Re: [Haskell-cafe] GHC vs GCC vs JHC

29 Mar 2010


      On 29/03/2010, at 02:27, Lennart Augustsson wrote:
...
Does anything change if you swap the first two rhss?
No, not as far as I can tell.
...
On Sun, Mar 28, 2010 at 1:28 AM, Roman Leshchinskiy  wrote:
...
On 28/03/2010, at 09:47, Lennart Augustsson wrote:
...
It's important to switch from mod to rem.  This can be done by a
simple abstract interpretation.
Also, changing the definition of rem from
a `rem` b
    | b == 0                     = divZeroError
    | a == minBound && b == (-1) = overflowError
    | otherwise                  =  a `remInt` b
to
a `rem` b
    | b == 0                     = divZeroError
    | b == (-1) && a == minBound = overflowError
    | otherwise                  =  a `remInt` b
speeds up the GHC version by about 20%. Figuring out why is left as an exercise to the reader :-)
Roman
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