MachineBasicBlock.h revision 2ad047e04dd4c19defade4799834efacb0024551
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 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 /// Weights - Keep track of the weights to the successors. This vector 75 /// has the same order as Successors, or it is empty if we don't use it 76 /// (disable optimization). 77 std::vector<uint32_t> Weights; 78 typedef std::vector<uint32_t>::iterator weight_iterator; 79 typedef std::vector<uint32_t>::const_iterator const_weight_iterator; 80 81 /// LiveIns - Keep track of the physical registers that are livein of 82 /// the basicblock. 83 std::vector<unsigned> LiveIns; 84 85 /// Alignment - Alignment of the basic block. Zero if the basic block does 86 /// not need to be aligned. 87 /// The alignment is specified as log2(bytes). 88 unsigned Alignment; 89 90 /// IsLandingPad - Indicate that this basic block is entered via an 91 /// exception handler. 92 bool IsLandingPad; 93 94 /// AddressTaken - Indicate that this basic block is potentially the 95 /// target of an indirect branch. 96 bool AddressTaken; 97 98 /// \brief since getSymbol is a relatively heavy-weight operation, the symbol 99 /// is only computed once and is cached. 100 mutable MCSymbol *CachedMCSymbol; 101 102 // Intrusive list support 103 MachineBasicBlock() {} 104 105 explicit MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb); 106 107 ~MachineBasicBlock(); 108 109 // MachineBasicBlocks are allocated and owned by MachineFunction. 110 friend class MachineFunction; 111 112public: 113 /// getBasicBlock - Return the LLVM basic block that this instance 114 /// corresponded to originally. Note that this may be NULL if this instance 115 /// does not correspond directly to an LLVM basic block. 116 /// 117 const BasicBlock *getBasicBlock() const { return BB; } 118 119 /// getName - Return the name of the corresponding LLVM basic block, or 120 /// "(null)". 121 StringRef getName() const; 122 123 /// getFullName - Return a formatted string to identify this block and its 124 /// parent function. 125 std::string getFullName() const; 126 127 /// hasAddressTaken - Test whether this block is potentially the target 128 /// of an indirect branch. 129 bool hasAddressTaken() const { return AddressTaken; } 130 131 /// setHasAddressTaken - Set this block to reflect that it potentially 132 /// is the target of an indirect branch. 133 void setHasAddressTaken() { AddressTaken = true; } 134 135 /// getParent - Return the MachineFunction containing this basic block. 136 /// 137 const MachineFunction *getParent() const { return xParent; } 138 MachineFunction *getParent() { return xParent; } 139 140 141 /// bundle_iterator - MachineBasicBlock iterator that automatically skips over 142 /// MIs that are inside bundles (i.e. walk top level MIs only). 143 template<typename Ty, typename IterTy> 144 class bundle_iterator 145 : public std::iterator<std::bidirectional_iterator_tag, Ty, ptrdiff_t> { 146 IterTy MII; 147 148 public: 149 bundle_iterator(IterTy mii) : MII(mii) {} 150 151 bundle_iterator(Ty &mi) : MII(mi) { 152 assert(!mi.isBundledWithPred() && 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->isBundledWithPred()) && 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 --MII; 180 while (MII->isBundledWithPred()); 181 return *this; 182 } 183 bundle_iterator &operator++() { // preincrement - Advance 184 while (MII->isBundledWithSucc()) 185 ++MII; 186 ++MII; 187 return *this; 188 } 189 bundle_iterator operator--(int) { // postdecrement operators... 190 bundle_iterator tmp = *this; 191 --*this; 192 return tmp; 193 } 194 bundle_iterator operator++(int) { // postincrement operators... 