)
-* TARGET_OPTION_RESTORE: Target Attributes. (line 110)
-* TARGET_OPTION_SAVE: Target Attributes. (line 104)
-* TARGET_OPTION_TRANSLATE_TABLE: Driver. (line 53)
-* TARGET_OS_CPP_BUILTINS: Run-time Target. (line 42)
-* TARGET_OVERRIDES_FORMAT_ATTRIBUTES: Misc. (line 875)
-* TARGET_OVERRIDES_FORMAT_ATTRIBUTES_COUNT: Misc. (line 881)
-* TARGET_OVERRIDES_FORMAT_INIT: Misc. (line 885)
-* TARGET_PASS_BY_REFERENCE: Register Arguments. (line 103)
-* TARGET_POSIX_IO: Misc. (line 564)
-* TARGET_PRETEND_OUTGOING_VARARGS_NAMED: Varargs. (line 152)
-* TARGET_PROMOTE_FUNCTION_ARGS: Storage Layout. (line 131)
-* TARGET_PROMOTE_FUNCTION_RETURN: Storage Layout. (line 136)
-* TARGET_PROMOTE_PROTOTYPES: Stack Arguments. (line 11)
-* TARGET_PTRMEMFUNC_VBIT_LOCATION: Type Layout. (line 235)
-* TARGET_RELAXED_ORDERING: Misc. (line 890)
-* TARGET_RESOLVE_OVERLOADED_BUILTIN: Misc. (line 667)
-* TARGET_RETURN_IN_MEMORY: Aggregate Return. (line 16)
-* TARGET_RETURN_IN_MSB: Scalar Return. (line 100)
-* TARGET_RTX_COSTS: Costs. (line 210)
-* TARGET_SCALAR_MODE_SUPPORTED_P: Register Arguments. (line 290)
-* TARGET_SCHED_ADJUST_COST: Scheduling. (line 37)
-* TARGET_SCHED_ADJUST_PRIORITY: Scheduling. (line 52)
-* TARGET_SCHED_CLEAR_SCHED_CONTEXT: Scheduling. (line 261)
-* TARGET_SCHED_DEPENDENCIES_EVALUATION_HOOK: Scheduling. (line 89)
-* TARGET_SCHED_DFA_NEW_CYCLE: Scheduling. (line 205)
-* TARGET_SCHED_DFA_POST_CYCLE_ADVANCE: Scheduling. (line 160)
-* TARGET_SCHED_DFA_POST_CYCLE_INSN: Scheduling. (line 144)
-* TARGET_SCHED_DFA_PRE_CYCLE_ADVANCE: Scheduling. (line 153)
-* TARGET_SCHED_DFA_PRE_CYCLE_INSN: Scheduling. (line 132)
-* TARGET_SCHED_FINISH: Scheduling. (line 109)
-* TARGET_SCHED_FINISH_GLOBAL: Scheduling. (line 126)
-* TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD: Scheduling.
- (line 168)
-* TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD: Scheduling.
- (line 196)
-* TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD_SPEC: Scheduling.
- (line 321)
-* TARGET_SCHED_FREE_SCHED_CONTEXT: Scheduling. (line 265)
-* TARGET_SCHED_GEN_CHECK: Scheduling. (line 309)
-* TARGET_SCHED_H_I_D_EXTENDED: Scheduling. (line 241)
-* TARGET_SCHED_INIT: Scheduling. (line 99)
-* TARGET_SCHED_INIT_DFA_POST_CYCLE_INSN: Scheduling. (line 149)
-* TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN: Scheduling. (line 141)
-* TARGET_SCHED_INIT_GLOBAL: Scheduling. (line 118)
-* TARGET_SCHED_INIT_SCHED_CONTEXT: Scheduling. (line 251)
-* TARGET_SCHED_IS_COSTLY_DEPENDENCE: Scheduling. (line 219)
-* TARGET_SCHED_ISSUE_RATE: Scheduling. (line 12)
-* TARGET_SCHED_NEEDS_BLOCK_P: Scheduling. (line 302)
-* TARGET_SCHED_REORDER: Scheduling. (line 60)
-* TARGET_SCHED_REORDER2: Scheduling. (line 77)
-* TARGET_SCHED_SET_SCHED_CONTEXT: Scheduling. (line 257)
-* TARGET_SCHED_SET_SCHED_FLAGS: Scheduling. (line 332)
-* TARGET_SCHED_SMS_RES_MII: Scheduling. (line 343)
-* TARGET_SCHED_SPECULATE_INSN: Scheduling. (line 291)
-* TARGET_SCHED_VARIABLE_ISSUE: Scheduling. (line 24)
-* TARGET_SECONDARY_RELOAD: Register Classes. (line 257)
-* TARGET_SECTION_TYPE_FLAGS: File Framework. (line 109)
-* TARGET_SET_CURRENT_FUNCTION: Misc. (line 739)
-* TARGET_SET_DEFAULT_TYPE_ATTRIBUTES: Target Attributes. (line 26)
-* TARGET_SETUP_INCOMING_VARARGS: Varargs. (line 101)
-* TARGET_SHIFT_TRUNCATION_MASK: Misc. (line 154)
-* TARGET_SPLIT_COMPLEX_ARG: Register Arguments. (line 251)
-* TARGET_STACK_PROTECT_FAIL: Stack Smashing Protection.
