X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FADT%2FDepthFirstIterator.h;h=519b18052b6dcba924b30ae5a6c75a3e53785e89;hb=ac39a035351a20928e087617e412aa6ce510181f;hp=7dba378cf14a365801a6e96d3f6cd9245055b087;hpb=7ed47a13356daed2a34cd2209a31f92552e3bdd8;p=oota-llvm.git

diff --git a/include/llvm/ADT/DepthFirstIterator.h b/include/llvm/ADT/DepthFirstIterator.h
index 7dba378cf14..519b18052b6 100644
--- a/include/llvm/ADT/DepthFirstIterator.h
+++ b/include/llvm/ADT/DepthFirstIterator.h
@@ -34,10 +34,10 @@
 #define LLVM_ADT_DEPTHFIRSTITERATOR_H
 
 #include "llvm/ADT/GraphTraits.h"
-#include "llvm/ADT/iterator"
 #include "llvm/ADT/SmallPtrSet.h"
-#include <vector>
+#include "llvm/ADT/PointerIntPair.h"
 #include <set>
+#include <vector>
 
 namespace llvm {
 
@@ -62,28 +62,35 @@ public:
 template<class GraphT,
 class SetType = llvm::SmallPtrSet<typename GraphTraits<GraphT>::NodeType*, 8>,
          bool ExtStorage = false, class GT = GraphTraits<GraphT> >
-class df_iterator : public forward_iterator<typename GT::NodeType, ptrdiff_t>,
+class df_iterator : public std::iterator<std::forward_iterator_tag,
+                                         typename GT::NodeType, ptrdiff_t>,
                     public df_iterator_storage<SetType, ExtStorage> {
-  typedef forward_iterator<typename GT::NodeType, ptrdiff_t> super;
+  typedef std::iterator<std::forward_iterator_tag,
+                        typename GT::NodeType, ptrdiff_t> super;
 
   typedef typename GT::NodeType          NodeType;
   typedef typename GT::ChildIteratorType ChildItTy;
+  typedef PointerIntPair<NodeType*, 1>   PointerIntTy;
 
   // VisitStack - Used to maintain the ordering.  Top = current block
   // First element is node pointer, second is the 'next child' to visit
-  std::vector<std::pair<NodeType *, ChildItTy> > VisitStack;
+  // if the int in PointerIntTy is 0, the 'next child' to visit is invalid
+  std::vector<std::pair<PointerIntTy, ChildItTy> > VisitStack;
 private:
   inline df_iterator(NodeType *Node) {
     this->Visited.insert(Node);
-    VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node)));
+    VisitStack.push_back(std::make_pair(PointerIntTy(Node, 0), 
+                                        GT::child_begin(Node)));
+  }
+  inline df_iterator() { 
+    // End is when stack is empty 
   }
-  inline df_iterator() { /* End is when stack is empty */ }
-
   inline df_iterator(NodeType *Node, SetType &S)
     : df_iterator_storage<SetType, ExtStorage>(S) {
     if (!S.count(Node)) {
+      VisitStack.push_back(std::make_pair(PointerIntTy(Node, 0), 
+                                          GT::child_begin(Node)));
       this->Visited.insert(Node);
-      VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node)));
     }
   }
   inline df_iterator(SetType &S)
@@ -91,6 +98,34 @@ private:
     // End is when stack is empty
   }
 
+  inline void toNext() {
+    do {
+      std::pair<PointerIntTy, ChildItTy> &Top = VisitStack.back();
+      NodeType *Node = Top.first.getPointer();
+      ChildItTy &It  = Top.second;
+      if (!Top.first.getInt()) {
+        // now retrieve the real begin of the children before we dive in
+        It = GT::child_begin(Node);
+        Top.first.setInt(1);
+      }
+
+      while (It != GT::child_end(Node)) {
+        NodeType *Next = *It++;
+        // Has our next sibling been visited?
+        if (Next && !this->Visited.count(Next)) {  
+          // No, do it now.
+          this->Visited.insert(Next);
+          VisitStack.push_back(std::make_pair(PointerIntTy(Next, 0), 
+                                              GT::child_begin(Next)));
+          return;
+        }
+      }
+
+      // Oops, ran out of successors... go up a level on the stack.
+      VisitStack.pop_back();
+    } while (!VisitStack.empty());
+  }
+
 public:
   typedef typename super::pointer pointer;
   typedef df_iterator<GraphT, SetType, ExtStorage, GT> _Self;
@@ -108,13 +143,12 @@ public:
   static inline _Self end(const GraphT& G, SetType &S) { return _Self(S); }
 
