1 // Copyright 2014 Google Inc. All Rights Reserved. 2 // 3 // Use of this source code is governed by a BSD-style license 4 // that can be found in the COPYING file in the root of the source 5 // tree. An additional intellectual property rights grant can be found 6 // in the file PATENTS. All contributing project authors may 7 // be found in the AUTHORS file in the root of the source tree. 8 // ----------------------------------------------------------------------------- 9 // 10 // Endian related functions. 11 12 #ifndef WEBP_UTILS_ENDIAN_INL_H_ 13 #define WEBP_UTILS_ENDIAN_INL_H_ 14 15 #ifdef HAVE_CONFIG_H 16 #include "../webp/config.h" 17 #endif 18 19 #include "../webp/types.h" 20 21 // some endian fix (e.g.: mips-gcc doesn't define __BIG_ENDIAN__) 22 #if !defined(WORDS_BIGENDIAN) && \ 23 (defined(__BIG_ENDIAN__) || defined(_M_PPC) || \ 24 (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))) 25 #define WORDS_BIGENDIAN 26 #endif 27 28 #if defined(WORDS_BIGENDIAN) 29 #define HToLE32 BSwap32 30 #define HToLE16 BSwap16 31 #else 32 #define HToLE32(x) (x) 33 #define HToLE16(x) (x) 34 #endif 35 36 #if !defined(HAVE_CONFIG_H) 37 #ifdef __GNUC__ 38 # define LOCAL_GCC_VERSION ((__GNUC__ << 8) | __GNUC_MINOR__) 39 #else 40 # define LOCAL_GCC_VERSION 0 41 #endif // __GNUC__ 42 43 #ifdef __clang__ 44 # define LOCAL_CLANG_VERSION ((__clang_major__ << 8) | __clang_minor__) 45 #else 46 # define LOCAL_CLANG_VERSION 0 47 #endif // __clang__ 48 49 // clang-3.3 and gcc-4.3 have builtin functions for swap32/swap64 50 #if LOCAL_GCC_VERSION >= 0x403 || LOCAL_CLANG_VERSION >= 0x303 51 #define HAVE_BUILTIN_BSWAP32 52 #define HAVE_BUILTIN_BSWAP64 53 #endif 54 // clang-3.3 and gcc-4.8 have a builtin function for swap16 55 #if LOCAL_GCC_VERSION >= 0x408 || LOCAL_CLANG_VERSION >= 0x303 56 #define HAVE_BUILTIN_BSWAP16 57 #endif 58 #endif // !HAVE_CONFIG_H 59 60 static WEBP_INLINE uint16_t BSwap16(uint16_t x) { 61 #if defined(HAVE_BUILTIN_BSWAP16) 62 return __builtin_bswap16(x); 63 #elif defined(_MSC_VER) 64 return _byteswap_ushort(x); 65 #else 66 // gcc will recognize a 'rorw $8, ...' here: 67 return (x >> 8) | ((x & 0xff) << 8); 68 #endif // HAVE_BUILTIN_BSWAP16 69 } 70 71 static WEBP_INLINE uint32_t BSwap32(uint32_t x) { 72 #if defined(HAVE_BUILTIN_BSWAP32) 73 return __builtin_bswap32(x); 74 #elif defined(__i386__) || defined(__x86_64__) 75 uint32_t swapped_bytes; 76 __asm__ volatile("bswap %0" : "=r"(swapped_bytes) : "0"(x)); 77 return swapped_bytes; 78 #elif defined(_MSC_VER) 79 return (uint32_t)_byteswap_ulong(x); 80 #else 81 return (x >> 24) | ((x >> 8) & 0xff00) | ((x << 8) & 0xff0000) | (x << 24); 82 #endif // HAVE_BUILTIN_BSWAP32 83 } 84 85 static WEBP_INLINE uint64_t BSwap64(uint64_t x) { 86 #if defined(HAVE_BUILTIN_BSWAP64) 87 return __builtin_bswap64(x); 88 #elif defined(__x86_64__) 89 uint64_t swapped_bytes; 90 __asm__ volatile("bswapq %0" : "=r"(swapped_bytes) : "0"(x)); 91 return swapped_bytes; 92 #elif defined(_MSC_VER) 93 return (uint64_t)_byteswap_uint64(x); 94 #else // generic code for swapping 64-bit values (suggested by bdb@) 95 x = ((x & 0xffffffff00000000ull) >> 32) | ((x & 0x00000000ffffffffull) << 32); 96 x = ((x & 0xffff0000ffff0000ull) >> 16) | ((x & 0x0000ffff0000ffffull) << 16); 97 x = ((x & 0xff00ff00ff00ff00ull) >> 8) | ((x & 0x00ff00ff00ff00ffull) << 8); 98 return x; 99 #endif // HAVE_BUILTIN_BSWAP64 100 } 101 102 #endif // WEBP_UTILS_ENDIAN_INL_H_ 103
