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/ADT/GraphTraits.h" 18 #include "llvm/CodeGen/MachineInstr.h" 19 #include "llvm/Support/DataTypes.h" 20 #include <functional> 21 22 namespace llvm { 23 24 class Pass; 25 class BasicBlock; 26 class MachineFunction; 27 class MCSymbol; 28 class SlotIndexes; 29 class StringRef; 30 class raw_ostream; 31 class MachineBranchProbabilityInfo; 32 33 template <> 34 struct ilist_traits<MachineInstr> : public ilist_default_traits<MachineInstr> { 35 private: 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 42 public: 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); 58 private: 59 void createNode(const MachineInstr &); 60 }; 61 62 class 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; 108 109 public: 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) {} 147 148 bundle_iterator(Ty &mi) : MII(mi) { 149 assert(!mi.isBundledWithPred() && 150 "It's not legal to initialize bundle_iterator with a bundled MI"); 151 } 152 bundle_iterator(Ty *mi) : MII(mi) { 153 assert((!mi || !mi->isBundledWithPred()) && 154 "It's not legal to initialize bundle_iterator with a bundled MI"); 155 } 156 // Template allows conversion from const to nonconst. 157 template<class OtherTy, class OtherIterTy> 158 bundle_iterator(const bundle_iterator<OtherTy, OtherIterTy> &I) 159 : MII(I.getInstrIterator()) {} 160 bundle_iterator() : MII(0) {} 161 162 Ty &operator*() const { return *MII; } 163 Ty *operator->() const { return &operator*(); } 164 165 operator Ty*() const { return MII; } 166 167 bool operator==(const bundle_iterator &x) const { 168 return MII == x.MII; 169 } 170 bool operator!=(const bundle_iterator &x) const { 171 return !operator==(x); 172 } 173 174 // Increment and decrement operators... 175 bundle_iterator &operator--() { // predecrement - Back up 176 do --MII; 177 while (MII->isBundledWithPred()); 178 return *this; 179 } 180 bundle_iterator &operator++() { // preincrement - Advance 181 while (MII->isBundledWithSucc()) 182 ++MII; 183 ++MII; 184 return *this; 185 } 186 bundle_iterator operator--(int) { // postdecrement operators... 187 bundle_iterator tmp = *this; 188 --*this; 189 return tmp; 190 } 191 bundle_iterator operator++(int) { // postincrement operators... 192 bundle_iterator tmp = *this; 193 ++*this; 194 return tmp; 195 } 196 197 IterTy getInstrIterator() const { 198 return MII; 199 } 200 }; 201 202 typedef Instructions::iterator instr_iterator; 203 typedef Instructions::const_iterator const_instr_iterator; 204 typedef std::reverse_iterator<instr_iterator> reverse_instr_iterator; 205 typedef 206 std::reverse_iterator<const_instr_iterator> const_reverse_instr_iterator; 207 208 typedef 209 bundle_iterator<MachineInstr,instr_iterator> iterator; 210 typedef 211 bundle_iterator<const MachineInstr,const_instr_iterator> const_iterator; 212 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 213 typedef std::reverse_iterator<iterator> reverse_iterator; 214 215 216 unsigned size() const { return (unsigned)Insts.size(); } 217 bool empty() const { return Insts.empty(); } 218 219 MachineInstr& front() { return Insts.front(); } 220 MachineInstr& back() { return Insts.back(); } 221 const MachineInstr& front() const { return Insts.front(); } 222 const MachineInstr& back() const { return Insts.back(); } 223 224 instr_iterator instr_begin() { return Insts.begin(); } 225 const_instr_iterator instr_begin() const { return Insts.begin(); } 226 instr_iterator instr_end() { return Insts.end(); } 227 const_instr_iterator instr_end() const { return Insts.end(); } 228 reverse_instr_iterator instr_rbegin() { return Insts.rbegin(); } 229 const_reverse_instr_iterator instr_rbegin() const { return Insts.rbegin(); } 230 reverse_instr_iterator instr_rend () { return Insts.rend(); } 231 const_reverse_instr_iterator instr_rend () const { return Insts.rend(); } 232 233 iterator begin() { return instr_begin(); } 234 const_iterator begin() const { return instr_begin(); } 235 iterator end () { return instr_end(); } 236 const_iterator end () const { return instr_end(); } 237 reverse_iterator rbegin() { return instr_rbegin(); } 238 const_reverse_iterator rbegin() const { return