Fix copy from physreg

Author: arsenm

llvm/lib/Target/AMDGPU/AMDGPURewriteAGPRCopyMFMA.cpp

@@ -128,10 +128,11 @@ bool AMDGPURewriteAGPRCopyMFMAImpl::run(MachineFunction &MF) const {
         continue;
 
       Register CopySrcReg = DefMI->getOperand(1).getReg();
-      LiveInterval &CopySrcLI = LIS.getInterval(CopySrcReg);
+      if (!CopySrcReg.isVirtual())
+        continue;
 
+      LiveInterval &CopySrcLI = LIS.getInterval(CopySrcReg);
       LiveQueryResult LRQ = CopySrcLI.Query(VNI->def.getRegSlot());
-
       MachineInstr *CopySrcMI = LIS.getInstructionFromIndex(LRQ.valueIn()->def);
       if (!CopySrcMI)
         continue;