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| author | Måns Rullgård <mans@mansr.com> | 2010-01-14 19:58:12 +0000 |
|---|---|---|
| committer | Måns Rullgård <mans@mansr.com> | 2010-01-14 19:58:12 +0000 |
| commit | 544f5a922f63faae775edcf04918c0d0ab87c470 (patch) | |
| tree | 73bf2971835f7a3c31fe810c1e206e47abaebacf | |
| parent | 669b5583302b6dc04afaaab78144a6536399cdc6 (diff) | |
| download | ffmpeg-544f5a922f63faae775edcf04918c0d0ab87c470.tar.gz | |
Optimise av_log2 with clz when available
10% faster flac decoding on x86 and ARM.
Originally committed as revision 21217 to svn://svn.ffmpeg.org/ffmpeg/trunk
| -rw-r--r-- | libavutil/common.h | 8 | ||||
| -rw-r--r-- | libavutil/intmath.h | 41 |
2 files changed, 49 insertions, 0 deletions
diff --git a/libavutil/common.h b/libavutil/common.h index a8a9bd39e6..c91e658af7 100644 --- a/libavutil/common.h +++ b/libavutil/common.h @@ -117,6 +117,10 @@ #endif #endif +#ifdef HAVE_AV_CONFIG_H +# include "intmath.h" +#endif + //rounded division & shift #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b)) /* assume b>0 */ @@ -138,6 +142,7 @@ extern const uint8_t ff_log2_tab[256]; extern const uint8_t av_reverse[256]; +#ifndef av_log2 static inline av_const int av_log2(unsigned int v) { int n = 0; @@ -153,7 +158,9 @@ static inline av_const int av_log2(unsigned int v) return n; } +#endif +#ifndef av_log2_16bit static inline av_const int av_log2_16bit(unsigned int v) { int n = 0; @@ -165,6 +172,7 @@ static inline av_const int av_log2_16bit(unsigned int v) return n; } +#endif /** * Clips a signed integer value into the amin-amax range. diff --git a/libavutil/intmath.h b/libavutil/intmath.h new file mode 100644 index 0000000000..39e14c28ae --- /dev/null +++ b/libavutil/intmath.h @@ -0,0 +1,41 @@ +/* + * 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 "config.h" +#include "common.h" + +#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4) + +#ifndef av_log2 + +#define av_log2(x) (31 - __builtin_clz((x)|1)) + +#ifndef av_log2_16bit +#define av_log2_16bit av_log2 +#endif + +#endif /* av_log2 */ + +#endif /* AV_GCC_VERSION_AT_LEAST(3,4) */ + +#endif /* AVUTIL_INTMATH_H */ |