- (line 17)
-* TARGET_STACK_PROTECT_GUARD: Stack Smashing Protection.
- (line 7)
-* TARGET_STRICT_ARGUMENT_NAMING: Varargs. (line 137)
-* TARGET_STRUCT_VALUE_RTX: Aggregate Return. (line 44)
-* TARGET_UNSPEC_MAY_TRAP_P: Misc. (line 731)
-* TARGET_UNWIND_EMIT: Dispatch Tables. (line 81)
-* TARGET_UNWIND_INFO: Exception Region Output.
- (line 56)
-* TARGET_UPDATE_STACK_BOUNDARY: Misc. (line 942)
-* TARGET_USE_ANCHORS_FOR_SYMBOL_P: Anchored Addresses. (line 55)
-* TARGET_USE_BLOCKS_FOR_CONSTANT_P: Addressing Modes. (line 233)
-* TARGET_USE_JCR_SECTION: Misc. (line 924)
-* TARGET_USE_LOCAL_THUNK_ALIAS_P: Misc. (line 859)
-* TARGET_USES_WEAK_UNWIND_INFO: Exception Handling. (line 129)
-* TARGET_VALID_DLLIMPORT_ATTRIBUTE_P: Target Attributes. (line 59)
-* TARGET_VALID_OPTION_ATTRIBUTE_P: Target Attributes. (line 93)
-* TARGET_VALID_POINTER_MODE: Register Arguments. (line 284)
-* TARGET_VECTOR_MODE_SUPPORTED_P: Register Arguments. (line 302)
-* TARGET_VECTOR_OPAQUE_P: Storage Layout. (line 479)
-* TARGET_VECTORIZE_BUILTIN_CONVERSION: Addressing Modes. (line 300)
-* TARGET_VECTORIZE_BUILTIN_MASK_FOR_LOAD: Addressing Modes. (line 249)
-* TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_EVEN: Addressing Modes. (line 275)
-* TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_ODD: Addressing Modes. (line 287)
-* TARGET_VECTORIZE_BUILTIN_VECTORIZED_FUNCTION: Addressing Modes.
- (line 315)
-* TARGET_VERSION: Run-time Target. (line 91)
-* TARGET_VTABLE_DATA_ENTRY_DISTANCE: Type Layout. (line 288)
-* TARGET_VTABLE_ENTRY_ALIGN: Type Layout. (line 282)
-* TARGET_VTABLE_USES_DESCRIPTORS: Type Layout. (line 271)
-* TARGET_WEAK_NOT_IN_ARCHIVE_TOC: Label Output. (line 245)
-* targetm: Target Structure. (line 7)
-* targets, makefile: Makefile. (line 6)
-* TCmode: Machine Modes. (line 197)
-* TDmode: Machine Modes. (line 94)
-* TEMPLATE_DECL: Declarations. (line 6)
-* Temporaries: Temporaries. (line 6)
-* termination routines: Initialization. (line 6)
-* testing constraints: C Constraint Interface.
- (line 6)
-* TEXT_SECTION_ASM_OP: Sections. (line 38)
-* TF_SIZE: Type Layout. (line 132)
-* TFmode: Machine Modes. (line 98)
-* THEN_CLAUSE: Function Bodies. (line 6)
-* THREAD_MODEL_SPEC: Driver. (line 225)
-* THROW_EXPR: Expression trees. (line 6)
-* THUNK_DECL: Declarations. (line 6)
-* THUNK_DELTA: Declarations. (line 6)
-* TImode: Machine Modes. (line 48)
-* TImode, in insn: Insns. (line 231)
-* tm.h macros: Target Macros. (line 6)
-* TQFmode: Machine Modes. (line 62)
-* TQmode: Machine Modes. (line 119)
-* TRAMPOLINE_ADJUST_ADDRESS: Trampolines. (line 62)
-* TRAMPOLINE_ALIGNMENT: Trampolines. (line 49)
-* TRAMPOLINE_SECTION: Trampolines. (line 40)
-* TRAMPOLINE_SIZE: Trampolines. (line 45)
-* TRAMPOLINE_TEMPLATE: Trampolines. (line 29)
-* trampolines for nested functions: Trampolines. (line 6)
-* TRANSFER_FROM_TRAMPOLINE: Trampolines. (line 124)
-* trap instruction pattern: Standard Names. (line 1374)
-* tree <1>: Macros and Functions.
