diff --git a/llvm/lib/Target/X86/X86InstrInfo.cpp b/llvm/lib/Target/X86/X86InstrInfo.cpp
--- a/llvm/lib/Target/X86/X86InstrInfo.cpp
+++ b/llvm/lib/Target/X86/X86InstrInfo.cpp
@@ -6409,7 +6409,7 @@
   case X86::CMP8ri: {
     MachineOperand &MO0 = DataMI->getOperand(0);
     MachineOperand &MO1 = DataMI->getOperand(1);
-    if (MO1.getImm() == 0) {
+    if (MO1.isImm() && MO1.getImm() == 0) {
       unsigned NewOpc;
       switch (DataMI->getOpcode()) {
       default: llvm_unreachable("Unreachable!");