RegionInfo.h revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338
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_REGIONINFO_H 28#define LLVM_ANALYSIS_REGIONINFO_H 29 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" 35#include <map> 36 37namespace llvm { 38 39class Region; 40class RegionInfo; 41class raw_ostream; 42class Loop; 43class LoopInfo; 44 45/// @brief Marker class to iterate over the elements of a Region in flat mode. 46/// 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 51/// returned. 52template <class GraphType> 53class FlatIt {}; 54 55/// @brief A RegionNode represents a subregion or a BasicBlock that is part of a 56/// Region. 57class RegionNode { 58 RegionNode(const RegionNode &) LLVM_DELETED_FUNCTION; 59 const RegionNode &operator=(const RegionNode &) LLVM_DELETED_FUNCTION; 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 remaining 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 Region(const Region &) LLVM_DELETED_FUNCTION; 206 const Region &operator=(const Region &) LLVM_DELETED_FUNCTION; 207 208 // Information necessary to manage this Region. 209 RegionInfo* RI; 210 DominatorTree *DT; 211 212 // The exit BasicBlock of this region. 213 // (The entry BasicBlock is part of RegionNode) 214 BasicBlock *exit; 215 216 typedef std::vector<Region*> RegionSet; 217 218 // The subregions of this region. 219 RegionSet children; 220 221 typedef std::map<BasicBlock*, RegionNode*> BBNodeMapT; 222 223 // Save the BasicBlock RegionNodes that are element of this Region. 224 mutable BBNodeMapT BBNodeMap; 225 226 /// 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; 229 230 /// 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. 232 /// (EXPENSIVE!) 233 void verifyWalk(BasicBlock* BB, std::set<BasicBlock*>* visitedBB) const; 234 235 /// verifyRegionNest - Verify if the region and its children are valid 236 /// regions (EXPENSIVE!) 237 void verifyRegionNest() const; 238 239public: 240 /// @brief Create a new region. 241 /// 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 247 /// region. 248 Region(BasicBlock *Entry, BasicBlock *Exit, RegionInfo* RI, 249 DominatorTree *DT, Region *Parent = 0); 250 251 /// Delete the Region and all its subregions. 252 ~Region(); 253 254 /// @brief Get the entry BasicBlock of the Region. 255 /// @return The entry BasicBlock of the region. 256 BasicBlock *getEntry() const { return RegionNode::getEntry(); } 257 258 /// @brief Replace the entry basic block of the region with the new basic 259 /// block. 260 /// 261 /// @param BB The new entry basic block of the region. 262 void replaceEntry(BasicBlock *BB); 263 264 /// @brief Replace the exit basic block of the region with the new basic 265 /// block. 266 /// 267 /// @param BB The new exit basic block of the region. 268 void replaceExit(BasicBlock *BB); 269 270 /// @brief Recursively replace the entry basic block of the region. 271 /// 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 274 /// this region. 275 /// 276 /// @param NewEntry The new entry basic block. 277 void replaceEntryRecursive(BasicBlock *NewEntry); 278 279 /// @brief Recursively replace the exit basic block of the region. 280 /// 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 283 /// this region. 284 /// 285 /// @param NewExit The new exit basic block. 286 void replaceExitRecursive(BasicBlock *NewExit); 287 288 /// @brief Get the exit BasicBlock of the Region. 289 /// @return The exit BasicBlock of the Region, NULL if this is the TopLevel 290 /// Region. 291 BasicBlock *getExit() const { return exit; } 292 293 /// @brief Get the parent of the Region. 294 /// @return The parent of the Region or NULL if this is a top level 295 /// Region. 296 Region *getParent() const { return RegionNode::getParent(); } 297 298 /// @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)); 302 } 303 304 /// @brief Get the nesting level of this Region. 305 /// 306 /// An toplevel Region has depth 0. 307 /// 308 /// @return The depth of the region. 309 unsigned getDepth() const; 310 311 /// @brief Check if a Region is the TopLevel region. 312 /// 313 /// The toplevel region represents the whole function. 314 bool isTopLevelRegion() const { return exit == NULL; } 315 316 /// @brief Return a new (non-canonical) region, that is obtained by joining 317 /// this region with its predecessors. 318 /// 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; 323 324 /// @brief Return the first block of this region's single entry edge, 325 /// if existing. 326 /// 327 /// @return The BasicBlock starting this region's single entry edge, 328 /// else NULL. 329 BasicBlock *getEnteringBlock() const; 330 331 /// @brief Return the first block of this region's single exit edge, 332 /// if existing. 333 /// 334 /// @return The BasicBlock starting this region's single exit edge, 335 /// else NULL. 336 BasicBlock *getExitingBlock() const; 337 338 /// @brief Is this a simple region? 339 /// 340 /// A region is simple if it has exactly one exit and one entry edge. 341 /// 342 /// @return True if the Region is simple. 