mirror of
https://github.com/RPCS3/llvm.git
synced 2024-12-13 23:18:58 +00:00
de32fedb8c
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@3076 91177308-0d34-0410-b5e6-96231b3b80d8
146 lines
4.9 KiB
C++
146 lines
4.9 KiB
C++
//===-- Support/PostOrderIterator.h - Generic PostOrder iterator -*- C++ -*--=//
|
|
//
|
|
// This file builds on the Support/GraphTraits.h file to build a generic graph
|
|
// post order iterator. This should work over any graph type that has a
|
|
// GraphTraits specialization.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_SUPPORT_POSTORDER_ITERATOR_H
|
|
#define LLVM_SUPPORT_POSTORDER_ITERATOR_H
|
|
|
|
#include "Support/GraphTraits.h"
|
|
#include <Support/iterator>
|
|
#include <stack>
|
|
#include <set>
|
|
|
|
template<class GraphT, class GT = GraphTraits<GraphT> >
|
|
class po_iterator : public forward_iterator<typename GT::NodeType, ptrdiff_t> {
|
|
typedef forward_iterator<typename GT::NodeType, ptrdiff_t> super;
|
|
typedef typename super::pointer pointer;
|
|
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 basic block pointer, second is the 'next child' to visit
|
|
std::stack<std::pair<NodeType *, ChildItTy> > VisitStack;
|
|
|
|
void traverseChild() {
|
|
while (VisitStack.top().second != GT::child_end(VisitStack.top().first)) {
|
|
NodeType *BB = *VisitStack.top().second++;
|
|
if (!Visited.count(BB)) { // If the block is not visited...
|
|
Visited.insert(BB);
|
|
VisitStack.push(make_pair(BB, GT::child_begin(BB)));
|
|
}
|
|
}
|
|
}
|
|
|
|
inline po_iterator(NodeType *BB) {
|
|
Visited.insert(BB);
|
|
VisitStack.push(make_pair(BB, GT::child_begin(BB)));
|
|
traverseChild();
|
|
}
|
|
inline po_iterator() { /* End is when stack is empty */ }
|
|
public:
|
|
typedef po_iterator<GraphT, GT> _Self;
|
|
|
|
// Provide static "constructors"...
|
|
static inline _Self begin(GraphT G) { return _Self(GT::getEntryNode(G)); }
|
|
static inline _Self end (GraphT G) { return _Self(); }
|
|
|
|
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.top().first;
|
|
}
|
|
|
|
// This is a nonstandard operator-> that dereferences the pointer an extra
|
|
// time... so that you can actually call methods ON the BasicBlock, because
|
|
// the contained type is a pointer. This allows BBIt->getTerminator() f.e.
|
|
//
|
|
inline NodeType *operator->() const { return operator*(); }
|
|
|
|
inline _Self& operator++() { // Preincrement
|
|
VisitStack.pop();
|
|
if (!VisitStack.empty())
|
|
traverseChild();
|
|
return *this;
|
|
}
|
|
|
|
inline _Self operator++(int) { // Postincrement
|
|
_Self tmp = *this; ++*this; return tmp;
|
|
}
|
|
};
|
|
|
|
// Provide global constructors that automatically figure out correct types...
|
|
//
|
|
template <class T>
|
|
po_iterator<T> po_begin(T G) { return po_iterator<T>::begin(G); }
|
|
template <class T>
|
|
po_iterator<T> po_end (T G) { return po_iterator<T>::end(G); }
|
|
|
|
// Provide global definitions of inverse post order iterators...
|
|
template <class T>
|
|
struct ipo_iterator : public po_iterator<Inverse<T> > {
|
|
ipo_iterator(const po_iterator<Inverse<T> > &V) :po_iterator<Inverse<T> >(V){}
|
|
};
|
|
|
|
template <class T>
|
|
ipo_iterator<T> ipo_begin(T G, bool Reverse = false) {
|
|
return ipo_iterator<T>::begin(G, Reverse);
|
|
}
|
|
|
|
template <class T>
|
|
ipo_iterator<T> ipo_end(T G){
|
|
return ipo_iterator<T>::end(G);
|
|
}
|
|
|
|
|
|
//===--------------------------------------------------------------------===//
|
|
// Reverse Post Order CFG iterator code
|
|
//===--------------------------------------------------------------------===//
|
|
//
|
|
// This is used to visit basic blocks in a method in reverse post order. This
|
|
// class is awkward to use because I don't know a good incremental algorithm to
|
|
// computer RPO from a graph. Because of this, the construction of the
|
|
// ReversePostOrderTraversal object is expensive (it must walk the entire graph
|
|
// with a postorder iterator to build the data structures). The moral of this
|
|
// story is: Don't create more ReversePostOrderTraversal classes than neccesary.
|
|
//
|
|
// This class should be used like this:
|
|
// {
|
|
// ReversePostOrderTraversal<Method*> RPOT(MethodPtr); // Expensive to create
|
|
// for (rpo_iterator I = RPOT.begin(); I != RPOT.end(); ++I) {
|
|
// ...
|
|
// }
|
|
// for (rpo_iterator I = RPOT.begin(); I != RPOT.end(); ++I) {
|
|
// ...
|
|
// }
|
|
// }
|
|
//
|
|
|
|
template<class GraphT, class GT = GraphTraits<GraphT> >
|
|
class ReversePostOrderTraversal {
|
|
typedef typename GT::NodeType NodeType;
|
|
std::vector<NodeType*> Blocks; // Block list in normal PO order
|
|
inline void Initialize(NodeType *BB) {
|
|
copy(po_begin(BB), po_end(BB), back_inserter(Blocks));
|
|
}
|
|
public:
|
|
typedef typename std::vector<NodeType*>::reverse_iterator rpo_iterator;
|
|
|
|
inline ReversePostOrderTraversal(GraphT G) {
|
|
Initialize(GT::getEntryNode(G));
|
|
}
|
|
|
|
// Because we want a reverse post order, use reverse iterators from the vector
|
|
inline rpo_iterator begin() { return Blocks.rbegin(); }
|
|
inline rpo_iterator end() { return Blocks.rend(); }
|
|
};
|
|
|
|
#endif
|