/* * 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 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_cstatic 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_cstatic 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 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#ifndef ff_clz#define ff_clz(v) __builtin_clz(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 *//* 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];}#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) * 0x022FDD63CC95386DU) >> 58];}#endif #ifndef ff_clz#define ff_clz ff_clz_cstatic av_always_inline av_const unsigned ff_clz_c(unsigned x){    unsigned i = sizeof(x) * 8;     while (x) {        x >>= 1;        i--;    }     return i;}#endif #if AV_GCC_VERSION_AT_LEAST(3,4)#ifndef av_parity#define av_parity __builtin_parity#endif#endif /** * @} */#endif /* AVUTIL_INTMATH_H */