instr_rbegin(); } 239 reverse_iterator rend () { return instr_rend(); } 240 const_reverse_iterator rend () const { return instr_rend(); } 241 242 243 // Machine-CFG iterators 244 typedef std::vector<MachineBasicBlock *>::iterator pred_iterator; 245 typedef std::vector<MachineBasicBlock *>::const_iterator const_pred_iterator; 246 typedef std::vector<MachineBasicBlock *>::iterator succ_iterator; 247 typedef std::vector<MachineBasicBlock *>::const_iterator const_succ_iterator; 248 typedef std::vector<MachineBasicBlock *>::reverse_iterator 249 pred_reverse_iterator; 250 typedef std::vector<MachineBasicBlock *>::const_reverse_iterator 251 const_pred_reverse_iterator; 252 typedef std::vector<MachineBasicBlock *>::reverse_iterator 253 succ_reverse_iterator; 254 typedef std::vector<MachineBasicBlock *>::const_reverse_iterator 255 const_succ_reverse_iterator; 256 257 pred_iterator pred_begin() { return Predecessors.begin(); } 258 const_pred_iterator pred_begin() const { return Predecessors.begin(); } 259 pred_iterator pred_end() { return Predecessors.end(); } 260 const_pred_iterator pred_end() const { return Predecessors.end(); } 261 pred_reverse_iterator pred_rbegin() 262 { return Predecessors.rbegin();} 263 const_pred_reverse_iterator pred_rbegin() const 264 { return Predecessors.rbegin();} 265 pred_reverse_iterator pred_rend() 266 { return Predecessors.rend(); } 267 const_pred_reverse_iterator pred_rend() const 268 { return Predecessors.rend(); } 269 unsigned pred_size() const { 270 return (unsigned)Predecessors.size(); 271 } 272 bool pred_empty() const { return Predecessors.empty(); } 273 succ_iterator succ_begin() { return Successors.begin(); } 274 const_succ_iterator succ_begin() const { return Successors.begin(); } 275 succ_iterator succ_end() { return Successors.end(); } 276 const_succ_iterator succ_end() const { return Successors.end(); } 277 succ_reverse_iterator succ_rbegin() 278 { return Successors.rbegin(); } 279 const_succ_reverse_iterator succ_rbegin() const 280 { return Successors.rbegin(); } 281 succ_reverse_iterator succ_rend() 282 { return Successors.rend(); } 283 const_succ_reverse_iterator succ_rend() const 284 { return Successors.rend(); } 285 unsigned succ_size() const { 286 return (unsigned)Successors.size(); 287 } 288 bool succ_empty() const { return Successors.empty(); } 289 290 // LiveIn management methods. 291 292 /// addLiveIn - Add the specified register as a live in. Note that it 293 /// is an error to add the same register to the same set more than once. 294 void addLiveIn(unsigned Reg) { LiveIns.push_back(Reg); } 295 296 /// removeLiveIn - Remove the specified register from the live in set. 297 /// 298 void removeLiveIn(unsigned Reg); 299 300 /// isLiveIn - Return true if the specified register is in the live in set. 301 /// 302 bool isLiveIn(unsigned Reg) const; 303 304 // Iteration support for live in sets. These sets are kept in sorted 305 // order by their register number. 306 typedef std::vector<unsigned>::const_iterator livein_iterator; 307 livein_iterator livein_begin() const { return LiveIns.begin(); } 308 livein_iterator livein_end() const { return LiveIns.end(); } 309 bool livein_empty() const { return LiveIns.empty(); } 310 311 /// getAlignment - Return alignment of the basic block. 312 /// The alignment is specified as log2(bytes). 313 /// 314 unsigned getAlignment() const { return Alignment; } 315 316 /// setAlignment - Set alignment of the basic block. 317 /// The alignment is specified as log2(bytes). 318 /// 319 void setAlignment(unsigned Align) { Alignment = Align; } 320 321 /// isLandingPad - Returns true if the block is a landing pad. That is 322 /// this basic block is entered via an exception handler. 323 bool isLandingPad() const { return IsLandingPad; } 324 325 /// setIsLandingPad - Indicates the block is a landing pad. That is 326 /// this basic block is entered via an exception handler. 327 void setIsLandingPad(bool V = true) { IsLandingPad = V; } 328 329 /// getLandingPadSuccessor - If this block has a successor that is a landing 330 /// pad, return it. Otherwise return NULL. 331 const MachineBasicBlock *getLandingPadSuccessor() const; 332 333 // Code Layout methods. 