[PATCH] D123962: [InstCombine] fold freeze of partial undef/poison vector constants

[Sanjay Patel via Phabricator via llvm-commits]

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We can always replace the undef elements in a vector constant with regular constants to get rid of the freeze:
https://alive2.llvm.org/ce/z/nfRb4F

The select diffs show that we might do better by adjusting the logic for a frozen select condition, but I think those are still improvements.


https://reviews.llvm.org/D123962

Files:
  llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
  llvm/test/Transforms/InstCombine/freeze-phi.ll
  llvm/test/Transforms/InstCombine/freeze.ll
  llvm/test/Transforms/InstCombine/select.ll

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