X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FADT%2FDepthFirstIterator.h;h=644544253ab7d3c9859b734fc987a772a48b393e;hb=b09c146b116359616f6cbd4c8b3328607e00ff42;hp=10ef3f378c86621a24c4abc1624a05e13d330c04;hpb=4846f4b87a31797ba0bc6c96862a1128acf16149;p=oota-llvm.git

diff --git a/include/llvm/ADT/DepthFirstIterator.h b/include/llvm/ADT/DepthFirstIterator.h
index 10ef3f378c8..644544253ab 100644
--- a/include/llvm/ADT/DepthFirstIterator.h
+++ b/include/llvm/ADT/DepthFirstIterator.h
@@ -1,6 +1,13 @@
-//===- Support/DepthFirstIterator.h - Depth First iterator ------*- C++ -*-===//
+//===- llvm/ADT/DepthFirstIterator.h - Depth First iterator -----*- C++ -*-===//
 //
-// This file builds on the Support/GraphTraits.h file to build generic depth
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file builds on the ADT/GraphTraits.h file to build generic depth
 // first graph iterator.  This file exposes the following functions/types:
 //
 // df_begin/df_end/df_iterator
@@ -9,54 +16,139 @@
 // idf_begin/idf_end/idf_iterator
 //   * Depth-first iteration on the 'inverse' graph.
 //
+// df_ext_begin/df_ext_end/df_ext_iterator
+//   * Normal depth-first iteration - visit a node and then all of its children.
+//     This iterator stores the 'visited' set in an external set, which allows
+//     it to be more efficient, and allows external clients to use the set for
+//     other purposes.
+//
+// idf_ext_begin/idf_ext_end/idf_ext_iterator
+//   * Depth-first iteration on the 'inverse' graph.
+//     This iterator stores the 'visited' set in an external set, which allows
+//     it to be more efficient, and allows external clients to use the set for
+//     other purposes.
+//
 //===----------------------------------------------------------------------===//
 
-#ifndef SUPPORT_DEPTHFIRSTITERATOR_H
-#define SUPPORT_DEPTHFIRSTITERATOR_H
+#ifndef LLVM_ADT_DEPTHFIRSTITERATOR_H
+#define LLVM_ADT_DEPTHFIRSTITERATOR_H
 
-#include "Support/GraphTraits.h"
-#include "Support/iterator"
-#include <vector>
+#include "llvm/ADT/GraphTraits.h"
+#include "llvm/ADT/PointerIntPair.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include <set>
+#include <vector>
+
+namespace llvm {
+
+// df_iterator_storage - A private class which is used to figure out where to
+// store the visited set.
+template<class SetType, bool External>   // Non-external set
+class df_iterator_storage {
+public:
+  SetType Visited;
+};
+
+template<class SetType>
+class df_iterator_storage<SetType, true> {
+public:
+  df_iterator_storage(SetType &VSet) : Visited(VSet) {}
+  df_iterator_storage(const df_iterator_storage &S) : Visited(S.Visited) {}
+  SetType &Visited;
+};
+
 
 // Generic Depth First Iterator
-template<class GraphT, class GT = GraphTraits<GraphT> >
-class df_iterator : public forward_iterator<typename GT::NodeType, ptrdiff_t> {
-  typedef forward_iterator<typename GT::NodeType, ptrdiff_t> super;
+template<class GraphT,
+class SetType = llvm::SmallPtrSet<typename GraphTraits<GraphT>::NodeType*, 8>,
+         bool ExtStorage = false, class GT = GraphTraits<GraphT> >
+class df_iterator : public std::iterator<std::forward_iterator_tag,
+                                         typename GT::NodeType, ptrdiff_t>,
+                    public df_iterator_storage<SetType, ExtStorage> {
+  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;
 
-  std::set<NodeType *> Visited;    // All of the blocks visited so far...
   // 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) {
-    Visited.insert(Node);
-    VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node)));
+    this->Visited.insert(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(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);
+    }
+  }
+  inline df_iterator(SetType &S)
+    : df_iterator_storage<SetType, ExtStorage>(S) {
+    // 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());
   }
-  inline df_iterator() { /* End is when stack is empty */ }
 
 public:
   typedef typename super::pointer pointer;
-  typedef df_iterator<GraphT, GT> _Self;
+  typedef df_iterator<GraphT, SetType, ExtStorage, GT> _Self;
 
   // Provide static begin and end methods as our public "constructors"
-  static inline _Self begin(GraphT G) {
+  static inline _Self begin(const GraphT& G) {
     return _Self(GT::getEntryNode(G));
   }
-  static inline _Self end(GraphT G) { return _Self(); }
+  static inline _Self end(const GraphT& G) { return _Self(); }
 
