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[SCEV] Use isKnownViaNonRecursiveReasoning for smax simplification
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Authored by loladiro on Apr 25 2019, 6:13 PM.

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Commit
rL331949: SCEV] Do not use induction in isKnownPredicate for simplification umax

changed the codepath for umax from isKnownPredicate to
isKnownViaNonRecursiveReasoning to avoid compile time blow up (and as
I found out also stack overflows). However, there is an exact copy of
the code for umax that was lacking this change. In D50167 I want to unify
these codepaths, but to avoid that being a behavior change for the smax
case, pull this independent bit out of it.

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rL LLVM

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loladiro created this revision.Apr 25 2019, 6:13 PM
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sanjoy accepted this revision.Apr 28 2019, 12:39 PM

and as I found out also stack overflows

For posterity, do you have some example IR and/or stack traces that you could attach to the commit message, or make a test case out of?

This revision is now accepted and ready to land.Apr 28 2019, 12:39 PM

and as I found out also stack overflows

For posterity, do you have some example IR and/or stack traces that you could attach to the commit message, or make a test case out of?

I looked around in my notes from back when I did that patch, but doesn't look like I recorded it. I think all I did was try changing umax back to isKnownPredicate and running the test suite.

This revision was automatically updated to reflect the committed changes.