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+//===- RegionIterator.h - Iterators to iteratate over Regions ---*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// This file defines the iterators to iterate over the elements of a Region.
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_ANALYSIS_REGION_ITERATOR_H
+#define LLVM_ANALYSIS_REGION_ITERATOR_H
+
+#include "llvm/ADT/GraphTraits.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/PointerIntPair.h"
+#include "llvm/Analysis/RegionInfo.h"
+#include "llvm/Support/CFG.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+//===----------------------------------------------------------------------===//
+/// @brief Hierachical RegionNode successor iterator.
+///
+/// This iterator iterates over all successors of a RegionNode.
+///
+/// For a BasicBlock RegionNode it skips all BasicBlocks that are not part of
+/// the parent Region. Furthermore for BasicBlocks that start a subregion, a
+/// RegionNode representing the subregion is returned.
+///
+/// For a subregion RegionNode there is just one successor. The RegionNode
+/// representing the exit of the subregion.
+template<class NodeType>
+class RNSuccIterator : public std::iterator<std::forward_iterator_tag,
+ NodeType, ptrdiff_t>
+{
+ typedef std::iterator<std::forward_iterator_tag, NodeType, ptrdiff_t> super;
+ // The iterator works in two modes, bb mode or region mode.
+ enum ItMode{
+ // In BB mode it returns all successors of this BasicBlock as its
+ // successors.
+ ItBB,
+ // In region mode there is only one successor, thats the regionnode mapping
+ // to the exit block of the regionnode
+ ItRgBegin, // At the beginning of the regionnode successor.
+ ItRgEnd // At the end of the regionnode successor.
+ };
+
+ // Use two bit to represent the mode iterator.
+ PointerIntPair<NodeType*, 2, enum ItMode> Node;
+
+ // The block successor iterator.
+ succ_iterator BItor;
+
+ // advanceRegionSucc - A region node has only one successor. It reaches end
+ // once we advance it.
+ void advanceRegionSucc() {
+ assert(Node.getInt() == ItRgBegin && "Cannot advance region successor!");
+ Node.setInt(ItRgEnd);
+ }
+
+ NodeType* getNode() const{ return Node.getPointer(); }
+
+ // isRegionMode - Is the current iterator in region mode?
+ bool isRegionMode() const { return Node.getInt() != ItBB; }
+
+ // Get the immediate successor. This function may return a Basic Block
+ // RegionNode or a subregion RegionNode.
+ RegionNode* getISucc(BasicBlock* BB) const {
+ RegionNode *succ;
+ succ = getNode()->getParent()->getNode(BB);
+ assert(succ && "BB not in Region or entered subregion!");
+ return succ;
+ }
+
+ // getRegionSucc - Return the successor basic block of a SubRegion RegionNode.
+ inline BasicBlock* getRegionSucc() const {
+ assert(Node.getInt() == ItRgBegin && "Cannot get the region successor!");
+ return getNode()->template getNodeAs<Region>()->getExit();
+ }
+
+ // isExit - Is this the exit BB of the Region?
+ inline bool isExit(BasicBlock* BB) const {
+ return getNode()->getParent()->getExit() == BB;
+ }
+public:
+ typedef RNSuccIterator<NodeType> Self;
+
+ typedef typename super::pointer pointer;
+
+ /// @brief Create begin iterator of a RegionNode.
+ inline RNSuccIterator(NodeType* node)
+ : Node(node, node->isSubRegion() ? ItRgBegin : ItBB),
+ BItor(succ_begin(node->getEntry())) {
+
+
+ // Skip the exit block
+ if (!isRegionMode())
+ while (succ_end(node->getEntry()) != BItor && isExit(*BItor))
+ ++BItor;
+
+ if (isRegionMode() && isExit(getRegionSucc()))
+ advanceRegionSucc();
+ }
+
+ /// @brief Create an end iterator.
