ffmpeg_files/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 libavutil/x86/bswap.h
  21  * byte swapping routines
  22  */
  23
  24 #ifndef MP_AVUTIL_X86_BSWAP_H
  25 #define MP_AVUTIL_X86_BSWAP_H
  26
  27 #include <stdint.h>
  28 #include "config.h"
  29 #include "libavutil/common.h"
  30
  31 #define bswap_16 bswap_16
  32 static av_always_inline av_const uint16_t bswap_16(uint16_t x)
  33 {
  34     __asm__("rorw $8, %0" : "+r"(x));
  35     return x;
  36 }
  37
  38 #define bswap_32 bswap_32
  39 static av_always_inline av_const uint32_t bswap_32(uint32_t x)
  40 {
  41 #if HAVE_BSWAP
  42     __asm__("bswap   %0" : "+r" (x));
  43 #else
  44     __asm__("rorw    $8,  %w0 \n\t"
  45             "rorl    $16, %0  \n\t"
  46             "rorw    $8,  %w0"
  47             : "+r"(x));
  48 #endif
  49     return x;
  50 }
  51
  52 #if ARCH_X86_64
  53 #define bswap_64 bswap_64
  54 static inline uint64_t av_const bswap_64(uint64_t x)
  55 {
  56     __asm__("bswap  %0": "=r" (x) : "0" (x));
  57     return x;
  58 }
  59 #endif
  60
  61 #endif /* AVUTIL_X86_BSWAP_H */