334 335 /// moveBefore/moveAfter - move 'this' block before or after the specified 336 /// block. This only moves the block, it does not modify the CFG or adjust 337 /// potential fall-throughs at the end of the block. 338 void moveBefore(MachineBasicBlock *NewAfter); 339 void moveAfter(MachineBasicBlock *NewBefore); 340 341 /// updateTerminator - Update the terminator instructions in block to account 342 /// for changes to the layout. If the block previously used a fallthrough, 343 /// it may now need a branch, and if it previously used branching it may now 344 /// be able to use a fallthrough. 345 void updateTerminator(); 346 347 // Machine-CFG mutators 348 349 /// addSuccessor - Add succ as a successor of this MachineBasicBlock. 350 /// The Predecessors list of succ is automatically updated. WEIGHT 351 /// parameter is stored in Weights list and it may be used by 352 /// MachineBranchProbabilityInfo analysis to calculate branch probability. 353 /// 354 /// Note that duplicate Machine CFG edges are not allowed. 355 /// 356 void addSuccessor(MachineBasicBlock *succ, uint32_t weight = 0); 357 358 /// removeSuccessor - Remove successor from the successors list of this 359 /// MachineBasicBlock. The Predecessors list of succ is automatically updated. 360 /// 361 void removeSuccessor(MachineBasicBlock *succ); 362 363 /// removeSuccessor - Remove specified successor from the successors list of 364 /// this MachineBasicBlock. The Predecessors list of succ is automatically 365 /// updated. Return the iterator to the element after the one removed. 366 /// 367 succ_iterator removeSuccessor(succ_iterator I); 368 369 /// replaceSuccessor - Replace successor OLD with NEW and update weight info. 370 /// 371 void replaceSuccessor(MachineBasicBlock *Old, MachineBasicBlock *New); 372 373 374 /// transferSuccessors - Transfers all the successors from MBB to this 375 /// machine basic block (i.e., copies all the successors fromMBB and 376 /// remove all the successors from fromMBB). 377 void transferSuccessors(MachineBasicBlock *fromMBB); 378 379 /// transferSuccessorsAndUpdatePHIs - Transfers all the successors, as 380 /// in transferSuccessors, and update PHI operands in the successor blocks 381 /// which refer to fromMBB to refer to this. 382 void transferSuccessorsAndUpdatePHIs(MachineBasicBlock *fromMBB); 383 384 /// isPredecessor - Return true if the specified MBB is a predecessor of this 385 /// block. 386 bool isPredecessor(const MachineBasicBlock *MBB) const; 387 388 /// isSuccessor - Return true if the specified MBB is a successor of this 389 /// block. 390 bool isSuccessor(const MachineBasicBlock *MBB) const; 391 392 /// isLayoutSuccessor - Return true if the specified MBB will be emitted 393 /// immediately after this block, such that if this block exits by 394 /// falling through, control will transfer to the specified MBB. Note 395 /// that MBB need not be a successor at all, for example if this block 396 /// ends with an unconditional branch to some other block. 397 bool isLayoutSuccessor(const MachineBasicBlock *MBB) const; 398 399 /// canFallThrough - Return true if the block can implicitly transfer 400 /// control to the block after it by falling off the end of it. This should 401 /// return false if it can reach the block after it, but it uses an explicit 402 /// branch to do so (e.g., a table jump). True is a conservative answer. 403 bool canFallThrough(); 404 405 /// Returns a pointer to the first instructon in this block that is not a 406 /// PHINode instruction. When adding instruction to the beginning of the 407 /// basic block, they should be added before the returned value, not before 408 /// the first instruction, which might be PHI. 409 /// Returns end() is there's no non-PHI instruction. 410 iterator getFirstNonPHI(); 411 412 /// SkipPHIsAndLabels - Return the first instruction in MBB after I that is 413 /// not a PHI or a label. This is the correct point to insert copies at the 414 /// beginning of a basic block. 