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/DominanceFrontier.h" 32#include "llvm/Analysis/PostDominators.h" 33#include "llvm/Support/Allocator.h" 34#include <map> 35 36namespace llvm { 37 38class Region; 39class RegionInfo; 40class raw_ostream; 41class Loop; 42class LoopInfo; 43 44/// @brief Marker class to iterate over the elements of a Region in flat mode. 45/// 46/// The class is used to either iterate in Flat mode or by not using it to not 47/// iterate in Flat mode. During a Flat mode iteration all Regions are entered 48/// and the iteration returns every BasicBlock. If the Flat mode is not 49/// selected for SubRegions just one RegionNode containing the subregion is 50/// returned. 51template <class GraphType> 52class FlatIt {}; 53 54/// @brief A RegionNode represents a subregion or a BasicBlock that is part of a 55/// Region. 56class RegionNode { 57 // DO NOT IMPLEMENT 58 RegionNode(const RegionNode &); 59 // DO NOT IMPLEMENT 60 const RegionNode &operator=(const RegionNode &); 61 62protected: 63 /// This is the entry basic block that starts this region node. If this is a 64 /// BasicBlock RegionNode, then entry is just the basic block, that this 65 /// RegionNode represents. Otherwise it is the entry of this (Sub)RegionNode. 66 /// 67 /// In the BBtoRegionNode map of the parent of this node, BB will always map 68 /// to this node no matter which kind of node this one is. 69 /// 70 /// The node can hold either a Region or a BasicBlock. 71 /// Use one bit to save, if this RegionNode is a subregion or BasicBlock 72 /// RegionNode. 73 PointerIntPair<BasicBlock*, 1, bool> entry; 74 75 /// @brief The parent Region of this RegionNode. 76 /// @see getParent() 77 Region* parent; 78 79public: 80 /// @brief Create a RegionNode. 81 /// 82 /// @param Parent The parent of this RegionNode. 83 /// @param Entry The entry BasicBlock of the RegionNode. If this 84 /// RegionNode represents a BasicBlock, this is the 85 /// BasicBlock itself. If it represents a subregion, this 86 /// is the entry BasicBlock of the subregion. 87 /// @param isSubRegion If this RegionNode represents a SubRegion. 88 inline RegionNode(Region* Parent, BasicBlock* Entry, bool isSubRegion = 0) 89 : entry(Entry, isSubRegion), parent(Parent) {} 90 91 /// @brief Get the parent Region of this RegionNode. 92 /// 93 /// The parent Region is the Region this RegionNode belongs to. If for 94 /// example a BasicBlock is element of two Regions, there exist two 95 /// RegionNodes for this BasicBlock. Each with the getParent() function 96 /// pointing to the Region this RegionNode belongs to. 97 /// 98 /// @return Get the parent Region of this RegionNode. 99 inline Region* getParent() const { return parent; } 100 101 /// @brief Get the entry BasicBlock of this RegionNode. 102 /// 103 /// If this RegionNode represents a BasicBlock this is just the BasicBlock 104 /// itself, otherwise we return the entry BasicBlock of the Subregion 105 /// 106 /// @return The entry BasicBlock of this RegionNode. 107 inline BasicBlock* getEntry() const { return entry.getPointer(); } 108 109 /// @brief Get the content of this RegionNode. 110 /// 111 /// This can be either a BasicBlock or a subregion. Before calling getNodeAs() 112 /// check the type of the content with the isSubRegion() function call. 113 /// 114 /// @return The content of this RegionNode. 115 template<class T> 116 inline T* getNodeAs() const; 117 118 /// @brief Is this RegionNode a subregion? 119 /// 120 /// @return True if it contains a subregion. False if it contains a 121 /// BasicBlock. 122 inline bool isSubRegion() const { 123 return entry.getInt(); 124 } 125}; 126 127/// Print a RegionNode. 128inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node); 129 130template<> 131inline BasicBlock* RegionNode::getNodeAs<BasicBlock>() const { 132 assert(!isSubRegion() && "This is not a BasicBlock RegionNode!"); 133 return getEntry(); 134} 135 136template<> 137inline Region* RegionNode::getNodeAs<Region>() const { 138 assert(isSubRegion() && "This is not a subregion RegionNode!"); 139 return reinterpret_cast<Region*>(const_cast<RegionNode*>(this)); 140} 141 142//===----------------------------------------------------------------------===// 143/// @brief A single entry single exit Region. 144/// 145/// A Region is a connected subgraph of a control flow graph that has exactly 146/// two connections to the remaining graph. It can be used to analyze or 147/// optimize parts of the control flow graph. 148/// 149/// A <em> simple Region </em> is connected to the remaining graph by just two 150/// edges. One edge entering the Region and another one leaving the Region. 151/// 152/// An <em> extended Region </em> (or just Region) is a subgraph that can be 153/// transform into a simple Region. The transformation is done by adding 154/// BasicBlocks that merge several entry or exit edges so that after the merge 155/// just one entry and one exit edge exists. 156/// 157/// The \e Entry of a Region is the first BasicBlock that is passed after 158/// entering the Region. It is an element of the Region. The entry BasicBlock 159/// dominates all BasicBlocks in the Region. 160/// 161/// The \e Exit of a Region is the first BasicBlock that is passed after 162/// leaving the Region. It is not an element of the Region. The exit BasicBlock, 163/// postdominates all BasicBlocks in the Region. 164/// 165/// A <em> canonical Region </em> cannot be constructed by combining smaller 166/// Regions. 167/// 168/// Region A is the \e parent of Region B, if B is completely contained in A. 169/// 170/// Two canonical Regions either do not intersect at all or one is 171/// the parent of the other. 172/// 173/// The <em> Program Structure Tree</em> is a graph (V, E) where V is the set of 174/// Regions in the control flow graph and E is the \e parent relation of these 175/// Regions. 176/// 177/// Example: 178/// 179/// \verbatim 180/// A simple control flow graph, that contains two regions. 181/// 182/// 1 183/// / | 184/// 2 | 185/// / \ 3 186/// 4 5 | 187/// | | | 188/// 6 7 8 189/// \ | / 190/// \ |/ Region A: 1 -> 9 {1,2,3,4,5,6,7,8} 191/// 9 Region B: 2 -> 9 {2,4,5,6,7} 192/// \endverbatim 193/// 194/// You can obtain more examples by either calling 195/// 196/// <tt> "opt -regions -analyze anyprogram.ll" </tt> 197/// or 198/// <tt> "opt -view-regions-only anyprogram.ll" </tt> 199/// 200/// on any LLVM file you are interested in. 201/// 202/// The first call returns a textual representation of the program structure 203/// tree, the second one creates a graphical representation using graphviz. 204class Region : public RegionNode { 205 friend class RegionInfo; 206 // DO NOT IMPLEMENT 207 Region(const Region &); 208 // DO NOT IMPLEMENT 209 const Region &operator=(const Region &); 210 211 // Information necessary to manage this Region. 212 RegionInfo* RI; 213 DominatorTree *DT; 214 215 // The exit BasicBlock of this region. 216 // (The entry BasicBlock is part of RegionNode) 217 BasicBlock *exit; 218 219 typedef std::vector<Region*> RegionSet; 220 221 // The subregions of this region. 222 RegionSet children; 223 224 typedef std::map<BasicBlock*, RegionNode*> BBNodeMapT; 225 226 // Save the BasicBlock RegionNodes that are element of this Region. 227 mutable BBNodeMapT BBNodeMap; 228 229 /// verifyBBInRegion - Check if a BB is in this Region. This check also works 230 /// if the region is incorrectly built. (EXPENSIVE!) 