X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FADT%2FDepthFirstIterator.h;h=c9317b8539b38175c826adb891c1a820c722bb67;hb=5e7bb43066143d35d57dee88a113d56bdc9375c8;hp=2961497adc3f6dcc067c5600e968747681f83fb2;hpb=697954c15da58bd8b186dbafdedd8b06db770201;p=oota-llvm.git

diff --git a/include/llvm/ADT/DepthFirstIterator.h b/include/llvm/ADT/DepthFirstIterator.h
index 2961497adc3..c9317b8539b 100644
--- a/include/llvm/ADT/DepthFirstIterator.h
+++ b/include/llvm/ADT/DepthFirstIterator.h
@@ -1,147 +1,291 @@
-//===- 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
-// first graph iterator.
+//                     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
+//   * Normal depth-first iteration - visit a node and then all of its children.
+//
+// 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 LLVM_SUPPORT_DEPTH_FIRST_ITERATOR_H
-#define LLVM_SUPPORT_DEPTH_FIRST_ITERATOR_H
+#ifndef LLVM_ADT_DEPTHFIRSTITERATOR_H
+#define LLVM_ADT_DEPTHFIRSTITERATOR_H
 
-#include "Support/GraphTraits.h"
-#include <iterator>
-#include <stack>
+#include "llvm/ADT/GraphTraits.h"
+#include "llvm/ADT/PointerIntPair.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/iterator_range.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 std::forward_iterator<typename GT::NodeType,
-                                                 ptrdiff_t> {
+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::stack<std::pair<NodeType *, ChildItTy> > VisitStack;
-  const bool Reverse;         // Iterate over children before self?
+  // if the int in PointerIntTy is 0, the 'next child' to visit is invalid
+  std::vector<std::pair<PointerIntTy, ChildItTy>> VisitStack;
+
 private:
-  void reverseEnterNode() {
-    std::pair<NodeType *, ChildItTy> &Top = VisitStack.top();
-    NodeType *Node = Top.first;
-    ChildItTy &It  = Top.second;
-    for (; It != GT::child_end(Node); ++It) {
-      NodeType *Child = *It;
-      if (!Visited.count(Child)) {
-	Visited.insert(Child);
-	VisitStack.push(std::make_pair(Child, GT::child_begin(Child)));
-	reverseEnterNode();
-	return;
-      }
+  inline df_iterator(NodeType *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);
+      }
 
-  inline df_iterator(NodeType *Node, bool reverse) : Reverse(reverse) {
-    Visited.insert(Node);
-    VisitStack.push(std::make_pair(Node, GT::child_begin(Node)));
-    if (Reverse) reverseEnterNode();
+      while (It != GT::child_end(Node)) {
+        NodeType *Next = *It++;
+        // Has our next sibling been visited?
+        if (Next && this->Visited.insert(Next).second) {
+          // No, do it now.
+          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 df_iterator<GraphT, GT> _Self;
+  typedef typename super::pointer pointer;
 
   // Provide static begin and end methods as our public "constructors"
-  static inline _Self begin(GraphT G, bool Reverse = false) {
-    return _Self(GT::getEntryNode(G), Reverse);
+  static df_iterator begin(const GraphT &G) {
+    return df_iterator(GT::getEntryNode(G));
   }
-  static inline _Self end(GraphT G) { return _Self(); }
+  static df_iterator end(const GraphT &G) { return df_iterator(); }
 
+  // Static begin and end methods as our public ctors for external iterators
+  static df_iterator begin(const GraphT &G, SetType &S) {
+    return df_iterator(GT::getEntryNode(G), S);
+  }
+  static df_iterator end(const GraphT &G, SetType &S) { return df_iterator(S); }
 
-  inline bool operator==(const _Self& x) const { 
+  bool operator==(const df_iterator &x) const {
     return VisitStack == x.VisitStack;
   }
-  inline bool operator!=(const _Self& x) const { return !operator==(x); }
+  bool operator!=(const df_iterator &x) const { return !(*this == x); }
 
-  inline pointer operator*() const { 
-    return VisitStack.top().first;
-  }
+  pointer operator*() const { return VisitStack.back().first.getPointer(); }
 
   // This is a nonstandard operator-> that dereferences the pointer an extra
   // time... so that you can actually call methods ON the Node, because
   // the contained type is a pointer.  This allows BBIt->getTerminator() f.e.
   //
-  inline NodeType *operator->() const { return operator*(); }
-
-  inline _Self& operator++() {   // Preincrement
-    if (Reverse) {               // Reverse Depth First Iterator
-      if (VisitStack.top().second == GT::child_end(VisitStack.top().first))
-	VisitStack.pop();
-      if (!VisitStack.empty())
-	reverseEnterNode();
-    } else {                     // Normal Depth First Iterator
-      do {
-	std::pair<NodeType *, ChildItTy> &Top = VisitStack.top();
-	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(std::make_pair(Next, GT::child_begin(Next)));
-	    return *this;
-	  }
-	}
-	
-	// Oops, ran out of successors... go up a level on the stack.
-	VisitStack.pop();
-      } while (!VisitStack.empty());
-    }
-    return *this; 
+  NodeType *operator->() const { return **this; }
+
+  df_iterator &operator++() { // Preincrement
+    toNext();
+    return *this;
   }
 
-  inline _Self operator++(int) { // Postincrement
-    _Self tmp = *this; ++*this; return tmp; 
+  /// \brief Skips all children of the current node and traverses to next node
+  ///
+  /// Note: This function takes care of incrementing the iterator. If you
+  /// always increment and call this function, you risk walking off the end.
+  df_iterator &skipChildren() {
+    VisitStack.pop_back();
+    if (!VisitStack.empty())
+      toNext();
+    return *this;
+  }
+
+  df_iterator operator++(int) { // Postincrement
+    df_iterator 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;
+  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();
+  }
+};
 
 // Provide global constructors that automatically figure out correct types...
 //
 template <class T>
-df_iterator<T> df_begin(T G, bool Reverse = false) {
-  return df_iterator<T>::begin(G, Reverse);
+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 inverse depth first iterators...
+// Provide an accessor method to use them in range-based patterns.
 template <class T>
-struct idf_iterator : public df_iterator<Inverse<T> > {
-  idf_iterator(const df_iterator<Inverse<T> > &V) :df_iterator<Inverse<T> >(V){}
+iterator_range<df_iterator<T>> depth_first(const T& G) {
+  return make_range(df_begin(G), df_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);
+}
+
+template <class T, class SetTy>
+iterator_range<df_ext_iterator<T, SetTy>> depth_first_ext(const T& G,
+                                                          SetTy &S) {
+  return make_range(df_ext_begin(G, S), df_ext_end(G, S));
+}
+
+// Provide global definitions of inverse depth first iterators...
+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, bool Reverse = false) {
-  return idf_iterator<T>::begin(G, Reverse);
+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 an accessor method to use them in range-based patterns.
+template <class T>
+iterator_range<idf_iterator<T>> inverse_depth_first(const T& G) {
+  return make_range(idf_begin(G), idf_end(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);
 }
 
+template <class T, class SetTy>
+iterator_range<idf_ext_iterator<T, SetTy>> inverse_depth_first_ext(const T& G,
+                                                                   SetTy &S) {
+  return make_range(idf_ext_begin(G, S), idf_ext_end(G, S));
+}
+
+} // End llvm namespace
+
 #endif