- (line 6)
-* tree: Tree overview. (line 6)
-* Tree SSA: Tree SSA. (line 6)
-* tree_code <1>: GIMPLE_OMP_FOR. (line 83)
-* tree_code <2>: GIMPLE_COND. (line 21)
-* tree_code <3>: GIMPLE_ASSIGN. (line 41)
-* tree_code: Manipulating GIMPLE statements.
- (line 31)
-* TREE_CODE: Tree overview. (line 6)
-* TREE_FILENAME: Working with declarations.
- (line 14)
-* tree_int_cst_equal: Expression trees. (line 6)
-* TREE_INT_CST_HIGH: Expression trees. (line 6)
-* TREE_INT_CST_LOW: Expression trees. (line 6)
-* tree_int_cst_lt: Expression trees. (line 6)
-* TREE_LINENO: Working with declarations.
- (line 20)
-* TREE_LIST: Containers. (line 6)
-* TREE_OPERAND: Expression trees. (line 6)
-* TREE_PUBLIC: Function Basics. (line 6)
-* TREE_PURPOSE: Containers. (line 6)
-* TREE_STRING_LENGTH: Expression trees. (line 6)
-* TREE_STRING_POINTER: Expression trees. (line 6)
-* TREE_TYPE <1>: Expression trees. (line 6)
-* TREE_TYPE <2>: Function Basics. (line 171)
-* TREE_TYPE <3>: Working with declarations.
- (line 11)
-* TREE_TYPE: Types. (line 6)
-* TREE_VALUE: Containers. (line 6)
-* TREE_VEC: Containers. (line 6)
-* TREE_VEC_ELT: Containers. (line 6)
-* TREE_VEC_LENGTH: Containers. (line 6)
-* Trees: Trees. (line 6)
-* TRULY_NOOP_TRUNCATION: Misc. (line 177)
-* TRUNC_DIV_EXPR: Expression trees. (line 6)
-* TRUNC_MOD_EXPR: Expression trees. (line 6)
-* truncate: Conversions. (line 38)
-* truncMN2 instruction pattern: Standard Names. (line 821)
-* TRUTH_AND_EXPR: Expression trees. (line 6)
-* TRUTH_ANDIF_EXPR: Expression trees. (line 6)
-* TRUTH_NOT_EXPR: Expression trees. (line 6)
-* TRUTH_OR_EXPR: Expression trees. (line 6)
-* TRUTH_ORIF_EXPR: Expression trees. (line 6)
-* TRUTH_XOR_EXPR: Expression trees. (line 6)
-* TRY_BLOCK: Function Bodies. (line 6)
-* TRY_HANDLERS: Function Bodies. (line 6)
-* TRY_STMTS: Function Bodies. (line 6)
-* tstM instruction pattern: Standard Names. (line 661)
-* Tuple specific accessors: Tuple specific accessors.
- (line 6)
-* tuples: Tuple representation.
