Index: llvm/trunk/lib/Analysis/ScalarEvolution.cpp
===================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolution.cpp
+++ llvm/trunk/lib/Analysis/ScalarEvolution.cpp
@@ -6144,7 +6144,7 @@
     // to obey basic rules for definitions dominating uses which this
     // analysis depends on.
     if (!DT.isReachableFromEntry(I->getParent()))
-      return getUnknown(V);
+      return getUnknown(UndefValue::get(V->getType()));
   } else if (ConstantInt *CI = dyn_cast<ConstantInt>(V))
     return getConstant(CI);
   else if (isa<ConstantPointerNull>(V))
Index: llvm/trunk/test/Analysis/ScalarEvolution/unreachable-code.ll
===================================================================
--- llvm/trunk/test/Analysis/ScalarEvolution/unreachable-code.ll
+++ llvm/trunk/test/Analysis/ScalarEvolution/unreachable-code.ll
@@ -1,7 +1,7 @@
 ; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
 
 ; CHECK: %t = add i64 %t, 1
-; CHECK: -->  %t
+; CHECK: -->  undef
 
 define void @foo() {
 entry: