MachineBasicBlock.h revision d4786e221c679fced994993d9ee7228572d4b148
1//===-- llvm/CodeGen/MachineBasicBlock.h ------------------------*- 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// Collect the sequence of machine instructions for a basic block. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_CODEGEN_MACHINEBASICBLOCK_H 15#define LLVM_CODEGEN_MACHINEBASICBLOCK_H 16 17#include "llvm/CodeGen/MachineInstr.h" 18#include "llvm/ADT/GraphTraits.h" 19#include "llvm/Support/DataTypes.h" 20#include <functional> 21 22namespace llvm { 23 24class Pass; 25class BasicBlock; 26class MachineFunction; 27class MCSymbol; 28class SlotIndexes; 29class StringRef; 30class raw_ostream; 31class MachineBranchProbabilityInfo; 32 33template <> 34struct ilist_traits<MachineInstr> : public ilist_default_traits<MachineInstr> { 35private: 36 mutable ilist_half_node<MachineInstr> Sentinel; 37 38 // this is only set by the MachineBasicBlock owning the LiveList 39 friend class MachineBasicBlock; 40 MachineBasicBlock* Parent; 41 42public: 43 MachineInstr *createSentinel() const { 44 return static_cast<MachineInstr*>(&Sentinel); 45 } 46 void destroySentinel(MachineInstr *) const {} 47 48 MachineInstr *provideInitialHead() const { return createSentinel(); } 49 MachineInstr *ensureHead(MachineInstr*) const { return createSentinel(); } 50 static void noteHead(MachineInstr*, MachineInstr*) {} 51 52 void addNodeToList(MachineInstr* N); 53 void removeNodeFromList(MachineInstr* N); 54 void transferNodesFromList(ilist_traits &SrcTraits, 55 ilist_iterator<MachineInstr> first, 56 ilist_iterator<MachineInstr> last); 57 void deleteNode(MachineInstr *N); 58private: 59 void createNode(const MachineInstr &); 60}; 61 62class MachineBasicBlock : public ilist_node<MachineBasicBlock> { 63 typedef ilist<MachineInstr> Instructions; 64 Instructions Insts; 65 const BasicBlock *BB; 66 int Number; 67 MachineFunction *xParent; 68 69 /// Predecessors/Successors - Keep track of the predecessor / successor 70 /// basicblocks. 71 std::vector<MachineBasicBlock *> Predecessors; 72 std::vector<MachineBasicBlock *> Successors; 73 74 75 /// Weights - Keep track of the weights to the successors. This vector 76 /// has the same order as Successors, or it is empty if we don't use it 77 /// (disable optimization). 78 std::vector<uint32_t> Weights; 79 typedef std::vector<uint32_t>::iterator weight_iterator; 80 typedef std::vector<uint32_t>::const_iterator const_weight_iterator; 81 82 /// LiveIns - Keep track of the physical registers that are livein of 83 /// the basicblock. 84 std::vector<unsigned> LiveIns; 85 86 /// Alignment - Alignment of the basic block. Zero if the basic block does 87 /// not need to be aligned. 88 /// The alignment is specified as log2(bytes). 89 unsigned Alignment; 90 91 /// IsLandingPad - Indicate that this basic block is entered via an 92 /// exception handler. 93 bool IsLandingPad; 94 95 /// AddressTaken - Indicate that this basic block is potentially the 96 /// target of an indirect branch. 97 bool AddressTaken; 98 99 // Intrusive list support 100 MachineBasicBlock() {} 101 102 explicit MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb); 103 104 ~MachineBasicBlock(); 105 106 // MachineBasicBlocks are allocated and owned by MachineFunction. 107 friend class MachineFunction; 108 109public: 110 /// getBasicBlock - Return the LLVM basic block that this instance 111 /// corresponded to originally. Note that this may be NULL if this instance 112 /// does not correspond directly to an LLVM basic block. 113 /// 114 const BasicBlock *getBasicBlock() const { return BB; } 115 116 /// getName - Return the name of the corresponding LLVM basic block, or 117 /// "(null)". 118 StringRef getName() const; 119 120 /// getFullName - Return a formatted string to identify this block and its 121 /// parent function. 