Re: [Haskell-cafe] GHC vs GCC

David Menendez wrote:

On Sat, Mar 27, 2010 at 12:56 AM, Thomas DuBuisson wrote:

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Using bang patterns didn't help almost anything here. Using rem instead of mod made the time go from 45s to 40s. Now, using -fvia-C really helped (when I used rem but not using mod). It went down to 10s. Bang patterns should have helped tons - it isn't GHC thats at fault here and yes it does tco. I attached a version w/ excessive bangs below. Did you compile with "ghc --make -O3 -fforce-recomp"?

Does -O3 actually do anything? GHC only goes up to -O2.

Well GHC has an -O3[1], but it's not a good idea to use it. Some of the "optimizations" that -O3 does can result in slower code for particular programs. Whereas -O2 is safe and never results in pessimizations. [1] Unless recent versions have removed it. -- Live well, ~wren