195 bundle_iterator tmp = *this; 196 ++*this; 197 return tmp; 198 } 199 200 IterTy getInstrIterator() const { 201 return MII; 202 } 203 }; 204 205 typedef Instructions::iterator instr_iterator; 206 typedef Instructions::const_iterator const_instr_iterator; 207 typedef std::reverse_iterator<instr_iterator> reverse_instr_iterator; 208 typedef 209 std::reverse_iterator<const_instr_iterator> const_reverse_instr_iterator; 210 211 typedef 212 bundle_iterator<MachineInstr,instr_iterator> iterator; 213 typedef 214 bundle_iterator<const MachineInstr,const_instr_iterator> const_iterator; 215 typedef std::reverse_iterator<const_iterator> const_reverse_iterator; 216 typedef std::reverse_iterator<iterator> reverse_iterator; 217 218 219 unsigned size() const { return (unsigned)Insts.size(); } 220 bool empty() const { return Insts.empty(); } 221 222 MachineInstr& front() { return Insts.front(); } 223 MachineInstr& back() { return Insts.back(); } 224 const MachineInstr& front() const { return Insts.front(); } 225 const MachineInstr& back() const { return Insts.back(); } 226 227 instr_iterator instr_begin() { return Insts.begin(); } 228 const_instr_iterator instr_begin() const { return Insts.begin(); } 229 instr_iterator instr_end() { return Insts.end(); } 230 const_instr_iterator instr_end() const { return Insts.end(); } 231 reverse_instr_iterator instr_rbegin() { return Insts.rbegin(); } 232 const_reverse_instr_iterator instr_rbegin() const { return Insts.rbegin(); } 233 reverse_instr_iterator instr_rend () { return Insts.rend(); } 234 const_reverse_instr_iterator instr_rend () const { return Insts.rend(); } 235 236 iterator begin() { return instr_begin(); } 237 const_iterator begin() const { return instr_begin(); } 238 iterator end () { return instr_end(); } 239 const_iterator end () const { return instr_end(); } 240 reverse_iterator rbegin() { return instr_rbegin(); } 241 const_reverse_iterator rbegin() const { return instr_rbegin(); } 242 reverse_iterator rend () { return instr_rend(); } 243 const_reverse_iterator rend () const { return instr_rend(); } 244 245 246 // Machine-CFG iterators 247 typedef std::vector<MachineBasicBlock *>::iterator pred_iterator; 248 typedef std::vector<MachineBasicBlock *>::const_iterator const_pred_iterator; 249 typedef std::vector<MachineBasicBlock *>::iterator succ_iterator; 250 typedef std::vector<MachineBasicBlock *>::const_iterator const_succ_iterator; 251 typedef std::vector<MachineBasicBlock *>::reverse_iterator 252 pred_reverse_iterator; 253 typedef std::vector<MachineBasicBlock *>::const_reverse_iterator 254 const_pred_reverse_iterator; 255 typedef std::vector<MachineBasicBlock *>::reverse_iterator 256 succ_reverse_iterator; 257 typedef std::vector<MachineBasicBlock *>::const_reverse_iterator 258 const_succ_reverse_iterator; 259 260 pred_iterator pred_begin() { return Predecessors.begin(); } 261 const_pred_iterator pred_begin() const { return Predecessors.begin(); } 262 pred_iterator pred_end() { return Predecessors.end(); } 263 const_pred_iterator pred_end() const { return Predecessors.end(); } 264 pred_reverse_iterator pred_rbegin() 265 { return Predecessors.rbegin();} 266 const_pred_reverse_iterator pred_rbegin() const 267 { return Predecessors.rbegin();} 268 pred_reverse_iterator pred_rend() 269 { return Predecessors.rend(); } 270 const_pred_reverse_iterator pred_rend() const 271 { return Predecessors.rend(); } 272 unsigned pred_size() const { 273 return (unsigned)Predecessors.size(); 274 } 275 bool pred_empty() const { return Predecessors.empty(); } 276 succ_iterator succ_begin() { return Successors.begin(); } 277 const_succ_iterator succ_begin() const { return Successors.begin(); } 278 succ_iterator succ_end() { return Successors.end(); } 279 const_succ_iterator succ_end() const { return Successors.end(); } 280 succ_reverse_iterator succ_rbegin() 281 { return Successors.rbegin(); } 282 const_succ_reverse_iterator succ_rbegin() const 283 { return Successors.rbegin(); } 284 succ_reverse_iterator succ_rend() 285 { return Successors.rend(); } 286 const_succ_reverse_iterator succ_rend() const 287 { return Successors.rend(); } 288 unsigned succ_size() const { 289 return (unsigned)Successors.size(); 290 } 291 bool succ_empty() const { return Successors.empty(); } 292 293 // LiveIn management methods. 294 295 /// addLiveIn - Add the specified register as a live in. Note that it 296 /// is an error to add the same register to the same set more than once. 297 void addLiveIn(unsigned Reg) { LiveIns.push_back(Reg); } 298 299 /// removeLiveIn - Remove the specified register from the live in set. 300 /// 301 void removeLiveIn(unsigned Reg); 302 303 /// isLiveIn - Return true if the specified register is in the live in set. 304 /// 305 bool isLiveIn(unsigned Reg) const; 306 307 // Iteration support for live in sets. These sets are kept in sorted 308 // order by their register number. 