Adding constant folding for Integer div and mod

Carter Schonwald carter.schonwald at
Fri Jul 19 23:47:53 CEST 2013

that said, please be *conservative* on how  you optimize floats, i'd rather
not have accidental unexpected numerical instability.  Its much easier to
validate correctness of optimizations for Words and Ints rather than Floats
and Doubles, the latter are complicated critters

On Fri, Jul 19, 2013 at 1:25 PM, Bryan O'Sullivan <bos at>wrote:

> On Fri, Jul 19, 2013 at 9:58 AM, Jan Stolarek <jan.stolarek at>wrote:
>> It seems that currently there are no built-in constant folding rules for
>> Integer div and mod. I plan on adding those rules, but before I do that I
>> wanted to ask whether there is a good reason that these rules don't exist?
> I would guess that Integer arithmetic doesn't affect people's performance
> much, because a lot of people steer away from Integer. I'd be focusing my
> attention on fixed-width numeric types and floating point, as likely to
> have a much larger real-world impact.
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