ffmpeg/libavcodec/bswap.h

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#ifndef __BSWAP_H__
#define __BSWAP_H__
#ifdef HAVE_BYTESWAP_H
#include <byteswap.h>
#else
#ifdef ARCH_X86
inline static unsigned short ByteSwap16(unsigned short x)
{
__asm("xchgb %b0,%h0" :
"=q" (x) :
"0" (x));
return x;
}
#define bswap_16(x) ByteSwap16(x)
inline static unsigned int ByteSwap32(unsigned int x)
{
#if __CPU__ > 386
__asm("bswap %0":
"=r" (x) :
#else
__asm("xchgb %b0,%h0\n"
" rorl $16,%0\n"
" xchgb %b0,%h0":
"=q" (x) :
#endif
"0" (x));
return x;
}
#define bswap_32(x) ByteSwap32(x)
inline static unsigned long long int ByteSwap64(unsigned long long int x)
{
register union { __extension__ uint64_t __ll;
uint32_t __l[2]; } __x;
asm("xchgl %0,%1":
"=r"(__x.__l[0]),"=r"(__x.__l[1]):
"0"(bswap_32((unsigned long)x)),"1"(bswap_32((unsigned long)(x>>32))));
return __x.__ll;
}
#define bswap_64(x) ByteSwap64(x)
#else
#define bswap_16(x) (((x) & 0x00ff) << 8 | ((x) & 0xff00) >> 8)
// code from bits/byteswap.h (C) 1997, 1998 Free Software Foundation, Inc.
#define bswap_32(x) \
((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >> 8) | \
(((x) & 0x0000ff00) << 8) | (((x) & 0x000000ff) << 24))
inline static uint64_t ByteSwap64(uint64_t x)
{
union {
uint64_t ll;
uint32_t l[2];
} w, r;
w.ll = x;
r.l[0] = bswap_32 (w.l[1]);
r.l[1] = bswap_32 (w.l[0]);
return r.ll;
}
#define bswap_64(x) ByteSwap64(x)
#endif /* !ARCH_X86 */
#endif /* !HAVE_BYTESWAP_H */
// be2me ... BigEndian to MachineEndian
// le2me ... LittleEndian to MachineEndian
#ifdef WORDS_BIGENDIAN
#define be2me_16(x) (x)
#define be2me_32(x) (x)
#define be2me_64(x) (x)
#define le2me_16(x) bswap_16(x)
#define le2me_32(x) bswap_32(x)
#define le2me_64(x) bswap_64(x)
#else
#define be2me_16(x) bswap_16(x)
#define be2me_32(x) bswap_32(x)
#define be2me_64(x) bswap_64(x)
#define le2me_16(x) (x)
#define le2me_32(x) (x)
#define le2me_64(x) (x)
#endif
#endif /* __BSWAP_H__ */