[vorbis-dev] Optimization and doubles vs. floats

Segher Boessenkool segher at eastsite.nl
Tue Aug 29 15:16:14 PDT 2000



> At this point, all of Vorbis will do just fine on floats.  Only the LSP used 
> to require the exponent headroom, and I replaced that code with a new 
> algorithm that has no such sensitivity.
> 
> Now that floats provide plenty of room, I'm thinking that taking the whole 
> sourcebase to float might be useful to relieve pressure on the cache 
> (regardless of relative FPU performance).  Segher, do you concur?

For pc architecture, yes. For some others storing floats to memory takes
exceptionally long. This are coincidentally almost exactly the machines
where cache doesn't matter anyway (because they have none, or lots).

But these machines will not be using Vorbis (I hope); so let's convert
to double. It will be a win on almost any target.

Ciao,

Segher

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