[PATCH] D122166: [InstCombine] try to narrow shifted bswap-of-zext

[Sanjay Patel via Phabricator via llvm-commits]

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This is the IR counterpart to 370ebc9d9a573d6 <https://reviews.llvm.org/rG370ebc9d9a573d6a0bcb0d7c3e0a57d55b7a7673> which provided a bswap narrowing fix for issue #53867.

Here we can be more general (although I'm not sure yet what would happen for illegal types in codegen - too rare to worry about?):
https://alive2.llvm.org/ce/z/3-CPfo

This assumes that we have moved the shift after the bswap as proposed in D122010 <https://reviews.llvm.org/D122010>.


https://reviews.llvm.org/D122166

Files:
  llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
  llvm/test/Transforms/InstCombine/lshr.ll

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