Oleg Galbert wrote:

I'm a newbie in Haskell. I tryed to compare performance of GHC compiled code and Ocaml compiled code on a small example:

test n cosx | n==0 = cosx | otherwise = test (n-1) (cosx+cos(cosx))

main = print ( test 10000000 0.0 )

I compiled it on Win NT :

ghc -o test_haskell.exe test_haskell.hs

<snip>

Does a stack usage depends on number of recursive calls? Is there a tail recursion optimization? <snip>

Yes and yes. To turn on the optimiser, add -O or -O2 to the compiler command line: [mjb67@mjb67 mjb67]$ ghc -o test_haskell test_haskell.hs [mjb67@mjb67 mjb67]$ ./test_haskell Stack space overflow: current size 1048576 bytes. Use `+RTS -Ksize' to increase it. [mjb67@mjb67 mjb67]$ ghc -O2 -o test_haskell test_haskell.hs [mjb67@mjb67 mjb67]$ ./test_haskell 1.5707963267948966 [mjb67@mjb67 mjb67]$ Hope this helps, Matthew (fellow Haskell newbie :-) )