[PATCH] D93403: AMDGPU: Remove SGPRSpillVGPRDefinedSet hack

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


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Comment at: llvm/lib/Target/AMDGPU/SILowerSGPRSpills.cpp:391
+  // Updated the reserved registers with any VGPRs added for SGPR spills.
+  if (NewReservedRegs)
+    MRI.freezeReservedRegs(MF);
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scott.linder wrote:
> Why is this `bool` needed? It seems like freezing the reserved regs is idempotent anyway. If anything I'd expect to just see `assert(MRI.reservedRegsFrozen())` to ensure you aren't running before regalloc, but maybe that's redundant?
reservedRegsFrozen is too stupid, it just checks if there are any reserved regs. I actually think that it's a fairly broken concept we should remove, or at least make an explicit property.

This is also one of those cases that's actually fairly expensive given the number of register tuples we have (I would like to reframe this in terms of frozen reg units, but haven't gotten around do fixing that)


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D93403/new/

https://reviews.llvm.org/D93403