- (line 6)
-* type: Types. (line 6)
-* type declaration: Declarations. (line 6)
-* TYPE_ALIGN: Types. (line 6)
-* TYPE_ARG_TYPES: Types. (line 6)
-* TYPE_ASM_OP: Label Output. (line 55)
-* TYPE_ATTRIBUTES: Attributes. (line 25)
-* TYPE_BINFO: Classes. (line 6)
-* TYPE_BUILT_IN: Types. (line 83)
-* TYPE_CANONICAL: Types. (line 6)
-* TYPE_CONTEXT: Types. (line 6)
-* TYPE_DECL: Declarations. (line 6)
-* TYPE_FIELDS <1>: Classes. (line 6)
-* TYPE_FIELDS: Types. (line 6)
-* TYPE_HAS_ARRAY_NEW_OPERATOR: Classes. (line 91)
-* TYPE_HAS_DEFAULT_CONSTRUCTOR: Classes. (line 76)
-* TYPE_HAS_MUTABLE_P: Classes. (line 81)
-* TYPE_HAS_NEW_OPERATOR: Classes. (line 88)
-* TYPE_MAIN_VARIANT: Types. (line 6)
-* TYPE_MAX_VALUE: Types. (line 6)
-* TYPE_METHOD_BASETYPE: Types. (line 6)
-* TYPE_METHODS: Classes. (line 6)
-* TYPE_MIN_VALUE: Types. (line 6)
-* TYPE_NAME: Types. (line 6)
-* TYPE_NOTHROW_P: Function Basics. (line 180)
-* TYPE_OFFSET_BASETYPE: Types. (line 6)
-* TYPE_OPERAND_FMT: Label Output. (line 66)
-* TYPE_OVERLOADS_ARRAY_REF: Classes. (line 99)
-* TYPE_OVERLOADS_ARROW: Classes. (line 102)
-* TYPE_OVERLOADS_CALL_EXPR: Classes. (line 95)
-* TYPE_POLYMORPHIC_P: Classes. (line 72)
-* TYPE_PRECISION: Types. (line 6)
-* TYPE_PTR_P: Types. (line 89)
-* TYPE_PTRFN_P: Types. (line 93)
-* TYPE_PTRMEM_P: Types. (line 6)
-* TYPE_PTROB_P: Types. (line 96)
-* TYPE_PTROBV_P: Types. (line 6)
-* TYPE_QUAL_CONST: Types. (line 6)
-* TYPE_QUAL_RESTRICT: Types. (line 6)
-* TYPE_QUAL_VOLATILE: Types. (line 6)
-* TYPE_RAISES_EXCEPTIONS: Function Basics. (line 175)
-* TYPE_SIZE: Types. (line 6)
-* TYPE_STRUCTURAL_EQUALITY_P: Types. (line 6)
-* TYPE_UNQUALIFIED: Types. (line 6)
-* TYPE_VFIELD: Classes. (line 6)
-* TYPENAME_TYPE: Types. (line 6)
-* TYPENAME_TYPE_FULLNAME: Types. (line 6)
-* TYPEOF_TYPE: Types. (line 6)
-* UDAmode: Machine Modes. (line 168)
-* udiv: Arithmetic. (line 125)
-* udivM3 instruction pattern: Standard Names. (line 222)
-* udivmodM4 instruction pattern: Standard Names. (line 428)
-* udot_prodM instruction pattern: Standard Names. (line 265)
-* UDQmode: Machine Modes. (line 136)
-* UHAmode: Machine Modes. (line 160)
-* UHQmode: Machine Modes. (line 128)
-* UINTMAX_TYPE: Type Layout. (line 224)
-* umaddMN4 instruction pattern: Standard Names. (line 375)
-* umax: Arithmetic. (line 144)
-* umaxM3 instruction pattern: Standard Names. (line 222)
-* umin: Arithmetic. (line 144)
-* uminM3 instruction pattern: Standard Names. (line 222)
-* umod: Arithmetic. (line 131)
-* umodM3 instruction pattern: Standard Names. (line 222)
-* umsubMN4 instruction pattern: Standard Names. (line 399)
-* umulhisi3 instruction pattern: Standard Names. (line 347)
-* umulM3_highpart instruction pattern: Standard Names. (line 361)
-* umulqihi3 instruction pattern: Standard Names. (line 347)
-* umulsidi3 instruction pattern: Standard Names. (line 347)
-* unchanging: Flags. (line 319)
-* unchanging, in call_insn: Flags. (line 19)
-* unchanging, in jump_insn, call_insn and insn: Flags. (line 39)
-* unchanging, in mem: Flags. (line 152)
-* unchanging, in subreg: Flags. (line 188)
-* unchanging, in symbol_ref: Flags. (line 10)
-* UNEQ_EXPR: Expression trees. (line 6)
-* UNGE_EXPR: Expression trees. (line 6)
-* UNGT_EXPR: Expression trees. (line 6)
-* UNION_TYPE <1>: Classes. (line 6)
-* UNION_TYPE: Types. (line 6)
-* unions, returning: Interface. (line 10)
-* UNITS_PER_SIMD_WORD: Storage Layout. (line 77)
-* UNITS_PER_WORD: Storage Layout. (line 67)
-* UNKNOWN_TYPE: Types. (line 6)
-* UNLE_EXPR: Expression trees. (line 6)
-* UNLIKELY_EXECUTED_TEXT_SECTION_NAME: Sections. (line 49)
-* UNLT_EXPR: Expression trees. (line 6)
-* UNORDERED_EXPR: Expression trees. (line 6)
-* unshare_all_rtl: Sharing. (line 58)
-* unsigned division: Arithmetic. (line 125)
-* unsigned division with unsigned saturation: Arithmetic. (line 125)
-* unsigned greater than: Comparisons. (line 64)
-* unsigned less than: Comparisons. (line 68)
-* unsigned minimum and maximum: Arithmetic. (line 144)
-* unsigned_fix: Conversions. (line 77)
-* unsigned_float: Conversions. (line 62)
-* unsigned_fract_convert: Conversions. (line 97)
-* unsigned_sat_fract: Conversions. (line 103)
-* unspec: Side Effects. (line 287)
-* unspec_volatile: Side Effects. (line 287)
-* untyped_call instruction pattern: Standard Names. (line 1012)
-* untyped_return instruction pattern: Standard Names. (line 1062)
-* UPDATE_PATH_HOST_CANONICALIZE (PATH): Filesystem. (line 59)
-* update_ssa: SSA. (line 76)
-* update_stmt <1>: SSA Operands. (line 6)
-* update_stmt: Manipulating GIMPLE statements.