122 std::string getFullName() const; 123 124 /// hasAddressTaken - Test whether this block is potentially the target 125 /// of an indirect branch. 126 bool hasAddressTaken() const { return AddressTaken; } 127 128 /// setHasAddressTaken - Set this block to reflect that it potentially 129 /// is the target of an indirect branch. 130 void setHasAddressTaken() { AddressTaken = true; } 131 132 /// getParent - Return the MachineFunction containing this basic block. 133 /// 134 const MachineFunction *getParent() const { return xParent; } 135 MachineFunction *getParent() { return xParent; } 136 137 138 /// bundle_iterator - MachineBasicBlock iterator that automatically skips over 139 /// MIs that are inside bundles (i.e. walk top level MIs only). 140 template<typename Ty, typename IterTy> 141 class bundle_iterator 142 : public std::iterator<std::bidirectional_iterator_tag, Ty, ptrdiff_t> { 143 IterTy MII; 144 145 public: 146 bundle_iterator(IterTy mii) : MII(mii) { 147 assert(!MII->isInsideBundle() && 148 "It's not legal to initialize bundle_iterator with a bundled MI"); 149 } 150 151 bundle_iterator(Ty &mi) : MII(mi) { 152 assert(!mi.isInsideBundle() && 153 "It's not legal to initialize bundle_iterator with a bundled MI"); 154 } 155 bundle_iterator(Ty *mi) : MII(mi) { 156 assert((!mi || !mi->isInsideBundle()) && 157 "It's not legal to initialize bundle_iterator with a bundled MI"); 158 } 159 // Template allows conversion from const to nonconst. 160 template<class OtherTy, class OtherIterTy> 161 bundle_iterator(const bundle_iterator<OtherTy, OtherIterTy> &I) 162 : MII(I.getInstrIterator()) {} 163 bundle_iterator() : MII(0) {} 164 165 Ty &operator*() const { return *MII; } 166 Ty *operator->() const { return &operator*(); } 167 168 operator Ty*() const { return MII; } 169 170 bool operator==(const bundle_iterator &x) const { 171 return MII == x.MII; 172 } 173 bool operator!=(const bundle_iterator &x) const { 174 return !operator==(x); 175 } 176 177 // Increment and decrement operators... 178 bundle_iterator &operator--() { // predecrement - Back up 179 do { 180 --MII; 181 } while (MII->isInsideBundle()); 182 return *this; 183 } 184 bundle_iterator &operator++() { // preincrement - Advance 185 do { 186 ++MII; 187 } while (MII->isInsideBundle()); 188 return *this; 189 } 190 bundle_iterator operator--(int) { // postdecrement operators... 191 bundle_iterator tmp = *this; 192 do { 193 --MII; 194 } while (MII->isInsideBundle()); 195 return tmp; 196 } 197 bundle_iterator operator++(int) { // postincrement operators... 198 bundle_iterator tmp = *this; 199 do { 200 ++MII; 201 } while (MII->isInsideBundle()); 202 return tmp; 203 } 204 205 IterTy getInstrIterator() const { 206 return MII; 207 } 208 }; 209 210 typedef Instructions::iterator instr_iterator; 211 typedef Instructions::const_iterator const_instr_iterator; 212 typedef std::reverse_iterator<instr_iterator> reverse_instr_iterator; 213 typedef 214 std::reverse_iterator<const_instr_iterator> const_reverse_instr_iterator; 215 216 typedef 217 bundle_iterator<MachineInstr,instr_iterator> iterator; 218 typedef 219 bundle_iterator<const MachineInstr,const_instr_iterator> const_iterator; 220 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 221 typedef std::reverse_iterator<iterator> reverse_iterator; 222 223 224 unsigned size() const { return (unsigned)Insts.size(); } 225 bool empty() const { return Insts.empty(); } 226 227 MachineInstr& front() { return Insts.front(); } 228 MachineInstr& back() { return Insts.back(); } 229 const MachineInstr& front() const { return Insts.front(); } 230 const MachineInstr& back() const { return Insts.back(); } 231 232 instr_iterator instr_begin() { return Insts.begin(); } 233 const_instr_iterator instr_begin() const { return Insts.begin(); } 234 instr_iterator instr_end() { return Insts.end(); } 235 const_instr_iterator instr_end() const { return Insts.end(); } 