[Haskell-cafe] Haskell performance question
Bulat Ziganshin
bulat.ziganshin at gmail.com
Thu Nov 8 16:29:21 EST 2007
Hello Don,
Thursday, November 8, 2007, 10:53:28 PM, you wrote:
>> a <- newArray (0,n-1) 1.0 :: IO (IOUArray Int Double)
>> forM_ [0..n-2] $ \i -> do { x <- readArray a i; y <- readArray a
>> (i+1); writeArray a (i+1) (x+y) }
oh, i was stupid. obviously, first thing you need to do is to use
unsafeRead/unsafeWrite operations. i'm wonder how this code is only
20x slower than C version, may be you need to use gcc -O3 -funroll-loops
and gcc3 (because gcc4 becomes slower)
--
Best regards,
Bulat mailto:Bulat.Ziganshin at gmail.com
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