- (line 141)
-* update_stmt_if_modified: Manipulating GIMPLE statements.
- (line 144)
-* UQQmode: Machine Modes. (line 123)
-* US Software GOFAST, floating point emulation library: Library Calls.
- (line 44)
-* us_ashift: Arithmetic. (line 168)
-* us_minus: Arithmetic. (line 36)
-* us_mult: Arithmetic. (line 92)
-* us_neg: Arithmetic. (line 81)
-* us_plus: Arithmetic. (line 14)
-* US_SOFTWARE_GOFAST: Library Calls. (line 45)
-* us_truncate: Conversions. (line 48)
-* usaddM3 instruction pattern: Standard Names. (line 222)
-* USAmode: Machine Modes. (line 164)
-* usashlM3 instruction pattern: Standard Names. (line 431)
-* usdivM3 instruction pattern: Standard Names. (line 222)
-* use: Side Effects. (line 162)
-* USE_C_ALLOCA: Host Misc. (line 19)
-* USE_LD_AS_NEEDED: Driver. (line 198)
-* USE_LOAD_POST_DECREMENT: Costs. (line 165)
-* USE_LOAD_POST_INCREMENT: Costs. (line 160)
-* USE_LOAD_PRE_DECREMENT: Costs. (line 175)
-* USE_LOAD_PRE_INCREMENT: Costs. (line 170)
-* use_optype_d: Manipulating GIMPLE statements.
- (line 101)
-* use_param: GTY Options. (line 113)
-* use_paramN: GTY Options. (line 131)
-* use_params: GTY Options. (line 139)
-* USE_SELECT_SECTION_FOR_FUNCTIONS: Sections. (line 185)
-* USE_STORE_POST_DECREMENT: Costs. (line 185)
-* USE_STORE_POST_INCREMENT: Costs. (line 180)
-* USE_STORE_PRE_DECREMENT: Costs. (line 195)
-* USE_STORE_PRE_INCREMENT: Costs. (line 190)
-* used: Flags. (line 337)
-* used, in symbol_ref: Flags. (line 215)
-* USER_LABEL_PREFIX: Instruction Output. (line 126)
-* USING_DECL: Declarations. (line 6)
-* USING_STMT: Function Bodies. (line 6)
-* usmaddMN4 instruction pattern: Standard Names. (line 383)
-* usmsubMN4 instruction pattern: Standard Names. (line 407)
-* usmulhisi3 instruction pattern: Standard Names. (line 351)
-* usmulM3 instruction pattern: Standard Names. (line 222)
-* usmulqihi3 instruction pattern: Standard Names. (line 351)
-* usmulsidi3 instruction pattern: Standard Names. (line 351)
-* usnegM2 instruction pattern: Standard Names. (line 449)
-* USQmode: Machine Modes. (line 132)
-* ussubM3 instruction pattern: Standard Names. (line 222)
-* usum_widenM3 instruction pattern: Standard Names. (line 275)
-* UTAmode: Machine Modes. (line 172)
-* UTQmode: Machine Modes. (line 140)
-* V in constraint: Simple Constraints. (line 43)
-* VA_ARG_EXPR: Expression trees. (line 6)
-* values, returned by functions: Scalar Return. (line 6)
-* VAR_DECL <1>: Expression trees. (line 6)
-* VAR_DECL: Declarations. (line 6)
-* varargs implementation: Varargs. (line 6)
-* variable: Declarations. (line 6)
-* vashlM3 instruction pattern: Standard Names. (line 445)
-* vashrM3 instruction pattern: Standard Names. (line 445)
-* vec_concat: Vector Operations. (line 25)
-* vec_duplicate: Vector Operations. (line 30)
-* VEC_EXTRACT_EVEN_EXPR: Expression trees. (line 6)
-* vec_extract_evenM instruction pattern: Standard Names. (line 176)
-* VEC_EXTRACT_ODD_EXPR: Expression trees. (line 6)
-* vec_extract_oddM instruction pattern: Standard Names. (line 183)
-* vec_extractM instruction pattern: Standard Names. (line 171)
-* vec_initM instruction pattern: Standard Names. (line 204)
