ffmpeg/libavutil/bswap.h

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/*
* copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file bswap.h
* byte swapping routines
*/
#ifndef AVUTIL_BSWAP_H
#define AVUTIL_BSWAP_H
#include <stdint.h>
#include "config.h"
#include "common.h"
static av_always_inline av_const uint16_t bswap_16(uint16_t x)
{
#if defined(ARCH_X86)
asm("rorw $8, %0" : "+r"(x));
#elif defined(ARCH_SH4)
asm("swap.b %0,%0" : "=r"(x) : "0"(x));
#elif defined(HAVE_ARMV6)
asm("rev16 %0, %0" : "+r"(x));
#else
x= (x>>8) | (x<<8);
#endif
return x;
}
static av_always_inline av_const uint32_t bswap_32(uint32_t x)
{
#if defined(ARCH_X86)
#ifdef HAVE_BSWAP
asm("bswap %0" : "+r" (x));
#else
asm("rorw $8, %w0 \n\t"
"rorl $16, %0 \n\t"
"rorw $8, %w0"
: "+r"(x));
#endif
#elif defined(ARCH_SH4)
asm("swap.b %0,%0\n"
"swap.w %0,%0\n"
"swap.b %0,%0\n"
: "=r"(x) : "0"(x));
#elif defined(HAVE_ARMV6)
asm("rev %0, %0" : "+r"(x));
#elif defined(ARCH_ARMV4L)
uint32_t t;
asm ("eor %1, %0, %0, ror #16 \n\t"
"bic %1, %1, #0xFF0000 \n\t"
"mov %0, %0, ror #8 \n\t"
"eor %0, %0, %1, lsr #8 \n\t"
: "+r"(x), "+r"(t));
#elif defined(ARCH_BFIN)
unsigned tmp;
asm("%1 = %0 >> 8 (V); \n\t"
"%0 = %0 << 8 (V); \n\t"
"%0 = %0 | %1; \n\t"
"%0 = PACK(%0.L, %0.H); \n\t"
: "+d"(x), "=&d"(tmp));
#else
x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
x= (x>>16) | (x<<16);
#endif
return x;
}
static inline uint64_t av_const bswap_64(uint64_t x)
{
#if 0
x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
return (x>>32) | (x<<32);
#elif defined(ARCH_X86_64)
asm("bswap %0": "=r" (x) : "0" (x));
return x;
#else
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;
#endif
}
// 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 /* AVUTIL_BSWAP_H */