These days -O2, which invokes the SpecConstr pass, can have a big effect, but only on some programs. Simon | -----Original Message----- | From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users-bounces@haskell.org] | On Behalf Of Neil Mitchell | Sent: 19 October 2006 11:22 | To: Donald Bruce Stewart | Cc: GHC Users Mailing List | Subject: Re: Benchmarking GHC | | Hi | | > > One thing that IME makes a difference is -funbox-strict-fields. It's | > > probably better to use pragmas for this, though. Another thing to | > > consider is garbage collection RTS flags, those can sometimes make a | > > big difference. | > | | I _don't_ want to speed up a particular program by modifying it, I | want to take a set of existing programs which are treated as black | boxes, and compile them all with the same flags. I don't want to | experiment to see which flags give the best particular result on a per | program basis, or even for the benchmark as a whole, I just want to | know what the "standard recommendation" is for people who want fast | code but not to understand anything. | | > All this and more on the under-publicised Performance wiki, | > http://haskell.org/haskellwiki/Performance | | It's a very good resource, and I've read it before :) | | Another way to treat my question is, the wiki says "Of course, if a | GHC compiled program runs slower than the same program compiled with | another Haskell compiler, then it's definitely a bug" - in this | sentance what does the command line look like in the GHC compiled | case? | | Thanks | | Neil | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users@haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users