343 bool isSimple() const; 344 345 /// @brief Returns the name of the Region. 346 /// @return The Name of the Region. 347 std::string getNameStr() const; 348 349 /// @brief Return the RegionInfo object, that belongs to this Region. 350 RegionInfo *getRegionInfo() const { 351 return RI; 352 } 353 354 /// PrintStyle - Print region in difference ways. 355 enum PrintStyle { PrintNone, PrintBB, PrintRN }; 356 357 /// @brief Print the region. 358 /// 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; 364 365 /// @brief Print the region to stderr. 366 void dump() const; 367 368 /// @brief Check if the region contains a BasicBlock. 369 /// 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; 373 374 /// @brief Check if the region contains another region. 375 /// 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 { 379 // Toplevel Region. 380 if (!getExit()) 381 return true; 382 383 return contains(SubRegion->getEntry()) 384 && (contains(SubRegion->getExit()) || SubRegion->getExit() == getExit()); 385 } 386 387 /// @brief Check if the region contains an Instruction. 388 /// 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()); 393 } 394 395 /// @brief Check if the region contains a loop. 396 /// 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; 403 404 /// @brief Get the outermost loop in the region that contains a loop. 405 /// 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. 408 /// 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; 413 414 /// @brief Get the outermost loop in the region that contains a basic block. 415 /// 416 /// Find for a basic block BB the outermost loop L that contains BB and is 417 /// itself contained in the region. 418 /// 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; 424 425 /// @brief Get the subregion that starts at a BasicBlock 426 /// 427 /// @param BB The BasicBlock the subregion should start. 428 /// @return The Subregion if available, otherwise NULL. 429 Region* getSubRegionNode(BasicBlock *BB) const; 430 431 /// @brief Get the RegionNode for a BasicBlock 432 /// 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 436 /// representing BB. 437 RegionNode* getNode(BasicBlock *BB) const; 438 439 /// @brief Get the BasicBlock RegionNode for a BasicBlock 440 /// 441 /// @param BB The BasicBlock for which the RegionNode is requested. 442 /// @return The RegionNode representing the BB. 443 RegionNode* getBBNode(BasicBlock *BB) const; 444 445 /// @brief Add a new subregion to this Region. 446 /// 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); 451 452 /// @brief Remove a subregion from this Region. 453 /// 454 /// The subregion is not deleted, as it will probably be inserted into another 455 /// region. 456 /// @param SubRegion The SubRegion that will be removed. 457 Region *removeSubRegion(Region *SubRegion); 458 459 /// @brief Move all direct child nodes of this Region to another Region. 460 /// 461 /// @param To The Region the child nodes will be transferred to. 462 void transferChildrenTo(Region *To); 463 464 /// @brief Verify if the region is a correct region. 465 /// 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; 469 470 /// @brief Clear the cache for BB RegionNodes. 471 /// 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(); 476 477 /// @name Subregion Iterators 478 /// 479 /// These iterators iterator over all subregions of this Region. 480 //@{ 481 typedef RegionSet::iterator iterator; 482 typedef RegionSet::const_iterator const_iterator; 483 484 iterator begin() { return children.begin(); } 485 iterator end() { return children.end(); } 486 487 const_iterator begin() const { return children.begin(); } 488 const_iterator end() const { return children.end(); } 489 //@} 490 491 /// @name BasicBlock Iterators 492 /// 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. 496 //@{ 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; 503 504 public: 505 typedef block_iterator_wrapper<IsConst> Self; 506 typedef typename super::pointer pointer; 507 508 // Construct the begin iterator. 509 block_iterator_wrapper(pointer Entry, pointer Exit) : super(df_begin(Entry)) 510 { 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 513 // be visited. 514 super::Visited.insert(Exit); 515 } 516 517 // Construct the end iterator. 518 block_iterator_wrapper() : super(df_end<pointer>((BasicBlock *)0)) {} 519 520 /*implicit*/ block_iterator_wrapper(super I) : super(I) {} 521 522 // 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*()); 527 } 528 }; 529 530 typedef block_iterator_wrapper<false> block_iterator; 531 typedef block_iterator_wrapper<true> const_block_iterator; 532 533 block_iterator block_begin() { 534 return block_iterator(getEntry(), getExit()); 535 } 536 537 block_iterator block_end() { 538 return block_iterator(); 539 } 540 541 const_block_iterator block_begin() const { 542 return const_block_iterator(getEntry(), getExit()); 543 } 544 const_block_iterator block_end() const { 545 return const_block_iterator(); 546 } 547 548 typedef iterator_range<block_iterator> block_range; 549 typedef iterator_range<const_block_iterator> const_block_range; 550 551 /// @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()); 554 } 555 556 /// @brief Returns a range view of the basic blocks in the region. 