[Haskell-cafe] C-like Haskell

Duncan Coutts duncan.coutts at worc.ox.ac.uk
Wed Jan 28 20:37:18 EST 2009


On Wed, 2009-01-28 at 20:23 -0500, Ross Mellgren wrote:
> Duncan, I think you must have some magics -- on my machine the  
> original code also takes forever.
> Running with +RTS -S indicates it's allocating several gig of memory  
> or more.

It runs in a tiny heap for me:

./circ2 +RTS -A10k -M20k -RTS
3141592653589764829

+RTS -S indicates it allocated 8,512 bytes.

> Applying some bang patterns gives me ~8s for 10^8 and somewhat more  
> than a minute for 10^9:

I wonder if it is the 64 vs 32 bit machine difference. I recall some ghc
ticket about Int64 having rather poor performance on 32bit x86 machines.
I don't have a 32bit x86 machine to hand so I cannot easily test it.

Duncan



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