| /* |
| * 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 |
| |
| /** |
| * @addtogroup lavu_internal |
| * @{ |
| */ |
| |
| #if ARCH_ARM |
| # include "arm/intmath.h" |
| #endif |
| |
| #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 */ |