ffmpeg/libavcodec/bswap.h

143 lines
2.8 KiB
C

/**
* @file bswap.h
* byte swap.
*/
#ifndef __BSWAP_H__
#define __BSWAP_H__
#ifdef HAVE_BYTESWAP_H
#include <byteswap.h>
#else
#ifdef ARCH_X86_64
# define LEGACY_REGS "=Q"
#else
# define LEGACY_REGS "=q"
#endif
#if defined(ARCH_X86) || defined(ARCH_X86_64)
static inline uint16_t ByteSwap16(uint16_t x)
{
__asm("xchgb %b0,%h0" :
LEGACY_REGS (x) :
"0" (x));
return x;
}
#define bswap_16(x) ByteSwap16(x)
static inline uint32_t ByteSwap32(uint32_t x)
{
#if __CPU__ > 386
__asm("bswap %0":
"=r" (x) :
#else
__asm("xchgb %b0,%h0\n"
" rorl $16,%0\n"
" xchgb %b0,%h0":
LEGACY_REGS (x) :
#endif
"0" (x));
return x;
}
#define bswap_32(x) ByteSwap32(x)
static inline uint64_t ByteSwap64(uint64_t x)
{
#ifdef ARCH_X86_64
__asm("bswap %0":
"=r" (x) :
"0" (x));
return x;
#else
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((uint32_t)x)),"1"(bswap_32((uint32_t)(x>>32))));
return __x.__ll;
#endif
}
#define bswap_64(x) ByteSwap64(x)
#elif defined(ARCH_SH4)
static inline uint16_t ByteSwap16(uint16_t x) {
__asm__("swap.b %0,%0":"=r"(x):"0"(x));
return x;
}
static inline uint32_t ByteSwap32(uint32_t x) {
__asm__(
"swap.b %0,%0\n"
"swap.w %0,%0\n"
"swap.b %0,%0\n"
:"=r"(x):"0"(x));
return x;
}
#define bswap_16(x) ByteSwap16(x)
#define bswap_32(x) ByteSwap32(x)
static inline uint64_t ByteSwap64(uint64_t x)
{
union {
uint64_t ll;
struct {
uint32_t l,h;
} l;
} r;
r.l.l = bswap_32 (x);
r.l.h = bswap_32 (x>>32);
return r.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))
static inline 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__ */