236 reverse_instr_iterator instr_rbegin() { return Insts.rbegin(); } 237 const_reverse_instr_iterator instr_rbegin() const { return Insts.rbegin(); } 238 reverse_instr_iterator instr_rend () { return Insts.rend(); } 239 const_reverse_instr_iterator instr_rend () const { return Insts.rend(); } 240 241 iterator begin() { return Insts.begin(); } 242 const_iterator begin() const { return Insts.begin(); } 243 iterator end() { 244 instr_iterator II = instr_end(); 245 if (II != instr_begin()) { 246 while (II->isInsideBundle()) 247 --II; 248 } 249 return II; 250 } 251 const_iterator end() const { 252 const_instr_iterator II = instr_end(); 253 if (II != instr_begin()) { 254 while (II->isInsideBundle()) 255 --II; 256 } 257 return II; 258 } 259 reverse_iterator rbegin() { 260 reverse_instr_iterator II = instr_rbegin(); 261 if (II != instr_rend()) { 262 while (II->isInsideBundle()) 263 ++II; 264 } 265 return II; 266 } 267 const_reverse_iterator rbegin() const { 268 const_reverse_instr_iterator II = instr_rbegin(); 269 if (II != instr_rend()) { 270 while (II->isInsideBundle()) 271 ++II; 272 } 273 return II; 274 } 275 reverse_iterator rend () { return Insts.rend(); } 276 const_reverse_iterator rend () const { return Insts.rend(); } 277 278 279 // Machine-CFG iterators 280 typedef std::vector<MachineBasicBlock *>::iterator pred_iterator; 281 typedef std::vector<MachineBasicBlock *>::const_iterator const_pred_iterator; 282 typedef std::vector<MachineBasicBlock *>::iterator succ_iterator; 283 typedef std::vector<MachineBasicBlock *>::const_iterator const_succ_iterator; 284 typedef std::vector<MachineBasicBlock *>::reverse_iterator 285 pred_reverse_iterator; 286 typedef std::vector<MachineBasicBlock *>::const_reverse_iterator 287 const_pred_reverse_iterator; 288 typedef std::vector<MachineBasicBlock *>::reverse_iterator 289 succ_reverse_iterator; 290 typedef std::vector<MachineBasicBlock *>::const_reverse_iterator 291 const_succ_reverse_iterator; 292 293 pred_iterator pred_begin() { return Predecessors.begin(); } 294 const_pred_iterator pred_begin() const { return Predecessors.begin(); } 295 pred_iterator pred_end() { return Predecessors.end(); } 296 const_pred_iterator pred_end() const { return Predecessors.end(); } 297 pred_reverse_iterator pred_rbegin() 298 { return Predecessors.rbegin();} 299 const_pred_reverse_iterator pred_rbegin() const 300 { return Predecessors.rbegin();} 301 pred_reverse_iterator pred_rend() 302 { return Predecessors.rend(); } 303 const_pred_reverse_iterator pred_rend() const 304 { return Predecessors.rend(); } 305 unsigned pred_size() const { 306 return (unsigned)Predecessors.size(); 307 } 308 bool pred_empty() const { return Predecessors.empty(); } 309 succ_iterator succ_begin() { return Successors.begin(); } 310 const_succ_iterator succ_begin() const { return Successors.begin(); } 311 succ_iterator succ_end() { return Successors.end(); } 312 const_succ_iterator succ_end() const { return Successors.end(); } 313 succ_reverse_iterator succ_rbegin() 314 { return Successors.rbegin(); } 315 const_succ_reverse_iterator succ_rbegin() const 316 { return Successors.rbegin(); } 317 succ_reverse_iterator succ_rend() 318 { return Successors.rend(); } 319 const_succ_reverse_iterator succ_rend() const 320 { return Successors.rend(); } 321 unsigned succ_size() const { 322 return (unsigned)Successors.size(); 323 } 324 bool succ_empty() const { return Successors.empty(); } 325 326 // LiveIn management methods. 327 328 /// addLiveIn - Add the specified register as a live in. Note that it 329 /// is an error to add the same register to the same set more than once. 330 void addLiveIn(unsigned Reg) { LiveIns.push_back(Reg); } 331 332 /// removeLiveIn - Remove the specified register from the live in set. 333 /// 334 void removeLiveIn(unsigned Reg); 335 336 /// isLiveIn - Return true if the specified register is in the live in set. 337 /// 338 bool isLiveIn(unsigned Reg) const; 339 340 // Iteration support for live in sets. These sets are kept in sorted 341 // order by their register number. 