+  // Static begin and end methods as our public ctors for external iterators
+  static inline _Self begin(const GraphT& G, SetType &S) {
+    return _Self(GT::getEntryNode(G), S);
+  }
+  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;
+  inline bool operator==(const _Self& x) const {
+    return VisitStack == x.VisitStack;
   }
   inline bool operator!=(const _Self& x) const { return !operator==(x); }
 
-  inline pointer operator*() const { 
-    return VisitStack.back().first;
+  inline pointer operator*() const {
+    return VisitStack.back().first.getPointer();
   }
 
   // This is a nonstandard operator-> that dereferences the pointer an extra
@@ -66,37 +158,39 @@ 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 (!Visited.count(Next)) {  // Has our next sibling been visited?
-          // No, do it now.
-          Visited.insert(Next);
-          VisitStack.push_back(std::make_pair(Next, GT::child_begin(Next)));
-          return *this;
-        }
-      }
-      
-      // Oops, ran out of successors... go up a level on the stack.
-      VisitStack.pop_back();
-    } while (!VisitStack.empty());
-    return *this; 
+    toNext();
+    return *this;
+  }
+
+  // skips all children of the current node and traverses to next node
+  //
+  inline _Self& skipChildren() {  
+    VisitStack.pop_back();
+    if (!VisitStack.empty())
+      toNext();
+    return *this;
   }
 
   inline _Self operator++(int) { // Postincrement
-    _Self tmp = *this; ++*this; return tmp; 
+    _Self tmp = *this; ++*this; return tmp;
   }
 
   // nodeVisited - return true if this iterator has already visited the
   // specified node.  This is public, and will probably be used to iterate over
   // nodes that a depth first iteration did not find: ie unreachable nodes.
   //
-  inline bool nodeVisited(NodeType *Node) const { 
-    return Visited.count(Node) != 0;
+  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();
   }
 };
 
@@ -104,29 +198,71 @@ public:
 // Provide global constructors that automatically figure out correct types...
 //
 template <class T>
-df_iterator<T> df_begin(T G) {
+df_iterator<T> df_begin(const T& G) {
   return df_iterator<T>::begin(G);
 }
 
 template <class T>
-df_iterator<T> df_end(T G) {
+df_iterator<T> df_end(const T& G) {
   return df_iterator<T>::end(G);
 }
 
+// Provide global definitions of external depth first iterators...
+template <class T, class SetTy = std::set<typename GraphTraits<T>::NodeType*> >
+struct df_ext_iterator : public df_iterator<T, SetTy, true> {
+  df_ext_iterator(const df_iterator<T, SetTy, true> &V)
+    : df_iterator<T, SetTy, true>(V) {}
+};
+
+template <class T, class SetTy>
+df_ext_iterator<T, SetTy> df_ext_begin(const T& G, SetTy &S) {
+  return df_ext_iterator<T, SetTy>::begin(G, S);
+}
+
+template <class T, class SetTy>
+df_ext_iterator<T, SetTy> df_ext_end(const T& G, SetTy &S) {
+  return df_ext_iterator<T, SetTy>::end(G, S);
+}
+
+
 // Provide global definitions of inverse depth first iterators...
-template <class T>
-struct idf_iterator : public df_iterator<Inverse<T> > {
-  idf_iterator(const df_iterator<Inverse<T> > &V) :df_iterator<Inverse<T> >(V){}
+template <class T,
+  class SetTy = llvm::SmallPtrSet<typename GraphTraits<T>::NodeType*, 8>,
+          bool External = false>
+struct idf_iterator : public df_iterator<Inverse<T>, SetTy, External> {
+  idf_iterator(const df_iterator<Inverse<T>, SetTy, External> &V)
+    : df_iterator<Inverse<T>, SetTy, External>(V) {}
 };
 
 template <class T>
-idf_iterator<T> idf_begin(T G) {
-  return idf_iterator<T>::begin(G);
+idf_iterator<T> idf_begin(const T& G) {
+  return idf_iterator<T>::begin(Inverse<T>(G));
 }
 
 template <class T>
-idf_iterator<T> idf_end(T G){
-  return idf_iterator<T>::end(G);
+idf_iterator<T> idf_end(const T& G){
+  return idf_iterator<T>::end(Inverse<T>(G));
+}
+
+// Provide global definitions of external inverse depth first iterators...
+template <class T, class SetTy = std::set<typename GraphTraits<T>::NodeType*> >
+struct idf_ext_iterator : public idf_iterator<T, SetTy, true> {
+  idf_ext_iterator(const idf_iterator<T, SetTy, true> &V)
+    : idf_iterator<T, SetTy, true>(V) {}
+  idf_ext_iterator(const df_iterator<Inverse<T>, SetTy, true> &V)
+    : idf_iterator<T, SetTy, true>(V) {}
+};
+
+template <class T, class SetTy>
+idf_ext_iterator<T, SetTy> idf_ext_begin(const T& G, SetTy &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) {
+  return idf_ext_iterator<T, SetTy>::end(Inverse<T>(G), S);
 }
 
+} // End llvm namespace
+
 #endif