1 //===- RegionInfo.h - SESE region analysis ----------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Calculate a program structure tree built out of single entry single exit
12 // The basic ideas are taken from "The Program Structure Tree - Richard Johnson,
13 // David Pearson, Keshav Pingali - 1994", however enriched with ideas from "The
14 // Refined Process Structure Tree - Jussi Vanhatalo, Hagen Voelyer, Jana
16 // The algorithm to calculate these data structures however is completely
17 // different, as it takes advantage of existing information already available
18 // in (Post)dominace tree and dominance frontier passes. This leads to a simpler
19 // and in practice hopefully better performing algorithm. The runtime of the
20 // algorithms described in the papers above are both linear in graph size,
21 // O(V+E), whereas this algorithm is not, as the dominance frontier information
22 // itself is not, but in practice runtime seems to be in the order of magnitude
23 // of dominance tree calculation.
25 //===----------------------------------------------------------------------===//
27 #ifndef LLVM_ANALYSIS_REGIONINFO_H
28 #define LLVM_ANALYSIS_REGIONINFO_H
30 #include "llvm/ADT/PointerIntPair.h"
31 #include "llvm/ADT/iterator_range.h"
32 #include "llvm/Analysis/DominanceFrontier.h"
33 #include "llvm/Analysis/PostDominators.h"
34 #include "llvm/Support/Allocator.h"
45 /// @brief Marker class to iterate over the elements of a Region in flat mode.
47 /// The class is used to either iterate in Flat mode or by not using it to not
48 /// iterate in Flat mode. During a Flat mode iteration all Regions are entered
49 /// and the iteration returns every BasicBlock. If the Flat mode is not
50 /// selected for SubRegions just one RegionNode containing the subregion is
52 template <class GraphType>
55 /// @brief A RegionNode represents a subregion or a BasicBlock that is part of a
58 RegionNode(const RegionNode &) LLVM_DELETED_FUNCTION;
59 const RegionNode &operator=(const RegionNode &) LLVM_DELETED_FUNCTION;
62 /// This is the entry basic block that starts this region node. If this is a
63 /// BasicBlock RegionNode, then entry is just the basic block, that this
64 /// RegionNode represents. Otherwise it is the entry of this (Sub)RegionNode.
66 /// In the BBtoRegionNode map of the parent of this node, BB will always map
67 /// to this node no matter which kind of node this one is.
69 /// The node can hold either a Region or a BasicBlock.
70 /// Use one bit to save, if this RegionNode is a subregion or BasicBlock
72 PointerIntPair<BasicBlock*, 1, bool> entry;
74 /// @brief The parent Region of this RegionNode.
79 /// @brief Create a RegionNode.
81 /// @param Parent The parent of this RegionNode.
82 /// @param Entry The entry BasicBlock of the RegionNode. If this
83 /// RegionNode represents a BasicBlock, this is the
84 /// BasicBlock itself. If it represents a subregion, this
85 /// is the entry BasicBlock of the subregion.
86 /// @param isSubRegion If this RegionNode represents a SubRegion.
87 inline RegionNode(Region* Parent, BasicBlock* Entry, bool isSubRegion = 0)
88 : entry(Entry, isSubRegion), parent(Parent) {}
90 /// @brief Get the parent Region of this RegionNode.
92 /// The parent Region is the Region this RegionNode belongs to. If for
93 /// example a BasicBlock is element of two Regions, there exist two
94 /// RegionNodes for this BasicBlock. Each with the getParent() function
95 /// pointing to the Region this RegionNode belongs to.
97 /// @return Get the parent Region of this RegionNode.
98 inline Region* getParent() const { return parent; }
100 /// @brief Get the entry BasicBlock of this RegionNode.
102 /// If this RegionNode represents a BasicBlock this is just the BasicBlock
103 /// itself, otherwise we return the entry BasicBlock of the Subregion
105 /// @return The entry BasicBlock of this RegionNode.
106 inline BasicBlock* getEntry() const { return entry.getPointer(); }
108 /// @brief Get the content of this RegionNode.
110 /// This can be either a BasicBlock or a subregion. Before calling getNodeAs()
111 /// check the type of the content with the isSubRegion() function call.
113 /// @return The content of this RegionNode.
115 inline T* getNodeAs() const;
117 /// @brief Is this RegionNode a subregion?