-* VEC_INTERLEAVE_HIGH_EXPR: Expression trees. (line 6)
-* vec_interleave_highM instruction pattern: Standard Names. (line 190)
-* VEC_INTERLEAVE_LOW_EXPR: Expression trees. (line 6)
-* vec_interleave_lowM instruction pattern: Standard Names. (line 197)
-* VEC_LSHIFT_EXPR: Expression trees. (line 6)
-* vec_merge: Vector Operations. (line 11)
-* VEC_PACK_FIX_TRUNC_EXPR: Expression trees. (line 6)
-* VEC_PACK_SAT_EXPR: Expression trees. (line 6)
-* vec_pack_sfix_trunc_M instruction pattern: Standard Names. (line 302)
-* vec_pack_ssat_M instruction pattern: Standard Names. (line 295)
-* VEC_PACK_TRUNC_EXPR: Expression trees. (line 6)
-* vec_pack_trunc_M instruction pattern: Standard Names. (line 288)
-* vec_pack_ufix_trunc_M instruction pattern: Standard Names. (line 302)
-* vec_pack_usat_M instruction pattern: Standard Names. (line 295)
-* VEC_RSHIFT_EXPR: Expression trees. (line 6)
-* vec_select: Vector Operations. (line 19)
-* vec_setM instruction pattern: Standard Names. (line 166)
-* vec_shl_M instruction pattern: Standard Names. (line 282)
-* vec_shr_M instruction pattern: Standard Names. (line 282)
-* VEC_UNPACK_FLOAT_HI_EXPR: Expression trees. (line 6)
-* VEC_UNPACK_FLOAT_LO_EXPR: Expression trees. (line 6)
-* VEC_UNPACK_HI_EXPR: Expression trees. (line 6)
-* VEC_UNPACK_LO_EXPR: Expression trees. (line 6)
-* vec_unpacks_float_hi_M instruction pattern: Standard Names.
- (line 324)
-* vec_unpacks_float_lo_M instruction pattern: Standard Names.
- (line 324)
-* vec_unpacks_hi_M instruction pattern: Standard Names. (line 309)
-* vec_unpacks_lo_M instruction pattern: Standard Names. (line 309)
-* vec_unpacku_float_hi_M instruction pattern: Standard Names.
- (line 324)
-* vec_unpacku_float_lo_M instruction pattern: Standard Names.
- (line 324)
-* vec_unpacku_hi_M instruction pattern: Standard Names. (line 317)
-* vec_unpacku_lo_M instruction pattern: Standard Names. (line 317)
-* VEC_WIDEN_MULT_HI_EXPR: Expression trees. (line 6)
-* VEC_WIDEN_MULT_LO_EXPR: Expression trees. (line 6)
-* vec_widen_smult_hi_M instruction pattern: Standard Names. (line 333)
-* vec_widen_smult_lo_M instruction pattern: Standard Names. (line 333)
-* vec_widen_umult_hi_M instruction pattern: Standard Names. (line 333)
-* vec_widen_umult_lo__M instruction pattern: Standard Names. (line 333)
-* vector: Containers. (line 6)
-* vector operations: Vector Operations. (line 6)
-* VECTOR_CST: Expression trees. (line 6)
-* VECTOR_STORE_FLAG_VALUE: Misc. (line 308)
-* virtual operands: SSA Operands. (line 6)
-* VIRTUAL_INCOMING_ARGS_REGNUM: Regs and Memory. (line 59)
-* VIRTUAL_OUTGOING_ARGS_REGNUM: Regs and Memory. (line 87)
-* VIRTUAL_STACK_DYNAMIC_REGNUM: Regs and Memory. (line 78)
-* VIRTUAL_STACK_VARS_REGNUM: Regs and Memory. (line 69)
-* VLIW: Processor pipeline description.
- (line 6)
-* vlshrM3 instruction pattern: Standard Names. (line 445)
-* VMS: Filesystem. (line 37)
-* VMS_DEBUGGING_INFO: VMS Debug. (line 9)
-* VOID_TYPE: Types. (line 6)
-* VOIDmode: Machine Modes. (line 190)
-* volatil: Flags. (line 351)
-* volatil, in insn, call_insn, jump_insn, code_label, barrier, and note: Flags.
