diff --git a/llvm/include/llvm/Support/GenericDomTree.h b/llvm/include/llvm/Support/GenericDomTree.h
--- a/llvm/include/llvm/Support/GenericDomTree.h
+++ b/llvm/include/llvm/Support/GenericDomTree.h
@@ -473,7 +473,7 @@
     // If either A or B is a entry block then it is nearest common dominator
     // (for forward-dominators).
     if (!isPostDominator()) {
-      NodeT &Entry = A->getParent()->front();
+      NodeT &Entry = *GraphTraits<NodeT *>::getEntryNode(A);
       if (A == &Entry || B == &Entry)
         return &Entry;
     }
diff --git a/llvm/lib/Transforms/Vectorize/VPlan.h b/llvm/lib/Transforms/Vectorize/VPlan.h
--- a/llvm/lib/Transforms/Vectorize/VPlan.h
+++ b/llvm/lib/Transforms/Vectorize/VPlan.h
@@ -2111,12 +2111,6 @@
     EntryBlock->setParent(this);
   }
 
-  // FIXME: DominatorTreeBase is doing 'A->getParent()->front()'. 'front' is a
-  // specific interface of llvm::Function, instead of using
-  // GraphTraints::getEntryNode. We should add a new template parameter to
-  // DominatorTreeBase representing the Graph type.
-  VPBlockBase &front() const { return *Entry; }
-
   const VPBlockBase *getExiting() const { return Exiting; }
   VPBlockBase *getExiting() { return Exiting; }