[PATCH] D60650: [LVI][CVP] Constrain values in with.overflow branches

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
nikic added reviewers: spatel, lebedev.ri, sanjoy.
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If a branch is conditional on `extractvalue(op.with.overflow(%x, C), 1)` then we can constrain the value of %x inside the branch based on makeGuaranteedNoWrapRegion(). We do this by extending the edge-value handling in LVI. This allows CVP to then fold comparisons against %x, as illustrated in the tests.


Repository:
  rL LLVM

https://reviews.llvm.org/D60650

Files:
  llvm/lib/Analysis/LazyValueInfo.cpp
  llvm/test/Transforms/CorrelatedValuePropagation/overflow_predicate.ll

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