On 12/04/2011, at 11:50 PM, Wilfried Kirschenmann wrote: > surprisingly, when removing the R.force from the code you attached, > performances are better (speed-up=2). I suppose but I am not sure that > this allow for loop fusions beetween the R.map ant the R.sum. > > I use ghc 7.0.3, Repa 2.0.0.3 and LLVM 2.9. > > By the end, the performances with this new version (0.48s) is 15x > better than my original version (6.9s) > However, the equivalent sequential C code is still 15x better (0.034s). > > This may indeed be explained by the fact that all computations are > performed inside the R.sum.
Yeah, the Repa fold and sum functions just use the equivalent Data.Vector ones. They're not parallelised and I haven't looked at the generated code. I'll add a ticket to the trac to fix these, but won't have time to work on it myself in the near future. Ben. _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
