Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA. */
-/* texmfmem.h: the memory_word type, which is too hard to translate
- automatically from Pascal. We have to make sure the byte-swapping
- that the (un)dumping routines do suffices to put things in the right
- place in memory.
-
- A memory_word can be broken up into a `twohalves' or a
- `fourquarters', and a `twohalves' can be further broken up. Here is
- a picture. ..._M = most significant byte, ..._L = least significant
- byte.
-
- If BigEndian:
- twohalves.v: RH_M RH_L LH_M LH_L
- twohalves.u: JNK1 JNK2 B0 B1
- fourquarters: B0 B1 B2 B3
-
- If LittleEndian:
- twohalves.v: LH_L LH_M RH_L RH_M
- twohalves.u: B1 B0 JNK1 JNK2
- fourquarters: B3 B2 B1 B0
-
- The halfword fields are four bytes if we are building a TeX or MF;
- this leads to further complications:
-
- BigEndian:
- twohalves.v: RH_MM RH_ML RH_LM RH_LL LH_MM LH_ML LH_LM LH_LL
- twohalves.u: ---------JUNK---------- B0 B1
- fourquarters: B0 B1 B2 B3
-
- LittleEndian:
- twohalves.v: LH_LL LH_LM LH_ML LH_MM RH_LL RH_LM RH_ML RH_MM
- twohalves.u: junkx junky B1 B0
- fourquarters: ---------JUNK---------- B3 B2 B1 B0
-
- I guess TeX and Metafont never refer to the B1 and B0 in the
- fourquarters structure as the B1 and B0 in the twohalves.u structure.
-
- This file can't be part of texmf.h, because texmf.h gets included by
- {tex,mf}d.h before the `halfword' etc. types are defined. So we
- include it from the change file instead.
+/*
+ meaning structure TeX Y&Y TeX
+ ----------------------------------------------------------------------
+ integer | int || 4: long | 8: long long | min_quarterword 0
+ ---------------------------------------------------------------------- max_quarterword FFFF
+ scaled | sc || 4: long | 8: long long | min_halfword
+ ----------------------------------------------------------------------
+ glue_ratio | gr || 4: float | 8: double |
+ ----------------------------------------------------------------------
+ halfword | lh | rh || 2: unsigned short | 4: unsigned long |
+ ----------------------------------------------------------------------
+ half+quarter | b0 | b1 | rh || |
+ ----------------------------------------------------------------------
+ quarter | b0 | b1 | b2 | b3 || 1: unsigned char | 2: unsigned short |
+ ----------------------------------------------------------------------
*/
-typedef union
+typedef struct
{
- struct
- {
-#ifdef WORDS_BIGENDIAN
- halfword RH, LH;
-#else
- halfword LH, RH;
-#endif
- } v;
-
- struct
- { /* Make B0,B1 overlap the most significant bytes of LH. */
#ifdef WORDS_BIGENDIAN
- halfword junk;
- quarterword B0, B1;
-#else /* not WORDS_BIGENDIAN */
- /* If 32-bit TeX/MF, have to have an extra two bytes of junk.
- I would like to break this line, but I'm afraid that some
- preprocessors don't properly handle backslash-newline in # commands. */
-#if (defined (TeX) && !defined (SMALLTeX)) || !defined (TeX) && !defined (SMALLMF)
- quarterword junkx, junky;
-#endif /* big TeX or big MF */
- quarterword B1, B0;
-#endif /* not WORDS_BIGENDIAN */
- } u;
-} twohalves;
+ halfword rh;
-/* new in Y&Y TeX 1.3 1996/Jan/18 used for hash [...] if SHORTHASH defined */
-typedef struct {
- struct
+ union
{
-#ifdef WORDS_BIGENDIAN
- quarterword RH, LH;
-#else
- quarterword LH, RH;
+ halfword lh;
+
+ struct
+ {
+ quarterword b0, b1;
+ };
+ };
#endif
- } v;
-} htwohalves;
+} two_halves;
typedef struct
{
- struct
- {
#ifdef WORDS_BIGENDIAN
- quarterword B0, B1, B2, B3;
+ quarterword b0, b1, b2, b3;
#else
- quarterword B3, B2, B1, B0;
+ quarterword b3, b2, b1, b0;
#endif
- } u;
-} fourquarters;
-
+} four_quarters;
typedef union
{
-#ifdef TeX
glue_ratio gr;
- twohalves hh;
-#else
- twohalves hhfield;
-#endif
-#ifdef WORDS_BIGENDIAN
+ two_halves hh;
integer cint;
- fourquarters qqqq;
-#else /* not WORDS_BIGENDIAN */
- struct
- {
-#if defined (TeX) && !defined (SMALLTeX) || !defined (TeX) && !defined (SMALLMF)
- halfword junk;
-#endif /* big TeX or big MF */
- integer CINT;
- } u;
-
- struct
- {
-#if defined (TeX) && !defined (SMALLTeX) || !defined (TeX) && !defined (SMALLMF)
- halfword junk;
-#endif /* big TeX or big MF */
- fourquarters QQQQ;
- } v;
-#endif /* not WORDS_BIGENDIAN */
+ four_quarters qqqq;
} memory_word;
-/* Attempt to reduce size of font_info array ... (and hence format files) */
-
-typedef struct
-{
- struct
- {
-#ifdef WORDS_BIGENDIAN
- unsigned char B0, B1, B2, B3;
-#else
- unsigned char B3, B2, B1, B0;
-#endif
- } u;
-} ffourquarters; /* was fourunsignedchars; */
-
-#define fquarterword unsigned char
-
-typedef union
-{
- integer cint;
- ffourquarters qqqq;
-} fmemoryword;
-
-/* To keep the original structure accesses working, we must go through
- the extra names C forced us to introduce. */
-#define b0 u.B0
-#define b1 u.B1
-#define b2 u.B2
-#define b3 u.B3
-
-#define rh v.RH
-#define lhfield v.LH
-
#ifndef WORDS_BIGENDIAN
#define cint u.CINT
#define qqqq v.QQQQ
-#endif
+#endif
\ No newline at end of file
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