309 typedef std::vector<unsigned>::const_iterator livein_iterator; 310 livein_iterator livein_begin() const { return LiveIns.begin(); } 311 livein_iterator livein_end() const { return LiveIns.end(); } 312 bool livein_empty() const { return LiveIns.empty(); } 313 314 /// getAlignment - Return alignment of the basic block. 315 /// The alignment is specified as log2(bytes). 316 /// 317 unsigned getAlignment() const { return Alignment; } 318 319 /// setAlignment - Set alignment of the basic block. 320 /// The alignment is specified as log2(bytes). 321 /// 322 void setAlignment(unsigned Align) { Alignment = Align; } 323 324 /// isLandingPad - Returns true if the block is a landing pad. That is 325 /// this basic block is entered via an exception handler. 326 bool isLandingPad() const { return IsLandingPad; } 327 328 /// setIsLandingPad - Indicates the block is a landing pad. That is 329 /// this basic block is entered via an exception handler. 330 void setIsLandingPad(bool V = true) { IsLandingPad = V; } 331 332 /// getLandingPadSuccessor - If this block has a successor that is a landing 333 /// pad, return it. Otherwise return NULL. 334 const MachineBasicBlock *getLandingPadSuccessor() const; 335 336 // Code Layout methods. 337 338 /// moveBefore/moveAfter - move 'this' block before or after the specified 339 /// block. This only moves the block, it does not modify the CFG or adjust 340 /// potential fall-throughs at the end of the block. 341 void moveBefore(MachineBasicBlock *NewAfter); 342 void moveAfter(MachineBasicBlock *NewBefore); 343 344 /// updateTerminator - Update the terminator instructions in block to account 345 /// for changes to the layout. If the block previously used a fallthrough, 346 /// it may now need a branch, and if it previously used branching it may now 347 /// be able to use a fallthrough. 348 void updateTerminator(); 349 350 // Machine-CFG mutators 351 352 /// addSuccessor - Add succ as a successor of this MachineBasicBlock. 353 /// The Predecessors list of succ is automatically updated. WEIGHT 354 /// parameter is stored in Weights list and it may be used by 355 /// MachineBranchProbabilityInfo analysis to calculate branch probability. 356 /// 357 /// Note that duplicate Machine CFG edges are not allowed. 358 /// 359 void addSuccessor(MachineBasicBlock *succ, uint32_t weight = 0); 360 361 /// removeSuccessor - Remove successor from the successors list of this 362 /// MachineBasicBlock. The Predecessors list of succ is automatically updated. 363 /// 364 void removeSuccessor(MachineBasicBlock *succ); 365 366 /// removeSuccessor - Remove specified successor from the successors list of 367 /// this MachineBasicBlock. The Predecessors list of succ is automatically 368 /// updated. Return the iterator to the element after the one removed. 369 /// 370 succ_iterator removeSuccessor(succ_iterator I); 371 372 /// replaceSuccessor - Replace successor OLD with NEW and update weight info. 373 /// 374 void replaceSuccessor(MachineBasicBlock *Old, MachineBasicBlock *New); 375 376 377 /// transferSuccessors - Transfers all the successors from MBB to this 378 /// machine basic block (i.e., copies all the successors fromMBB and 379 /// remove all the successors from fromMBB). 380 void transferSuccessors(MachineBasicBlock *fromMBB); 381 382 /// transferSuccessorsAndUpdatePHIs - Transfers all the successors, as 383 /// in transferSuccessors, and update PHI operands in the successor blocks 384 /// which refer to fromMBB to refer to this. 385 void transferSuccessorsAndUpdatePHIs(MachineBasicBlock *fromMBB); 386 387 /// isPredecessor - Return true if the specified MBB is a predecessor of this 388 /// block. 389 bool isPredecessor(const MachineBasicBlock *MBB) const; 390 391 /// isSuccessor - Return true if the specified MBB is a successor of this 392 /// block. 