[PATCH] D139818: [IndVars][NFCI] Avoid supposedly redundant query to save some CT

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev added inline comments.


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Comment at: llvm/lib/Transforms/Scalar/IndVarSimplify.cpp:1388
+  if (SE->isKnownPredicate(Pred, LHSS, RHSS, BI)) {
+    foldExit(L, ExitingBB, /*IsTaken*/ false, DeadInsts);
     return true;
----------------
nikic wrote:
> If I put an `assert(*EV)` here, I get an assertion failure in llvm/test/Transforms/IndVarSimplify/2014-06-21-congruent-constant.ll. So it looks like this can trigger. Unfortunately this is a test chock full of UB, but maybe it's possible to extract a more meaningful test from it?
Failing assertion doesn't mean it can't be optimized by other means, but need more study.


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  https://reviews.llvm.org/D139818/new/

https://reviews.llvm.org/D139818