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_UTILS_H_
13#define WEBP_UTILS_ENDIAN_INL_UTILS_H_
14
15#ifdef HAVE_CONFIG_H
16#include "src/webp/config.h"
17#endif
18
19#include "src/dsp/dsp.h"
20#include "src/webp/types.h"
21
22#if defined(WORDS_BIGENDIAN)
23#define HToLE32 BSwap32
24#define HToLE16 BSwap16
25#else
26#define HToLE32(x) (x)
27#define HToLE16(x) (x)
28#endif
29
30#if !defined(HAVE_CONFIG_H)
31#if LOCAL_GCC_PREREQ(4,8) || __has_builtin(__builtin_bswap16)
32#define HAVE_BUILTIN_BSWAP16
33#endif
34#if LOCAL_GCC_PREREQ(4,3) || __has_builtin(__builtin_bswap32)
35#define HAVE_BUILTIN_BSWAP32
36#endif
37#if LOCAL_GCC_PREREQ(4,3) || __has_builtin(__builtin_bswap64)
38#define HAVE_BUILTIN_BSWAP64
39#endif
40#endif // !HAVE_CONFIG_H
41
42static WEBP_INLINE uint16_t BSwap16(uint16_t x) {
43#if defined(HAVE_BUILTIN_BSWAP16)
44 return __builtin_bswap16(x);
45#elif defined(_MSC_VER)
46 return _byteswap_ushort(x);
47#else
48 // gcc will recognize a 'rorw $8, ...' here:
49 return (x >> 8) | ((x & 0xff) << 8);
50#endif // HAVE_BUILTIN_BSWAP16
51}
52
53static WEBP_INLINE uint32_t BSwap32(uint32_t x) {
54#if defined(WEBP_USE_MIPS32_R2)
55 uint32_t ret;
56 __asm__ volatile (
57 "wsbh %[ret], %[x] \n\t"
58 "rotr %[ret], %[ret], 16 \n\t"
59 : [ret]"=r"(ret)
60 : [x]"r"(x)
61 );
62 return ret;
63#elif defined(HAVE_BUILTIN_BSWAP32)
64 return __builtin_bswap32(x);
65#elif defined(__i386__) || defined(__x86_64__)
66 uint32_t swapped_bytes;
67 __asm__ volatile("bswap %0" : "=r"(swapped_bytes) : "0"(x));
68 return swapped_bytes;
69#elif defined(_MSC_VER)
70 return (uint32_t)_byteswap_ulong(x);
71#else
72 return (x >> 24) | ((x >> 8) & 0xff00) | ((x << 8) & 0xff0000) | (x << 24);
73#endif // HAVE_BUILTIN_BSWAP32
74}
75
76static WEBP_INLINE uint64_t BSwap64(uint64_t x) {
77#if defined(HAVE_BUILTIN_BSWAP64)
78 return __builtin_bswap64(x);
79#elif defined(__x86_64__)
80 uint64_t swapped_bytes;
81 __asm__ volatile("bswapq %0" : "=r"(swapped_bytes) : "0"(x));
82 return swapped_bytes;
83#elif defined(_MSC_VER)
84 return (uint64_t)_byteswap_uint64(x);
85#else // generic code for swapping 64-bit values (suggested by bdb@)
86 x = ((x & 0xffffffff00000000ull) >> 32) | ((x & 0x00000000ffffffffull) << 32);
87 x = ((x & 0xffff0000ffff0000ull) >> 16) | ((x & 0x0000ffff0000ffffull) << 16);
88 x = ((x & 0xff00ff00ff00ff00ull) >> 8) | ((x & 0x00ff00ff00ff00ffull) << 8);
89 return x;
90#endif // HAVE_BUILTIN_BSWAP64
91}
92
93#endif // WEBP_UTILS_ENDIAN_INL_UTILS_H_
94