[PATCH] D100566: [SCEV] Add a ad-hoc pattern on isImpliedCondBalancedTypes

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

This needs better test coverage for the various conditions in the code, like step sign, nowrap flags, possibly predicates. Either as IR test cases, or as unit tests.



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Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:10468
+      if (StepCst && (AddRec->getNoWrapFlags(SCEV::FlagNSW) ||
+                      AddRec->getNoWrapFlags(SCEV::FlagNUW))) {
+        if (!StepCst->getValue()->isNegative()) {
----------------
As you are working with signed predicates here, you need nsw. nuw is not enough. Of course, you could handle the analogous case with unsigned predicates, in which case you need nuw (and only nuw, the step sign doesn't matter in that case).


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  https://reviews.llvm.org/D100566/new/

https://reviews.llvm.org/D100566