[PATCH] D127495: Don't use the S30 and S31 regs for the pic code .

[Justin Hibbits via Phabricator via llvm-commits]

chmeee added a comment.

I'm not sure of the proper use of S31 in general, since ABI makes r31 the frame pointer in general.  If we stick with only supporting the ABI, and not supporting alternatives, I think S31 should just be removed in general, unless we support omitting the frame pointer.

But I think in general S31 shouldn't be conditional on PIC, since its use is orthogonal.  Maybe a different change?



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Comment at: llvm/lib/Target/PowerPC/PPCCallingConv.td:280
 def CSR_SPE : CalleeSavedRegs<(add S14, S15, S16, S17, S18, S19, S20, S21, S22,
                                    S23, S24, S25, S26, S27, S28, S29, S30, S31
                               )>;
----------------
Should S31 be dropped up here, too?  Or should this remain as the list of all callee saved registers?


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  https://reviews.llvm.org/D127495/new/

https://reviews.llvm.org/D127495