X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FGenericDomTree.h;h=8bae582d18c750ae828bed0e948b66f25e43046b;hb=HEAD;hp=5d11766ef44a52f7634bf6115bd23b7fb909e521;hpb=5d6f997e0a4ed5baf58f600b5230dec9bdac736a;p=oota-llvm.git

diff --git a/include/llvm/Support/GenericDomTree.h b/include/llvm/Support/GenericDomTree.h
index 5d11766ef44..8bae582d18c 100644
--- a/include/llvm/Support/GenericDomTree.h
+++ b/include/llvm/Support/GenericDomTree.h
@@ -243,6 +243,8 @@ protected:
     this->Roots.clear();
     Vertex.clear();
     RootNode = nullptr;
+    DFSInfoValid = false;
+    SlowQueries = 0;
   }
 
   // NewBB is split and now it has one successor. Update dominator tree to
@@ -369,8 +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())
@@ -378,6 +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
@@ -663,6 +667,12 @@ public:
   /// updateDFSNumbers - Assign In and Out numbers to the nodes while walking
   /// dominator tree in dfs order.
   void updateDFSNumbers() const {
+
+    if (DFSInfoValid) {
+      SlowQueries = 0;
+      return;
+    }
+
     unsigned DFSNum = 0;
 
     SmallVector<std::pair<const DomTreeNodeBase<NodeT> *,
@@ -714,24 +724,16 @@ public:
     if (!this->IsPostDominators) {
       // Initialize root
       NodeT *entry = TraitsTy::getEntryNode(&F);
-      this->Roots.push_back(entry);
-      this->IDoms[entry] = nullptr;
-      this->DomTreeNodes[entry] = nullptr;
+      addRoot(entry);
 
       Calculate<FT, NodeT *>(*this, F);
     } else {
       // Initialize the roots list
       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);
-
-        // Prepopulate maps so that we don't get iterator invalidation issues
-        // later.
-        this->IDoms[I] = nullptr;
-        this->DomTreeNodes[I] = nullptr;
-      }
+           I != E; ++I)
+        if (TraitsTy::child_begin(&*I) == TraitsTy::child_end(&*I))
+          addRoot(&*I);
 
       Calculate<FT, Inverse<NodeT *>>(*this, F);
     }