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Diffstat (limited to 'clang-r353983/include/llvm/Analysis/RegionIterator.h')
| -rw-r--r-- | clang-r353983/include/llvm/Analysis/RegionIterator.h | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/clang-r353983/include/llvm/Analysis/RegionIterator.h b/clang-r353983/include/llvm/Analysis/RegionIterator.h new file mode 100644 index 00000000..72bc5bbc --- /dev/null +++ b/clang-r353983/include/llvm/Analysis/RegionIterator.h @@ -0,0 +1,359 @@ +//===- RegionIterator.h - Iterators to iteratate over Regions ---*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// This file defines the iterators to iterate over the elements of a Region. +//===----------------------------------------------------------------------===// + +#ifndef LLVM_ANALYSIS_REGIONITERATOR_H +#define LLVM_ANALYSIS_REGIONITERATOR_H + +#include "llvm/ADT/DepthFirstIterator.h" +#include "llvm/ADT/GraphTraits.h" +#include "llvm/ADT/PointerIntPair.h" +#include "llvm/Analysis/RegionInfo.h" +#include "llvm/IR/CFG.h" +#include <cassert> +#include <iterator> +#include <type_traits> + +namespace llvm { + +class BasicBlock; + +//===----------------------------------------------------------------------===// +/// Hierarchical 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 NodeRef, class BlockT, class RegionT> +class RNSuccIterator + : public std::iterator<std::forward_iterator_tag, NodeRef> { + using super = std::iterator<std::forward_iterator_tag, NodeRef>; + using BlockTraits = GraphTraits<BlockT *>; + using SuccIterTy = typename BlockTraits::ChildIteratorType; + + // 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. + }; + + static_assert(std::is_pointer<NodeRef>::value, + "FIXME: Currently RNSuccIterator only supports NodeRef as " + "pointers due to the use of pointer-specific data structures " + "(e.g. PointerIntPair and SmallPtrSet) internally. Generalize " + "it to support non-pointer types"); + + // Use two bit to represent the mode iterator. + PointerIntPair<NodeRef, 2, ItMode> Node; + + // The block successor iterator. + SuccIterTy 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); + } + + NodeRef 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. + NodeRef getISucc(BlockT *BB) const { + NodeRef 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 BlockT* getRegionSucc() const { + assert(Node.getInt() == ItRgBegin && "Cannot get the region successor!"); + return getNode()->template getNodeAs<RegionT>()->getExit(); + } + + // isExit - Is this the exit BB of the Region? + inline bool isExit(BlockT* BB) const { + return getNode()->getParent()->getExit() == BB; + } + +public: + using Self = RNSuccIterator<NodeRef, BlockT, RegionT>; + using value_type = typename super::value_type; + + /// Create begin iterator of a RegionNode. + inline RNSuccIterator(NodeRef node) + : Node(node, node->isSubRegion() ? ItRgBegin : ItBB), + BItor(BlockTraits::child_begin(node->getEntry())) { + // Skip the exit block + if (!isRegionMode()) + while (BlockTraits::child_end(node->getEntry()) != BItor && isExit(*BItor)) + ++BItor; + + if (isRegionMode() && isExit(getRegionSucc())) + advanceRegionSucc(); + } + + /// Create an end iterator. + inline RNSuccIterator(NodeRef node, bool) + : Node(node, node->isSubRegion() ? ItRgEnd : ItBB), + BItor(BlockTraits::child_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 value_type operator*() const { + BlockT *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 != BlockTraits::child_end(getNode()->getEntry()) + && isExit(*BItor)); + } + return *this; + } + + inline Self operator++(int) { + Self tmp = *this; + ++*this; + return tmp; + } +}; + +//===----------------------------------------------------------------------===// +/// 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 NodeRef, class BlockT, class RegionT> +class RNSuccIterator<FlatIt<NodeRef>, BlockT, RegionT> + : public std::iterator<std::forward_iterator_tag, NodeRef> { + using