Performance on amd64

John Skaller skaller at
Tue Jul 5 05:38:25 EDT 2005

        Can someone comment on the Debian package for Ubuntu Hoary
        providing ghc-6.2.2 with binary for amd64?
        I'm asking because I'm unexpectedly getting really bad 
        performance as you can see here:
        and here:
        These links are unstable, this one should always have
        the latest results:
        The compilation is using:
        ghc -O3 -fvia-C -optc -O3 
        which can probably be tweaked, any advice on that appreciated.
        The actual test script measures real time performance
        by running programs at random.. there are lots of samples,
        the graphs are statistically reliable, and the randomness
        should eliminate most biases.
        For ackermann, the test is actually measuring how many
        words are required in the stack per call: the more the slower.
        For takfp, ghc is way behind, and Ocaml is actually way
        ahead since I think it uses doubles where the C based
        systems are using single precision (this affects the
        size of a stack frame) .. not sure about ghc, is Float
        a C float or a double in ghc?

I may try to build from source if this is expected to
provide better performance.

John Skaller <skaller at users dot sourceforge dot net>
Download Felix:
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