On Sun, Oct 26, 2014 at 08:49:07PM +1100, Matt Oliver wrote: > intmath.h already uses the gcc builtin intrinsics for log2 and ctz. This > patch just adds the equivalent icl and msvc intrinsics. All added > intrinsics have the same function (i.e. with respect to input 0s etc.) as > the existing gcc builtins.
> intmath.h | 37 +++++++++++++++++++++++++++++++------
> 1 file changed, 31 insertions(+), 6 deletions(-)
> 26a67ffba2f85535b6ac5dcb7643ec89c1d81d5f
> 0001-avutil-intmath-enable-builtin-intrinsics-for-icl-and.patch
> From 8b2a0cc3e265750650b4399ad051ae2e98a24f42 Mon Sep 17 00:00:00 2001
> From: Matthew Oliver <protogo...@gmail.com>
> Date: Wed, 22 Oct 2014 00:30:53 +1100
> Subject: [PATCH] avutil/intmath: enable builtin intrinsics for icl and
> msvc.
>
> ---
> libavutil/intmath.h | 37 +++++++++++++++++++++++++++++++------
> 1 file changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/libavutil/intmath.h b/libavutil/intmath.h
> index 8f7a69e..7d836d9 100644
> --- a/libavutil/intmath.h
> +++ b/libavutil/intmath.h
> @@ -35,21 +35,29 @@
> * @{
> */
>
> -#if HAVE_FAST_CLZ && AV_GCC_VERSION_AT_LEAST(3,4)
> -
> +#if HAVE_FAST_CLZ
> +#if 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 */
> -
> +#elif defined( __INTEL_COMPILER )
> +#ifndef ff_log2
> +# define ff_log2(x) (_bit_scan_reverse(x|1))
> +# ifndef ff_log2_16bit
> +# define ff_log2_16bit av_log2
> +# endif
> +#endif /* ff_log2 */
> +#endif
> #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
> +#if !defined( _MSC_VER )
> static av_always_inline av_const int ff_log2_c(unsigned int v)
> {
> int n = 0;
> @@ -65,6 +73,15 @@ static av_always_inline av_const int ff_log2_c(unsigned
> int v)
>
> return n;
> }
> +#else
> +static av_always_inline av_const int ff_log2_c(unsigned int v)
> +{
> + int n = 0;
> + _BitScanReverse((unsigned long *)&n, v|1);
strict aliasing violation
[...]
> int c;
> -
> +#if !defined( _MSC_VER )
> if (v & 0x1)
> return 0;
>
> @@ -127,7 +150,9 @@ static av_always_inline av_const int ff_ctz_c(int v)
> c += 2;
> }
> c -= v & 0x1;
> -
> +#else
> + _BitScanForward( (unsigned long *)&c, v );
here too
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
Observe your enemies, for they first find out your faults. -- Antisthenes
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