342 typedef std::vector<unsigned>::const_iterator livein_iterator; 343 livein_iterator livein_begin() const { return LiveIns.begin(); } 344 livein_iterator livein_end() const { return LiveIns.end(); } 345 bool livein_empty() const { return LiveIns.empty(); } 346 347 /// getAlignment - Return alignment of the basic block. 348 /// The alignment is specified as log2(bytes). 349 /// 350 unsigned getAlignment() const { return Alignment; } 351 352 /// setAlignment - Set alignment of the basic block. 353 /// The alignment is specified as log2(bytes). 354 /// 355 void setAlignment(unsigned Align) { Alignment = Align; } 356 357 /// isLandingPad - Returns true if the block is a landing pad. That is 358 /// this basic block is entered via an exception handler. 359 bool isLandingPad() const { return IsLandingPad; } 360 361 /// setIsLandingPad - Indicates the block is a landing pad. That is 362 /// this basic block is entered via an exception handler. 363 void setIsLandingPad(bool V = true) { IsLandingPad = V; } 364 365 /// getLandingPadSuccessor - If this block has a successor that is a landing 366 /// pad, return it. Otherwise return NULL. 367 const MachineBasicBlock *getLandingPadSuccessor() const; 368 369 // Code Layout methods. 370 371 /// moveBefore/moveAfter - move 'this' block before or after the specified 372 /// block. This only moves the block, it does not modify the CFG or adjust 373 /// potential fall-throughs at the end of the block. 374 void moveBefore(MachineBasicBlock *NewAfter); 375 void moveAfter(MachineBasicBlock *NewBefore); 376 377 /// updateTerminator - Update the terminator instructions in block to account 378 /// for changes to the layout. If the block previously used a fallthrough, 379 /// it may now need a branch, and if it previously used branching it may now 380 /// be able to use a fallthrough. 381 void updateTerminator(); 382 383 // Machine-CFG mutators 384 385 /// addSuccessor - Add succ as a successor of this MachineBasicBlock. 386 /// The Predecessors list of succ is automatically updated. WEIGHT 387 /// parameter is stored in Weights list and it may be used by 388 /// MachineBranchProbabilityInfo analysis to calculate branch probability. 389 /// 390 void addSuccessor(MachineBasicBlock *succ, uint32_t weight = 0); 391 392 /// removeSuccessor - Remove successor from the successors list of this 393 /// MachineBasicBlock. The Predecessors list of succ is automatically updated. 394 /// 395 void removeSuccessor(MachineBasicBlock *succ); 396 397 /// removeSuccessor - Remove specified successor from the successors list of 398 /// this MachineBasicBlock. The Predecessors list of succ is automatically 399 /// updated. Return the iterator to the element after the one removed. 400 /// 401 succ_iterator removeSuccessor(succ_iterator I); 402 403 /// replaceSuccessor - Replace successor OLD with NEW and update weight info. 404 /// 405 void replaceSuccessor(MachineBasicBlock *Old, MachineBasicBlock *New); 406 407 408 /// transferSuccessors - Transfers all the successors from MBB to this 409 /// machine basic block (i.e., copies all the successors fromMBB and 410 /// remove all the successors from fromMBB). 411 void transferSuccessors(MachineBasicBlock *fromMBB); 412 413 /// transferSuccessorsAndUpdatePHIs - Transfers all the successors, as 414 /// in transferSuccessors, and update PHI operands in the successor blocks 415 /// which refer to fromMBB to refer to this. 416 void transferSuccessorsAndUpdatePHIs(MachineBasicBlock *fromMBB); 417 418 /// isSuccessor - Return true if the specified MBB is a successor of this 419 /// block. 