[PATCH] D48032: [RegisterCoalescer] Avoid erasing copy that breaks subranges

[Krzysztof Parzyszek via Phabricator via llvm-commits]

kparzysz added a comment.

What exactly is done wrong in the testcase without your change?  I see one extra IMPLICIT_DEF in the output, compared to running it with your change.

Updating live ranges should work correctly, disabling erasing copies is not the right thing to do.

Could you run the input through -run-pass=none first?  It will produce a slightly better-looking .mir.


Repository:
  rL LLVM

https://reviews.llvm.org/D48032