231 void verifyBBInRegion(BasicBlock* BB) const; 232 233 /// verifyWalk - Walk over all the BBs of the region starting from BB and 234 /// verify that all reachable basic blocks are elements of the region. 235 /// (EXPENSIVE!) 236 void verifyWalk(BasicBlock* BB, std::set<BasicBlock*>* visitedBB) const; 237 238 /// verifyRegionNest - Verify if the region and its children are valid 239 /// regions (EXPENSIVE!) 240 void verifyRegionNest() const; 241 242public: 243 /// @brief Create a new region. 244 /// 245 /// @param Entry The entry basic block of the region. 246 /// @param Exit The exit basic block of the region. 247 /// @param RI The region info object that is managing this region. 248 /// @param DT The dominator tree of the current function. 249 /// @param Parent The surrounding region or NULL if this is a top level 250 /// region. 251 Region(BasicBlock *Entry, BasicBlock *Exit, RegionInfo* RI, 252 DominatorTree *DT, Region *Parent = 0); 253 254 /// Delete the Region and all its subregions. 255 ~Region(); 256 257 /// @brief Get the entry BasicBlock of the Region. 258 /// @return The entry BasicBlock of the region. 259 BasicBlock *getEntry() const { return RegionNode::getEntry(); } 260 261 /// @brief Replace the entry basic block of the region with the new basic 262 /// block. 263 /// 264 /// @param BB The new entry basic block of the region. 265 void replaceEntry(BasicBlock *BB); 266 267 /// @brief Replace the exit basic block of the region with the new basic 268 /// block. 269 /// 270 /// @param BB The new exit basic block of the region. 271 void replaceExit(BasicBlock *BB); 272 273 /// @brief Get the exit BasicBlock of the Region. 274 /// @return The exit BasicBlock of the Region, NULL if this is the TopLevel 275 /// Region. 276 BasicBlock *getExit() const { return exit; } 277 278 /// @brief Get the parent of the Region. 279 /// @return The parent of the Region or NULL if this is a top level 280 /// Region. 281 Region *getParent() const { return RegionNode::getParent(); } 282 283 /// @brief Get the RegionNode representing the current Region. 284 /// @return The RegionNode representing the current Region. 285 RegionNode* getNode() const { 286 return const_cast<RegionNode*>(reinterpret_cast<const RegionNode*>(this)); 287 } 288 289 /// @brief Get the nesting level of this Region. 290 /// 291 /// An toplevel Region has depth 0. 292 /// 293 /// @return The depth of the region. 294 unsigned getDepth() const; 295 296 /// @brief Check if a Region is the TopLevel region. 297 /// 298 /// The toplevel region represents the whole function. 299 bool isTopLevelRegion() const { return exit == NULL; } 300 301 /// @brief Return a new (non canonical) region, that is obtained by joining 302 /// this region with its predecessors. 303 /// 304 /// @return A region also starting at getEntry(), but reaching to the next 305 /// basic block that forms with getEntry() a (non canonical) region. 306 /// NULL if such a basic block does not exist. 307 Region *getExpandedRegion() const; 308 309 /// @brief Return the first block of this region's single entry edge, 310 /// if existing. 311 /// 312 /// @return The BasicBlock starting this region's single entry edge, 313 /// else NULL. 314 BasicBlock *getEnteringBlock() const; 315 316 /// @brief Return the first block of this region's single exit edge, 317 /// if existing. 318 /// 319 /// @return The BasicBlock starting this region's single exit edge, 320 /// else NULL. 321 BasicBlock *getExitingBlock() const; 322 323 /// @brief Is this a simple region? 324 /// 325 /// A region is simple if it has exactly one exit and one entry edge. 326 /// 327 /// @return True if the Region is simple. 328 bool isSimple() const; 329 330 /// @brief Returns the name of the Region. 331 /// @return The Name of the Region. 