[vorbis-dev] Trying to build on Windows (Part 2)

Segher Boessenkool segher at wanadoo.nl
Sun Dec 17 08:43:04 PST 2000

Firelight Multimedia wrote:
> Are you kidding? It takes 5.5-6% cpu on my p3-500 just to play 1 stereo
> file! (from the reference source)..  unless althon does things a lot better
> than the pentium, or you have your own optimiziations, i think those cpu
> measurements seem quite suspicious.

I optimized the decoder on an Athlon 500, so I'm not surprised it works
well on it. But I develop on other platforms as well, and performance
seems to be good on all machines I tested; the optimizations are not
machine-dependant, although some code was rewritten to help the compiler
on register-starved (i.e., x86) machines. This optimizations are in the
reference source, btw.

> Brett
> ps, i tried vorbis with the new intel beta compiler with simd and platform
> targeting, i got excited when it said it vectorized about 20 of the loops in
> the vorbis project (with SSE and MMX) , but it actually went slower for some
> reason (6.5%) .. bummer.

When all the obvious optimizations and the high-level (algorithmic)
optimizations will be done, I'll be looking at vectorizing. But it's
not worth it at the moment, unless your compiler can do it for you,
which it probably can't, as you found out already.



p.s. If anyone wants me to do optimizations for Intel machines, buy one for
me, and give me some money to buy food ;-)

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