summaryrefslogtreecommitdiff
path: root/libavutil/intmath.h
blob: 2cb313240b76028a49fd4dabdbf21d997c858ce1 (plain)
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
/*
 * Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef AVUTIL_INTMATH_H
#define AVUTIL_INTMATH_H

#include <stdint.h>

#include "config.h"
#include "attributes.h"

#if ARCH_ARM
#   include "arm/intmath.h"
#endif

/**
 * @addtogroup lavu_internal
 * @{
 */

#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)

#ifndef ff_log2
#   define ff_log2(x) (31 - __builtin_clz((x)|1))
#   ifndef ff_log2_16bit
#      define ff_log2_16bit av_log2
#   endif
#endif /* ff_log2 */

#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */

extern const uint8_t ff_log2_tab[256];

#ifndef ff_log2
#define ff_log2 ff_log2_c
static av_always_inline av_const int ff_log2_c(unsigned int v)
{
    int n = 0;
    if (v & 0xffff0000) {
        v >>= 16;
        n += 16;
    }
    if (v & 0xff00) {
        v >>= 8;
        n += 8;
    }
    n += ff_log2_tab[v];

    return n;
}
#endif

#ifndef ff_log2_16bit
#define ff_log2_16bit ff_log2_16bit_c
static av_always_inline av_const int ff_log2_16bit_c(unsigned int v)
{
    int n = 0;
    if (v & 0xff00) {
        v >>= 8;
        n += 8;
    }
    n += ff_log2_tab[v];

    return n;
}
#endif

#define av_log2       ff_log2
#define av_log2_16bit ff_log2_16bit

/**
 * @}
 */
#endif /* AVUTIL_INTMATH_H */