RegionInfo.h revision cc5d992bc167ded99b039ed8fdde190a586a1562
1//===- RegionInfo.h - SESE region analysis ----------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// Calculate a program structure tree built out of single entry single exit 11// regions. 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 15// Koehler - 2009". 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. 24// 25//===----------------------------------------------------------------------===// 26 27#ifndef LLVM_ANALYSIS_REGION_INFO_H 28#define LLVM_ANALYSIS_REGION_INFO_H 29 30#include "llvm/ADT/PointerIntPair.h" 31#include "llvm/Analysis/Dominators.h" 32#include "llvm/Analysis/PostDominators.h" 33#include "llvm/Support/Allocator.h" 34 35namespace llvm { 36 37class Region; 38class RegionInfo; 39class raw_ostream; 40class Loop; 41class LoopInfo; 42 43/// @brief Marker class to iterate over the elements of a Region in flat mode. 44/// 45/// The class is used to either iterate in Flat mode or by not using it to not 46/// iterate in Flat mode. During a Flat mode iteration all Regions are entered 47/// and the iteration returns every BasicBlock. If the Flat mode is not 48/// selected for SubRegions just one RegionNode containing the subregion is 49/// returned. 50template <class GraphType> 51class FlatIt {}; 52 53/// @brief A RegionNode represents a subregion or a BasicBlock that is part of a 54/// Region. 55class RegionNode { 56 // DO NOT IMPLEMENT 57 RegionNode(const RegionNode &); 58 // DO NOT IMPLEMENT 59 const RegionNode &operator=(const RegionNode &); 60 61protected: 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. 65 /// 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. 68 /// 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 71 /// RegionNode. 72 PointerIntPair<BasicBlock*, 1, bool> entry; 73 74 /// @brief The parent Region of this RegionNode. 75 /// @see getParent() 76 Region* parent; 77 78public: 79 /// @brief Create a RegionNode. 80 /// 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) {} 89 90 /// @brief Get the parent Region of this RegionNode. 91 /// 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. 96 /// 97 /// @return Get the parent Region of this RegionNode. 98 inline Region* getParent() const { return parent; } 99 100 /// @brief Get the entry BasicBlock of this RegionNode. 101 /// 102 /// If this RegionNode represents a BasicBlock this is just the BasicBlock 103 /// itself, otherwise we return the entry BasicBlock of the Subregion 104 /// 105 /// @return The entry BasicBlock of this RegionNode. 106 inline BasicBlock* getEntry() const { return entry.getPointer(); } 107 108 /// @brief Get the content of this RegionNode. 109 /// 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. 112 /// 113 /// @return The content of this RegionNode. 114 template<class T> 115 inline T* getNodeAs() const; 116 117 /// @brief Is this RegionNode a subregion? 118 /// 119 /// @return True if it contains a subregion. False if it contains a 120 /// BasicBlock. 121 inline bool isSubRegion() const { 122 return entry.getInt(); 123 } 124}; 125 126/// Print a RegionNode. 127inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node); 128 129template<> 130inline BasicBlock* RegionNode::getNodeAs<BasicBlock>() const { 131 assert(!isSubRegion() && "This is not a BasicBlock RegionNode!"); 132 return getEntry(); 133} 134 135template<> 136inline Region* RegionNode::getNodeAs<Region>() const { 137 assert(isSubRegion() && "This is not a subregion RegionNode!"); 138 return reinterpret_cast<Region*>(const_cast<RegionNode*>(this)); 139} 140 141//===----------------------------------------------------------------------===// 142/// @brief A single entry single exit Region. 143/// 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. 147/// 148/// A <em> simple Region </em> is connected to the remaing graph by just two 149/// edges. One edge entering the Region and another one leaving the Region. 