In thinking about it I figured it may be because I was using Integer and not Int; I recompiled without -fall-strict and with Int instead of Integer. In that case, mkArray1: 27.27u 2.37s 0:32.32 91.7% mkArray2: 25.88u 2.33s 0:30.97 91.0% So here there's basically no difference in performance; the one with zeros is just a bit faster than the other, but probably not significantly so. So this case didn't show a problem with undefined. Could there ever be a problem or is the compiler smart enough to catch this? - Hal -- Hal Daume III "Computer science is no more about computers | hdaume@isi.edu than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume On Wed, 15 May 2002, Simon Marlow wrote:
[ moved to glasgow-haskell-users@haskell.org ]
The timing results were:
mkArray1: 11.42u 0.79s 0:13.47 90.6% mkArray2: 24.55u 2.31s 0:30.12 89.1%
Which is actually *slower*. Any ideas why? (These were compiled with ghc 5.02.3 -O2 -fvia-c -fall-strict)
What are the results without -fall-strict? (-fall-strict is an old experimental flag and almost certainly doesn't do anything reasonable. We've de-documented it in the HEAD).
Cheers, Simon _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users