Int vs Word performance?
marlowsd at gmail.com
Fri Feb 27 11:34:37 EST 2009
Claus Reinke wrote:
>>> Here is a trivial example with drastic difference between
>>> T = Int and T = Word (~2.5x here):
>>> main = print $ foldl' (+) 0 [1..100000000::T]
> A quick grep shows almost no specialization at all for Word, or for
> IntXX/WordXX (see below). Still, none of that seems to explain the
> example repeated at the top of this message.
The Enum instance for Int uses specialised implementations of enumFromTo
and friends, whereas the Word version uses the generic integralEnumFromTo.
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