[FFmpeg-devel] [PATCH] Some IWMMXT functions for libavcodec #2

Michael Niedermayer michaelni
Sat May 17 16:42:30 CEST 2008

On Sat, May 17, 2008 at 01:19:28PM +0400, Dmitry Antipov wrote:
> Michael Niedermayer wrote:
> > the iterations are always an even number IIRC, but dont hesitate to add a
> > assert(!(h&1));
> But both vsad_intra16_c() and vsse_intra16_c() has an outer loop
> 'for(y=1; y<h; y++)', so, if H if always even, the number of iterations
> is always odd. For loop unrolled by 2, this means we either need an
> additional check within the loop body, or move the last iteration outside
> of the loop.

No you can jump in the middle, see the equivalent mmx functions.
I of course do not know if this is optimal or if its better to
copy one of the pieces like you do below

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In a rich man's house there is no place to spit but his face.
-- Diogenes of Sinope
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