420 bool isSuccessor(const MachineBasicBlock *MBB) const; 421 422 /// isLayoutSuccessor - Return true if the specified MBB will be emitted 423 /// immediately after this block, such that if this block exits by 424 /// falling through, control will transfer to the specified MBB. Note 425 /// that MBB need not be a successor at all, for example if this block 426 /// ends with an unconditional branch to some other block. 427 bool isLayoutSuccessor(const MachineBasicBlock *MBB) const; 428 429 /// canFallThrough - Return true if the block can implicitly transfer 430 /// control to the block after it by falling off the end of it. This should 431 /// return false if it can reach the block after it, but it uses an explicit 432 /// branch to do so (e.g., a table jump). True is a conservative answer. 433 bool canFallThrough(); 434 435 /// Returns a pointer to the first instructon in this block that is not a 436 /// PHINode instruction. When adding instruction to the beginning of the 437 /// basic block, they should be added before the returned value, not before 438 /// the first instruction, which might be PHI. 439 /// Returns end() is there's no non-PHI instruction. 440 iterator getFirstNonPHI(); 441 442 /// SkipPHIsAndLabels - Return the first instruction in MBB after I that is 443 /// not a PHI or a label. This is the correct point to insert copies at the 444 /// beginning of a basic block. 445 iterator SkipPHIsAndLabels(iterator I); 446 447 /// getFirstTerminator - returns an iterator to the first terminator 448 /// instruction of this basic block. If a terminator does not exist, 449 /// it returns end() 450 iterator getFirstTerminator(); 451 const_iterator getFirstTerminator() const; 452 453 /// getFirstInstrTerminator - Same getFirstTerminator but it ignores bundles 454 /// and return an instr_iterator instead. 455 instr_iterator getFirstInstrTerminator(); 456 457 /// getLastNonDebugInstr - returns an iterator to the last non-debug 458 /// instruction in the basic block, or end() 459 iterator getLastNonDebugInstr(); 460 const_iterator getLastNonDebugInstr() const; 461 462 /// SplitCriticalEdge - Split the critical edge from this block to the 463 /// given successor block, and return the newly created block, or null 464 /// if splitting is not possible. 465 /// 466 /// This function updates LiveVariables, MachineDominatorTree, and 467 /// MachineLoopInfo, as applicable. 468 MachineBasicBlock *SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P); 469 470 void pop_front() { Insts.pop_front(); } 471 void pop_back() { Insts.pop_back(); } 472 void push_back(MachineInstr *MI) { Insts.push_back(MI); } 473 474 template<typename IT> 475 void insert(instr_iterator I, IT S, IT E) { 476 Insts.insert(I, S, E); 477 } 478 instr_iterator insert(instr_iterator I, MachineInstr *M) { 479 return Insts.insert(I, M); 480 } 481 instr_iterator insertAfter(instr_iterator I, MachineInstr *M) { 482 return Insts.insertAfter(I, M); 483 } 484 485 template<typename IT> 486 void insert(iterator I, IT S, IT E) { 487 Insts.insert(I.getInstrIterator(), S, E); 488 } 489 iterator insert(iterator I, MachineInstr *M) { 490 return Insts.insert(I.getInstrIterator(), M); 491 } 492 iterator insertAfter(iterator I, MachineInstr *M) { 493 return Insts.insertAfter(I.getInstrIterator(), M); 494 } 495 496 /// erase - Remove the specified element or range from the instruction list. 497 /// These functions delete any instructions removed. 