[PATCH] D117907: [NewGVN] do phi(undef, x) -> x only if x is not poison

[Nuno Lopes via Phabricator via llvm-commits]

nlopes created this revision.
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phi([undef, A], [x, B]) -> x is only correct x is guaranteed to be a non-poison value. Otherwise we would be changing an undef to poison in the branch A.

This patch fixes this bug in NewGVN.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D117907

Files:
  llvm/lib/Transforms/Scalar/NewGVN.cpp
  llvm/test/Transforms/NewGVN/completeness.ll
  llvm/test/Transforms/NewGVN/phi-edge-handling.ll
  llvm/test/Transforms/NewGVN/pr31682.ll
  llvm/test/Transforms/NewGVN/pr32403.ll
  llvm/test/Transforms/NewGVN/pr32838.ll
  llvm/test/Transforms/NewGVN/pr34135.ll

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