super = std::iterator<std::forward_iterator_tag, NodeRef>; + using BlockTraits = GraphTraits<BlockT *>; + using SuccIterTy = typename BlockTraits::ChildIteratorType; + + NodeRef Node; + SuccIterTy Itor; + +public: + using Self = RNSuccIterator<FlatIt<NodeRef>, BlockT, RegionT>; + using value_type = typename super::value_type; + + /// 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(NodeRef node) + : Node(node), Itor(BlockTraits::child_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 (BlockTraits::child_end(Node->getEntry()) != Itor && + Node->getParent()->getExit() == *Itor) + ++Itor; + } + + /// Create an end iterator + inline RNSuccIterator(NodeRef node, bool) + : Node(node), Itor(BlockTraits::child_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 value_type operator*() const { + BlockT *BB = *Itor; + + // Get the iterating region. + RegionT *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; + } +}; + +template <class NodeRef, class BlockT, class RegionT> +inline RNSuccIterator<NodeRef, BlockT, RegionT> succ_begin(NodeRef Node) { + return RNSuccIterator<NodeRef, BlockT, RegionT>(Node); +} + +template <class NodeRef, class BlockT, class RegionT> +inline RNSuccIterator<NodeRef, BlockT, RegionT> succ_end(NodeRef Node) { + return RNSuccIterator<NodeRef, BlockT, RegionT>(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, BlockT, RegionT) \ + template <> struct GraphTraits<NodeT *> { \ + using NodeRef = NodeT *; \ + using ChildIteratorType = RNSuccIterator<NodeRef, BlockT, RegionT>; \ + static NodeRef getEntryNode(NodeRef N) { return N; } \ + static inline ChildIteratorType child_begin(NodeRef N) { \ + return RNSuccIterator<NodeRef, BlockT, RegionT>(N); \ + } \ + static inline ChildIteratorType child_end(NodeRef N) { \ + return RNSuccIterator<NodeRef, BlockT, RegionT>(N, true); \ + } \ + }; \ + template <> struct GraphTraits<FlatIt<NodeT *>> { \ + using NodeRef = NodeT *; \ + using ChildIteratorType = \ + RNSuccIterator<FlatIt<NodeRef>, BlockT, RegionT>; \ + static NodeRef getEntryNode(NodeRef N) { return N; } \ + static inline ChildIteratorType child_begin(NodeRef N) { \ + return RNSuccIterator<FlatIt<NodeRef>, BlockT, RegionT>(N); \ + } \ + static inline ChildIteratorType child_end(NodeRef N) { \ + return RNSuccIterator<FlatIt<NodeRef>, BlockT, RegionT>(N, true); \ + } \ + } + +#define RegionGraphTraits(RegionT, NodeT) \ + template <> struct GraphTraits<RegionT *> : public GraphTraits<NodeT *> { \ + using nodes_iterator = df_iterator<NodeRef>; \ + static NodeRef 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 *>> { \ + using nodes_iterator = \ + df_iterator<NodeRef, df_iterator_default_set<NodeRef>, false, \ + GraphTraits<FlatIt<NodeRef>>>; \ + static NodeRef 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, BasicBlock, Region); +RegionNodeGraphTraits(const RegionNode, BasicBlock, Region); + +RegionGraphTraits(Region, RegionNode); +RegionGraphTraits(const Region, const RegionNode); + +template <> struct GraphTraits<RegionInfo*> + : public GraphTraits<FlatIt<RegionNode*>> { + using nodes_iterator = + df_iterator<NodeRef, df_iterator_default_set<NodeRef>, false, + GraphTraits<FlatIt<NodeRef>>>; + + static NodeRef 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)); + } +}; + +template <> struct GraphTraits<RegionInfoPass*> + : public GraphTraits<RegionInfo *> { + using nodes_iterator = + df_iterator<NodeRef, df_iterator_default_set<NodeRef>, false, + GraphTraits<FlatIt<NodeRef>>>; + + static NodeRef getEntryNode(RegionInfoPass *RI) { + return GraphTraits<RegionInfo*>::getEntryNode(&RI->getRegionInfo()); + } + + static nodes_iterator nodes_begin(RegionInfoPass* RI) { + return GraphTraits<RegionInfo*>::nodes_begin(&RI->getRegionInfo()); + } + + static nodes_iterator nodes_end(RegionInfoPass *RI) { + return GraphTraits<RegionInfo*>::nodes_end(&RI->getRegionInfo()); + } +}; + +} // end namespace llvm + +#endif // LLVM_ANALYSIS_REGIONITERATOR_H |