dons: > bulat.ziganshin: > > Hello Achim, > > > > Friday, February 20, 2009, 11:44:49 PM, you wrote: > > > > >> > Turning this into a ticket with associated test will: > > >> > > >> but why you think that this is untypical and needs a ticket? ;) > > >> > > > Bulat, you are right in every aspect. You never did anything wrong. > > > > Achim, this is simplest code one can imagine. so when Simon will go to > > check ghc optimizations, he will try it without any reports. but > > Simon, unlike Don, never said that ghc may be compared to gcc. Don, on > > the other hand, say this everyday. when he is asked for code that > > shows this, he declined to answer. so - why YOU think that ghc > > generates fast code and this example is something unusual? can you > > provide any *technical* arguments or will continue to make personal > > attacks together with Don? > > Bulat, you misunderstand, it is not personal! We just want something to > work on. Something specific. > > For example, you've identified loop unrolling as something that could > very profitably be improved in GHC, and Claus even wrote a prototype to > see what kind of speedups to guess. > > This is a great contribution! Now we know where to hunt.
And just to summarise what we have seen: ghc -O2 naive left fold 15.680 gcc -O0 4.500 ghc manual recursion -fasm 1.328 ghc manual recursion 1.035 ghc naive left fold "stream fusion" 0.967 gcc -O1 0.892 ghc "-funroll-loops" -D8 0.623 gcc -O3 -funroll-loops 0.318 ghc "-funroll-loops" -D64 0.088 So what did we learn here? -- Don _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe