third_party/aom/aom_util/endian_inl.h

   1 /*
   2  * Copyright (c) 2016, Alliance for Open Media. All rights reserved
   3  *
   4  * This source code is subject to the terms of the BSD 2 Clause License and
   5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
   6  * was not distributed with this source code in the LICENSE file, you can
   7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
   8  * Media Patent License 1.0 was not distributed with this source code in the
   9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
  10  */
  11 //
  12 // Endian related functions.
  13
  14 #ifndef AOM_AOM_UTIL_ENDIAN_INL_H_
  15 #define AOM_AOM_UTIL_ENDIAN_INL_H_
  16
  17 #include <stdlib.h>
  18
  19 #include "config/aom_config.h"
  20
  21 #include "aom/aom_integer.h"
  22
  23 #if defined(__GNUC__)
  24 #define LOCAL_GCC_VERSION ((__GNUC__ << 8) | __GNUC_MINOR__)
  25 #define LOCAL_GCC_PREREQ(maj, min) (LOCAL_GCC_VERSION >= (((maj) << 8) | (min)))
  26 #else
  27 #define LOCAL_GCC_VERSION 0
  28 #define LOCAL_GCC_PREREQ(maj, min) 0
  29 #endif
  30
  31 // handle clang compatibility
  32 #ifndef __has_builtin
  33 #define __has_builtin(x) 0
  34 #endif
  35
  36 // some endian fix (e.g.: mips-gcc doesn't define __BIG_ENDIAN__)
  37 #if !defined(WORDS_BIGENDIAN) &&                   \
  38     (defined(__BIG_ENDIAN__) || defined(_M_PPC) || \
  39      (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)))
  40 #define WORDS_BIGENDIAN
  41 #endif
  42
  43 #if defined(WORDS_BIGENDIAN)
  44 #define HToLE32 BSwap32
  45 #define HToLE16 BSwap16
  46 #define HToBE64(x) (x)
  47 #define HToBE32(x) (x)
  48 #else
  49 #define HToLE32(x) (x)
  50 #define HToLE16(x) (x)
  51 #define HToBE64(X) BSwap64(X)
  52 #define HToBE32(X) BSwap32(X)
  53 #endif
  54
  55 #if LOCAL_GCC_PREREQ(4, 8) || __has_builtin(__builtin_bswap16)
  56 #define HAVE_BUILTIN_BSWAP16
  57 #endif
  58
  59 #if LOCAL_GCC_PREREQ(4, 3) || __has_builtin(__builtin_bswap32)
  60 #define HAVE_BUILTIN_BSWAP32
  61 #endif
  62
  63 #if LOCAL_GCC_PREREQ(4, 3) || __has_builtin(__builtin_bswap64)
  64 #define HAVE_BUILTIN_BSWAP64
  65 #endif
  66
  67 #if HAVE_MIPS32 && defined(__mips__) && !defined(__mips64) && \
  68     defined(__mips_isa_rev) && (__mips_isa_rev >= 2) && (__mips_isa_rev < 6)
  69 #define AOM_USE_MIPS32_R2
  70 #endif
  71
  72 static INLINE uint16_t BSwap16(uint16_t x) {
  73 #if defined(HAVE_BUILTIN_BSWAP16)
  74   return __builtin_bswap16(x);
  75 #elif defined(_MSC_VER)
  76   return _byteswap_ushort(x);
  77 #else
  78   // gcc will recognize a 'rorw $8, ...' here:
  79   return (x >> 8) | ((x & 0xff) << 8);
  80 #endif  // HAVE_BUILTIN_BSWAP16
  81 }
  82
  83 static INLINE uint32_t BSwap32(uint32_t x) {
  84 #if defined(AOM_USE_MIPS32_R2)
  85   uint32_t ret;
  86   __asm__ volatile(
  87       "wsbh   %[ret], %[x]          \n\t"
  88       "rotr   %[ret], %[ret],  16   \n\t"
  89       : [ret] "=r"(ret)
  90       : [x] "r"(x));
  91   return ret;
  92 #elif defined(HAVE_BUILTIN_BSWAP32)
  93   return __builtin_bswap32(x);
  94 #elif defined(__i386__) || defined(__x86_64__)
  95   uint32_t swapped_bytes;
  96   __asm__ volatile("bswap %0" : "=r"(swapped_bytes) : "0"(x));
  97   return swapped_bytes;
  98 #elif defined(_MSC_VER)
  99   return (uint32_t)_byteswap_ulong(x);
 100 #else
 101   return (x >> 24) | ((x >> 8) & 0xff00) | ((x << 8) & 0xff0000) | (x << 24);
 102 #endif  // HAVE_BUILTIN_BSWAP32
 103 }
 104
 105 static INLINE uint64_t BSwap64(uint64_t x) {
 106 #if defined(HAVE_BUILTIN_BSWAP64)
 107   return __builtin_bswap64(x);
 108 #elif defined(__x86_64__)
 109   uint64_t swapped_bytes;
 110   __asm__ volatile("bswapq %0" : "=r"(swapped_bytes) : "0"(x));
 111   return swapped_bytes;
 112 #elif defined(_MSC_VER)
 113   return (uint64_t)_byteswap_uint64(x);
 114 #else   // generic code for swapping 64-bit values (suggested by bdb@)
 115   x = ((x & 0xffffffff00000000ull) >> 32) | ((x & 0x00000000ffffffffull) << 32);
 116   x = ((x & 0xffff0000ffff0000ull) >> 16) | ((x & 0x0000ffff0000ffffull) << 16);
 117   x = ((x & 0xff00ff00ff00ff00ull) >> 8) | ((x & 0x00ff00ff00ff00ffull) << 8);
 118   return x;
 119 #endif  // HAVE_BUILTIN_BSWAP64
 120 }
 121
 122 #endif  // AOM_AOM_UTIL_ENDIAN_INL_H_