332 std::string getNameStr() const; 333 334 /// @brief Return the RegionInfo object, that belongs to this Region. 335 RegionInfo *getRegionInfo() const { 336 return RI; 337 } 338 339 /// PrintStyle - Print region in difference ways. 340 enum PrintStyle { PrintNone, PrintBB, PrintRN }; 341 342 /// @brief Print the region. 343 /// 344 /// @param OS The output stream the Region is printed to. 345 /// @param printTree Print also the tree of subregions. 346 /// @param level The indentation level used for printing. 347 void print(raw_ostream& OS, bool printTree = true, unsigned level = 0, 348 enum PrintStyle Style = PrintNone) const; 349 350 /// @brief Print the region to stderr. 351 void dump() const; 352 353 /// @brief Check if the region contains a BasicBlock. 354 /// 355 /// @param BB The BasicBlock that might be contained in this Region. 356 /// @return True if the block is contained in the region otherwise false. 357 bool contains(const BasicBlock *BB) const; 358 359 /// @brief Check if the region contains another region. 360 /// 361 /// @param SubRegion The region that might be contained in this Region. 362 /// @return True if SubRegion is contained in the region otherwise false. 363 bool contains(const Region *SubRegion) const { 364 // Toplevel Region. 365 if (!getExit()) 366 return true; 367 368 return contains(SubRegion->getEntry()) 369 && (contains(SubRegion->getExit()) || SubRegion->getExit() == getExit()); 370 } 371 372 /// @brief Check if the region contains an Instruction. 373 /// 374 /// @param Inst The Instruction that might be contained in this region. 375 /// @return True if the Instruction is contained in the region otherwise false. 376 bool contains(const Instruction *Inst) const { 377 return contains(Inst->getParent()); 378 } 379 380 /// @brief Check if the region contains a loop. 381 /// 382 /// @param L The loop that might be contained in this region. 383 /// @return True if the loop is contained in the region otherwise false. 384 /// In case a NULL pointer is passed to this function the result 385 /// is false, except for the region that describes the whole function. 386 /// In that case true is returned. 387 bool contains(const Loop *L) const; 388 389 /// @brief Get the outermost loop in the region that contains a loop. 390 /// 391 /// Find for a Loop L the outermost loop OuterL that is a parent loop of L 392 /// and is itself contained in the region. 393 /// 394 /// @param L The loop the lookup is started. 395 /// @return The outermost loop in the region, NULL if such a loop does not 396 /// exist or if the region describes the whole function. 397 Loop *outermostLoopInRegion(Loop *L) const; 398 399 /// @brief Get the outermost loop in the region that contains a basic block. 400 /// 401 /// Find for a basic block BB the outermost loop L that contains BB and is 402 /// itself contained in the region. 403 /// 404 /// @param LI A pointer to a LoopInfo analysis. 405 /// @param BB The basic block surrounded by the loop. 406 /// @return The outermost loop in the region, NULL if such a loop does not 407 /// exist or if the region describes the whole function. 408 Loop *outermostLoopInRegion(LoopInfo *LI, BasicBlock* BB) const; 409 410 /// @brief Get the subregion that starts at a BasicBlock 411 /// 412 /// @param BB The BasicBlock the subregion should start. 413 /// @return The Subregion if available, otherwise NULL. 414 Region* getSubRegionNode(BasicBlock *BB) const; 415 416 /// @brief Get the RegionNode for a BasicBlock 417 /// 418 /// @param BB The BasicBlock at which the RegionNode should start. 419 /// @return If available, the RegionNode that represents the subregion 420 /// starting at BB. If no subregion starts at BB, the RegionNode 421 /// representing BB. 422 RegionNode* getNode(BasicBlock *BB) const; 423 424 /// @brief Get the BasicBlock RegionNode for a BasicBlock 425 /// 426 /// @param BB The BasicBlock for which the RegionNode is requested. 