Switching to quotRem gave no measurable improvements.
After switching to ByteString, the code now runs in 9 seconds, which outperforms my C version. But honestly, I have no idea why.

New code:
http://lpaste.net/100136

$ ghc --make -O3 303only012.hs && time ./303only012 50000000 > /dev/null
./303only012 50000000 > /dev/null  9.72s user 0.21s system 90% cpu 10.961 total

@Alois, I'm not sure how criterion can help compare my code with the C version, since in the C version I cannot measure the exec time of only012 only. What did you have in mind?

Thanks everyone!


-- 
Cp


On Wed, Feb 19, 2014 at 7:24 PM, Levent Erkok <erkokl@gmail.com> wrote:
Also, prefer quotRem over divMod as the former is faster. See here: http://stackoverflow.com/questions/339719/when-is-the-difference-between-quotrem-and-divmod-useful


On Wed, Feb 19, 2014 at 10:19 AM, Gregory Collins <greg@gregorycollins.net> wrote:

On Wed, Feb 19, 2014 at 9:36 AM, Charles-Pierre Astolfi <cpa@crans.org> wrote:
So there's a difference, but I'm not sure if it's related to my algorithm or related to IO/RTS.

Text.Printf is slower than the C version (and uses String). Use Data.ByteString.putStr instead.


--
Gregory Collins <greg@gregorycollins.net>

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