[PATCH] D46298: AMDGPU: Remove deadcode in isSDNodeSourceOfDivergence()

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added a comment.

In https://reviews.llvm.org/D46298#1110597, @tstellar wrote:

> In https://reviews.llvm.org/D46298#1086262, @alex-t wrote:
>
> > Could you please clarify - why do you consider that check meaningless for r600?
> >  I see that this line :   " const SISubtarget &ST = MF->getSubtarget<SISubtarget>(); "  is misleading and in fact is not correct.
> >  I'd better check and choose the R600Subtarget or SISubtarget.
> >  If I understand right we need just check which subtarget to retrieve for physregs check.
> >
> > Since we consider any VGPR formal argument as divergent it does not matter R600 or SI at all.
> >  We need to choose right TargetRegisterInfo (r600 or SI again)
> >
> > So, for virtual register :    if (MRI.isLiveIn(Reg) && TRI.isVGPR(Reg) )  return true
> >
> > Or I maybe don't know something substantial? :)
>
>
> I would expect the TRI.isVGPR() call to crash if this was called from an R600 code path, so that made me think this was dead code.


I agree isVGPR should be illegal to call for R600


Repository:
  rL LLVM

https://reviews.llvm.org/D46298