427 /// @return The RegionNode representing the BB. 428 RegionNode* getBBNode(BasicBlock *BB) const; 429 430 /// @brief Add a new subregion to this Region. 431 /// 432 /// @param SubRegion The new subregion that will be added. 433 /// @param moveChildren Move the children of this region, that are also 434 /// contained in SubRegion into SubRegion. 435 void addSubRegion(Region *SubRegion, bool moveChildren = false); 436 437 /// @brief Remove a subregion from this Region. 438 /// 439 /// The subregion is not deleted, as it will probably be inserted into another 440 /// region. 441 /// @param SubRegion The SubRegion that will be removed. 442 Region *removeSubRegion(Region *SubRegion); 443 444 /// @brief Move all direct child nodes of this Region to another Region. 445 /// 446 /// @param To The Region the child nodes will be transferred to. 447 void transferChildrenTo(Region *To); 448 449 /// @brief Verify if the region is a correct region. 450 /// 451 /// Check if this is a correctly build Region. This is an expensive check, as 452 /// the complete CFG of the Region will be walked. 453 void verifyRegion() const; 454 455 /// @brief Clear the cache for BB RegionNodes. 456 /// 457 /// After calling this function the BasicBlock RegionNodes will be stored at 458 /// different memory locations. RegionNodes obtained before this function is 459 /// called are therefore not comparable to RegionNodes abtained afterwords. 460 void clearNodeCache(); 461 462 /// @name Subregion Iterators 463 /// 464 /// These iterators iterator over all subregions of this Region. 465 //@{ 466 typedef RegionSet::iterator iterator; 467 typedef RegionSet::const_iterator const_iterator; 468 469 iterator begin() { return children.begin(); } 470 iterator end() { return children.end(); } 471 472 const_iterator begin() const { return children.begin(); } 473 const_iterator end() const { return children.end(); } 474 //@} 475 476 /// @name BasicBlock Iterators 477 /// 478 /// These iterators iterate over all BasicBlocks that are contained in this 479 /// Region. The iterator also iterates over BasicBlocks that are elements of 480 /// a subregion of this Region. It is therefore called a flat iterator. 481 //@{ 482 template <bool IsConst> 483 class block_iterator_wrapper 484 : public df_iterator<typename conditional<IsConst, 485 const BasicBlock, 486 BasicBlock>::type*> { 487 typedef df_iterator<typename conditional<IsConst, 488 const BasicBlock, 489 BasicBlock>::type*> 490 super; 491 public: 492 typedef block_iterator_wrapper<IsConst> Self; 493 typedef typename super::pointer pointer; 494 495 // Construct the begin iterator. 496 block_iterator_wrapper(pointer Entry, pointer Exit) : super(df_begin(Entry)) 497 { 498 // Mark the exit of the region as visited, so that the children of the 499 // exit and the exit itself, i.e. the block outside the region will never 500 // be visited. 501 super::Visited.insert(Exit); 502 } 503 504 // Construct the end iterator. 505 block_iterator_wrapper() : super(df_end<pointer>((BasicBlock *)0)) {} 506 507 /*implicit*/ block_iterator_wrapper(super I) : super(I) {} 508 509 // FIXME: Even a const_iterator returns a non-const BasicBlock pointer. 510 // This was introduced for backwards compatibility, but should 511 // be removed as soon as all users are fixed. 