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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
|
/*
* Copyright (c) 2010 Mans Rullgard <mans@mansr.com>
*
* 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
*/
#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
#if ARCH_X86
# include "x86/intmath.h"
#endif
#if HAVE_FAST_CLZ
#if defined( __INTEL_COMPILER )
#ifndef ff_log2
# define ff_log2(x) (_bit_scan_reverse((x)|1))
# ifndef ff_log2_16bit
# define ff_log2_16bit av_log2
# endif
#endif /* ff_log2 */
#elif 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) */
#endif
extern const uint8_t ff_log2_tab[256];
#ifndef ff_log2
#define ff_log2 ff_log2_c
#if !defined( _MSC_VER )
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;
}
#else
static av_always_inline av_const int ff_log2_c(unsigned int v)
{
unsigned long n;
_BitScanReverse(&n, v|1);
return n;
}
#define ff_log2_16bit av_log2
#endif
#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
/**
* @addtogroup lavu_math
* @{
*/
#if HAVE_FAST_CLZ
#if defined( __INTEL_COMPILER )
#ifndef ff_ctz
#define ff_ctz(v) _bit_scan_forward(v)
#endif
#elif AV_GCC_VERSION_AT_LEAST(3,4)
#ifndef ff_ctz
#define ff_ctz(v) __builtin_ctz(v)
#endif
#ifndef ff_ctzll
#define ff_ctzll(v) __builtin_ctzll(v)
#endif
#endif
#endif
#ifndef ff_ctz
#define ff_ctz ff_ctz_c
/**
* Trailing zero bit count.
*
* @param v input value. If v is 0, the result is undefined.
* @return the number of trailing 0-bits
*/
#if !defined( _MSC_VER )
/* We use the De-Bruijn method outlined in:
* http://supertech.csail.mit.edu/papers/debruijn.pdf. */
static av_always_inline av_const int ff_ctz_c(int v)
{
static const uint8_t debruijn_ctz32[32] = {
0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
};
return debruijn_ctz32[(uint32_t)((v & -v) * 0x077CB531U) >> 27];
}
#else
static av_always_inline av_const int ff_ctz_c( int v )
{
unsigned long c;
_BitScanForward(&c, v);
return c;
}
#endif
#endif
#ifndef ff_ctzll
#define ff_ctzll ff_ctzll_c
/* We use the De-Bruijn method outlined in:
* http://supertech.csail.mit.edu/papers/debruijn.pdf. */
static av_always_inline av_const int ff_ctzll_c(long long v)
{
static const uint8_t debruijn_ctz64[64] = {
0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28,
62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11,
63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10,
51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12
};
return debruijn_ctz64[(uint64_t)((v & -v) * 0x022FDD63CC95386D) >> 58];
}
#endif
/**
* @}
*/
#endif /* AVUTIL_INTMATH_H */
|