393 bool isSuccessor(const MachineBasicBlock *MBB) const; 394 395 /// isLayoutSuccessor - Return true if the specified MBB will be emitted 396 /// immediately after this block, such that if this block exits by 397 /// falling through, control will transfer to the specified MBB. Note 398 /// that MBB need not be a successor at all, for example if this block 399 /// ends with an unconditional branch to some other block. 400 bool isLayoutSuccessor(const MachineBasicBlock *MBB) const; 401 402 /// canFallThrough - Return true if the block can implicitly transfer 403 /// control to the block after it by falling off the end of it. This should 404 /// return false if it can reach the block after it, but it uses an explicit 405 /// branch to do so (e.g., a table jump). True is a conservative answer. 406 bool canFallThrough(); 407 408 /// Returns a pointer to the first instructon in this block that is not a 409 /// PHINode instruction. When adding instruction to the beginning of the 410 /// basic block, they should be added before the returned value, not before 411 /// the first instruction, which might be PHI. 412 /// Returns end() is there's no non-PHI instruction. 413 iterator getFirstNonPHI(); 414 415 /// SkipPHIsAndLabels - Return the first instruction in MBB after I that is 416 /// not a PHI or a label. This is the correct point to insert copies at the 417 /// beginning of a basic block. 418 iterator SkipPHIsAndLabels(iterator I); 419 420 /// getFirstTerminator - returns an iterator to the first terminator 421 /// instruction of this basic block. If a terminator does not exist, 422 /// it returns end() 423 iterator getFirstTerminator(); 424 const_iterator getFirstTerminator() const; 425 426 /// getFirstInstrTerminator - Same getFirstTerminator but it ignores bundles 427 /// and return an instr_iterator instead. 428 instr_iterator getFirstInstrTerminator(); 429 430 /// getLastNonDebugInstr - returns an iterator to the last non-debug 431 /// instruction in the basic block, or end() 432 iterator getLastNonDebugInstr(); 433 const_iterator getLastNonDebugInstr() const; 434 435 /// SplitCriticalEdge - Split the critical edge from this block to the 436 /// given successor block, and return the newly created block, or null 437 /// if splitting is not possible. 438 /// 439 /// This function updates LiveVariables, MachineDominatorTree, and 440 /// MachineLoopInfo, as applicable. 441 MachineBasicBlock *SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P); 442 443 void pop_front() { Insts.pop_front(); } 444 void pop_back() { Insts.pop_back(); } 445 void push_back(MachineInstr *MI) { Insts.push_back(MI); } 446 447 /// Insert MI into the instruction list before I, possibly inside a bundle. 448 /// 449 /// If the insertion point is inside a bundle, MI will be added to the bundle, 450 /// otherwise MI will not be added to any bundle. That means this function 451 /// alone can't be used to prepend or append instructions to bundles. See 452 /// MIBundleBuilder::insert() for a more reliable way of doing that. 453 instr_iterator insert(instr_iterator I, MachineInstr *M); 454 455 /// Insert a range of instructions into the instruction list before I. 456 template<typename IT> 457 void insert(iterator I, IT S, IT E) { 458 Insts.insert(I.getInstrIterator(), S, E); 459 } 460 461 /// Insert MI into the instruction list before I. 462 iterator insert(iterator I, MachineInstr *MI) { 463 assert(!MI->isBundledWithPred() && !MI->isBundledWithSucc() && 464 "Cannot insert instruction with bundle flags"); 465 return Insts.insert(I.getInstrIterator(), MI); 466 } 467 468 /// Insert MI into the instruction list after I. 469 iterator insertAfter(iterator I, MachineInstr *MI) { 470 assert(!MI->isBundledWithPred() && !MI->isBundledWithSucc() && 471 "Cannot insert instruction with bundle flags"); 472 return Insts.insertAfter(I.getInstrIterator(), MI); 473 } 474 475 /// Remove an instruction from the instruction list and delete it. 476 /// 477 /// If the instruction is part of a bundle, the other instructions in the 478 /// bundle will still be bundled after removing the single instruction. 