150/// 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. 155/// 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. 159/// 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. 163/// 164/// A <em> canonical Region </em> cannot be constructed by combining smaller 165/// Regions. 166/// 167/// Region A is the \e parent of Region B, if B is completely contained in A. 168/// 169/// Two canonical Regions either do not intersect at all or one is 170/// the parent of the other. 171/// 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 174/// Regions. 175/// 176/// Example: 177/// 178/// \verbatim 179/// A simple control flow graph, that contains two regions. 180/// 181/// 1 182/// / | 183/// 2 | 184/// / \ 3 185/// 4 5 | 186/// | | | 187/// 6 7 8 188/// \ | / 189/// \ |/ Region A: 1 -> 9 {1,2,3,4,5,6,7,8} 190/// 9 Region B: 2 -> 9 {2,4,5,6,7} 191/// \endverbatim 192/// 193/// You can obtain more examples by either calling 194/// 195/// <tt> "opt -regions -analyze anyprogram.ll" </tt> 196/// or 197/// <tt> "opt -view-regions-only anyprogram.ll" </tt> 198/// 199/// on any LLVM file you are interested in. 200/// 201/// The first call returns a textual representation of the program structure 202/// tree, the second one creates a graphical representation using graphviz. 203class Region : public RegionNode { 204 friend class RegionInfo; 205 // DO NOT IMPLEMENT 206 Region(const Region &); 207 // DO NOT IMPLEMENT 208 const Region &operator=(const Region &); 209 210 // Information necessary to manage this Region. 211 RegionInfo* RI; 212 DominatorTree *DT; 213 214 // The exit BasicBlock of this region. 215 // (The entry BasicBlock is part of RegionNode) 216 BasicBlock *exit; 217 218 typedef std::vector<Region*> RegionSet; 219 220 // The subregions of this region. 221 RegionSet children; 222 223 typedef std::map<BasicBlock*, RegionNode*> BBNodeMapT; 224 225 // Save the BasicBlock RegionNodes that are element of this Region. 226 mutable BBNodeMapT BBNodeMap; 227 228 /// verifyBBInRegion - Check if a BB is in this Region. This check also works 229 /// if the region is incorrectly built. (EXPENSIVE!) 230 void verifyBBInRegion(BasicBlock* BB) const; 231 232 /// verifyWalk - Walk over all the BBs of the region starting from BB and 233 /// verify that all reachable basic blocks are elements of the region. 234 /// (EXPENSIVE!) 235 void verifyWalk(BasicBlock* BB, std::set<BasicBlock*>* visitedBB) const; 236 237 /// verifyRegionNest - Verify if the region and its children are valid 238 /// regions (EXPENSIVE!) 239 void verifyRegionNest() const; 240 241public: 242 /// @brief Create a new region. 243 /// 244 /// @param Entry The entry basic block of the region. 245 /// @param Exit The exit basic block of the region. 246 /// @param RI The region info object that is managing this region. 247 /// @param DT The dominator tree of the current function. 248 /// @param Parent The surrounding region or NULL if this is a top level 249 /// region. 250 Region(BasicBlock *Entry, BasicBlock *Exit, RegionInfo* RI, 251 DominatorTree *DT, Region *Parent = 0); 252 253 /// Delete the Region and all its subregions. 254 ~Region(); 255 256 /// @brief Get the entry BasicBlock of the Region. 257 /// @return The entry BasicBlock of the region. 258 BasicBlock *getEntry() const { return RegionNode::getEntry(); } 259 260 /// @brief Replace the entry basic block of the region with the new basic 261 /// block. 262 /// 263 /// @param BB The new entry basic block of the region. 264 void replaceEntry(BasicBlock *BB); 265 266 /// @brief Replace the exit basic block of the region with the new basic 267 /// block. 268 /// 269 /// @param BB The new exit basic block of the region. 270 void replaceExit(BasicBlock *BB); 271 272 /// @brief Get the exit BasicBlock of the Region. 273 /// @return The exit BasicBlock of the Region, NULL if this is the TopLevel 274 /// Region. 275 BasicBlock *getExit() const { return exit; } 276 277 /// @brief Get the parent of the Region. 