[PATCH] D113035: [InstCombine] enhance vector bitwise select matching

[Sanjay Patel via Phabricator via llvm-commits]

spatel created this revision.
spatel added reviewers: lebedev.ri, RKSimon, nlopes.
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(Cond & C) | (~bitcast(Cond) & D) --> bitcast (select Cond, (bc C), (bc D))

This is part of fixing:
https://llvm.org/PR34047

That report shows a case where a bitcast is sitting between the select condition candidate and its 'not' value due to current cast canonicalization rules.
There's a restriction that might be violated in existing matching, but I still need to investigate if that is possible -
Alive2 shows we can only do this transform safely when the bitcast is from narrow to wide vector elements:
https://alive2.llvm.org/ce/z/Hf66qh


https://reviews.llvm.org/D113035

Files:
  llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
  llvm/test/Transforms/InstCombine/logical-select.ll

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