415 iterator SkipPHIsAndLabels(iterator I); 416 417 /// getFirstTerminator - returns an iterator to the first terminator 418 /// instruction of this basic block. If a terminator does not exist, 419 /// it returns end() 420 iterator getFirstTerminator(); 421 const_iterator getFirstTerminator() const; 422 423 /// getFirstInstrTerminator - Same getFirstTerminator but it ignores bundles 424 /// and return an instr_iterator instead. 425 instr_iterator getFirstInstrTerminator(); 426 427 /// getLastNonDebugInstr - returns an iterator to the last non-debug 428 /// instruction in the basic block, or end() 429 iterator getLastNonDebugInstr(); 430 const_iterator getLastNonDebugInstr() const; 431 432 /// SplitCriticalEdge - Split the critical edge from this block to the 433 /// given successor block, and return the newly created block, or null 434 /// if splitting is not possible. 435 /// 436 /// This function updates LiveVariables, MachineDominatorTree, and 437 /// MachineLoopInfo, as applicable. 438 MachineBasicBlock *SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P); 439 440 void pop_front() { Insts.pop_front(); } 441 void pop_back() { Insts.pop_back(); } 442 void push_back(MachineInstr *MI) { Insts.push_back(MI); } 443 444 /// Insert MI into the instruction list before I, possibly inside a bundle. 445 /// 446 /// If the insertion point is inside a bundle, MI will be added to the bundle, 447 /// otherwise MI will not be added to any bundle. That means this function 448 /// alone can't be used to prepend or append instructions to bundles. See 449 /// MIBundleBuilder::insert() for a more reliable way of doing that. 450 instr_iterator insert(instr_iterator I, MachineInstr *M); 451 452 /// Insert a range of instructions into the instruction list before I. 453 template<typename IT> 454 void insert(iterator I, IT S, IT E) { 455 Insts.insert(I.getInstrIterator(), S, E); 456 } 457 458 /// Insert MI into the instruction list before I. 459 iterator insert(iterator I, MachineInstr *MI) { 460 assert(!MI->isBundledWithPred() && !MI->isBundledWithSucc() && 461 "Cannot insert instruction with bundle flags"); 462 return Insts.insert(I.getInstrIterator(), MI); 463 } 464 465 /// Insert MI into the instruction list after I. 466 iterator insertAfter(iterator I, MachineInstr *MI) { 467 assert(!MI->isBundledWithPred() && !MI->isBundledWithSucc() && 468 "Cannot insert instruction with bundle flags"); 469 return Insts.insertAfter(I.getInstrIterator(), MI); 470 } 471 472 /// Remove an instruction from the instruction list and delete it. 473 /// 474 /// If the instruction is part of a bundle, the other instructions in the 475 /// bundle will still be bundled after removing the single instruction. 476 instr_iterator erase(instr_iterator I); 477 478 /// Remove an instruction from the instruction list and delete it. 479 /// 480 /// If the instruction is part of a bundle, the other instructions in the 481 /// bundle will still be bundled after removing the single instruction. 482 instr_iterator erase_instr(MachineInstr *I) { 483 return erase(instr_iterator(I)); 484 } 485 486 /// Remove a range of instructions from the instruction list and delete them. 487 iterator erase(iterator I, iterator E) { 488 return Insts.erase(I.getInstrIterator(), E.getInstrIterator()); 489 } 490 491 /// Remove an instruction or bundle from the instruction list and delete it. 492 /// 493 /// If I points to a bundle of instructions, they are all erased. 494 iterator erase(iterator I) { 495 return erase(I, llvm::next(I)); 496 } 497 498 /// Remove an instruction from the instruction list and delete it. 499 /// 500 /// If I is the head of a bundle of instructions, the whole bundle will be 501 /// erased. 502 iterator erase(MachineInstr *I) { 503 return erase(iterator(I)); 504 } 505 506 /// Remove the unbundled instruction from the instruction list without 507 /// deleting it. 508 /// 509 /// This function can not be used to remove bundled instructions, use 510 /// remove_instr to remove individual instructions from a bundle. 511 MachineInstr *remove(MachineInstr *I) { 512 assert(!I->isBundled() && "Cannot remove bundled instructions"); 513 return Insts.remove(I); 514 } 515 516 /// Remove the possibly bundled instruction from the instruction list 517 /// without deleting it. 518 /// 519 /// If the instruction is part of a bundle, the other instructions in the 520 /// bundle will still be bundled after removing the single instruction. 