xref: /third_party/ffmpeg/libavutil/x86/bswap.h (revision cabdff1a) 
1/*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19/**
20 * @file
21 * byte swapping routines
22 */
23
24#ifndef AVUTIL_X86_BSWAP_H
25#define AVUTIL_X86_BSWAP_H
26
27#include <stdint.h>
28#if defined(_MSC_VER)
29#include <stdlib.h>
30#include <intrin.h>
31#endif
32#include "config.h"
33#include "libavutil/attributes.h"
34
35#if defined(_MSC_VER)
36
37#define av_bswap16 av_bswap16
38static av_always_inline av_const uint16_t av_bswap16(uint16_t x)
39{
40    return _rotr16(x, 8);
41}
42
43#define av_bswap32 av_bswap32
44static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
45{
46    return _byteswap_ulong(x);
47}
48
49#if ARCH_X86_64
50#define av_bswap64 av_bswap64
51static inline uint64_t av_const av_bswap64(uint64_t x)
52{
53    return _byteswap_uint64(x);
54}
55#endif
56
57
58#elif HAVE_INLINE_ASM
59
60#if AV_GCC_VERSION_AT_MOST(4,0)
61#define av_bswap16 av_bswap16
62static av_always_inline av_const unsigned av_bswap16(unsigned x)
63{
64    __asm__("rorw $8, %w0" : "+r"(x));
65    return x;
66}
67#endif /* AV_GCC_VERSION_AT_MOST(4,0) */
68
69#if AV_GCC_VERSION_AT_MOST(4,4) || defined(__INTEL_COMPILER)
70#define av_bswap32 av_bswap32
71static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
72{
73    __asm__("bswap   %0" : "+r" (x));
74    return x;
75}
76
77#if ARCH_X86_64
78#define av_bswap64 av_bswap64
79static inline uint64_t av_const av_bswap64(uint64_t x)
80{
81    __asm__("bswap  %0": "=r" (x) : "0" (x));
82    return x;
83}
84#endif
85#endif /* AV_GCC_VERSION_AT_MOST(4,4) */
86
87#endif /* HAVE_INLINE_ASM */
88#endif /* AVUTIL_X86_BSWAP_H */
89