On Tue, Dec 15, 2009 at 10:30 AM, Maciej Piechotka
My results (ghc 6.12.1, Core 2 Duo 2.8 GHz, Linux 2.6.32, Gentoo):
Not Optimized & not compiled: First: 12.47 secs, 1530911440 bytes Second: 17.40 secs, 1929614816 bytes Optimized & compiled: First: 1.24 secs, 966280832 bytes Second: 1.11 secs, 966277152 bytes
Seconded, I consistently get 0.350 seconds vs 0.300 when compiling the original code via -O2.
Repeating gave similar results - first being better w/out optimalization as 1.2:1.7 and second being better with optimalizations (-O).
Why the first one is better unoptimalized?
I think thats not a specific enough question. I replaced the 'Integer' with 'Int' and found (via -ddump-asm) that the assembly is _identical_. A test shows what you would expect - the performance was identical. So the question in my mind is what presumably trivial optimization doesn't happen when Integer is used? Thomas