aboutsummaryrefslogtreecommitdiffstats
path: root/libavutil/bswap.h
blob: ee75f88c348e0f774c112cb91b51ea6f1d76b425 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/*
 * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file bswap.h
 * byte swap.
 */

#ifndef FFMPEG_BSWAP_H
#define FFMPEG_BSWAP_H

#include <stdint.h>
#include "common.h"

#ifdef HAVE_BYTESWAP_H
#include <byteswap.h>
#else

#ifdef ARCH_X86_64
#  define LEGACY_REGS "=Q"
#else
#  define LEGACY_REGS "=q"
#endif

static av_always_inline uint16_t bswap_16(uint16_t x)
{
#if defined(ARCH_X86)
    __asm("rorw $8, %0"   :
          LEGACY_REGS (x) :
          "0" (x));
#elif defined(ARCH_SH4)
    __asm__("swap.b %0,%0":"=r"(x):"0"(x));
#else
    x= (x>>8) | (x<<8);
#endif
    return x;
}

static av_always_inline uint32_t bswap_32(uint32_t x)
{
#if defined(ARCH_X86)
#if __CPU__ != 386
    __asm("bswap   %0":
          "=r" (x)    :
#else
    __asm("xchgb   %b0,%h0\n"
          "rorl    $16,%0 \n"
          "xchgb   %b0,%h0":
          LEGACY_REGS (x)  :
#endif
          "0" (x));
#elif defined(ARCH_SH4)
    __asm__("swap.b %0,%0\n"
            "swap.w %0,%0\n"
            "swap.b %0,%0\n"
            :"=r"(x):"0"(x));
#elif defined(ARCH_ARM)
    uint32_t t;
    __asm__ ("eor %1, %0, %0, ror #16 \n\t"
             "bic %1, %1, #0xFF0000   \n\t"
             "mov %0, %0, ror #8      \n\t"
             "eor %0, %0, %1, lsr #8  \n\t"
             : "+r"(x), "+r"(t));
#elif defined(ARCH_BFIN)
    unsigned tmp;
    asm("%1 = %0 >> 8 (V);      \n\t"
        "%0 = %0 << 8 (V);      \n\t"
        "%0 = %0 | %1;          \n\t"
        "%0 = PACK(%0.L, %0.H); \n\t"
        : "+d"(x), "=&d"(tmp));
#else
    x= ((x<<8)&0xFF00FF00) | ((x>>8)&0x00FF00FF);
    x= (x>>16) | (x<<16);
#endif
    return x;
}

static inline uint64_t bswap_64(uint64_t x)
{
#if 0
    x= ((x<< 8)&0xFF00FF00FF00FF00ULL) | ((x>> 8)&0x00FF00FF00FF00FFULL);
    x= ((x<<16)&0xFFFF0000FFFF0000ULL) | ((x>>16)&0x0000FFFF0000FFFFULL);
    return (x>>32) | (x<<32);
#elif defined(ARCH_X86_64)
  __asm("bswap  %0":
        "=r" (x)   :
        "0" (x));
  return x;
#else
    union {
        uint64_t ll;
        uint32_t l[2];
    } w, r;
    w.ll = x;
    r.l[0] = bswap_32 (w.l[1]);
    r.l[1] = bswap_32 (w.l[0]);
    return r.ll;
#endif
}

#endif  /* !HAVE_BYTESWAP_H */

// be2me ... BigEndian to MachineEndian
// le2me ... LittleEndian to MachineEndian

#ifdef WORDS_BIGENDIAN
#define be2me_16(x) (x)
#define be2me_32(x) (x)
#define be2me_64(x) (x)
#define le2me_16(x) bswap_16(x)
#define le2me_32(x) bswap_32(x)
#define le2me_64(x) bswap_64(x)
#else
#define be2me_16(x) bswap_16(x)
#define be2me_32(x) bswap_32(x)
#define be2me_64(x) bswap_64(x)
#define le2me_16(x) (x)
#define le2me_32(x) (x)
#define le2me_64(x) (x)
#endif

#endif /* FFMPEG_BSWAP_H */