diff --git a/llvm/lib/CodeGen/Analysis.cpp b/llvm/lib/CodeGen/Analysis.cpp
index 8e11fe1..ac0d40e 100644
--- a/llvm/lib/CodeGen/Analysis.cpp
+++ b/llvm/lib/CodeGen/Analysis.cpp
@@ -295,7 +295,8 @@
     } else if (const InsertValueInst *IVI = dyn_cast<InsertValueInst>(V)) {
       // Value may come from either the aggregate or the scalar
       ArrayRef<unsigned> InsertLoc = IVI->getIndices();
-      if (std::equal(InsertLoc.rbegin(), InsertLoc.rend(),
+      assert(ValLoc.size() >= InsertLoc.size() && "extracting too deeply");
+      if (std::equal(InsertLoc.begin(), InsertLoc.end(),
                      ValLoc.rbegin())) {
         // The type being inserted is a nested sub-type of the aggregate; we
         // have to remove those initial indices to get the location we're