278 /// @return The parent of the Region or NULL if this is a top level 279 /// Region. 280 Region *getParent() const { return RegionNode::getParent(); } 281 282 /// @brief Get the RegionNode representing the current Region. 283 /// @return The RegionNode representing the current Region. 284 RegionNode* getNode() const { 285 return const_cast<RegionNode*>(reinterpret_cast<const RegionNode*>(this)); 286 } 287 288 /// @brief Get the nesting level of this Region. 289 /// 290 /// An toplevel Region has depth 0. 291 /// 292 /// @return The depth of the region. 293 unsigned getDepth() const; 294 295 /// @brief Check if a Region is the TopLevel region. 296 /// 297 /// The toplevel region represents the whole function. 298 bool isTopLevelRegion() const { return exit == NULL; } 299 300 /// @brief Return a new (non canonical) region, that is obtained by joining 301 /// this region with its predecessors. 302 /// 303 /// @return A region also starting at getEntry(), but reaching to the next 304 /// basic block that forms with getEntry() a (non canonical) region. 305 /// NULL if such a basic block does not exist. 306 Region *getExpandedRegion() const; 307 308 /// @brief Return the first block of this region's single entry edge, 309 /// if existing. 310 /// 311 /// @return The BasicBlock starting this region's single entry edge, 312 /// else NULL. 313 BasicBlock *getEnteringBlock() const; 314 315 /// @brief Return the first block of this region's single exit edge, 316 /// if existing. 317 /// 318 /// @return The BasicBlock starting this region's single exit edge, 319 /// else NULL. 320 BasicBlock *getExitingBlock() const; 321 322 /// @brief Is this a simple region? 323 /// 324 /// A region is simple if it has exactly one exit and one entry edge. 325 /// 326 /// @return True if the Region is simple. 327 bool isSimple() const; 328 329 /// @brief Returns the name of the Region. 330 /// @return The Name of the Region. 331 std::string getNameStr() const; 332 333 /// @brief Return the RegionInfo object, that belongs to this Region. 334 RegionInfo *getRegionInfo() const { 335 return RI; 336 } 337 338 /// PrintStyle - Print region in difference ways. 339 enum PrintStyle { PrintNone, PrintBB, PrintRN }; 340 341 /// @brief Print the region. 342 /// 343 /// @param OS The output stream the Region is printed to. 344 /// @param printTree Print also the tree of subregions. 345 /// @param level The indentation level used for printing. 346 void print(raw_ostream& OS, bool printTree = true, unsigned level = 0, 347 enum PrintStyle Style = PrintNone) const; 348 349 /// @brief Print the region to stderr. 350 void dump() const; 351 352 /// @brief Check if the region contains a BasicBlock. 353 /// 354 /// @param BB The BasicBlock that might be contained in this Region. 355 /// @return True if the block is contained in the region otherwise false. 356 bool contains(const BasicBlock *BB) const; 357 358 /// @brief Check if the region contains another region. 359 /// 360 /// @param SubRegion The region that might be contained in this Region. 361 /// @return True if SubRegion is contained in the region otherwise false. 362 bool contains(const Region *SubRegion) const { 363 // Toplevel Region. 364 if (!getExit()) 365 return true; 366 367 return contains(SubRegion->getEntry()) 368 && (contains(SubRegion->getExit()) || SubRegion->getExit() == getExit()); 369 } 370 371 /// @brief Check if the region contains an Instruction. 372 /// 373 /// @param Inst The Instruction that might be contained in this region. 374 /// @return True if the Instruction is contained in the region otherwise false. 375 bool contains(const Instruction *Inst) const { 376 return contains(Inst->getParent()); 377 } 378 379 /// @brief Check if the region contains a loop. 380 /// 381 /// @param L The loop that might be contained in this region. 382 /// @return True if the loop is contained in the region otherwise false. 