Module: libav Branch: master Commit: 7bfda7d157eb6f7a2df908addd60221a7a6f5eb0
Author: Ganesh Ajjanagadde <[email protected]> Committer: Vittorio Giovara <[email protected]> Date: Wed Feb 22 12:53:33 2017 -0500 intmath: add faster clz support --- libavutil/intmath.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/libavutil/intmath.h b/libavutil/intmath.h index a5ee652..780bbab 100644 --- a/libavutil/intmath.h +++ b/libavutil/intmath.h @@ -44,6 +44,10 @@ # endif #endif /* ff_log2 */ +#ifndef ff_clz +# define ff_clz(v) __builtin_clz(v) +#endif /* ff_clz */ + #endif /* AV_GCC_VERSION_AT_LEAST(3,4) */ extern const uint8_t ff_log2_tab[256]; @@ -132,6 +136,21 @@ static av_always_inline av_const int ff_ctz_c(int v) } #endif +#ifndef ff_clz +#define ff_clz ff_clz_c +static av_always_inline av_const unsigned ff_clz_c(unsigned x) +{ + unsigned i = sizeof(x) * 8; + + while (x) { + x >>= 1; + i--; + } + + return i; +} +#endif + /** * Trailing zero bit count. * _______________________________________________ libav-commits mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-commits
