Re: Faster, GHC, and floating point.

--- ajb@spamcop.net wrote:

Quoting JP Bernardy :

...

1. Use -fexcess-precision, unless you really need the exact (lesser) precision. Otherwise each intermediate result is spilled in memory. This hurts!

Yes, but it does avoid incorrect numerics, which hurts fewer times, but when it does, it hurts a LOT more. :-)

With an SSE processor, it is possible to have both speed and exact precision, passing -optc-march=pentium4 -optc-mfpmath=sse to ghc, in addition to -fexcess-precision. BTW, as requested, I've contributed a page about this to the haskell wiki. http://haskell.org/hawiki/FasterFloatingPointWithGhc Cheers, JP. __________________________________ Do you Yahoo!? The New Yahoo! Shopping - with improved product search http://shopping.yahoo.com