ref: 8ced62f2506c98e692de701728a9049947772352
dir: /vpx_util/endian_inl.h/
// Copyright 2014 Google Inc. All Rights Reserved. // // Use of this source code is governed by a BSD-style license // that can be found in the COPYING file in the root of the source // tree. An additional intellectual property rights grant can be found // in the file PATENTS. All contributing project authors may // be found in the AUTHORS file in the root of the source tree. // ----------------------------------------------------------------------------- // // Endian related functions. #ifndef VPX_UTIL_ENDIAN_INL_H_ #define VPX_UTIL_ENDIAN_INL_H_ #include <stdlib.h> #include "./vpx_config.h" #include "vpx/vpx_integer.h" #if defined(__GNUC__) # define LOCAL_GCC_VERSION ((__GNUC__ << 8) | __GNUC_MINOR__) # define LOCAL_GCC_PREREQ(maj, min) \ (LOCAL_GCC_VERSION >= (((maj) << 8) | (min))) #else # define LOCAL_GCC_VERSION 0 # define LOCAL_GCC_PREREQ(maj, min) 0 #endif // handle clang compatibility #ifndef __has_builtin # define __has_builtin(x) 0 #endif // some endian fix (e.g.: mips-gcc doesn't define __BIG_ENDIAN__) #if !defined(WORDS_BIGENDIAN) && \ (defined(__BIG_ENDIAN__) || defined(_M_PPC) || \ (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))) #define WORDS_BIGENDIAN #endif #if defined(WORDS_BIGENDIAN) #define HToLE32 BSwap32 #define HToLE16 BSwap16 #define HToBE64(x) (x) #define HToBE32(x) (x) #else #define HToLE32(x) (x) #define HToLE16(x) (x) #define HToBE64(X) BSwap64(X) #define HToBE32(X) BSwap32(X) #endif #if LOCAL_GCC_PREREQ(4, 8) || __has_builtin(__builtin_bswap16) #define HAVE_BUILTIN_BSWAP16 #endif #if LOCAL_GCC_PREREQ(4, 3) || __has_builtin(__builtin_bswap32) #define HAVE_BUILTIN_BSWAP32 #endif #if LOCAL_GCC_PREREQ(4, 3) || __has_builtin(__builtin_bswap64) #define HAVE_BUILTIN_BSWAP64 #endif #if HAVE_MIPS32 && defined(__mips__) && !defined(__mips64) && \ defined(__mips_isa_rev) && (__mips_isa_rev >= 2) && (__mips_isa_rev < 6) #define VPX_USE_MIPS32_R2 #endif static INLINE uint16_t BSwap16(uint16_t x) { #if defined(HAVE_BUILTIN_BSWAP16) return __builtin_bswap16(x); #elif defined(_MSC_VER) return _byteswap_ushort(x); #else // gcc will recognize a 'rorw $8, ...' here: return (x >> 8) | ((x & 0xff) << 8); #endif // HAVE_BUILTIN_BSWAP16 } static INLINE uint32_t BSwap32(uint32_t x) { #if defined(VPX_USE_MIPS32_R2) uint32_t ret; __asm__ volatile ( "wsbh %[ret], %[x] \n\t" "rotr %[ret], %[ret], 16 \n\t" : [ret]"=r"(ret) : [x]"r"(x) ); return ret; #elif defined(HAVE_BUILTIN_BSWAP32) return __builtin_bswap32(x); #elif defined(__i386__) || defined(__x86_64__) uint32_t swapped_bytes; __asm__ volatile("bswap %0" : "=r"(swapped_bytes) : "0"(x)); return swapped_bytes; #elif defined(_MSC_VER) return (uint32_t)_byteswap_ulong(x); #else return (x >> 24) | ((x >> 8) & 0xff00) | ((x << 8) & 0xff0000) | (x << 24); #endif // HAVE_BUILTIN_BSWAP32 } static INLINE uint64_t BSwap64(uint64_t x) { #if defined(HAVE_BUILTIN_BSWAP64) return __builtin_bswap64(x); #elif defined(__x86_64__) uint64_t swapped_bytes; __asm__ volatile("bswapq %0" : "=r"(swapped_bytes) : "0"(x)); return swapped_bytes; #elif defined(_MSC_VER) return (uint64_t)_byteswap_uint64(x); #else // generic code for swapping 64-bit values (suggested by bdb@) x = ((x & 0xffffffff00000000ull) >> 32) | ((x & 0x00000000ffffffffull) << 32); x = ((x & 0xffff0000ffff0000ull) >> 16) | ((x & 0x0000ffff0000ffffull) << 16); x = ((x & 0xff00ff00ff00ff00ull) >> 8) | ((x & 0x00ff00ff00ff00ffull) << 8); return x; #endif // HAVE_BUILTIN_BSWAP64 } #endif // VPX_UTIL_ENDIAN_INL_H_