add support for "external" depth first iterators, which store the 'visited' set

outside of the iterator itself.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9090 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2003-10-13 16:34:26 +00:00
parent a0137d3d82
commit 9061e992d5
2 changed files with 198 additions and 22 deletions

View File

@ -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 @@ public:
}
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 @@ public:
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 @@ public:
// 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 @@ df_iterator<T> df_end(T G) {
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>
@ -129,4 +197,24 @@ 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

View File

@ -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 @@ public:
}
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 @@ public:
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 @@ public:
// 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 @@ df_iterator<T> df_end(T G) {
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>
@ -129,4 +197,24 @@ 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