ffmpeg/libavutil/x86/bswap.h

   1 /*
   2  * This file is part of FFmpeg.
   3  *
   4  * FFmpeg is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * FFmpeg is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with FFmpeg; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 /**
  20  * @file
  21  * byte swapping routines
  22  */
  23
  24 #ifndef AVUTIL_X86_BSWAP_H
  25 #define AVUTIL_X86_BSWAP_H
  26
  27 #include <stdint.h>
  28 #include "config.h"
  29 #include "libavutil/attributes.h"
  30
  31 #if HAVE_INLINE_ASM
  32
  33 #if !AV_GCC_VERSION_AT_LEAST(4,1)
  34 #define av_bswap16 av_bswap16
  35 static av_always_inline av_const unsigned av_bswap16(unsigned x)
  36 {
  37     __asm__("rorw $8, %w0" : "+r"(x));
  38     return x;
  39 }
  40 #endif /* !AV_GCC_VERSION_AT_LEAST(4,1) */
  41
  42 #if !AV_GCC_VERSION_AT_LEAST(4,5)
  43 #define av_bswap32 av_bswap32
  44 static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
  45 {
  46     __asm__("bswap   %0" : "+r" (x));
  47     return x;
  48 }
  49
  50 #if ARCH_X86_64
  51 #define av_bswap64 av_bswap64
  52 static inline uint64_t av_const av_bswap64(uint64_t x)
  53 {
  54     __asm__("bswap  %0": "=r" (x) : "0" (x));
  55     return x;
  56 }
  57 #endif
  58 #endif /* !AV_GCC_VERSION_AT_LEAST(4,5) */
  59
  60 #endif /* HAVE_INLINE_ASM */
  61 #endif /* AVUTIL_X86_BSWAP_H */