+ inline RNSuccIterator(NodeType* node, bool)
+ : Node(node, node->isSubRegion() ? ItRgEnd : ItBB),
+ BItor(succ_end(node->getEntry())) {}
+
+ inline bool operator==(const Self& x) const {
+ assert(isRegionMode() == x.isRegionMode() && "Broken iterator!");
+ if (isRegionMode())
+ return Node.getInt() == x.Node.getInt();
+ else
+ return BItor == x.BItor;
+ }
+
+ inline bool operator!=(const Self& x) const { return !operator==(x); }
+
+ inline pointer operator*() const {
+ BasicBlock* BB = isRegionMode() ? getRegionSucc() : *BItor;
+ assert(!isExit(BB) && "Iterator out of range!");
+ return getISucc(BB);
+ }
+
+ inline Self& operator++() {
+ if(isRegionMode()) {
+ // The Region only has 1 successor.
+ advanceRegionSucc();
+ } else {
+ // Skip the exit.
+ do
+ ++BItor;
+ while (BItor != succ_end(getNode()->getEntry())
+ && isExit(*BItor));
+ }
+ return *this;
+ }
+
+ inline Self operator++(int) {
+ Self tmp = *this;
+ ++*this;
+ return tmp;
+ }
+
+ inline const Self &operator=(const Self &I) {
+ if (this != &I) {
+ assert(getNode()->getParent() == I.getNode()->getParent()
+ && "Cannot assign iterators of two different regions!");
+ Node = I.Node;
+ BItor = I.BItor;
+ }
+ return *this;
+ }
+};
+
+
+//===----------------------------------------------------------------------===//
+/// @brief Flat RegionNode iterator.
+///
+/// The Flat Region iterator will iterate over all BasicBlock RegionNodes that
+/// are contained in the Region and its subregions. This is close to a virtual
+/// control flow graph of the Region.
+template<class NodeType>
+class RNSuccIterator<FlatIt<NodeType> >
+ : public std::iterator<std::forward_iterator_tag, NodeType, ptrdiff_t>
+{
+ typedef std::iterator<std::forward_iterator_tag, NodeType, ptrdiff_t> super;
+ NodeType* Node;
+ succ_iterator Itor;
+
+public:
+ typedef RNSuccIterator<FlatIt<NodeType> > Self;
+ typedef typename super::pointer pointer;
+
+ /// @brief Create the iterator from a RegionNode.
+ ///
+ /// Note that the incoming node must be a bb node, otherwise it will trigger
+ /// an assertion when we try to get a BasicBlock.
+ inline RNSuccIterator(NodeType* node) : Node(node),
+ Itor(succ_begin(node->getEntry())) {
+ assert(!Node->isSubRegion()
+ && "Subregion node not allowed in flat iterating mode!");
+ assert(Node->getParent() && "A BB node must have a parent!");
+
+ // Skip the exit block of the iterating region.
+ while (succ_end(Node->getEntry()) != Itor
+ && Node->getParent()->getExit() == *Itor)
+ ++Itor;
+ }
+ /// @brief Create an end iterator
+ inline RNSuccIterator(NodeType* node, bool) : Node(node),
+ Itor(succ_end(node->getEntry())) {
+ assert(!Node->isSubRegion()
+ && "Subregion node not allowed in flat iterating mode!");
+ }
+
+ inline bool operator==(const Self& x) const {
+ assert(Node->getParent() == x.Node->getParent()
+ && "Cannot compare iterators of different regions!");
+
+ return Itor == x.Itor && Node == x.Node;
+ }
+
+ inline bool operator!=(const Self& x) const { return !operator==(x); }
+
+ inline pointer operator*() const {
+ BasicBlock* BB = *Itor;
+
+ // Get the iterating region.
+ Region* Parent = Node->getParent();
+
+ // The only case that the successor reaches out of the region is it reaches
+ // the exit of the region.
+ assert(Parent->getExit() != BB && "iterator out of range!");
+
+ return Parent->getBBNode(BB);
+ }
+
+ inline Self& operator++() {
+ // Skip the exit block of the iterating region.
+ do
+ ++Itor;
+ while (Itor != succ_end(Node->getEntry())
+ && Node->getParent()->getExit() == *Itor);
+
+ return *this;
+ }
+
+ inline Self operator++(int) {
+ Self tmp = *this;
+ ++*this;
+ return tmp;
+ }
+
+ inline const Self &operator=(const Self &I) {
+ if (this != &I) {
+ assert(Node->getParent() == I.Node->getParent()
+ && "Cannot assign iterators to two different regions!");
+ Node = I.Node;
+ Itor = I.Itor;
+ }
+ return *this;
+ }
+};
+
+template<class NodeType>
+inline RNSuccIterator<NodeType> succ_begin(NodeType* Node) {
+ return RNSuccIterator<NodeType>(Node);
+}
+
+template<class NodeType>
+inline RNSuccIterator<NodeType> succ_end(NodeType* Node) {
+ return RNSuccIterator<NodeType>(Node, true);
+}
+
+//===--------------------------------------------------------------------===//
+// RegionNode GraphTraits specialization so the bbs in the region can be
+// iterate by generic graph iterators.
