[llvm] [AMDGPU] Add MachineVerifer check to detect illegal copies from VGPR to SGPR (PR #105494)

[Christudasan Devadasan via llvm-commits]

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@@ -4613,15 +4613,45 @@ static bool isSubRegOf(const SIRegisterInfo &TRI,
          SubReg.getReg() == SuperVec.getReg();
 }
 
+// Verify the illegal copy from VGPR to SGPR for generic opcode COPY
+bool SIInstrInfo::verifyCopy(const MachineInstr &MI,
+                             const MachineRegisterInfo &MRI,
+                             StringRef &ErrInfo) const {
+  const MachineOperand &Dst = MI.getOperand(0);
+  const MachineOperand &Src = MI.getOperand(1);
+
+  Register DstReg = Dst.getReg();
+  Register SrcReg = Src.getReg();
+  // This is a check for copy from an VGPR to SGPR
+  if (RI.isVGPR(MRI, SrcReg) && RI.isSGPRReg(MRI, DstReg)) {
+    ErrInfo = "illegal copy from VGPR to SGPR";
+    return false;
+  }
+
+  // This is a check for copy from an AGPR to SGPR
+  if (RI.isAGPR(MRI, SrcReg) && RI.isSGPRReg(MRI, DstReg)) {
+    ErrInfo = "illegal copy from AGPR to SGPR";
+    return false;
+  }
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cdevadas wrote:

I would prefer a single check with RI.isVectorRegister() that includes both VGPRs and AGPRs. Change the error message to "illegal copy from vector register to SGPR"

https://github.com/llvm/llvm-project/pull/105494