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
28 #elif defined(__INTEL_COMPILER)
29 #include <immintrin.h>
35 #if (defined(__INTEL_COMPILER) && (__INTEL_COMPILER>=1216)) || defined(_MSC_VER)
36 # if defined(__INTEL_COMPILER)
37 # define ff_log2(x) (_bit_scan_reverse((x)|1))
39 # define ff_log2 ff_log2_x86
40 static av_always_inline av_const int ff_log2_x86(unsigned int v)
43 _BitScanReverse(&n, v|1);
47 # define ff_log2_16bit av_log2
49 # define ff_ctz(v) _tzcnt_u32(v)
52 # define ff_ctzll(v) _tzcnt_u64(v)
54 # define ff_ctzll ff_ctzll_x86
55 static av_always_inline av_const int ff_ctzll_x86(long long v)
57 return ((uint32_t)v == 0) ? _tzcnt_u32((uint32_t)(v >> 32)) + 32 : _tzcnt_u32((uint32_t)v);
61 #endif /* __INTEL_COMPILER */
63 #endif /* HAVE_FAST_CLZ */
67 /* Our generic version of av_popcount is faster than GCC's built-in on
68 * CPUs that don't support the popcnt instruction.
70 #if defined(__POPCNT__)
71 #define av_popcount __builtin_popcount
73 #define av_popcount64 __builtin_popcountll
76 #endif /* __POPCNT__ */
80 #if AV_GCC_VERSION_AT_LEAST(5,1)
81 #define av_mod_uintp2 __builtin_ia32_bzhi_si
83 /* GCC releases before 5.1.0 have a broken bzhi builtin, so for those we
84 * implement it using inline assembly
86 #define av_mod_uintp2 av_mod_uintp2_bmi2
87 static av_always_inline av_const unsigned av_mod_uintp2_bmi2(unsigned a, unsigned p)
89 if (av_builtin_constant_p(p))
90 return a & ((1 << p) - 1);
93 __asm__ ("bzhi %2, %1, %0 \n\t" : "=r"(x) : "rm"(a), "r"(p));
97 #endif /* AV_GCC_VERSION_AT_LEAST */
101 #endif /* __GNUC__ */
103 #endif /* AVUTIL_X86_INTMATH_H */