[Haskell-cafe] Fastest saturating add?

I have a function that's called many (many) times, which involves a saturating addition (addition without overflow). In other words, I'd like ((254 :: Word8) + 10) to equal 255 (which is maxBound::Word8), not 8 (which is what you get with overflow). My current code, without particular regard to performance, is simply: satAdd :: Word8 -> Word8 -> Word8 satAdd x y = let m = x + y in if m < x then 255 else m This seems like the type of code somebody's already worked on the performance for, though I can't find much Haskell-specific in searches online. Is there a faster way to do this? Thanks! Tom