[FFmpeg-devel] [PATCH] Altivec vector_fmul_scalar

Diego Biurrun diego
Tue Jan 6 18:31:42 CET 2009


On Tue, Jan 06, 2009 at 04:49:00PM +0200, Siarhei Siamashka wrote:
> 
> Sorry for barging it, but can you also try to benchmark an Altivec variant of
> the following patch (or even benchmark it as-is without Altivec)?
> http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2008-September/053256.html
> 
> It should be much more useful for PPC platform than for the others because of 
> two reasons:
> 1. Vorbis uses "nonnative" bitstream byte order on PPC and UPDATE_CACHE
> operations are supposed to be more expensive there. As the patch optimizes
> bitstream reading to vastly reduce the number of such operations, benefit on
> PPC should be better.
> 2. As PPC uses intrinsics anyway, it avoids the controversy of mixing C and
> inline assembly :)
> 
> I'm not expecting replies posted in *this* thread and hijacking it was not my
> intention.
> 
> PS. This is also some kind of ping, asking for review/comments of that old
> patch, because it seems to be forgotten now. The performance improvement for
> vorbis is too good to be ignored.

Just send a ping to the original thread or propose the patch again..

Diego




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