119 /// @return True if it contains a subregion. False if it contains a
121 inline bool isSubRegion() const {
122 return entry.getInt();
126 /// Print a RegionNode.
127 inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node);
130 inline BasicBlock* RegionNode::getNodeAs<BasicBlock>() const {
131 assert(!isSubRegion() && "This is not a BasicBlock RegionNode!");
136 inline Region* RegionNode::getNodeAs<Region>() const {
137 assert(isSubRegion() && "This is not a subregion RegionNode!");
138 return reinterpret_cast<Region*>(const_cast<RegionNode*>(this));
141 //===----------------------------------------------------------------------===//
142 /// @brief A single entry single exit Region.
144 /// A Region is a connected subgraph of a control flow graph that has exactly
145 /// two connections to the remaining graph. It can be used to analyze or
146 /// optimize parts of the control flow graph.
148 /// A <em> simple Region </em> is connected to the remaining graph by just two
149 /// edges. One edge entering the Region and another one leaving the Region.
151 /// An <em> extended Region </em> (or just Region) is a subgraph that can be
152 /// transform into a simple Region. The transformation is done by adding
153 /// BasicBlocks that merge several entry or exit edges so that after the merge
154 /// just one entry and one exit edge exists.
156 /// The \e Entry of a Region is the first BasicBlock that is passed after
157 /// entering the Region. It is an element of the Region. The entry BasicBlock
158 /// dominates all BasicBlocks in the Region.
160 /// The \e Exit of a Region is the first BasicBlock that is passed after
161 /// leaving the Region. It is not an element of the Region. The exit BasicBlock,
162 /// postdominates all BasicBlocks in the Region.
164 /// A <em> canonical Region </em> cannot be constructed by combining smaller
167 /// Region A is the \e parent of Region B, if B is completely contained in A.
169 /// Two canonical Regions either do not intersect at all or one is
170 /// the parent of the other.
172 /// The <em> Program Structure Tree</em> is a graph (V, E) where V is the set of
173 /// Regions in the control flow graph and E is the \e parent relation of these
179 /// A simple control flow graph, that contains two regions.
189 /// \ |/ Region A: 1 -> 9 {1,2,3,4,5,6,7,8}
190 /// 9 Region B: 2 -> 9 {2,4,5,6,7}
193 /// You can obtain more examples by either calling
195 /// <tt> "opt -regions -analyze anyprogram.ll" </tt>
197 /// <tt> "opt -view-regions-only anyprogram.ll" </tt>
199 /// on any LLVM file you are interested in.
201 /// The first call returns a textual representation of the program structure
202 /// tree, the second one creates a graphical representation using graphviz.
203 class Region : public RegionNode {
204 friend class RegionInfo;
205 Region(const Region &) LLVM_DELETED_FUNCTION;
206 const Region &operator=(const Region &) LLVM_DELETED_FUNCTION;
208 // Information necessary to manage this Region.
212 // The exit BasicBlock of this region.
213 // (The entry BasicBlock is part of RegionNode)
216 typedef std::vector<Region*> RegionSet;
218 // The subregions of this region.
221 typedef std::map<BasicBlock*, RegionNode*> BBNodeMapT;
223 // Save the BasicBlock RegionNodes that are element of this Region.
224 mutable BBNodeMapT BBNodeMap;
226 /// verifyBBInRegion - Check if a BB is in this Region. This check also works
227 /// if the region is incorrectly built. (EXPENSIVE!)
228 void verifyBBInRegion(BasicBlock* BB) const;
230 /// verifyWalk - Walk over all the BBs of the region starting from BB and
231 /// verify that all reachable basic blocks are elements of the region.
233 void verifyWalk(BasicBlock* BB, std::set<BasicBlock*>* visitedBB) const;
235 /// verifyRegionNest - Verify if the region and its children are valid
236 /// regions (EXPENSIVE!)
237 void verifyRegionNest() const;
240 /// @brief Create a new region.
242 /// @param Entry The entry basic block of the region.
243 /// @param Exit The exit basic block of the region.
244 /// @param RI The region info object that is managing this region.
245 /// @param DT The dominator tree of the current function.
246 /// @param Parent The surrounding region or NULL if this is a top level
248 Region(BasicBlock *Entry, BasicBlock *Exit, RegionInfo* RI,
249 DominatorTree *DT, Region *Parent = 0);
251 /// Delete the Region and all its subregions.