+//
+// NodeT can either be region node or const region node, otherwise child_begin
+// and child_end fail.
+
+#define RegionNodeGraphTraits(NodeT) \
+ template<> struct GraphTraits<NodeT*> { \
+ typedef NodeT NodeType; \
+ typedef RNSuccIterator<NodeType> ChildIteratorType; \
+ static NodeType *getEntryNode(NodeType* N) { return N; } \
+ static inline ChildIteratorType child_begin(NodeType *N) { \
+ return RNSuccIterator<NodeType>(N); \
+ } \
+ static inline ChildIteratorType child_end(NodeType *N) { \
+ return RNSuccIterator<NodeType>(N, true); \
+ } \
+}; \
+template<> struct GraphTraits<FlatIt<NodeT*> > { \
+ typedef NodeT NodeType; \
+ typedef RNSuccIterator<FlatIt<NodeT> > ChildIteratorType; \
+ static NodeType *getEntryNode(NodeType* N) { return N; } \
+ static inline ChildIteratorType child_begin(NodeType *N) { \
+ return RNSuccIterator<FlatIt<NodeType> >(N); \
+ } \
+ static inline ChildIteratorType child_end(NodeType *N) { \
+ return RNSuccIterator<FlatIt<NodeType> >(N, true); \
+ } \
+}
+
+#define RegionGraphTraits(RegionT, NodeT) \
+template<> struct GraphTraits<RegionT*> \
+ : public GraphTraits<NodeT*> { \
+ typedef df_iterator<NodeType*> nodes_iterator; \
+ static NodeType *getEntryNode(RegionT* R) { \
+ return R->getNode(R->getEntry()); \
+ } \
+ static nodes_iterator nodes_begin(RegionT* R) { \
+ return nodes_iterator::begin(getEntryNode(R)); \
+ } \
+ static nodes_iterator nodes_end(RegionT* R) { \
+ return nodes_iterator::end(getEntryNode(R)); \
+ } \
+}; \
+template<> struct GraphTraits<FlatIt<RegionT*> > \
+ : public GraphTraits<FlatIt<NodeT*> > { \
+ typedef df_iterator<NodeType*, SmallPtrSet<NodeType*, 8>, false, \
+ GraphTraits<FlatIt<NodeType*> > > nodes_iterator; \
+ static NodeType *getEntryNode(RegionT* R) { \
+ return R->getBBNode(R->getEntry()); \
+ } \
+ static nodes_iterator nodes_begin(RegionT* R) { \
+ return nodes_iterator::begin(getEntryNode(R)); \
+ } \
+ static nodes_iterator nodes_end(RegionT* R) { \
+ return nodes_iterator::end(getEntryNode(R)); \
+ } \
+}
+
+RegionNodeGraphTraits(RegionNode);
+RegionNodeGraphTraits(const RegionNode);
+
+RegionGraphTraits(Region, RegionNode);
+RegionGraphTraits(const Region, const RegionNode);
+
+template <> struct GraphTraits<RegionInfo*>
+ : public GraphTraits<FlatIt<RegionNode*> > {
+ typedef df_iterator<NodeType*, SmallPtrSet<NodeType*, 8>, false,
+ GraphTraits<FlatIt<NodeType*> > > nodes_iterator;
+
+ static NodeType *getEntryNode(RegionInfo *RI) {
+ return GraphTraits<FlatIt<Region*> >::getEntryNode(RI->getTopLevelRegion());
+ }
+ static nodes_iterator nodes_begin(RegionInfo* RI) {
+ return nodes_iterator::begin(getEntryNode(RI));
+ }
+ static nodes_iterator nodes_end(RegionInfo *RI) {
+ return nodes_iterator::end(getEntryNode(RI));
+ }
+};
+
+} // End namespace llvm
+
+#endif