[PATCH] D124168: DeadMachineInstructionElim: Switch to using LiveRegUnits

[Matthias Braun via Phabricator via llvm-commits]

MatzeB added a comment.

I don't know what the state of this is nowadays, but doesn't this risk problems with the old problem of `XMM` and `YMM` not being differentiated within the register units? On windows XMM registers are preserved but YMM register are clobbered. With this change we would likely register XMM and YMM as clobbered. I haven't thought things through here, is this pass still safe with this in mind?


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  https://reviews.llvm.org/D124168/new/

https://reviews.llvm.org/D124168