[PATCH] D124185: [DAG] Fold freeze(bitcast(x)) -> bitcast(freeze(x))

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon created this revision.
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This is a very specific fold to fix an upstream poor codegen issue.

InstCombine has the much more flexible pushFreezeToPreventPoisonFromPropagating but I don't think we're quite there with DAG/TLI handling for canCreateUndefOrPoison/isGuaranteedNotToBeUndefOrPoison value tracking yet.

Fixes #54911


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D124185

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/test/CodeGen/X86/bitcast-int-to-vector-bool.ll

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