[PATCH] D71390: [PowerPC] Modify the hasSideEffects of MTLR and MFLR from 1 to 0

[Kai Luo via Phabricator via llvm-commits]

lkail added a comment.

Seems currently we haven't modeled `mtlr` correctly. In `PPCFrameLowering`

  if (MustSaveLR)
    BuildMI(MBB, StackUpdateLoc, dl, MTLRInst).addReg(ScratchReg);

We might lack a `implicit-def` of `$lr` here. As a result, we might get wrong code if set `hasSideEffect = 0` for `mtlr`. What do you think?


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https://reviews.llvm.org/D71390