Print undefined/unknown debug value as "undef".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107818 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp b/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
index 44c8a51..717614f 100644
--- a/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
+++ b/lib/Target/X86/AsmPrinter/X86MCInstLower.cpp
@@ -505,7 +505,12 @@
   O << V.getName();
   O << " <- ";
   // Frame address.  Currently handles register +- offset only.
-  O << '['; printOperand(MI, 0, O); O << '+'; printOperand(MI, 3, O);
+  O << '['; 
+  if (MI->getOperand(0).isReg() && MI->getOperand(0).getReg())
+    printOperand(MI, 0, O); 
+  else
+    O << "undef";
+  O << '+'; printOperand(MI, 3, O);
   O << ']';
   O << "+";
   printOperand(MI, NOps-2, O);