- (line 44)
-* volatil, in label_ref and reg_label: Flags. (line 65)
-* volatil, in mem, asm_operands, and asm_input: Flags. (line 94)
-* volatil, in reg: Flags. (line 116)
-* volatil, in subreg: Flags. (line 188)
-* volatil, in symbol_ref: Flags. (line 224)
-* volatile memory references: Flags. (line 352)
-* voptype_d: Manipulating GIMPLE statements.
- (line 108)
-* voting between constraint alternatives: Class Preferences. (line 6)
-* vrotlM3 instruction pattern: Standard Names. (line 445)
-* vrotrM3 instruction pattern: Standard Names. (line 445)
-* walk_dominator_tree: SSA. (line 256)
-* walk_gimple_op: Statement and operand traversals.
- (line 32)
-* walk_gimple_seq: Statement and operand traversals.
- (line 50)
-* walk_gimple_stmt: Statement and operand traversals.
- (line 13)
-* walk_use_def_chains: SSA. (line 232)
-* WCHAR_TYPE: Type Layout. (line 192)
-* WCHAR_TYPE_SIZE: Type Layout. (line 200)
-* which_alternative: Output Statement. (line 59)
-* WHILE_BODY: Function Bodies. (line 6)
-* WHILE_COND: Function Bodies. (line 6)
-* WHILE_STMT: Function Bodies. (line 6)
-* WIDEST_HARDWARE_FP_SIZE: Type Layout. (line 147)
-* WINT_TYPE: Type Layout. (line 205)
-* word_mode: Machine Modes. (line 336)
-* WORD_REGISTER_OPERATIONS: Misc. (line 63)
-* WORD_SWITCH_TAKES_ARG: Driver. (line 20)
-* WORDS_BIG_ENDIAN: Storage Layout. (line 29)
-* WORDS_BIG_ENDIAN, effect on subreg: Regs and Memory. (line 217)
-* X in constraint: Simple Constraints. (line 114)
-* x-HOST: Host Fragment. (line 6)
-* XCmode: Machine Modes. (line 197)
-* XCOFF_DEBUGGING_INFO: DBX Options. (line 13)
-* XEXP: Accessors. (line 6)
-* XF_SIZE: Type Layout. (line 131)
-* XFmode: Machine Modes. (line 79)
-* XINT: Accessors. (line 6)
-* xm-MACHINE.h <1>: Host Misc. (line 6)
-* xm-MACHINE.h: Filesystem. (line 6)
-* xor: Arithmetic. (line 163)
-* xor, canonicalization of: Insn Canonicalizations.
- (line 84)
-* xorM3 instruction pattern: Standard Names. (line 222)
-* XSTR: Accessors. (line 6)
-* XVEC: Accessors. (line 41)
-* XVECEXP: Accessors. (line 48)
-* XVECLEN: Accessors. (line 44)
-* XWINT: Accessors. (line 6)
-* zero_extend: Conversions. (line 28)
-* zero_extendMN2 instruction pattern: Standard Names. (line 831)
-* zero_extract: Bit-Fields. (line 30)
-* zero_extract, canonicalization of: Insn Canonicalizations.
