2 * Copyright (c) 2015 James Almer
4 * This file is part of FFmpeg.
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.
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.
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
21 #ifndef AVUTIL_X86_INTMATH_H
22 #define AVUTIL_X86_INTMATH_H
29 /* Our generic version of av_popcount is faster than GCC's built-in on
30 * CPUs that don't support the popcnt instruction.
32 #if defined(__POPCNT__)
33 #define av_popcount __builtin_popcount
35 #define av_popcount64 __builtin_popcountll
38 #endif /* __POPCNT__ */
42 #if AV_GCC_VERSION_AT_LEAST(5,1)
43 #define av_mod_uintp2 __builtin_ia32_bzhi_si
45 /* GCC releases before 5.1.0 have a broken bzhi builtin, so for those we
46 * implement it using inline assembly
48 #define av_mod_uintp2 av_mod_uintp2_bmi2
49 static av_always_inline av_const unsigned av_mod_uintp2_bmi2(unsigned a, unsigned p)
51 if (av_builtin_constant_p(p))
52 return a & ((1 << p) - 1);
55 __asm__ ("bzhi %2, %1, %0 \n\t" : "=r"(x) : "rm"(a), "r"(p));
59 #endif /* AV_GCC_VERSION_AT_LEAST */
65 #endif /* AVUTIL_X86_INTMATH_H */