Hello John, Thursday, January 19, 2006, 4:42:47 AM, you wrote:
sorry, with the "gcc -O3 -ffast-math -fstrict-aliasing -funroll-loops" the C version is 50 times faster than best Haskell one... it's the loop from C version:
JM> I believe something similar to what I noted here is the culprit: JM> http://www.haskell.org//pipermail/glasgow-haskell-users/2005-October/009174.... i mean this when i wrote that jhc must be better. i just forget than jhc is not yet supports arrays JM> GHCs indirect calls are really killing its performance in tight loops. I JM> think there is room for collaboration between the various compilers JM> there, since we are all moving to a c-- back end (in theory) we could JM> work on a common c-- -> C translator that searches out such uneeded JM> indirections and zaps them before they get to gcc which doesn't handle JM> them well at all. using your ideas to dramatical speed up simple loops will be very good. GHC is very good in high-level optimizations, but it simply ignores the problem of compilation simple imperative-style code -- Best regards, Bulat mailto:bulatz@HotPOP.com