521 MachineInstr *remove_instr(MachineInstr *I); 522 523 void clear() { 524 Insts.clear(); 525 } 526 527 /// Take an instruction from MBB 'Other' at the position From, and insert it 528 /// into this MBB right before 'Where'. 529 /// 530 /// If From points to a bundle of instructions, the whole bundle is moved. 531 void splice(iterator Where, MachineBasicBlock *Other, iterator From) { 532 // The range splice() doesn't allow noop moves, but this one does. 533 if (Where != From) 534 splice(Where, Other, From, llvm::next(From)); 535 } 536 537 /// Take a block of instructions from MBB 'Other' in the range [From, To), 538 /// and insert them into this MBB right before 'Where'. 539 /// 540 /// The instruction at 'Where' must not be included in the range of 541 /// instructions to move. 542 void splice(iterator Where, MachineBasicBlock *Other, 543 iterator From, iterator To) { 544 Insts.splice(Where.getInstrIterator(), Other->Insts, 545 From.getInstrIterator(), To.getInstrIterator()); 546 } 547 548 /// removeFromParent - This method unlinks 'this' from the containing 549 /// function, and returns it, but does not delete it. 550 MachineBasicBlock *removeFromParent(); 551 552 /// eraseFromParent - This method unlinks 'this' from the containing 553 /// function and deletes it. 554 void eraseFromParent(); 555 556 /// ReplaceUsesOfBlockWith - Given a machine basic block that branched to 557 /// 'Old', change the code and CFG so that it branches to 'New' instead. 558 void ReplaceUsesOfBlockWith(MachineBasicBlock *Old, MachineBasicBlock *New); 559 560 /// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in 561 /// the CFG to be inserted. If we have proven that MBB can only branch to 562 /// DestA and DestB, remove any other MBB successors from the CFG. DestA and 563 /// DestB can be null. Besides DestA and DestB, retain other edges leading 564 /// to LandingPads (currently there can be only one; we don't check or require 565 /// that here). Note it is possible that DestA and/or DestB are LandingPads. 566 bool CorrectExtraCFGEdges(MachineBasicBlock *DestA, 567 MachineBasicBlock *DestB, 568 bool isCond); 569 570 /// findDebugLoc - find the next valid DebugLoc starting at MBBI, skipping 571 /// any DBG_VALUE instructions. Return UnknownLoc if there is none. 572 DebugLoc findDebugLoc(instr_iterator MBBI); 573 DebugLoc findDebugLoc(iterator MBBI) { 574 return findDebugLoc(MBBI.getInstrIterator()); 575 } 576 577 /// Possible outcome of a register liveness query to computeRegisterLiveness() 578 enum LivenessQueryResult { 579 LQR_Live, ///< Register is known to be live. 580 LQR_OverlappingLive, ///< Register itself is not live, but some overlapping 581 ///< register is. 582 LQR_Dead, ///< Register is known to be dead. 583 LQR_Unknown ///< Register liveness not decidable from local 584 ///< neighborhood. 585 }; 586 587 /// computeRegisterLiveness - Return whether (physical) register \c Reg 588 /// has been <def>ined and not <kill>ed as of just before \c MI. 589 /// 590 /// Search is localised to a neighborhood of 591 /// \c Neighborhood instructions before (searching for defs or kills) and 592 /// Neighborhood instructions after (searching just for defs) MI. 593 /// 594 /// \c Reg must be a physical register. 595 LivenessQueryResult computeRegisterLiveness(const TargetRegisterInfo *TRI, 596 unsigned Reg, MachineInstr *MI, 597 unsigned Neighborhood=10); 598 599 // Debugging methods. 600 void dump() const; 601 void print(raw_ostream &OS, SlotIndexes* = 0) const; 602 603 /// getNumber - MachineBasicBlocks are uniquely numbered at the function 604 /// level, unless they're not in a MachineFunction yet, in which case this 605 /// will return -1. 606 /// 607 int getNumber() const { return Number; } 608 void setNumber(int N) { Number = N; } 609 610 /// getSymbol - Return the MCSymbol for this basic block. 611 /// 612 MCSymbol *getSymbol() const; 613 614 615 private: 616 /// getWeightIterator - Return weight iterator corresponding to the I 617 /// successor iterator. 