254 /// @brief Get the entry BasicBlock of the Region.
255 /// @return The entry BasicBlock of the region.
256 BasicBlock *getEntry() const { return RegionNode::getEntry(); }
258 /// @brief Replace the entry basic block of the region with the new basic
261 /// @param BB The new entry basic block of the region.
262 void replaceEntry(BasicBlock *BB);
264 /// @brief Replace the exit basic block of the region with the new basic
267 /// @param BB The new exit basic block of the region.
268 void replaceExit(BasicBlock *BB);
270 /// @brief Recursively replace the entry basic block of the region.
272 /// This function replaces the entry basic block with a new basic block. It
273 /// also updates all child regions that have the same entry basic block as
276 /// @param NewEntry The new entry basic block.
277 void replaceEntryRecursive(BasicBlock *NewEntry);
279 /// @brief Recursively replace the exit basic block of the region.
281 /// This function replaces the exit basic block with a new basic block. It
282 /// also updates all child regions that have the same exit basic block as
285 /// @param NewExit The new exit basic block.
286 void replaceExitRecursive(BasicBlock *NewExit);
288 /// @brief Get the exit BasicBlock of the Region.
289 /// @return The exit BasicBlock of the Region, NULL if this is the TopLevel
291 BasicBlock *getExit() const { return exit; }
293 /// @brief Get the parent of the Region.
294 /// @return The parent of the Region or NULL if this is a top level
296 Region *getParent() const { return RegionNode::getParent(); }
298 /// @brief Get the RegionNode representing the current Region.
299 /// @return The RegionNode representing the current Region.
300 RegionNode* getNode() const {
301 return const_cast<RegionNode*>(reinterpret_cast<const RegionNode*>(this));
304 /// @brief Get the nesting level of this Region.
306 /// An toplevel Region has depth 0.
308 /// @return The depth of the region.
309 unsigned getDepth() const;
311 /// @brief Check if a Region is the TopLevel region.
313 /// The toplevel region represents the whole function.
314 bool isTopLevelRegion() const { return exit == NULL; }
316 /// @brief Return a new (non-canonical) region, that is obtained by joining
317 /// this region with its predecessors.
319 /// @return A region also starting at getEntry(), but reaching to the next
320 /// basic block that forms with getEntry() a (non-canonical) region.
321 /// NULL if such a basic block does not exist.
322 Region *getExpandedRegion() const;
324 /// @brief Return the first block of this region's single entry edge,
327 /// @return The BasicBlock starting this region's single entry edge,
329 BasicBlock *getEnteringBlock() const;
331 /// @brief Return the first block of this region's single exit edge,
334 /// @return The BasicBlock starting this region's single exit edge,
336 BasicBlock *getExitingBlock() const;
338 /// @brief Is this a simple region?
340 /// A region is simple if it has exactly one exit and one entry edge.
342 /// @return True if the Region is simple.
343 bool isSimple() const;
345 /// @brief Returns the name of the Region.
346 /// @return The Name of the Region.
347 std::string getNameStr() const;
349 /// @brief Return the RegionInfo object, that belongs to this Region.
350 RegionInfo *getRegionInfo() const {
354 /// PrintStyle - Print region in difference ways.
355 enum PrintStyle { PrintNone, PrintBB, PrintRN };
357 /// @brief Print the region.
359 /// @param OS The output stream the Region is printed to.
360 /// @param printTree Print also the tree of subregions.
361 /// @param level The indentation level used for printing.
362 void print(raw_ostream& OS, bool printTree = true, unsigned level = 0,
363 enum PrintStyle Style = PrintNone) const;
365 /// @brief Print the region to stderr.
368 /// @brief Check if the region contains a BasicBlock.
370 /// @param BB The BasicBlock that might be contained in this Region.
371 /// @return True if the block is contained in the region otherwise false.
372 bool contains(const BasicBlock *BB) const;
374 /// @brief Check if the region contains another region.
376 /// @param SubRegion The region that might be contained in this Region.
377 /// @return True if SubRegion is contained in the region otherwise false.
378 bool contains(const Region *SubRegion) const {
383 return contains(SubRegion->getEntry())
384 && (contains(SubRegion->getExit()) || SubRegion->getExit() == getExit());
387 /// @brief Check if the region contains an Instruction.
389 /// @param Inst The Instruction that might be contained in this region.
390 /// @return True if the Instruction is contained in the region otherwise false.
