On Mon, Feb 28, 2005 at 02:55:56PM +0000, Ganesh Sittampalam wrote:
Hi,
The following either eats memory until killed or segfaults (I can't pin down a reason for the difference). Tested with GHC 6.2.2 and 6.4.20050212, with various different libgmp3s under various Redhat and Debian platforms, and WinXP.
Prelude> :m +Data.Bits Prelude Data.Bits> 18446658724119492593 `shiftL` (-3586885994363551744) :: Integer
Cheers,
Ganesh
shiftL for Integer is defined in fptools/libraries/base/Data/Bits.hs: class Num a => Bits a where shiftL :: a -> Int -> a x `shiftL` i = x `shift` i instance Bits Integer where shift x i | i >= 0 = x * 2^i | otherwise = x `div` 2^(-i) IOW, for y < 0: x `shiftL` y = x `shift` y = x `div` 2^(-y) and calculating, in your case, 2^3586885994363551744 is not something your computer is going to like... as it's probably a number which doesn't fit in our universe :) Still, a segfault might point at a bug, which I unfortunately won't be able to say much about. (Due to lack of knowledge & information.) Greetings, Remi -- Nobody can be exactly like me. Even I have trouble doing it.