557 /// 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()); 561 } 562 //@} 563 564 /// @name Element Iterators 565 /// 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. 569 //@{ 570 typedef df_iterator<RegionNode*, SmallPtrSet<RegionNode*, 8>, false, 571 GraphTraits<RegionNode*> > element_iterator; 572 573 typedef df_iterator<const RegionNode*, SmallPtrSet<const RegionNode*, 8>, 574 false, GraphTraits<const RegionNode*> > 575 const_element_iterator; 576 577 element_iterator element_begin(); 578 element_iterator element_end(); 579 580 const_element_iterator element_begin() const; 581 const_element_iterator element_end() const; 582 //@} 583}; 584 585//===----------------------------------------------------------------------===// 586/// @brief Analysis that detects all canonical Regions. 587/// 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 590/// Tree. 591class RegionInfo : public FunctionPass { 592 typedef DenseMap<BasicBlock*,BasicBlock*> BBtoBBMap; 593 typedef DenseMap<BasicBlock*, Region*> BBtoRegionMap; 594 typedef SmallPtrSet<Region*, 4> RegionSet; 595 596 RegionInfo(const RegionInfo &) LLVM_DELETED_FUNCTION; 597 const RegionInfo &operator=(const RegionInfo &) LLVM_DELETED_FUNCTION; 598 599 DominatorTree *DT; 600 PostDominatorTree *PDT; 601 DominanceFrontier *DF; 602 603 /// The top level region. 604 Region *TopLevelRegion; 605 606 /// Map every BB to the smallest region, that contains BB. 607 BBtoRegionMap BBtoRegion; 608 609 // 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; 614 615 // 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; 618 619 // 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; 623 624 // 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; 627 628 // isTrivialRegion - A region is trivial, if it contains only one BB. 629 bool isTrivialRegion(BasicBlock *entry, BasicBlock *exit) const; 630 631 // createRegion - Creates a single entry single exit region. 632 Region *createRegion(BasicBlock *entry, BasicBlock *exit); 633 634 // findRegionsWithEntry - Detect all regions starting with bb 'entry'. 635 void findRegionsWithEntry(BasicBlock *entry, BBtoBBMap *ShortCut); 636 637 // scanForRegions - Detects regions in F. 638 void scanForRegions(Function &F, BBtoBBMap *ShortCut); 639 640 // getTopMostParent - Get the top most parent with the same entry block. 641 Region *getTopMostParent(Region *region); 642 643 // buildRegionsTree - build the region hierarchy after all region detected. 644 void buildRegionsTree(DomTreeNode *N, Region *region); 645 646 // Calculate - detecte all regions in function and build the region tree. 647 void Calculate(Function& F); 648 649 void releaseMemory() override; 650 651 // updateStatistics - Update statistic about created regions. 652 void updateStatistics(Region *R); 653 654 // 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; 657 658public: 659 static char ID; 660 explicit RegionInfo(); 661 662 ~RegionInfo(); 663 664 /// @name FunctionPass interface 665 //@{ 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; 670 //@} 671 672 /// @brief Get the smallest region that contains a BasicBlock. 673 /// 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; 678 679 /// @brief Set the smallest region that surrounds a basic block. 680 /// 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); 684 685 /// @brief A shortcut for getRegionFor(). 686 /// 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; 691 692 /// @brief Return the exit of the maximal refined region, that starts at a 693 /// BasicBlock. 694 /// 695 /// @param BB The BasicBlock the refined region starts. 696 BasicBlock *getMaxRegionExit(BasicBlock *BB) const; 697 698 /// @brief Find the smallest region that contains two regions. 699 /// 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; 704 705 /// @brief Find the smallest region that contains two basic blocks. 706 /// 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)); 712 } 713 714 /// @brief Find the smallest region that contains a set of regions. 715 /// 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; 719 720 /// @brief Find the smallest region that contains a set of basic blocks. 721 /// 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; 725 726 Region *getTopLevelRegion() const { 727 return TopLevelRegion; 728 } 729 730 /// @brief Update RegionInfo after a basic block was split. 731 /// 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); 735 736 /// @brief Clear the Node Cache for all Regions. 737 /// 738 /// @see Region::clearNodeCache() 739 void clearNodeCache() { 740 if (TopLevelRegion) 741 TopLevelRegion->clearNodeCache(); 742 } 743}; 744 745inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node) { 746 if (Node.isSubRegion()) 747 return OS << Node.getNodeAs<Region>()->getNameStr(); 748 else 749 return OS << Node.getNodeAs<BasicBlock>()->getName(); 750} 751} // End llvm namespace 752#endif 753 754