[PATCH] D29448: [RegAlloc] Don’t freeze reserved registers again if it is not necessary

[Volkan Keles via Phabricator via llvm-commits]

volkan added a comment.

In https://reviews.llvm.org/D29448#672445, @qcolombet wrote:

> What happen if we just freeze in the regalloc code?
>  Basically, are there any other pass that needs to know about that?


Yes, this cause a lot of failures. DeadMachineInstructionElim, LiveVariables and MachineVerifier use reserved register.


https://reviews.llvm.org/D29448