[PATCH] D132939: [TwoAddressInstruction] rewrite INSERT_SUBREG to SUBREG_TO_REG if upper bits zero

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

This transform should be in target-specific code so we can ensure the safety.  (Or it could use a target hook if it really needs to be in TwoAddressInstructionPass for some reason.)


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D132939/new/

https://reviews.llvm.org/D132939