8 Nov
2007
8 Nov
'07
4:29 p.m.
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@gmail.com