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Diffstat (limited to 'media/libav/libavutil/intmath.h')
-rw-r--r-- | media/libav/libavutil/intmath.h | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/media/libav/libavutil/intmath.h b/media/libav/libavutil/intmath.h new file mode 100644 index 000000000..a5ee6525e --- /dev/null +++ b/media/libav/libavutil/intmath.h @@ -0,0 +1,146 @@ +/* + * 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 */ |