ocaml/byterun/reverse.h

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/* Swap byte-order in 16-bit, 32-bit and 64-bit words */
#ifndef _reverse_
#define _reverse_
#define Reverse_short(s) { \
char * _p; \
int _a; \
_p = (char *) (s); \
_a = _p[0]; \
_p[0] = _p[1]; \
_p[1] = _a; \
}
#define Reverse_int32(w) { \
char * _p; \
int _a; \
_p = (char *) (w); \
_a = _p[0]; \
_p[0] = _p[3]; \
_p[3] = _a; \
_a = _p[1]; \
_p[1] = _p[2]; \
_p[2] = _a; \
}
#define Reverse_int64(d) { \
char * _p; \
int _a; \
_p = (char *) (d); \
_a = _p[0]; \
_p[0] = _p[7]; \
_p[7] = _a; \
_a = _p[1]; \
_p[1] = _p[6]; \
_p[6] = _a; \
_a = _p[2]; \
_p[2] = _p[5]; \
_p[5] = _a; \
_a = _p[3]; \
_p[3] = _p[4]; \
_p[4] = _a; \
}
#ifdef SIXTYFOUR
#define Reverse_word Reverse_int64
#else
#define Reverse_word Reverse_int32
#endif
#define Reverse_double Reverse_int64
#endif /* _reverse_ */