FFmpeg
bswap.h
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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 <intrin.h>
30 #endif
31 #include "config.h"
32 #include "libavutil/attributes.h"
33 
34 #if defined(_MSC_VER)
35 
36 #define av_bswap16 av_bswap16
37 static av_always_inline av_const uint16_t av_bswap16(uint16_t x)
38 {
39  return _rotr16(x, 8);
40 }
41 
42 #define av_bswap32 av_bswap32
43 static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
44 {
45  return _byteswap_ulong(x);
46 }
47 
48 #if ARCH_X86_64
49 #define av_bswap64 av_bswap64
50 static inline uint64_t av_const av_bswap64(uint64_t x)
51 {
52  return _byteswap_uint64(x);
53 }
54 #endif
55 
56 
57 #elif HAVE_INLINE_ASM
58 
59 #if AV_GCC_VERSION_AT_MOST(4,0)
60 #define av_bswap16 av_bswap16
61 static av_always_inline av_const unsigned av_bswap16(unsigned x)
62 {
63  __asm__("rorw $8, %w0" : "+r"(x));
64  return x;
65 }
66 #endif /* AV_GCC_VERSION_AT_MOST(4,0) */
67 
68 #if AV_GCC_VERSION_AT_MOST(4,4) || defined(__INTEL_COMPILER)
69 #define av_bswap32 av_bswap32
70 static av_always_inline av_const uint32_t av_bswap32(uint32_t x)
71 {
72  __asm__("bswap %0" : "+r" (x));
73  return x;
74 }
75 
76 #if ARCH_X86_64
77 #define av_bswap64 av_bswap64
78 static inline uint64_t av_const av_bswap64(uint64_t x)
79 {
80  __asm__("bswap %0": "=r" (x) : "0" (x));
81  return x;
82 }
83 #endif
84 #endif /* AV_GCC_VERSION_AT_MOST(4,4) */
85 
86 #endif /* HAVE_INLINE_ASM */
87 #endif /* AVUTIL_X86_BSWAP_H */
av_const
#define av_const
Definition: attributes.h:78
av_bswap32
#define av_bswap32
Definition: bswap.h:33
av_bswap16
#define av_bswap16
Definition: bswap.h:31
attributes.h
av_always_inline
#define av_always_inline
Definition: attributes.h:43
config.h
av_bswap64
static uint64_t av_const av_bswap64(uint64_t x)
Definition: bswap.h:73