[Ffmpeg-devel] mmx/sse optimizations

Rich Felker dalias
Thu Dec 22 23:36:39 CET 2005


On Thu, Dec 22, 2005 at 02:22:00PM -0800, Mike Melanson wrote:
> Guillaume POIRIER wrote:
> >Well, just like when using high level languages, it's all a matter of
> >how much dev time your are willing to trade against code speed (and
> >platform-independent). It's sometimes not worth spending so much time
> >writing Da Best asm code...
> 
> 	Well stated. IOW, it's all a matter of trade-offs. Felker doesn't 
> understand trade-offs. He is always in search of the perfect solution 
> (which does not exist).

I understand tradeoffs perfectly well, and that they make your code
worse. If you have slow C code, someone will eventually write good asm
to replace it. If you have half-ass mmx code that people already
perceive as being fast, no one will even optimize it properly.

Same thing goes for free and non-free (if you have almost-free crap no
one will ever bother to write real free version), etc. Compromise is
the situation in which everyone loses. Seeing it as the situation
where everyone wins is naive.

Rich





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