[PATCH] D124930: [DagCombine] Fold (X & ~Y) | Y with truncated not

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
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This extends the `(X & ~Y) | Y` to `X | Y` fold to also work if `~Y` is a truncated not (when taking into account the mask `X`). This is done by exporting the infrastructure added in D124856 <https://reviews.llvm.org/D124856> and reusing it here.

I've retained the old value of `AllowUndefs=false`, though probably this can be switched to true with extra test coverage.


https://reviews.llvm.org/D124930

Files:
  llvm/include/llvm/CodeGen/SelectionDAGNodes.h
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  llvm/test/CodeGen/X86/add-and-not.ll

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