On Fri, Jun 27, 2003 at 12:10:55PM -0500, Shawn P. Garbett wrote:
- -------------------------------------- New Haskell version with Unboxed Array Note:it was a simple change of import and type - ----------------------------------------- import Data.Array.Unboxed
a :: UArray Int Int a = array (0,15) [(i, i) | i <- [0 .. 15] ]
acc :: Int -> Int -> Int acc s 0 = s acc s n = acc (s + (a ! (n `mod` 16))) (n-1)
main :: IO () main = do print $ acc 0 100000000
I'd be curious to see timing on the following: import Data.Array.Unboxed import Data.Bits a :: UArray Int Int a = array (0,15) [(i, i) | i <- [0 .. 15] ] acc :: Int -> Int -> Int acc s 0 = s acc s n = acc (s + (a ! (n .&. 15))) (n-1) main :: IO () main = do print $ acc 0 100000000 All I've done eliminated the mod call in favor of a bitwise and. I would hope that the C compiler would do that, at least if it gives any improvement. -- David Roundy http://civet.berkeley.edu/droundy/