/* * Copyright (c) 2010 Mans Rullgard <mans@mansr.com> * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; 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 /** * @addtogroup lavu_internal * @{ */ #if HAVE_FAST_CLZ && 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) */ extern const uint8_t ff_log2_tab[256]; #ifndef ff_log2 #define ff_log2 ff_log2_c 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; } #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 && AV_GCC_VERSION_AT_LEAST(3,4) #ifndef ff_ctz #define ff_ctz(v) __builtin_ctz(v) #endif #endif #ifndef ff_ctz #define ff_ctz ff_ctz_c static av_always_inline av_const int ff_ctz_c(int v) { int c; if (v & 0x1) return 0; c = 1; if (!(v & 0xffff)) { v >>= 16; c += 16; } if (!(v & 0xff)) { v >>= 8; c += 8; } if (!(v & 0xf)) { v >>= 4; c += 4; } if (!(v & 0x3)) { v >>= 2; c += 2; } c -= v & 0x1; return c; } #endif /** * Trailing zero bit count. * * @param v input value. If v is 0, the result is undefined. * @return the number of trailing 0-bits */ int av_ctz(int v); /** * @} */ #endif /* AVUTIL_INTMATH_H */