Merge commit 'ed65140d3fb1' from apple/main into swift/next

Author: git apple-llvm automerger

llvm/lib/Target/AMDGPU/SIInstrInfo.cpp

@@ -4303,10 +4303,13 @@ bool SIInstrInfo::isLegalRegOperand(const MachineRegisterInfo &MRI,
     return false;
 
   Register Reg = MO.getReg();
-  const TargetRegisterClass *RC =
-      Reg.isVirtual() ? MRI.getRegClass(Reg) : RI.getPhysRegClass(Reg);
 
   const TargetRegisterClass *DRC = RI.getRegClass(OpInfo.RegClass);
+  if (Reg.isPhysical())
+    return DRC->contains(Reg);
+
+  const TargetRegisterClass *RC = MRI.getRegClass(Reg);
+
   if (MO.getSubReg()) {
     const MachineFunction *MF = MO.getParent()->getParent()->getParent();
     const TargetRegisterClass *SuperRC = RI.getLargestLegalSuperClass(RC, *MF);