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Diffstat (limited to 'include/llvm/Analysis/RegionIterator.h')
| -rw-r--r-- | include/llvm/Analysis/RegionIterator.h | 342 |
1 files changed, 342 insertions, 0 deletions
diff --git a/include/llvm/Analysis/RegionIterator.h b/include/llvm/Analysis/RegionIterator.h new file mode 100644 index 000000000000..ced5b528cbb1 --- /dev/null +++ b/include/llvm/Analysis/RegionIterator.h @@ -0,0 +1,342 @@ +//===- 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 |