Index: llvm/utils/TableGen/CodeGenInstruction.cpp
===================================================================
--- llvm.orig/utils/TableGen/CodeGenInstruction.cpp
+++ llvm/utils/TableGen/CodeGenInstruction.cpp
@@ -191,7 +191,7 @@ CGIOperandList::ParseOperandName(const s
       return std::make_pair(OpIdx, i);
 
   // Otherwise, didn't find it!
-  PrintFatalError(TheDef->getName() + ": unknown suboperand name in '" + Op + "'");
+  llvm_unreachable(TheDef->getName() + ": unknown suboperand name in '" + Op + "'");
 }
 
 static void ParseConstraint(const std::string &CStr, CGIOperandList &Ops) {