[PATCH] D157564: [MCP] Invalidate copy for super register in copy source

Thu Aug 10 13:52:58 PDT 2023

jrbyrnes added inline comments.

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Comment at: llvm/lib/CodeGen/MachineCopyPropagation.cpp:191-192

     MCRegister Src = CopyOperands->Source->getReg().asMCReg();
     MCRegister Def = CopyOperands->Destination->getReg().asMCReg();

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arsenm wrote:
> Can we track all of this in regunits? Following registers is way more confusing
There are many places that use register MCRegister equality / `isSubRegisterEq` on CopyOperands->Destination / Source. In order to prove equality for regunits, we would need to iteratively do set equality which seems like it would make things more complicated. Maybe I've missed something?

Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D157564/new/

https://reviews.llvm.org/D157564