   inline bool operator==(const _Self& x) const {
-    return VisitStack.size() == x.VisitStack.size() &&
-           VisitStack == x.VisitStack;
+    return VisitStack == x.VisitStack;
   }
   inline bool operator!=(const _Self& x) const { return !operator==(x); }
 
   inline pointer operator*() const {
-    return VisitStack.back().first;
+    return VisitStack.back().first.getPointer();
   }
 
   // This is a nonstandard operator-> that dereferences the pointer an extra
@@ -124,24 +158,16 @@ public:
   inline NodeType *operator->() const { return operator*(); }
 
   inline _Self& operator++() {   // Preincrement
-    do {
-      std::pair<NodeType *, ChildItTy> &Top = VisitStack.back();
-      NodeType *Node = Top.first;
-      ChildItTy &It  = Top.second;
-
-      while (It != GT::child_end(Node)) {
-        NodeType *Next = *It++;
-        if (!this->Visited.count(Next)) {  // Has our next sibling been visited?
-          // No, do it now.
-          this->Visited.insert(Next);
-          VisitStack.push_back(std::make_pair(Next, GT::child_begin(Next)));
-          return *this;
-        }
-      }
+    toNext();
+    return *this;
+  }
 
-      // Oops, ran out of successors... go up a level on the stack.
-      VisitStack.pop_back();
-    } while (!VisitStack.empty());
+  // skips all children of the current node and traverses to next node
+  //
+  inline _Self& skipChildren() {  
+    VisitStack.pop_back();
+    if (!VisitStack.empty())
+      toNext();
     return *this;
   }
 
@@ -156,6 +182,16 @@ public:
   inline bool nodeVisited(NodeType *Node) const {
     return this->Visited.count(Node) != 0;
   }
+
+  /// getPathLength - Return the length of the path from the entry node to the
+  /// current node, counting both nodes.
+  unsigned getPathLength() const { return VisitStack.size(); }
+
+  /// getPath - Return the n'th node in the path from the entry node to the
+  /// current node.
+  NodeType *getPath(unsigned n) const {
+    return VisitStack[n].first.getPointer();
+  }
 };
 
 
@@ -200,14 +236,12 @@ struct idf_iterator : public df_iterator<Inverse<T>, SetTy, External> {
 
 template <class T>
 idf_iterator<T> idf_begin(const T& G) {
-  Inverse<T> DummyG;
-  return idf_iterator<T>::begin(DummyG);
+  return idf_iterator<T>::begin(Inverse<T>(G));
 }
 
 template <class T>
 idf_iterator<T> idf_end(const T& G){
-  Inverse<T> DummyG;
-  return idf_iterator<T>::end(DummyG);
+  return idf_iterator<T>::end(Inverse<T>(G));
 }
 
 // Provide global definitions of external inverse depth first iterators...
@@ -221,14 +255,12 @@ struct idf_ext_iterator : public idf_iterator<T, SetTy, true> {
 
 template <class T, class SetTy>
 idf_ext_iterator<T, SetTy> idf_ext_begin(const T& G, SetTy &S) {
-  Inverse<T> DummyG(G);
-  return idf_ext_iterator<T, SetTy>::begin(DummyG, S);
+  return idf_ext_iterator<T, SetTy>::begin(Inverse<T>(G), S);
 }
 
 template <class T, class SetTy>
 idf_ext_iterator<T, SetTy> idf_ext_end(const T& G, SetTy &S) {
-  Inverse<T> DummyG(G);
-  return idf_ext_iterator<T, SetTy>::end(DummyG, S);
+  return idf_ext_iterator<T, SetTy>::end(Inverse<T>(G), S);
 }
 
 } // End llvm namespace