On 05/08/06, Chris Kuklewicz
I suggest trying something, using "/usr/bin/ghc -O3 -optc-O3" like this:
{-# OPTIONS_GHC -funbox-strict-fields #-}
import Foreign import Control.Monad
data Cam = Cam { snap_width :: !Int , snap_height :: !Int , snap_bytespp :: !Int , snap_size :: !Int , cam_img :: Ptr Word8 , cam_obj :: ForeignPtr () }
type F = Word8 -> Word8 -> Word8 -> Int -> Int -> Int
{-# INLINE cam_snap_3 #-} cam_snap_3 :: Cam -> F -> Int -> IO Int cam_snap_3 cam f x = let end = snap_size cam loop ptr n x | ptr `seq` n `seq` x `seq` False = undefined | n >= end = return x | otherwise = do r <- peek ptr g <- peek (advancePtr ptr 1) b <- peek (advancePtr ptr 2) loop (advancePtr ptr 3) (n+3) (f r g b n x) in loop (cam_img cam) 0 x
Ah, so excessive laziness and IO were killing it! Thanks! This works most excellently :)