383 /// In case a NULL pointer is passed to this function the result 384 /// is false, except for the region that describes the whole function. 385 /// In that case true is returned. 386 bool contains(const Loop *L) const; 387 388 /// @brief Get the outermost loop in the region that contains a loop. 389 /// 390 /// Find for a Loop L the outermost loop OuterL that is a parent loop of L 391 /// and is itself contained in the region. 392 /// 393 /// @param L The loop the lookup is started. 394 /// @return The outermost loop in the region, NULL if such a loop does not 395 /// exist or if the region describes the whole function. 396 Loop *outermostLoopInRegion(Loop *L) const; 397 398 /// @brief Get the outermost loop in the region that contains a basic block. 399 /// 400 /// Find for a basic block BB the outermost loop L that contains BB and is 401 /// itself contained in the region. 402 /// 403 /// @param LI A pointer to a LoopInfo analysis. 404 /// @param BB The basic block surrounded by the loop. 405 /// @return The outermost loop in the region, NULL if such a loop does not 406 /// exist or if the region describes the whole function. 407 Loop *outermostLoopInRegion(LoopInfo *LI, BasicBlock* BB) const; 408 409 /// @brief Get the subregion that starts at a BasicBlock 410 /// 411 /// @param BB The BasicBlock the subregion should start. 412 /// @return The Subregion if available, otherwise NULL. 413 Region* getSubRegionNode(BasicBlock *BB) const; 414 415 /// @brief Get the RegionNode for a BasicBlock 416 /// 417 /// @param BB The BasicBlock at which the RegionNode should start. 418 /// @return If available, the RegionNode that represents the subregion 419 /// starting at BB. If no subregion starts at BB, the RegionNode 420 /// representing BB. 421 RegionNode* getNode(BasicBlock *BB) const; 422 423 /// @brief Get the BasicBlock RegionNode for a BasicBlock 424 /// 425 /// @param BB The BasicBlock for which the RegionNode is requested. 426 /// @return The RegionNode representing the BB. 427 RegionNode* getBBNode(BasicBlock *BB) const; 428 429 /// @brief Add a new subregion to this Region. 430 /// 431 /// @param SubRegion The new subregion that will be added. 432 /// @param moveChildren Move the children of this region, that are also 433 /// contained in SubRegion into SubRegion. 434 void addSubRegion(Region *SubRegion, bool moveChildren = false); 435 436 /// @brief Remove a subregion from this Region. 437 /// 438 /// The subregion is not deleted, as it will probably be inserted into another 439 /// region. 440 /// @param SubRegion The SubRegion that will be removed. 441 Region *removeSubRegion(Region *SubRegion); 442 443 /// @brief Move all direct child nodes of this Region to another Region. 444 /// 445 /// @param To The Region the child nodes will be transfered to. 446 void transferChildrenTo(Region *To); 447 448 /// @brief Verify if the region is a correct region. 449 /// 450 /// Check if this is a correctly build Region. This is an expensive check, as 451 /// the complete CFG of the Region will be walked. 452 void verifyRegion() const; 453 454 /// @brief Clear the cache for BB RegionNodes. 455 /// 456 /// After calling this function the BasicBlock RegionNodes will be stored at 457 /// different memory locations. RegionNodes obtained before this function is 458 /// called are therefore not comparable to RegionNodes abtained afterwords. 459 void clearNodeCache(); 460 461 /// @name Subregion Iterators 462 /// 463 /// These iterators iterator over all subregions of this Region. 464 //@{ 465 typedef RegionSet::iterator iterator; 466 typedef RegionSet::const_iterator const_iterator; 467 468 iterator begin() { return children.begin(); } 469 iterator end() { return children.end(); } 470 471 const_iterator begin() const { return children.begin(); } 472 const_iterator end() const { return children.end(); } 473 //@} 474 475 /// @name BasicBlock Iterators 476 /// 477 /// These iterators iterate over all BasicBlock RegionNodes that are 478 /// contained in this Region. The iterator also iterates over BasicBlocks 479 /// that are elements of a subregion of this Region. It is therefore called a 480 /// flat iterator. 