Re: Minutes from Feb 21 LSE Call

Linus Torvalds (torvalds@transmeta.com)
Sun, 23 Feb 2003 13:41:45 -0800 (PST)


On 23 Feb 2003, Xavier Bestel wrote:
> Le dim 23/02/2003 à 20:17, Linus Torvalds a écrit :
>
> > And the baroque instruction encoding on the x86 is actually a _good_
> > thing: it's a rather dense encoding, which means that you win on icache.
> > It's a bit hard to decode, but who cares? Existing chips do well at
> > decoding, and thanks to the icache win they tend to perform better - and
> > they load faster too (which is important - you can make your CPU have
> > big caches, but _nothing_ saves you from the cold-cache costs).
>
> Next step: hardware gzip ?

Not gzip, no. It needs to be a random-access compression with reasonably
small blocks, not something designed for streaming. Which makes it harder
to do right and efficiently.

But ARM has Thumb (not the same thing, but same idea), and at least some
PPC chips have a page-based compressor - IBM calls it "CodePack" in case
you want to google for it.

Linus

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