479 instr_iterator erase(instr_iterator I); 480 481 /// Remove an instruction from the instruction list and delete it. 482 /// 483 /// If the instruction is part of a bundle, the other instructions in the 484 /// bundle will still be bundled after removing the single instruction. 485 instr_iterator erase_instr(MachineInstr *I) { 486 return erase(instr_iterator(I)); 487 } 488 489 /// Remove a range of instructions from the instruction list and delete them. 490 iterator erase(iterator I, iterator E) { 491 return Insts.erase(I.getInstrIterator(), E.getInstrIterator()); 492 } 493 494 /// Remove an instruction or bundle from the instruction list and delete it. 495 /// 496 /// If I points to a bundle of instructions, they are all erased. 497 iterator erase(iterator I) { 498 return erase(I, llvm::next(I)); 499 } 500 501 /// Remove an instruction from the instruction list and delete it. 502 /// 503 /// If I is the head of a bundle of instructions, the whole bundle will be 504 /// erased. 505 iterator erase(MachineInstr *I) { 506 return erase(iterator(I)); 507 } 508 509 /// Remove the unbundled instruction from the instruction list without 510 /// deleting it. 511 /// 512 /// This function can not be used to remove bundled instructions, use 513 /// remove_instr to remove individual instructions from a bundle. 514 MachineInstr *remove(MachineInstr *I) { 515 assert(!I->isBundled() && "Cannot remove bundled instructions"); 516 return Insts.remove(I); 517 } 518 519 /// Remove the possibly bundled instruction from the instruction list 520 /// without deleting it. 521 /// 522 /// If the instruction is part of a bundle, the other instructions in the 523 /// bundle will still be bundled after removing the single instruction. 524 MachineInstr *remove_instr(MachineInstr *I); 525 526 void clear() { 527 Insts.clear(); 528 } 529 530 /// Take an instruction from MBB 'Other' at the position From, and insert it 531 /// into this MBB right before 'Where'. 532 /// 533 /// If From points to a bundle of instructions, the whole bundle is moved. 534 void splice(iterator Where, MachineBasicBlock *Other, iterator From) { 535 // The range splice() doesn't allow noop moves, but this one does. 536 if (Where != From) 537 splice(Where, Other, From, llvm::next(From)); 538 } 539 540 /// Take a block of instructions from MBB 'Other' in the range [From, To), 541 /// and insert them into this MBB right before 'Where'. 542 /// 543 /// The instruction at 'Where' must not be included in the range of 544 /// instructions to move. 545 void splice(iterator Where, MachineBasicBlock *Other, 546 iterator From, 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 /// Possible outcome of a register liveness query to computeRegisterLiveness() 581 enum LivenessQueryResult { 582 LQR_Live, ///< Register is known to be live. 583 LQR_OverlappingLive, ///< Register itself is not live, but some overlapping 584 ///< register is. 585 LQR_Dead, ///< Register is known to be dead. 586 LQR_Unknown ///< Register liveness not decidable from local 587 ///< neighborhood. 588 }; 589 590 /// computeRegisterLiveness - Return whether (physical) register \c Reg 591 /// has been <def>ined and not <kill>ed as of just before \c MI. 592 /// 593 /// Search is localised to a neighborhood of 594 /// \c Neighborhood instructions before (searching for defs or kills) and 595 /// Neighborhood instructions after (searching just for defs) MI. 596 /// 597 /// \c Reg must be a physical register. 598 LivenessQueryResult computeRegisterLiveness(const TargetRegisterInfo *TRI, 599 unsigned Reg, MachineInstr *MI, 600 unsigned Neighborhood=10); 601 602 // Debugging methods. 603 void dump() const; 604 void print(raw_ostream &OS, SlotIndexes* = 0) const; 605 606 /// getNumber - MachineBasicBlocks are uniquely numbered at the function 607 /// level, unless they're not in a MachineFunction yet, in which case this 608 /// will return -1. 609 /// 610 int getNumber() const { return Number; } 611 void setNumber(int N) { Number = N; } 612 613 /// getSymbol - Return the MCSymbol for this basic block. 614 /// 615 MCSymbol *getSymbol() const; 616 617 618private: 619 /// getWeightIterator - Return weight iterator corresponding to the I 620 /// successor iterator. 