[llvm] [PPC][AIX] Save/restore r31 in prolog/epilog when using base pointer (PR #100182)

[Sean Fertile via llvm-commits]

https://github.com/mandlebug commented:

I know this PR has already been approved but would it be possible to instead update the initialization of `HasFP` to include the `Subtarget.isAIXABI()) && RegInfo->hasBasePointer(MF)`, as well as modify the `needsFP` helper function to take `RegInfo` and Subtarget as arguments and put the check of `RegInfo->hasBasePointer(MF) && Subtarget.isAIXABI())` into its body? My worry is that under refactoring or updating we could add a new check that missies the AIX condition. having them in the init/helper-body removes that possibility.

https://github.com/llvm/llvm-project/pull/100182