512 BasicBlock *operator*() const { 513 return const_cast<BasicBlock*>(super::operator*()); 514 } 515 }; 516 517 typedef block_iterator_wrapper<false> block_iterator; 518 typedef block_iterator_wrapper<true> const_block_iterator; 519 520 block_iterator block_begin() { 521 return block_iterator(getEntry(), getExit()); 522 } 523 524 block_iterator block_end() { 525 return block_iterator(); 526 } 527 528 const_block_iterator block_begin() const { 529 return const_block_iterator(getEntry(), getExit()); 530 } 531 const_block_iterator block_end() const { 532 return const_block_iterator(); 533 } 534 //@} 535 536 /// @name Element Iterators 537 /// 538 /// These iterators iterate over all BasicBlock and subregion RegionNodes that 539 /// are direct children of this Region. It does not iterate over any 540 /// RegionNodes that are also element of a subregion of this Region. 541 //@{ 542 typedef df_iterator<RegionNode*, SmallPtrSet<RegionNode*, 8>, false, 543 GraphTraits<RegionNode*> > element_iterator; 544 545 typedef df_iterator<const RegionNode*, SmallPtrSet<const RegionNode*, 8>, 546 false, GraphTraits<const RegionNode*> > 547 const_element_iterator; 548 549 element_iterator element_begin(); 550 element_iterator element_end(); 551 552 const_element_iterator element_begin() const; 553 const_element_iterator element_end() const; 554 //@} 555}; 556 557//===----------------------------------------------------------------------===// 558/// @brief Analysis that detects all canonical Regions. 559/// 560/// The RegionInfo pass detects all canonical regions in a function. The Regions 561/// are connected using the parent relation. This builds a Program Structure 562/// Tree. 563class RegionInfo : public FunctionPass { 564 typedef DenseMap<BasicBlock*,BasicBlock*> BBtoBBMap; 565 typedef DenseMap<BasicBlock*, Region*> BBtoRegionMap; 566 typedef SmallPtrSet<Region*, 4> RegionSet; 567 568 // DO NOT IMPLEMENT 569 RegionInfo(const RegionInfo &); 570 // DO NOT IMPLEMENT 571 const RegionInfo &operator=(const RegionInfo &); 572 573 DominatorTree *DT; 574 PostDominatorTree *PDT; 575 DominanceFrontier *DF; 576 577 /// The top level region. 578 Region *TopLevelRegion; 579 580 /// Map every BB to the smallest region, that contains BB. 581 BBtoRegionMap BBtoRegion; 582 583 // isCommonDomFrontier - Returns true if BB is in the dominance frontier of 584 // entry, because it was inherited from exit. In the other case there is an 585 // edge going from entry to BB without passing exit. 586 bool isCommonDomFrontier(BasicBlock* BB, BasicBlock* entry, 587 BasicBlock* exit) const; 588 589 // isRegion - Check if entry and exit surround a valid region, based on 590 // dominance tree and dominance frontier. 591 bool isRegion(BasicBlock* entry, BasicBlock* exit) const; 592 593 // insertShortCut - Saves a shortcut pointing from entry to exit. 594 // This function may extend this shortcut if possible. 595 void insertShortCut(BasicBlock* entry, BasicBlock* exit, 596 BBtoBBMap* ShortCut) const; 597 598 // getNextPostDom - Returns the next BB that postdominates N, while skipping 599 // all post dominators that cannot finish a canonical region. 600 DomTreeNode *getNextPostDom(DomTreeNode* N, BBtoBBMap *ShortCut) const; 601 602 // isTrivialRegion - A region is trivial, if it contains only one BB. 603 bool isTrivialRegion(BasicBlock *entry, BasicBlock *exit) const; 604 605 // createRegion - Creates a single entry single exit region. 606 Region *createRegion(BasicBlock *entry, BasicBlock *exit); 607 608 // findRegionsWithEntry - Detect all regions starting with bb 'entry'. 609 void findRegionsWithEntry(BasicBlock *entry, BBtoBBMap *ShortCut); 610 611 // scanForRegions - Detects regions in F. 612 void scanForRegions(Function &F, BBtoBBMap *ShortCut); 613 614 // getTopMostParent - Get the top most parent with the same entry block. 615 Region *getTopMostParent(Region *region); 616 617 // buildRegionsTree - build the region hierarchy after all region detected. 