621 weight_iterator getWeightIterator(succ_iterator I); 622 const_weight_iterator getWeightIterator(const_succ_iterator I) const; 623 624 friend class MachineBranchProbabilityInfo; 625 626 /// getSuccWeight - Return weight of the edge from this block to MBB. This 627 /// method should NOT be called directly, but by using getEdgeWeight method 628 /// from MachineBranchProbabilityInfo class. 629 uint32_t getSuccWeight(const_succ_iterator Succ) const; 630 631 632 // Methods used to maintain doubly linked list of blocks... 633 friend struct ilist_traits<MachineBasicBlock>; 634 635 // Machine-CFG mutators 636 637 /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock. 638 /// Don't do this unless you know what you're doing, because it doesn't 639 /// update pred's successors list. Use pred->addSuccessor instead. 640 /// 641 void addPredecessor(MachineBasicBlock *pred); 642 643 /// removePredecessor - Remove pred as a predecessor of this 644 /// MachineBasicBlock. Don't do this unless you know what you're 645 /// doing, because it doesn't update pred's successors list. Use 646 /// pred->removeSuccessor instead. 647 /// 648 void removePredecessor(MachineBasicBlock *pred); 649}; 650 651raw_ostream& operator<<(raw_ostream &OS, const MachineBasicBlock &MBB); 652 653void WriteAsOperand(raw_ostream &, const MachineBasicBlock*, bool t); 654 655// This is useful when building IndexedMaps keyed on basic block pointers. 656struct MBB2NumberFunctor : 657 public std::unary_function<const MachineBasicBlock*, unsigned> { 658 unsigned operator()(const MachineBasicBlock *MBB) const { 659 return MBB->getNumber(); 660 } 661}; 662 663//===--------------------------------------------------------------------===// 664// GraphTraits specializations for machine basic block graphs (machine-CFGs) 665//===--------------------------------------------------------------------===// 666 667// Provide specializations of GraphTraits to be able to treat a 668// MachineFunction as a graph of MachineBasicBlocks... 669// 670 671template <> struct GraphTraits<MachineBasicBlock *> { 672 typedef MachineBasicBlock NodeType; 673 typedef MachineBasicBlock::succ_iterator ChildIteratorType; 674 675 static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; } 676 static inline ChildIteratorType child_begin(NodeType *N) { 677 return N->succ_begin(); 678 } 679 static inline ChildIteratorType child_end(NodeType *N) { 680 return N->succ_end(); 681 } 682}; 683 684template <> struct GraphTraits<const MachineBasicBlock *> { 685 typedef const MachineBasicBlock NodeType; 686 typedef MachineBasicBlock::const_succ_iterator ChildIteratorType; 687 688 static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; } 689 static inline ChildIteratorType child_begin(NodeType *N) { 690 return N->succ_begin(); 691 } 692 static inline ChildIteratorType child_end(NodeType *N) { 693 return N->succ_end(); 694 } 695}; 696 697// Provide specializations of GraphTraits to be able to treat a 698// MachineFunction as a graph of MachineBasicBlocks... and to walk it 699// in inverse order. Inverse order for a function is considered 700// to be when traversing the predecessor edges of a MBB 701// instead of the successor edges. 702// 703template <> struct GraphTraits<Inverse<MachineBasicBlock*> > { 704 typedef MachineBasicBlock NodeType; 705 typedef MachineBasicBlock::pred_iterator ChildIteratorType; 706 static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) { 707 return G.Graph; 708 } 709 static inline ChildIteratorType child_begin(NodeType *N) { 710 return N->pred_begin(); 711 } 712 static inline ChildIteratorType child_end(NodeType *N) { 713 return N->pred_end(); 714 } 715}; 716 717template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > { 718 typedef const MachineBasicBlock NodeType; 719 typedef MachineBasicBlock::const_pred_iterator ChildIteratorType; 720 static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) { 721 return G.Graph; 722 } 723 static inline ChildIteratorType child_begin(NodeType *N) { 724 return N->pred_begin(); 725 } 726 static inline ChildIteratorType child_end(NodeType *N) { 727 return N->pred_end(); 728 } 729}; 730 731} // End llvm namespace 732 733#endif 734