[llvm-branch-commits] [llvm] Backport 45d2d7757feb386186f69af6ef57bde7b5adc2db to release/18.x (PR #79839)

[Jay Foad via llvm-branch-commits]

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@@ -6883,6 +6883,23 @@ bool AMDGPULegalizerInfo::legalizeStackSave(MachineInstr &MI,
   return true;
 }
 
+bool AMDGPULegalizerInfo::legalizeWaveID(MachineInstr &MI,
+                                         MachineIRBuilder &B) const {
+  // With architected SGPRs, waveIDinGroup is in TTMP8[29:25].
+  if (!ST.hasArchitectedSGPRs())
+    return false;
+  LLT S32 = LLT::scalar(32);
+  Register DstReg = MI.getOperand(0).getReg();
+  Register TTMP8 =
+      getFunctionLiveInPhysReg(B.getMF(), B.getTII(), AMDGPU::TTMP8,
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jayfoad wrote:

True, 66c710ec9dcdbdec6cadd89b972d8945983dc92f improved this to avoid adding liveins. I wasn't going to bother backporting that since I didn't think it was required for correctness. But I have cherry-picked it into this PR now.

https://github.com/llvm/llvm-project/pull/79839