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 AVUTIL_BSWAP_H
  27 #define AVUTIL_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 #elif defined(HAVE_ARMV6)
  44     asm("rev16 %0, %0" : "+r"(x));
  45 #else
  46     x= (x>>8) | (x<<8);
  47 #endif
  48     return x;
  49 }
  50
  51 static av_always_inline av_const uint32_t bswap_32(uint32_t x)
  52 {
  53 #if defined(ARCH_X86)
  54 #ifdef HAVE_BSWAP
  55     asm("bswap   %0" : "+r" (x));
  56 #else
  57     asm("rorw    $8,  %w0 \n\t"
  58         "rorl    $16, %0  \n\t"
  59         "rorw    $8,  %w0"
  60         : "+r"(x));
  61 #endif
  62 #elif defined(ARCH_SH4)
  63     asm("swap.b %0,%0\n"
  64         "swap.w %0,%0\n"
  65         "swap.b %0,%0\n"
  66         : "=r"(x) : "0"(x));
  67 #elif defined(HAVE_ARMV6)
  68     asm("rev %0, %0" : "+r"(x));
  69 #elif defined(ARCH_ARMV4L)
  70     uint32_t t;
  71     asm ("eor %1, %0, %0, ror #16 \n\t"
  72          "bic %1, %1, #0xFF0000   \n\t"
  73          "mov %0, %0, ror #8      \n\t"
  74          "eor %0, %0, %1, lsr #8  \n\t"
  75          : "+r"(x), "+r"(t));
  76 #elif defined(ARCH_BFIN)
  77     unsigned tmp;
  78     asm("%1 = %0 >> 8 (V);      \n\t"
  79         "%0 = %0 << 8 (V);      \n\t"
  80         "%0 = %0 | %1;          \n\t"
  81         "%0 = PACK(%0.L, %0.H); \n\t"
  82         : "+d"(x), "=&d"(tmp));
  83 #else
  84     x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
  85     x= (x>>16) | (x<<16);
  86 #endif
  87     return x;
  88 }
  89
  90 static inline uint64_t av_const bswap_64(uint64_t x)
  91 {
  92 #if 0
  93     x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
  94     x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
  95     return (x>>32) | (x<<32);
  96 #elif defined(ARCH_X86_64)
  97   asm("bswap  %0": "=r" (x) : "0" (x));
  98   return x;
  99 #else
 100     union {
 101         uint64_t ll;
 102         uint32_t l[2];
 103     } w, r;
 104     w.ll = x;
 105     r.l[0] = bswap_32 (w.l[1]);
 106     r.l[1] = bswap_32 (w.l[0]);
 107     return r.ll;
 108 #endif
 109 }
 110
 111 #endif  /* !HAVE_BYTESWAP_H */
 112
 113 // be2me ... BigEndian to MachineEndian
 114 // le2me ... LittleEndian to MachineEndian
 115
 116 #ifdef WORDS_BIGENDIAN
 117 #define be2me_16(x) (x)
 118 #define be2me_32(x) (x)
 119 #define be2me_64(x) (x)
 120 #define le2me_16(x) bswap_16(x)
 121 #define le2me_32(x) bswap_32(x)
 122 #define le2me_64(x) bswap_64(x)
 123 #else
 124 #define be2me_16(x) bswap_16(x)
 125 #define be2me_32(x) bswap_32(x)
 126 #define be2me_64(x) bswap_64(x)
 127 #define le2me_16(x) (x)
 128 #define le2me_32(x) (x)
 129 #define le2me_64(x) (x)
 130 #endif
 131
 132 #endif /* AVUTIL_BSWAP_H */