618 weight_iterator getWeightIterator(succ_iterator I); 619 const_weight_iterator getWeightIterator(const_succ_iterator I) const; 620 621 friend class MachineBranchProbabilityInfo; 622 623 /// getSuccWeight - Return weight of the edge from this block to MBB. This 624 /// method should NOT be called directly, but by using getEdgeWeight method 625 /// from MachineBranchProbabilityInfo class. 626 uint32_t getSuccWeight(const_succ_iterator Succ) const; 627 628 629 // Methods used to maintain doubly linked list of blocks... 630 friend struct ilist_traits<MachineBasicBlock>; 631 632 // Machine-CFG mutators 633 634 /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock. 635 /// Don't do this unless you know what you're doing, because it doesn't 636 /// update pred's successors list. Use pred->addSuccessor instead. 637 /// 638 void addPredecessor(MachineBasicBlock *pred); 639 640 /// removePredecessor - Remove pred as a predecessor of this 641 /// MachineBasicBlock. Don't do this unless you know what you're 642 /// doing, because it doesn't update pred's successors list. Use 643 /// pred->removeSuccessor instead. 644 /// 645 void removePredecessor(MachineBasicBlock *pred); 646 }; 647 648 raw_ostream& operator<<(raw_ostream &OS, const MachineBasicBlock &MBB); 649 650 void WriteAsOperand(raw_ostream &, const MachineBasicBlock*, bool t); 651 652 // This is useful when building IndexedMaps keyed on basic block pointers. 653 struct MBB2NumberFunctor : 654 public std::unary_function<const MachineBasicBlock*, unsigned> { 655 unsigned operator()(const MachineBasicBlock *MBB) const { 656 return MBB->getNumber(); 657 } 658 }; 659 660 //===--------------------------------------------------------------------===// 661 // GraphTraits specializations for machine basic block graphs (machine-CFGs) 662 //===--------------------------------------------------------------------===// 663 664 // Provide specializations of GraphTraits to be able to treat a 665 // MachineFunction as a graph of MachineBasicBlocks... 666 // 667 668 template <> struct GraphTraits<MachineBasicBlock *> { 669 typedef MachineBasicBlock NodeType; 670 typedef MachineBasicBlock::succ_iterator ChildIteratorType; 671 672 static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; } 673 static inline ChildIteratorType child_begin(NodeType *N) { 674 return N->succ_begin(); 675 } 676 static inline ChildIteratorType child_end(NodeType *N) { 677 return N->succ_end(); 678 } 679 }; 680 681 template <> struct GraphTraits<const MachineBasicBlock *> { 682 typedef const MachineBasicBlock NodeType; 683 typedef MachineBasicBlock::const_succ_iterator ChildIteratorType; 684 685 static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; } 686 static inline ChildIteratorType child_begin(NodeType *N) { 687 return N->succ_begin(); 688 } 689 static inline ChildIteratorType child_end(NodeType *N) { 690 return N->succ_end(); 691 } 692 }; 693 694 // Provide specializations of GraphTraits to be able to treat a 695 // MachineFunction as a graph of MachineBasicBlocks... and to walk it 696 // in inverse order. Inverse order for a function is considered 697 // to be when traversing the predecessor edges of a MBB 698 // instead of the successor edges. 699 // 700 template <> struct GraphTraits<Inverse<MachineBasicBlock*> > { 701 typedef MachineBasicBlock NodeType; 702 typedef MachineBasicBlock::pred_iterator ChildIteratorType; 703 static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) { 704 return G.Graph; 705 } 706 static inline ChildIteratorType child_begin(NodeType *N) { 707 return N->pred_begin(); 708 } 709 static inline ChildIteratorType child_end(NodeType *N) { 710 return N->pred_end(); 711 } 712 }; 713 714 template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > { 715 typedef const MachineBasicBlock NodeType; 716 typedef MachineBasicBlock::const_pred_iterator ChildIteratorType; 717 static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) { 718 return G.Graph; 719 } 720 static inline ChildIteratorType child_begin(NodeType *N) { 721 return N->pred_begin(); 722 } 723 static inline ChildIteratorType child_end(NodeType *N) { 724 return N->pred_end(); 725 } 726 }; 727 728 } // End llvm namespace 729 730 #endif 731