618 void buildRegionsTree(DomTreeNode *N, Region *region); 619 620 // Calculate - detecte all regions in function and build the region tree. 621 void Calculate(Function& F); 622 623 void releaseMemory(); 624 625 // updateStatistics - Update statistic about created regions. 626 void updateStatistics(Region *R); 627 628 // isSimple - Check if a region is a simple region with exactly one entry 629 // edge and exactly one exit edge. 630 bool isSimple(Region* R) const; 631 632public: 633 static char ID; 634 explicit RegionInfo(); 635 636 ~RegionInfo(); 637 638 /// @name FunctionPass interface 639 //@{ 640 virtual bool runOnFunction(Function &F); 641 virtual void getAnalysisUsage(AnalysisUsage &AU) const; 642 virtual void print(raw_ostream &OS, const Module *) const; 643 virtual void verifyAnalysis() const; 644 //@} 645 646 /// @brief Get the smallest region that contains a BasicBlock. 647 /// 648 /// @param BB The basic block. 649 /// @return The smallest region, that contains BB or NULL, if there is no 650 /// region containing BB. 651 Region *getRegionFor(BasicBlock *BB) const; 652 653 /// @brief Set the smallest region that surrounds a basic block. 654 /// 655 /// @param BB The basic block surrounded by a region. 656 /// @param R The smallest region that surrounds BB. 657 void setRegionFor(BasicBlock *BB, Region *R); 658 659 /// @brief A shortcut for getRegionFor(). 660 /// 661 /// @param BB The basic block. 662 /// @return The smallest region, that contains BB or NULL, if there is no 663 /// region containing BB. 664 Region *operator[](BasicBlock *BB) const; 665 666 /// @brief Return the exit of the maximal refined region, that starts at a 667 /// BasicBlock. 668 /// 669 /// @param BB The BasicBlock the refined region starts. 670 BasicBlock *getMaxRegionExit(BasicBlock *BB) const; 671 672 /// @brief Find the smallest region that contains two regions. 673 /// 674 /// @param A The first region. 675 /// @param B The second region. 676 /// @return The smallest region containing A and B. 677 Region *getCommonRegion(Region* A, Region *B) const; 678 679 /// @brief Find the smallest region that contains two basic blocks. 680 /// 681 /// @param A The first basic block. 682 /// @param B The second basic block. 683 /// @return The smallest region that contains A and B. 684 Region* getCommonRegion(BasicBlock* A, BasicBlock *B) const { 685 return getCommonRegion(getRegionFor(A), getRegionFor(B)); 686 } 687 688 /// @brief Find the smallest region that contains a set of regions. 689 /// 690 /// @param Regions A vector of regions. 691 /// @return The smallest region that contains all regions in Regions. 692 Region* getCommonRegion(SmallVectorImpl<Region*> &Regions) const; 693 694 /// @brief Find the smallest region that contains a set of basic blocks. 695 /// 696 /// @param BBs A vector of basic blocks. 697 /// @return The smallest region that contains all basic blocks in BBS. 698 Region* getCommonRegion(SmallVectorImpl<BasicBlock*> &BBs) const; 699 700 Region *getTopLevelRegion() const { 701 return TopLevelRegion; 702 } 703 704 /// @brief Update RegionInfo after a basic block was split. 705 /// 706 /// @param NewBB The basic block that was created before OldBB. 707 /// @param OldBB The old basic block. 708 void splitBlock(BasicBlock* NewBB, BasicBlock *OldBB); 709 710 /// @brief Clear the Node Cache for all Regions. 711 /// 712 /// @see Region::clearNodeCache() 713 void clearNodeCache() { 714 if (TopLevelRegion) 715 TopLevelRegion->clearNodeCache(); 716 } 717}; 718 719inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node) { 720 if (Node.isSubRegion()) 721 return OS << Node.getNodeAs<Region>()->getNameStr(); 722 else 723 return OS << Node.getNodeAs<BasicBlock>()->getName(); 724} 725} // End llvm namespace 726#endif 727 728