391 bool contains(const Instruction *Inst) const {
392 return contains(Inst->getParent());
395 /// @brief Check if the region contains a loop.
397 /// @param L The loop that might be contained in this region.
398 /// @return True if the loop is contained in the region otherwise false.
399 /// In case a NULL pointer is passed to this function the result
400 /// is false, except for the region that describes the whole function.
401 /// In that case true is returned.
402 bool contains(const Loop *L) const;
404 /// @brief Get the outermost loop in the region that contains a loop.
406 /// Find for a Loop L the outermost loop OuterL that is a parent loop of L
407 /// and is itself contained in the region.
409 /// @param L The loop the lookup is started.
410 /// @return The outermost loop in the region, NULL if such a loop does not
411 /// exist or if the region describes the whole function.
412 Loop *outermostLoopInRegion(Loop *L) const;
414 /// @brief Get the outermost loop in the region that contains a basic block.
416 /// Find for a basic block BB the outermost loop L that contains BB and is
417 /// itself contained in the region.
419 /// @param LI A pointer to a LoopInfo analysis.
420 /// @param BB The basic block surrounded by the loop.
421 /// @return The outermost loop in the region, NULL if such a loop does not
422 /// exist or if the region describes the whole function.
423 Loop *outermostLoopInRegion(LoopInfo *LI, BasicBlock* BB) const;
425 /// @brief Get the subregion that starts at a BasicBlock
427 /// @param BB The BasicBlock the subregion should start.
428 /// @return The Subregion if available, otherwise NULL.
429 Region* getSubRegionNode(BasicBlock *BB) const;
431 /// @brief Get the RegionNode for a BasicBlock
433 /// @param BB The BasicBlock at which the RegionNode should start.
434 /// @return If available, the RegionNode that represents the subregion
435 /// starting at BB. If no subregion starts at BB, the RegionNode
437 RegionNode* getNode(BasicBlock *BB) const;
439 /// @brief Get the BasicBlock RegionNode for a BasicBlock
441 /// @param BB The BasicBlock for which the RegionNode is requested.
442 /// @return The RegionNode representing the BB.
443 RegionNode* getBBNode(BasicBlock *BB) const;
445 /// @brief Add a new subregion to this Region.
447 /// @param SubRegion The new subregion that will be added.
448 /// @param moveChildren Move the children of this region, that are also
449 /// contained in SubRegion into SubRegion.
450 void addSubRegion(Region *SubRegion, bool moveChildren = false);
452 /// @brief Remove a subregion from this Region.
454 /// The subregion is not deleted, as it will probably be inserted into another
456 /// @param SubRegion The SubRegion that will be removed.
457 Region *removeSubRegion(Region *SubRegion);
459 /// @brief Move all direct child nodes of this Region to another Region.
461 /// @param To The Region the child nodes will be transferred to.
462 void transferChildrenTo(Region *To);
464 /// @brief Verify if the region is a correct region.
466 /// Check if this is a correctly build Region. This is an expensive check, as
467 /// the complete CFG of the Region will be walked.
468 void verifyRegion() const;
470 /// @brief Clear the cache for BB RegionNodes.
472 /// After calling this function the BasicBlock RegionNodes will be stored at
473 /// different memory locations. RegionNodes obtained before this function is
474 /// called are therefore not comparable to RegionNodes abtained afterwords.
475 void clearNodeCache();
477 /// @name Subregion Iterators
479 /// These iterators iterator over all subregions of this Region.
481 typedef RegionSet::iterator iterator;
482 typedef RegionSet::const_iterator const_iterator;
484 iterator begin() { return children.begin(); }
485 iterator end() { return children.end(); }
487 const_iterator begin() const { return children.begin(); }
488 const_iterator end() const { return children.end(); }
491 /// @name BasicBlock Iterators
493 /// These iterators iterate over all BasicBlocks that are contained in this
494 /// Region. The iterator also iterates over BasicBlocks that are elements of
495 /// a subregion of this Region. It is therefore called a flat iterator.
497 template <bool IsConst>
498 class block_iterator_wrapper
499 : public df_iterator<typename std::conditional<IsConst, const BasicBlock,
500 BasicBlock>::type *> {
501 typedef df_iterator<typename std::conditional<IsConst, const BasicBlock,
502 BasicBlock>::type *> super;
505 typedef block_iterator_wrapper<IsConst> Self;
506 typedef typename super::pointer pointer;
508 // Construct the begin iterator.
