1 files changed, 8 insertions, 6 deletions

diff --git a/include/llvm/Support/GenericDomTree.h b/include/llvm/Support/GenericDomTree.h
index 63678bb98bb1..8751f272cd29 100644
--- a/include/llvm/Support/GenericDomTree.h
+++ b/include/llvm/Support/GenericDomTree.h
@@ -371,8 +371,9 @@ public:
   void releaseMemory() { reset(); }
 
   /// getNode - return the (Post)DominatorTree node for the specified basic
-  /// block.  This is the same as using operator[] on this class.
-  ///
+  /// block.  This is the same as using operator[] on this class.  The result
+  /// may (but is not required to) be null for a forward (backwards)
+  /// statically unreachable block.
   DomTreeNodeBase<NodeT> *getNode(NodeT *BB) const {
     auto I = DomTreeNodes.find(BB);
     if (I != DomTreeNodes.end())
@@ -380,6 +381,7 @@ public:
     return nullptr;
   }
 
+  /// See getNode.
   DomTreeNodeBase<NodeT> *operator[](NodeT *BB) const { return getNode(BB); }
 
   /// getRootNode - This returns the entry node for the CFG of the function.  If
@@ -732,13 +734,13 @@ public:
       for (typename TraitsTy::nodes_iterator I = TraitsTy::nodes_begin(&F),
                                              E = TraitsTy::nodes_end(&F);
            I != E; ++I) {
-        if (TraitsTy::child_begin(I) == TraitsTy::child_end(I))
-          addRoot(I);
+        if (TraitsTy::child_begin(&*I) == TraitsTy::child_end(&*I))
+          addRoot(&*I);
 
         // Prepopulate maps so that we don't get iterator invalidation issues
         // later.
-        this->IDoms[I] = nullptr;
-        this->DomTreeNodes[I] = nullptr;
+        this->IDoms[&*I] = nullptr;
+        this->DomTreeNodes[&*I] = nullptr;
       }
 
       Calculate<FT, Inverse<NodeT *>>(*this, F);