[PATCH] D48102: Improve handling of COPY instructions with identical value numbers

[Krzysztof Parzyszek via Phabricator via llvm-commits]

kparzysz added a comment.

My fix for the redef/undef issue was trying to avoid cases where we treat "undef" values from different registers as identical.  I guess this could be relaxed (i.e. we can treat all undef values as identical), but we'd have to make sure that this equality is only used to allow removing an undef value (i.e. to allow pruning it without following it with extendToIndices).


Repository:
  rL LLVM

https://reviews.llvm.org/D48102