498 /// 499 instr_iterator erase(instr_iterator I) { 500 return Insts.erase(I); 501 } 502 instr_iterator erase(instr_iterator I, instr_iterator E) { 503 return Insts.erase(I, E); 504 } 505 instr_iterator erase_instr(MachineInstr *I) { 506 instr_iterator MII(I); 507 return erase(MII); 508 } 509 510 iterator erase(iterator I); 511 iterator erase(iterator I, iterator E) { 512 return Insts.erase(I.getInstrIterator(), E.getInstrIterator()); 513 } 514 iterator erase(MachineInstr *I) { 515 iterator MII(I); 516 return erase(MII); 517 } 518 519 /// remove - Remove the instruction from the instruction list. This function 520 /// does not delete the instruction. WARNING: Note, if the specified 521 /// instruction is a bundle this function will remove all the bundled 522 /// instructions as well. It is up to the caller to keep a list of the 523 /// bundled instructions and re-insert them if desired. This function is 524 /// *not recommended* for manipulating instructions with bundles. Use 525 /// splice instead. 526 MachineInstr *remove(MachineInstr *I); 527 void clear() { 528 Insts.clear(); 529 } 530 531 /// splice - Take an instruction from MBB 'Other' at the position From, 532 /// and insert it into this MBB right before 'where'. 533 void splice(instr_iterator where, MachineBasicBlock *Other, 534 instr_iterator From) { 535 Insts.splice(where, Other->Insts, From); 536 } 537 void splice(iterator where, MachineBasicBlock *Other, iterator From); 538 539 /// splice - Take a block of instructions from MBB 'Other' in the range [From, 540 /// To), and insert them into this MBB right before 'where'. 541 void splice(instr_iterator where, MachineBasicBlock *Other, instr_iterator From, 542 instr_iterator To) { 543 Insts.splice(where, Other->Insts, From, To); 544 } 545 void splice(iterator where, MachineBasicBlock *Other, iterator From, 546 iterator To) { 547 Insts.splice(where.getInstrIterator(), Other->Insts, 548 From.getInstrIterator(), To.getInstrIterator()); 549 } 550 551 /// removeFromParent - This method unlinks 'this' from the containing 552 /// function, and returns it, but does not delete it. 553 MachineBasicBlock *removeFromParent(); 554 555 /// eraseFromParent - This method unlinks 'this' from the containing 556 /// function and deletes it. 557 void eraseFromParent(); 558 559 /// ReplaceUsesOfBlockWith - Given a machine basic block that branched to 560 /// 'Old', change the code and CFG so that it branches to 'New' instead. 561 void ReplaceUsesOfBlockWith(MachineBasicBlock *Old, MachineBasicBlock *New); 562 563 /// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in 564 /// the CFG to be inserted. If we have proven that MBB can only branch to 565 /// DestA and DestB, remove any other MBB successors from the CFG. DestA and 566 /// DestB can be null. Besides DestA and DestB, retain other edges leading 567 /// to LandingPads (currently there can be only one; we don't check or require 568 /// that here). Note it is possible that DestA and/or DestB are LandingPads. 569 bool CorrectExtraCFGEdges(MachineBasicBlock *DestA, 570 MachineBasicBlock *DestB, 571 bool isCond); 572 573 /// findDebugLoc - find the next valid DebugLoc starting at MBBI, skipping 574 /// any DBG_VALUE instructions. Return UnknownLoc if there is none. 575 DebugLoc findDebugLoc(instr_iterator MBBI); 576 DebugLoc findDebugLoc(iterator MBBI) { 577 return findDebugLoc(MBBI.getInstrIterator()); 578 } 579 580 // Debugging methods. 581 void dump() const; 582 void print(raw_ostream &OS, SlotIndexes* = 0) const; 583 584 /// getNumber - MachineBasicBlocks are uniquely numbered at the function 585 /// level, unless they're not in a MachineFunction yet, in which case this 586 /// will return -1. 587 /// 588 int getNumber() const { return Number; } 589 void setNumber(int N) { Number = N; } 590 591 /// getSymbol - Return the MCSymbol for this basic block. 592 /// 593 MCSymbol *getSymbol() const; 594 595 596private: 597 /// getWeightIterator - Return weight iterator corresponding to the I 598 /// successor iterator. 599 weight_iterator getWeightIterator(succ_iterator I); 600 const_weight_iterator getWeightIterator(const_succ_iterator I) const; 601 602 friend class MachineBranchProbabilityInfo; 603 604 /// getSuccWeight - Return weight of the edge from this block to MBB. This 605 /// method should NOT be called directly, but by using getEdgeWeight method 606 /// from MachineBranchProbabilityInfo class. 