[PATCH] D125657: [RegisterCoalescer] fix dst subreg replacement during remat copy trick

[Quentin Colombet via Phabricator via llvm-commits]

qcolombet added a comment.

Hi @ivafanas,

Any chance you can provide a test case with the patch?
In particular, I'd like to confirm how we end up in this situation. (I suppose we have a copy that fed back to a phi?)

For the record, I believe this problem has been here for ages, because trivial rematerialization has been limited to instruction with no operands for the most part. Put differently, I'm not surprised you're running into bugs like this.
I'm actually surprised your instruction is trivially rematerializable to begin with.

Cheers,
-Quentin


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D125657/new/

https://reviews.llvm.org/D125657