libavutil/bswap.h

   1 /*
   2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 /**
  22  * @file bswap.h
  23  * byte swapping routines
  24  */
  25
  26 #ifndef FFMPEG_BSWAP_H
  27 #define FFMPEG_BSWAP_H
  28
  29 #include <stdint.h>
  30 #include "config.h"
  31 #include "common.h"
  32
  33 #ifdef HAVE_BYTESWAP_H
  34 #include <byteswap.h>
  35 #else
  36
  37 static av_always_inline av_const uint16_t bswap_16(uint16_t x)
  38 {
  39 #if defined(ARCH_X86)
  40     asm("rorw $8, %0" : "+r"(x));
  41 #elif defined(ARCH_SH4)
  42     asm("swap.b %0,%0" : "=r"(x) : "0"(x));
  43 #else
  44     x= (x>>8) | (x<<8);
  45 #endif
  46     return x;
  47 }
  48
  49 static av_always_inline av_const uint32_t bswap_32(uint32_t x)
  50 {
  51 #if defined(ARCH_X86)
  52 #ifdef HAVE_BSWAP
  53     asm("bswap   %0" : "+r" (x));
  54 #else
  55     asm("rorw    $8,  %w0 \n\t"
  56         "rorl    $16, %0  \n\t"
  57         "rorw    $8,  %w0"
  58         : "+r"(x));
  59 #endif
  60 #elif defined(ARCH_SH4)
  61     asm("swap.b %0,%0\n"
  62         "swap.w %0,%0\n"
  63         "swap.b %0,%0\n"
  64         : "=r"(x) : "0"(x));
  65 #elif defined(ARCH_ARM)
  66     uint32_t t;
  67     asm ("eor %1, %0, %0, ror #16 \n\t"
  68          "bic %1, %1, #0xFF0000   \n\t"
  69          "mov %0, %0, ror #8      \n\t"
  70          "eor %0, %0, %1, lsr #8  \n\t"
  71          : "+r"(x), "+r"(t));
  72 #elif defined(ARCH_BFIN)
  73     unsigned tmp;
  74     asm("%1 = %0 >> 8 (V);      \n\t"
  75         "%0 = %0 << 8 (V);      \n\t"
  76         "%0 = %0 | %1;          \n\t"
  77         "%0 = PACK(%0.L, %0.H); \n\t"
  78         : "+d"(x), "=&d"(tmp));
  79 #else
  80     x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
  81     x= (x>>16) | (x<<16);
  82 #endif
  83     return x;
  84 }
  85
  86 static inline uint64_t av_const bswap_64(uint64_t x)
  87 {
  88 #if 0
  89     x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
  90     x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
  91     return (x>>32) | (x<<32);
  92 #elif defined(ARCH_X86_64)
  93   asm("bswap  %0": "=r" (x) : "0" (x));
  94   return x;
  95 #else
  96     union {
  97         uint64_t ll;
  98         uint32_t l[2];
  99     } w, r;
 100     w.ll = x;
 101     r.l[0] = bswap_32 (w.l[1]);
 102     r.l[1] = bswap_32 (w.l[0]);
 103     return r.ll;
 104 #endif
 105 }
 106
 107 #endif  /* !HAVE_BYTESWAP_H */
 108
 109 // be2me ... BigEndian to MachineEndian
 110 // le2me ... LittleEndian to MachineEndian
 111
 112 #ifdef WORDS_BIGENDIAN
 113 #define be2me_16(x) (x)
 114 #define be2me_32(x) (x)
 115 #define be2me_64(x) (x)
 116 #define le2me_16(x) bswap_16(x)
 117 #define le2me_32(x) bswap_32(x)
 118 #define le2me_64(x) bswap_64(x)
 119 #else
 120 #define be2me_16(x) bswap_16(x)
 121 #define be2me_32(x) bswap_32(x)
 122 #define be2me_64(x) bswap_64(x)
 123 #define le2me_16(x) (x)
 124 #define le2me_32(x) (x)
 125 #define le2me_64(x) (x)
 126 #endif
 127
 128 #endif /* FFMPEG_BSWAP_H */