509 block_iterator_wrapper(pointer Entry, pointer Exit) : super(df_begin(Entry))
511 // Mark the exit of the region as visited, so that the children of the
512 // exit and the exit itself, i.e. the block outside the region will never
514 super::Visited.insert(Exit);
517 // Construct the end iterator.
518 block_iterator_wrapper() : super(df_end<pointer>((BasicBlock *)0)) {}
520 /*implicit*/ block_iterator_wrapper(super I) : super(I) {}
522 // FIXME: Even a const_iterator returns a non-const BasicBlock pointer.
523 // This was introduced for backwards compatibility, but should
524 // be removed as soon as all users are fixed.
525 BasicBlock *operator*() const {
526 return const_cast<BasicBlock*>(super::operator*());
530 typedef block_iterator_wrapper<false> block_iterator;
531 typedef block_iterator_wrapper<true> const_block_iterator;
533 block_iterator block_begin() {
534 return block_iterator(getEntry(), getExit());
537 block_iterator block_end() {
538 return block_iterator();
541 const_block_iterator block_begin() const {
542 return const_block_iterator(getEntry(), getExit());
544 const_block_iterator block_end() const {
545 return const_block_iterator();
548 typedef iterator_range<block_iterator> block_range;
549 typedef iterator_range<const_block_iterator> const_block_range;
551 /// @brief Returns a range view of the basic blocks in the region.
552 inline block_range blocks() {
553 return block_range(block_begin(), block_end());
556 /// @brief Returns a range view of the basic blocks in the region.
558 /// This is the 'const' version of the range view.
559 inline const_block_range blocks() const {
560 return const_block_range(block_begin(), block_end());
564 /// @name Element Iterators
566 /// These iterators iterate over all BasicBlock and subregion RegionNodes that
567 /// are direct children of this Region. It does not iterate over any
568 /// RegionNodes that are also element of a subregion of this Region.
570 typedef df_iterator<RegionNode*, SmallPtrSet<RegionNode*, 8>, false,
571 GraphTraits<RegionNode*> > element_iterator;
573 typedef df_iterator<const RegionNode*, SmallPtrSet<const RegionNode*, 8>,
574 false, GraphTraits<const RegionNode*> >
575 const_element_iterator;
577 element_iterator element_begin();
578 element_iterator element_end();
580 const_element_iterator element_begin() const;
581 const_element_iterator element_end() const;
585 //===----------------------------------------------------------------------===//
586 /// @brief Analysis that detects all canonical Regions.
588 /// The RegionInfo pass detects all canonical regions in a function. The Regions
589 /// are connected using the parent relation. This builds a Program Structure
591 class RegionInfo : public FunctionPass {
592 typedef DenseMap<BasicBlock*,BasicBlock*> BBtoBBMap;
593 typedef DenseMap<BasicBlock*, Region*> BBtoRegionMap;
594 typedef SmallPtrSet<Region*, 4> RegionSet;
596 RegionInfo(const RegionInfo &) LLVM_DELETED_FUNCTION;
597 const RegionInfo &operator=(const RegionInfo &) LLVM_DELETED_FUNCTION;
600 PostDominatorTree *PDT;
601 DominanceFrontier *DF;
603 /// The top level region.
604 Region *TopLevelRegion;
606 /// Map every BB to the smallest region, that contains BB.
607 BBtoRegionMap BBtoRegion;
609 // isCommonDomFrontier - Returns true if BB is in the dominance frontier of
610 // entry, because it was inherited from exit. In the other case there is an
611 // edge going from entry to BB without passing exit.
612 bool isCommonDomFrontier(BasicBlock* BB, BasicBlock* entry,
613 BasicBlock* exit) const;
615 // isRegion - Check if entry and exit surround a valid region, based on
616 // dominance tree and dominance frontier.
617 bool isRegion(BasicBlock* entry, BasicBlock* exit) const;
619 // insertShortCut - Saves a shortcut pointing from entry to exit.
620 // This function may extend this shortcut if possible.
621 void insertShortCut(BasicBlock* entry, BasicBlock* exit,
622 BBtoBBMap* ShortCut) const;
624 // getNextPostDom - Returns the next BB that postdominates N, while skipping
625 // all post dominators that cannot finish a canonical region.
