[llvm-commits] CVS: llvm/include/Support/DepthFirstIterator.h
Chris Lattner
lattner at cs.uiuc.edu
Mon Oct 13 11:35:02 PDT 2003
Changes in directory llvm/include/Support:
DepthFirstIterator.h updated: 1.8 -> 1.9
---
Log message:
add support for "external" depth first iterators, which store the 'visited' set
outside of the iterator itself.
---
Diffs of the changes: (+99 -11)
Index: llvm/include/Support/DepthFirstIterator.h
diff -u llvm/include/Support/DepthFirstIterator.h:1.8 llvm/include/Support/DepthFirstIterator.h:1.9
--- llvm/include/Support/DepthFirstIterator.h:1.8 Mon Oct 13 10:45:33 2003
+++ llvm/include/Support/DepthFirstIterator.h Mon Oct 13 11:34:26 2003
@@ -9,6 +9,18 @@
// 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
@@ -19,28 +31,59 @@
#include <vector>
#include <set>
+// 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> {
+template<class GraphT, class SetType =
+ std::set<typename GraphTraits<GraphT>::NodeType*>,
+ bool ExtStorage = false, class GT = GraphTraits<GraphT> >
+class df_iterator : public forward_iterator<typename GT::NodeType, ptrdiff_t>,
+ public df_iterator_storage<SetType, ExtStorage> {
typedef forward_iterator<typename GT::NodeType, ptrdiff_t> super;
typedef typename GT::NodeType NodeType;
typedef typename GT::ChildIteratorType ChildItTy;
- 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;
private:
inline df_iterator(NodeType *Node) {
- Visited.insert(Node);
+ this->Visited.insert(Node);
VisitStack.push_back(std::make_pair(Node, 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)) {
+ this->Visited.insert(Node);
+ VisitStack.push_back(std::make_pair(Node, GT::child_begin(Node)));
+ }
+ }
+ inline df_iterator(SetType &S)
+ : df_iterator_storage<SetType, ExtStorage>(S) {
+ // 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) {
@@ -48,6 +91,11 @@
}
static inline _Self end(GraphT G) { return _Self(); }
+ // Static begin and end methods as our public ctors for external iterators
+ static inline _Self begin(GraphT G, SetType &S) {
+ return _Self(GT::getEntryNode(G), S);
+ }
+ static inline _Self end(GraphT G, SetType &S) { return _Self(S); }
inline bool operator==(const _Self& x) const {
return VisitStack.size() == x.VisitStack.size() &&
@@ -73,9 +121,9 @@
while (It != GT::child_end(Node)) {
NodeType *Next = *It++;
- if (!Visited.count(Next)) { // Has our next sibling been visited?
+ if (!this->Visited.count(Next)) { // Has our next sibling been visited?
// No, do it now.
- Visited.insert(Next);
+ this->Visited.insert(Next);
VisitStack.push_back(std::make_pair(Next, GT::child_begin(Next)));
return *this;
}
@@ -96,7 +144,7 @@
// nodes that a depth first iteration did not find: ie unreachable nodes.
//
inline bool nodeVisited(NodeType *Node) const {
- return Visited.count(Node) != 0;
+ return this->Visited.count(Node) != 0;
}
};
@@ -113,10 +161,30 @@
return df_iterator<T>::end(G);
}
+// Provide global definitions of external depth first iterators...
+template <class T, class SetTy>
+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(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(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 = std::set<typename GraphTraits<T>::NodeType*>,
+ 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>
@@ -128,5 +196,25 @@
idf_iterator<T> idf_end(T G){
return idf_iterator<T>::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(T G, SetTy &S) {
+ return idf_ext_iterator<T, SetTy>::begin(G, S);
+}
+
+template <class T, class SetTy>
+idf_ext_iterator<T, SetTy> idf_ext_end(T G, SetTy &S) {
+ return idf_ext_iterator<T, SetTy>::end(G, S);
+}
+
#endif
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