[FFmpeg-devel] [PATCH] SPARC VIS simple_idct try #2

Michael Niedermayer michaelni
Thu Aug 23 01:29:53 CEST 2007


On Wed, Aug 22, 2007 at 11:45:57AM +0200, Balatoni Denes wrote:
> > also you permute the input explicitly instead of setting
> > idct_permutation_type properly
> In the row iteration it is not only permuted, but also shifted right four 
> bits. But there is no shift instruction. So if you know a significantly 
> faster way to shift the input right four bits, than do tell me.

there is a shift instruction, sllx, wheres the problem with using that?
also iam realizing now that you read and work just with 32bits at a time
while the registers really are 64bit
so unles sparc need 2x as much time for 64bit instructions this is very

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Complexity theory is the science of finding the exact solution to an
approximation. Benchmarking OTOH is finding an approximation of the exact
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