Don't call getValueType() on a null SDValue

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90415 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 06ffdd6..64331b0 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -546,7 +546,8 @@
         To[0].getNode()->dump(&DAG);
         errs() << " and " << NumTo-1 << " other values\n";
         for (unsigned i = 0, e = NumTo; i != e; ++i)
-          assert(N->getValueType(i) == To[i].getValueType() &&
+          assert((!To[i].getNode() ||
+                  N->getValueType(i) == To[i].getValueType()) &&
                  "Cannot combine value to value of different type!"));
   WorkListRemover DeadNodes(*this);
   DAG.ReplaceAllUsesWith(N, To, &DeadNodes);