- (line 96)
-
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-Node: `GIMPLE_BIND'\7f584618
-Node: `GIMPLE_CALL'\7f586425
-Node: `GIMPLE_CATCH'\7f590684
-Node: `GIMPLE_CHANGE_DYNAMIC_TYPE'\7f591842
-Node: `GIMPLE_COND'\7f593175
-Node: `GIMPLE_EH_FILTER'\7f595981
-Node: `GIMPLE_LABEL'\7f597467
-Node: `GIMPLE_NOP'\7f598442
-Node: `GIMPLE_OMP_ATOMIC_LOAD'\7f598811
-Node: `GIMPLE_OMP_ATOMIC_STORE'\7f599721
-Node: `GIMPLE_OMP_CONTINUE'\7f600360
-Node: `GIMPLE_OMP_CRITICAL'\7f601710
-Node: `GIMPLE_OMP_FOR'\7f602646
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-Node: `GIMPLE_OMP_ORDERED'\7f606539
-Node: `GIMPLE_OMP_PARALLEL'\7f606939
-Node: `GIMPLE_OMP_RETURN'\7f609708
-Node: `GIMPLE_OMP_SECTION'\7f610358
-Node: `GIMPLE_OMP_SECTIONS'\7f611024
-Node: `GIMPLE_OMP_SINGLE'\7f612628
-Node: `GIMPLE_PHI'\7f613564
-Node: `GIMPLE_RESX'\7f614977
-Node: `GIMPLE_RETURN'\7f615696
-Node: `GIMPLE_SWITCH'\7f616264
-Node: `GIMPLE_TRY'\7f618394
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-Node: GIMPLE sequences\7f621067
-Node: Sequence iterators\7f624273
-Node: Adding a new GIMPLE statement code\7f632728
-Node: Statement and operand traversals\7f634008
-Node: Tree SSA\7f636618
-Node: Annotations\7f638338
-Node: SSA Operands\7f638864
-Node: SSA\7f653395
-Node: Alias analysis\7f665686
-Node: Loop Analysis and Representation\7f673142
-Node: Loop representation\7f674323
-Node: Loop querying\7f681243
-Node: Loop manipulation\7f684076
-Node: LCSSA\7f686444
-Node: Scalar evolutions\7f688516
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-Node: Number of iterations\7f693686
-Node: Dependency analysis\7f696495
-Node: Lambda\7f702863
-Node: Omega\7f704533
-Node: Control Flow\7f706098
-Node: Basic Blocks\7f707093
-Node: Edges\7f711661
-Node: Profile information\7f720223
-Node: Maintaining the CFG\7f724909
-Node: Liveness information\7f731791
-Node: Machine Desc\7f733918
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-Node: Patterns\7f738427
-Node: Example\7f741865
-Node: RTL Template\7f743300
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-Node: Class Preferences\7f791693
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-Node: Peephole Definitions\7f951051
-Node: define_peephole\7f952304
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-Node: Defining Attributes\7f962808
-Node: Expressions\7f965328
-Node: Tagging Insns\7f971930
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-Node: Insn Lengths\7f978657
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-Node: Delay Slots\7f982885
-Node: Processor pipeline description\7f986109
-Ref: Processor pipeline description-Footnote-1\7f1003475
-Node: Conditional Execution\7f1003797
-Node: Constant Definitions\7f1006650
-Node: Iterators\7f1008245
-Node: Mode Iterators\7f1008692
-Node: Defining Mode Iterators\7f1009670
-Node: Substitutions\7f1011164
-Node: Examples\7f1013405
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-Node: Driver\7f1021402
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-Node: Storage Layout\7f1054970
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-Node: Registers\7f1093341
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-Node: Anchored Addresses\7f1265257
-Node: Condition Code\7f1267918
-Node: Costs\7f1276207
-Node: Scheduling\7f1289306
-Node: Sections\7f1307867
-Node: PIC\7f1322517
-Node: Assembler Format\7f1324507
-Node: File Framework\7f1325645
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-Node: Data Output\7f1333817
-Node: Uninitialized Data\7f1341576
-Node: Label Output\7f1346647
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-Node: Instruction Output\7f1380728
-Node: Dispatch Tables\7f1389722
-Node: Exception Region Output\7f1393517
-Node: Alignment Output\7f1399277
-Node: Debugging Info\7f1403440
-Node: All Debuggers\7f1404110
-Node: DBX Options\7f1406965
-Node: DBX Hooks\7f1412414
-Node: File Names and DBX\7f1414340
-Node: SDB and DWARF\7f1416451
-Node: VMS Debug\7f1420443
-Node: Floating Point\7f1421013
-Node: Mode Switching\7f1425836
-Node: Target Attributes\7f1429762
-Node: Emulated TLS\7f1436526
-Node: MIPS Coprocessors\7f1439916
-Node: PCH Target\7f1441485
-Node: C++ ABI\7f1443006
-Node: Misc\7f1447625
-Ref: TARGET_SHIFT_TRUNCATION_MASK\7f1454995
-Node: Host Config\7f1497502
-Node: Host Common\7f1498570
-Node: Filesystem\7f1500949
-Node: Host Misc\7f1505064
-Node: Fragments\7f1507203
-Node: Target Fragment\7f1508398
-Node: Host Fragment\7f1514288
-Node: Collect2\7f1514528
-Node: Header Dirs\7f1517071
-Node: Type Information\7f1518494
-Node: GTY Options\7f1520785
-Node: GGC Roots\7f1531460
-Node: Files\7f1532180
-Node: Invoking the garbage collector\7f1534930
-Node: Plugins\7f1535983
-Node: Funding\7f1546348
-Node: GNU Project\7f1548835
-Node: Copying\7f1549484
-Node: GNU Free Documentation License\7f1587015
-Node: Contributors\7f1609424
-Node: Option Index\7f1645754
-Node: Concept Index\7f1646339
-\1f
-End Tag Table
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