On 15/07/07, Donald Bruce Stewart <[EMAIL PROTECTED]> wrote:
hughperkins: > > Hey, I just realized I can shave off another 30% in C# ;-) > So now the timings become:Ok. So do the same thing to the Haskell program. The compilers should produce pretty much identical assembly. {-# OPTIONS -O2 -optc-O -fbang-patterns #-} import Control.Monad.ST import Data.Array.ST import Data.Array.Base import System import Control.Monad import Data.Bits main = print (pureSieve 10000000) pureSieve :: Int -> Int pureSieve n = runST( sieve n ) sieve n = do a <- newArray (0,n-1) True :: ST s (STUArray s Int Bool) let cutoff = truncate (sqrt (fromIntegral n)) + 1 go a n cutoff 2 0 go !a !m cutoff !n !c | n == m = return c | otherwise = do e <- unsafeRead a n if e then if n < cutoff then let loop !j | j < m = do x <- unsafeRead a j when x $ unsafeWrite a j False
Surely you can remove the read here, and just always do the write? -- Sebastian Sylvan +44(0)7857-300802 UIN: 44640862 _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
