[LLVMdev] ScalarEvolution::createNodeForPHI

[Andrew Trick]

On Oct 2, 2013, at 4:30 PM, Hal Finkel <hfinkel at anl.gov> wrote:

>> I’m not sure how to make sense of an NUW flag coming from a sub.
> 
> I thought that sub nuw a, b just meant that we were allowed to assume that a >= b. No?

That’s a reasonable interpretation. The problem is that we canonicalize to add a, -b. This is a problem in Reassociate and SCEV.

-Andy
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