[vorbis-dev] Optimization and doubles vs. floats

[Segher Boessenkool]

>   I saw some mail go by a bit ago about doubles-vs-floats, but I seem to have lost it.
> 
>   I'm interested in rewriting the mdct code using Altivec on MacOS X.  Altivec doesn't support doubles, though -- the only floating point vector type is single precision floats.  Vorbis currently has doubles everywhere -- is this really necessary?   Doubles are supposedly faster than floats in the PPC FPU, but the Altivec unit is definitely going to be faster.

The mdct will be ok using floats. Don't know if all the rest of vorbis likes
floats, though.

Which algo are you planning to use for the mdct? Oh, and Altivec is 128 bit,
right?

Ciao,

Segher

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