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intmath.h
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1 /*
2  * Copyright (c) 2015 James Almer
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #ifndef AVUTIL_X86_INTMATH_H
22 #define AVUTIL_X86_INTMATH_H
23 
24 #include <stdint.h>
25 #include "config.h"
26 
27 #if defined(__GNUC__)
28 
29 /* Our generic version of av_popcount is faster than GCC's built-in on
30  * CPUs that don't support the popcnt instruction.
31  */
32 #if defined(__POPCNT__)
33  #define av_popcount __builtin_popcount
34 #if ARCH_X86_64
35  #define av_popcount64 __builtin_popcountll
36 #endif
37 
38 #endif /* __POPCNT__ */
39 
40 #if defined(__BMI2__)
41 
42 #define av_mod_uintp2 av_mod_uintp2_bmi2
43 static av_always_inline av_const unsigned av_mod_uintp2_bmi2(unsigned a, unsigned p)
44 {
45  if (av_builtin_constant_p(p))
46  return a & ((1 << p) - 1);
47  else {
48  unsigned x;
49  __asm__ ("bzhi %2, %1, %0 \n\t" : "=r"(x) : "rm"(a), "r"(p));
50  return x;
51  }
52 }
53 
54 #endif /* __BMI2__ */
55 
56 #endif /* __GNUC__ */
57 
58 #endif /* AVUTIL_X86_INTMATH_H */
#define av_const
Definition: attributes.h:68
#define av_builtin_constant_p
Definition: attributes.h:147
#define av_always_inline
Definition: attributes.h:37