[vorbis-dev] SIMD instructions

[Segher Boessenkool]

Felix von Leitner wrote:
> 
> Vorbis does not appear to use any SIMD instructions.
> 
> A short look around in the source code indicates that it would be
> possible and might even yield big performance improvements.  Why has
> nobody done it yet?

Because libvorbis is just reference code; there are way bigger
performance improvements to be made by writing a performance-
optimized deecoder/encoder and simd'ing _that_.

> So my question at this point is: which functions need more performance
> the worst.  I find that splitting the packages makes profiling more of a
> hassle, but I will do it, if there are no good profiling data.

Trig transforms; and for decoder, huffman decode; and for encoder,
all of the psy model stuff.

<p>Segher
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