[Haskell-cafe] Toy compression algorithms [was: A very edgy language]

[Stefan O'Rear]

On Sun, Jul 08, 2007 at 12:10:04PM +0100, Andrew Coppin wrote:
> (Realistically though. My program takes a [Word8] and turns it into a 
> [Bool] before running a parser over it. The GHC optimiser doesn't really 
> stand a hope in hell of optimising that into a program that reads a machine 
> word into a CPU register and starts playing with bit flips on it...)

Actually, if you're very lucky (fusion is just as hard in Haskell as it
is in real life), it *does*.  It seems to fit nicely into the
stream-fusion framework.

> PS. Are those zlib libraries actually written in Haskell? Or are they a 
> thin layer on top of a C library?

Yup, they wrap C's zlib.

> PPS. Does GHC make use of MMX, SSE, et al?

No (in spirit - the native code generator uses 1-element SSE operations
for floating point because it's easier to optimize than "FPU" code).

Stefan