626 DomTreeNode *getNextPostDom(DomTreeNode* N, BBtoBBMap *ShortCut) const;
628 // isTrivialRegion - A region is trivial, if it contains only one BB.
629 bool isTrivialRegion(BasicBlock *entry, BasicBlock *exit) const;
631 // createRegion - Creates a single entry single exit region.
632 Region *createRegion(BasicBlock *entry, BasicBlock *exit);
634 // findRegionsWithEntry - Detect all regions starting with bb 'entry'.
635 void findRegionsWithEntry(BasicBlock *entry, BBtoBBMap *ShortCut);
637 // scanForRegions - Detects regions in F.
638 void scanForRegions(Function &F, BBtoBBMap *ShortCut);
640 // getTopMostParent - Get the top most parent with the same entry block.
641 Region *getTopMostParent(Region *region);
643 // buildRegionsTree - build the region hierarchy after all region detected.
644 void buildRegionsTree(DomTreeNode *N, Region *region);
646 // Calculate - detecte all regions in function and build the region tree.
647 void Calculate(Function& F);
649 void releaseMemory() override;
651 // updateStatistics - Update statistic about created regions.
652 void updateStatistics(Region *R);
654 // isSimple - Check if a region is a simple region with exactly one entry
655 // edge and exactly one exit edge.
656 bool isSimple(Region* R) const;
660 explicit RegionInfo();
664 /// @name FunctionPass interface
666 bool runOnFunction(Function &F) override;
667 void getAnalysisUsage(AnalysisUsage &AU) const override;
668 void print(raw_ostream &OS, const Module *) const override;
669 void verifyAnalysis() const override;
672 /// @brief Get the smallest region that contains a BasicBlock.
674 /// @param BB The basic block.
675 /// @return The smallest region, that contains BB or NULL, if there is no
676 /// region containing BB.
677 Region *getRegionFor(BasicBlock *BB) const;
679 /// @brief Set the smallest region that surrounds a basic block.
681 /// @param BB The basic block surrounded by a region.
682 /// @param R The smallest region that surrounds BB.
683 void setRegionFor(BasicBlock *BB, Region *R);
685 /// @brief A shortcut for getRegionFor().
687 /// @param BB The basic block.
688 /// @return The smallest region, that contains BB or NULL, if there is no
689 /// region containing BB.
690 Region *operator[](BasicBlock *BB) const;
692 /// @brief Return the exit of the maximal refined region, that starts at a
695 /// @param BB The BasicBlock the refined region starts.
696 BasicBlock *getMaxRegionExit(BasicBlock *BB) const;
698 /// @brief Find the smallest region that contains two regions.
700 /// @param A The first region.
701 /// @param B The second region.
702 /// @return The smallest region containing A and B.
703 Region *getCommonRegion(Region* A, Region *B) const;
705 /// @brief Find the smallest region that contains two basic blocks.
707 /// @param A The first basic block.
708 /// @param B The second basic block.
709 /// @return The smallest region that contains A and B.
710 Region* getCommonRegion(BasicBlock* A, BasicBlock *B) const {
711 return getCommonRegion(getRegionFor(A), getRegionFor(B));
714 /// @brief Find the smallest region that contains a set of regions.
716 /// @param Regions A vector of regions.
717 /// @return The smallest region that contains all regions in Regions.
718 Region* getCommonRegion(SmallVectorImpl<Region*> &Regions) const;
720 /// @brief Find the smallest region that contains a set of basic blocks.
722 /// @param BBs A vector of basic blocks.
723 /// @return The smallest region that contains all basic blocks in BBS.
724 Region* getCommonRegion(SmallVectorImpl<BasicBlock*> &BBs) const;
726 Region *getTopLevelRegion() const {
727 return TopLevelRegion;
730 /// @brief Update RegionInfo after a basic block was split.
732 /// @param NewBB The basic block that was created before OldBB.
733 /// @param OldBB The old basic block.
734 void splitBlock(BasicBlock* NewBB, BasicBlock *OldBB);
736 /// @brief Clear the Node Cache for all Regions.
738 /// @see Region::clearNodeCache()
739 void clearNodeCache() {
741 TopLevelRegion->clearNodeCache();
745 inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node) {
746 if (Node.isSubRegion())
747 return OS << Node.getNodeAs<Region>()->getNameStr();
749 return OS << Node.getNodeAs<BasicBlock>()->getName();
751 } // End llvm namespace