+++ /dev/null
-.\" Copyright 2004 Andries Brouwer <aeb@cwi.nl>.
-.\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
-.\" <mtk.manpages@gmail.com>
-.\"
-.\" %%%LICENSE_START(VERBATIM)
-.\" Permission is granted to make and distribute verbatim copies of this
-.\" manual provided the copyright notice and this permission notice are
-.\" preserved on all copies.
-.\"
-.\" Permission is granted to copy and distribute modified versions of this
-.\" manual under the conditions for verbatim copying, provided that the
-.\" entire resulting derived work is distributed under the terms of a
-.\" permission notice identical to this one.
-.\"
-.\" Since the Linux kernel and libraries are constantly changing, this
-.\" manual page may be incorrect or out-of-date. The author(s) assume no
-.\" responsibility for errors or omissions, or for damages resulting from
-.\" the use of the information contained herein. The author(s) may not
-.\" have taken the same level of care in the production of this manual,
-.\" which is licensed free of charge, as they might when working
-.\" professionally.
-.\"
-.\" Formatted or processed versions of this manual, if unaccompanied by
-.\" the source, must acknowledge the copyright and authors of this work.
-.\" %%%LICENSE_END
-.\"
-.\" Inspired by a page by Walter Harms created 2002-08-10
-.\"
-.TH LOGB 3 2014-02-28 "" "Linux Programmer's Manual"
-.SH NAME
-logb, logbf, logbl \- get exponent of a floating-point value
-.SH SYNOPSIS
-.B #include <math.h>
-.sp
-.BI "double logb(double " x );
-.br
-.BI "float logbf(float " x );
-.br
-.BI "long double logbl(long double " x );
-.sp
-Link with \fI\-lm\fP.
-.sp
-.in -4n
-Feature Test Macro Requirements for glibc (see
-.BR feature_test_macros (7)):
-.in
-.sp
-.ad l
-.BR logb ():
-.RS 4
-_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500 ||
-_XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED || _ISOC99_SOURCE ||
-_POSIX_C_SOURCE\ >=\ 200112L;
-.br
-or
-.I cc\ -std=c99
-.RE
-.br
-.BR logbf (),
-.BR logbl ():
-.RS 4
-_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 600 || _ISOC99_SOURCE ||
-_POSIX_C_SOURCE\ >=\ 200112L;
-.br
-or
-.I cc\ -std=c99
-.RE
-.ad b
-.SH DESCRIPTION
-These functions extract the exponent from the
-internal floating-point representation of
-.I x
-and return it as a floating-point value.
-The integer constant
-.BR FLT_RADIX ,
-defined in
-.IR <float.h> ,
-indicates the radix used for the system's floating-point representation.
-If
-.B FLT_RADIX
-is 2,
-.BI logb( x )
-is equal to
-.BI floor(log2( x ))\fR,
-except that it is probably faster.
-.LP
-If
-.I x
-is subnormal,
-.BR logb ()
-returns the exponent
-.I x
-would have if it were normalized.
-.SH RETURN VALUE
-On success, these functions return the exponent of
-.IR x .
-
-If
-.I x
-is a NaN,
-a NaN is returned.
-
-If
-.I x
-is zero, then a pole error occurs, and the functions return
-.RB - HUGE_VAL ,
-.RB - HUGE_VALF ,
-or
-.RB - HUGE_VALL ,
-respectively.
-
-If
-.I x
-is negative infinity or positive infinity, then
-positive infinity is returned.
-.SH ERRORS
-See
-.BR math_error (7)
-for information on how to determine whether an error has occurred
-when calling these functions.
-.PP
-The following errors can occur:
-.TP
-Pole error: \fIx\fP is 0
-.\" .I errno
-.\" is set to
-.\" .BR ERANGE .
-A divide-by-zero floating-point exception
-.RB ( FE_DIVBYZERO )
-is raised.
-.PP
-These functions do not set
-.IR errno .
-.\" FIXME . Is it intentional that these functions do not set errno?
-.\" log(), log2(), log10() do set errno
-.\" Bug raised: http://sources.redhat.com/bugzilla/show_bug.cgi?id=6793
-.\"
-.\" .SH HISTORY
-.\" The
-.\" .BR logb ()
-.\" function occurs in 4.3BSD.
-.\" see IEEE.3 in the 4.3BSD manual
-.SH ATTRIBUTES
-.SS Multithreading (see pthreads(7))
-The
-.BR logb (),
-.BR logbf (),
-and
-.BR logbl ()
-functions are thread-safe.
-.SH CONFORMING TO
-C99, POSIX.1-2001.
-.SH SEE ALSO
-.BR ilogb (3),
-.BR log (3)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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