481 //@{ 482 typedef df_iterator<RegionNode*, SmallPtrSet<RegionNode*, 8>, false, 483 GraphTraits<FlatIt<RegionNode*> > > block_iterator; 484 485 typedef df_iterator<const RegionNode*, SmallPtrSet<const RegionNode*, 8>, 486 false, GraphTraits<FlatIt<const RegionNode*> > > 487 const_block_iterator; 488 489 block_iterator block_begin(); 490 block_iterator block_end(); 491 492 const_block_iterator block_begin() const; 493 const_block_iterator block_end() const; 494 //@} 495 496 /// @name Element Iterators 497 /// 498 /// These iterators iterate over all BasicBlock and subregion RegionNodes that 499 /// are direct children of this Region. It does not iterate over any 500 /// RegionNodes that are also element of a subregion of this Region. 501 //@{ 502 typedef df_iterator<RegionNode*, SmallPtrSet<RegionNode*, 8>, false, 503 GraphTraits<RegionNode*> > element_iterator; 504 505 typedef df_iterator<const RegionNode*, SmallPtrSet<const RegionNode*, 8>, 506 false, GraphTraits<const RegionNode*> > 507 const_element_iterator; 508 509 element_iterator element_begin(); 510 element_iterator element_end(); 511 512 const_element_iterator element_begin() const; 513 const_element_iterator element_end() const; 514 //@} 515}; 516 517//===----------------------------------------------------------------------===// 518/// @brief Analysis that detects all canonical Regions. 519/// 520/// The RegionInfo pass detects all canonical regions in a function. The Regions 521/// are connected using the parent relation. This builds a Program Structure 522/// Tree. 523class RegionInfo : public FunctionPass { 524 typedef DenseMap<BasicBlock*,BasicBlock*> BBtoBBMap; 525 typedef DenseMap<BasicBlock*, Region*> BBtoRegionMap; 526 typedef SmallPtrSet<Region*, 4> RegionSet; 527 528 // DO NOT IMPLEMENT 529 RegionInfo(const RegionInfo &); 530 // DO NOT IMPLEMENT 531 const RegionInfo &operator=(const RegionInfo &); 532 533 DominatorTree *DT; 534 PostDominatorTree *PDT; 535 DominanceFrontier *DF; 536 537 /// The top level region. 538 Region *TopLevelRegion; 539 540 /// Map every BB to the smallest region, that contains BB. 541 BBtoRegionMap BBtoRegion; 542 543 // isCommonDomFrontier - Returns true if BB is in the dominance frontier of 544 // entry, because it was inherited from exit. In the other case there is an 545 // edge going from entry to BB without passing exit. 546 bool isCommonDomFrontier(BasicBlock* BB, BasicBlock* entry, 547 BasicBlock* exit) const; 548 549 // isRegion - Check if entry and exit surround a valid region, based on 550 // dominance tree and dominance frontier. 551 bool isRegion(BasicBlock* entry, BasicBlock* exit) const; 552 553 // insertShortCut - Saves a shortcut pointing from entry to exit. 554 // This function may extend this shortcut if possible. 555 void insertShortCut(BasicBlock* entry, BasicBlock* exit, 556 BBtoBBMap* ShortCut) const; 557 558 // getNextPostDom - Returns the next BB that postdominates N, while skipping 559 // all post dominators that cannot finish a canonical region. 560 DomTreeNode *getNextPostDom(DomTreeNode* N, BBtoBBMap *ShortCut) const; 561 562 // isTrivialRegion - A region is trivial, if it contains only one BB. 563 bool isTrivialRegion(BasicBlock *entry, BasicBlock *exit) const; 564 565 // createRegion - Creates a single entry single exit region. 566 Region *createRegion(BasicBlock *entry, BasicBlock *exit); 567 568 // findRegionsWithEntry - Detect all regions starting with bb 'entry'. 569 void findRegionsWithEntry(BasicBlock *entry, BBtoBBMap *ShortCut); 570 571 // scanForRegions - Detects regions in F. 572 void scanForRegions(Function &F, BBtoBBMap *ShortCut); 573 574 // getTopMostParent - Get the top most parent with the same entry block. 