diff --git a/lib/Target/X86/X86CodeEmitter.cpp b/lib/Target/X86/X86CodeEmitter.cpp
index ef2255de19c..84772ea72fc 100644
--- a/lib/Target/X86/X86CodeEmitter.cpp
+++ b/lib/Target/X86/X86CodeEmitter.cpp
@@ -702,6 +702,7 @@ void Emitter<CodeEmitter>::emitInstruction(const MachineInstr &MI,
     // base address.
     switch (Opcode) {
     default: 
+    MI.dump();
       llvm_unreachable("psuedo instructions should be removed before code"
                        " emission");
       break;