[PATCH] D156345: RegisterCoalescer: Add implicit-def of super register when coalescing SUBREG_TO_REG

Fri Jul 28 04:12:45 PDT 2023

arsenm added a comment.

In D156345#4541601 <https://reviews.llvm.org/D156345#4541601>, @qcolombet wrote:

>> This does not yet fix the regression. The isCopyInstr handling needs to start handling implicit-defs on any instruction.
>
> What do you mean here?

I mean this stack of patches is really 2 pieces, with supporting changes. This is part 1, D156346 <https://reviews.llvm.org/D156346> is part 2 which stops considering MOV with implicit-def as a simple copy

> In my mind, if we have implicit defs on a copy, then we should probably not consider the related instruction as a copy to begin with.

That's the net effect of D156346 <https://reviews.llvm.org/D156346> (except for COPY proper)

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D156345/new/

https://reviews.llvm.org/D156345