607 uint32_t getSuccWeight(const MachineBasicBlock *succ) const; 608 609 610 // Methods used to maintain doubly linked list of blocks... 611 friend struct ilist_traits<MachineBasicBlock>; 612 613 // Machine-CFG mutators 614 615 /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock. 616 /// Don't do this unless you know what you're doing, because it doesn't 617 /// update pred's successors list. Use pred->addSuccessor instead. 618 /// 619 void addPredecessor(MachineBasicBlock *pred); 620 621 /// removePredecessor - Remove pred as a predecessor of this 622 /// MachineBasicBlock. Don't do this unless you know what you're 623 /// doing, because it doesn't update pred's successors list. Use 624 /// pred->removeSuccessor instead. 625 /// 626 void removePredecessor(MachineBasicBlock *pred); 627}; 628 629raw_ostream& operator<<(raw_ostream &OS, const MachineBasicBlock &MBB); 630 631void WriteAsOperand(raw_ostream &, const MachineBasicBlock*, bool t); 632 633// This is useful when building IndexedMaps keyed on basic block pointers. 634struct MBB2NumberFunctor : 635 public std::unary_function<const MachineBasicBlock*, unsigned> { 636 unsigned operator()(const MachineBasicBlock *MBB) const { 637 return MBB->getNumber(); 638 } 639}; 640 641//===--------------------------------------------------------------------===// 642// GraphTraits specializations for machine basic block graphs (machine-CFGs) 643//===--------------------------------------------------------------------===// 644 645// Provide specializations of GraphTraits to be able to treat a 646// MachineFunction as a graph of MachineBasicBlocks... 647// 648 649template <> struct GraphTraits<MachineBasicBlock *> { 650 typedef MachineBasicBlock NodeType; 651 typedef MachineBasicBlock::succ_iterator ChildIteratorType; 652 653 static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; } 654 static inline ChildIteratorType child_begin(NodeType *N) { 655 return N->succ_begin(); 656 } 657 static inline ChildIteratorType child_end(NodeType *N) { 658 return N->succ_end(); 659 } 660}; 661 662template <> struct GraphTraits<const MachineBasicBlock *> { 663 typedef const MachineBasicBlock NodeType; 664 typedef MachineBasicBlock::const_succ_iterator ChildIteratorType; 665 666 static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; } 667 static inline ChildIteratorType child_begin(NodeType *N) { 668 return N->succ_begin(); 669 } 670 static inline ChildIteratorType child_end(NodeType *N) { 671 return N->succ_end(); 672 } 673}; 674 675// Provide specializations of GraphTraits to be able to treat a 676// MachineFunction as a graph of MachineBasicBlocks... and to walk it 677// in inverse order. Inverse order for a function is considered 678// to be when traversing the predecessor edges of a MBB 679// instead of the successor edges. 680// 681template <> struct GraphTraits<Inverse<MachineBasicBlock*> > { 682 typedef MachineBasicBlock NodeType; 683 typedef MachineBasicBlock::pred_iterator ChildIteratorType; 684 static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) { 685 return G.Graph; 686 } 687 static inline ChildIteratorType child_begin(NodeType *N) { 688 return N->pred_begin(); 689 } 690 static inline ChildIteratorType child_end(NodeType *N) { 691 return N->pred_end(); 692 } 693}; 694 695template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > { 696 typedef const MachineBasicBlock NodeType; 697 typedef MachineBasicBlock::const_pred_iterator ChildIteratorType; 698 static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) { 699 return G.Graph; 700 } 701 static inline ChildIteratorType child_begin(NodeType *N) { 702 return N->pred_begin(); 703 } 704 static inline ChildIteratorType child_end(NodeType *N) { 705 return N->pred_end(); 706 } 707}; 708 709} // End llvm namespace 710 711#endif 712