575 Region *getTopMostParent(Region *region); 576 577 // buildRegionsTree - build the region hierarchy after all region detected. 578 void buildRegionsTree(DomTreeNode *N, Region *region); 579 580 // Calculate - detecte all regions in function and build the region tree. 581 void Calculate(Function& F); 582 583 void releaseMemory(); 584 585 // updateStatistics - Update statistic about created regions. 586 void updateStatistics(Region *R); 587 588 // isSimple - Check if a region is a simple region with exactly one entry 589 // edge and exactly one exit edge. 590 bool isSimple(Region* R) const; 591 592public: 593 static char ID; 594 explicit RegionInfo(); 595 596 ~RegionInfo(); 597 598 /// @name FunctionPass interface 599 //@{ 600 virtual bool runOnFunction(Function &F); 601 virtual void getAnalysisUsage(AnalysisUsage &AU) const; 602 virtual void print(raw_ostream &OS, const Module *) const; 603 virtual void verifyAnalysis() const; 604 //@} 605 606 /// @brief Get the smallest region that contains a BasicBlock. 607 /// 608 /// @param BB The basic block. 609 /// @return The smallest region, that contains BB or NULL, if there is no 610 /// region containing BB. 611 Region *getRegionFor(BasicBlock *BB) const; 612 613 /// @brief Set the smallest region that surrounds a basic block. 614 /// 615 /// @param BB The basic block surrounded by a region. 616 /// @param R The smallest region that surrounds BB. 617 void setRegionFor(BasicBlock *BB, Region *R); 618 619 /// @brief A shortcut for getRegionFor(). 620 /// 621 /// @param BB The basic block. 622 /// @return The smallest region, that contains BB or NULL, if there is no 623 /// region containing BB. 624 Region *operator[](BasicBlock *BB) const; 625 626 /// @brief Return the exit of the maximal refined region, that starts at a 627 /// BasicBlock. 628 /// 629 /// @param BB The BasicBlock the refined region starts. 630 BasicBlock *getMaxRegionExit(BasicBlock *BB) const; 631 632 /// @brief Find the smallest region that contains two regions. 633 /// 634 /// @param A The first region. 635 /// @param B The second region. 636 /// @return The smallest region containing A and B. 637 Region *getCommonRegion(Region* A, Region *B) const; 638 639 /// @brief Find the smallest region that contains two basic blocks. 640 /// 641 /// @param A The first basic block. 642 /// @param B The second basic block. 643 /// @return The smallest region that contains A and B. 644 Region* getCommonRegion(BasicBlock* A, BasicBlock *B) const { 645 return getCommonRegion(getRegionFor(A), getRegionFor(B)); 646 } 647 648 /// @brief Find the smallest region that contains a set of regions. 649 /// 650 /// @param Regions A vector of regions. 651 /// @return The smallest region that contains all regions in Regions. 652 Region* getCommonRegion(SmallVectorImpl<Region*> &Regions) const; 653 654 /// @brief Find the smallest region that contains a set of basic blocks. 655 /// 656 /// @param BBs A vector of basic blocks. 657 /// @return The smallest region that contains all basic blocks in BBS. 658 Region* getCommonRegion(SmallVectorImpl<BasicBlock*> &BBs) const; 659 660 Region *getTopLevelRegion() const { 661 return TopLevelRegion; 662 } 663 664 /// @brief Update RegionInfo after a basic block was split. 665 /// 666 /// @param NewBB The basic block that was created before OldBB. 667 /// @param OldBB The old basic block. 668 void splitBlock(BasicBlock* NewBB, BasicBlock *OldBB); 669 670 /// @brief Clear the Node Cache for all Regions. 671 /// 672 /// @see Region::clearNodeCache() 673 void clearNodeCache() { 674 if (TopLevelRegion) 675 TopLevelRegion->clearNodeCache(); 676 } 677}; 678 679inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node) { 680 if (Node.isSubRegion()) 681 return OS << Node.getNodeAs<Region>()->getNameStr(); 682 else 683 return OS << Node.getNodeAs<BasicBlock>()->getNameStr(); 684} 685} // End llvm namespace 686#endif 687 688