1 //===-- llvm/CodeGen/MachineBasicBlock.h ------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // Collect the sequence of machine instructions for a basic block.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CODEGEN_MACHINEBASICBLOCK_H
15 #define LLVM_CODEGEN_MACHINEBASICBLOCK_H
17 #include "llvm/CodeGen/MachineInstr.h"
18 #include "llvm/ADT/GraphTraits.h"
19 #include "llvm/Support/DataTypes.h"
26 class MachineFunction;
31 class MachineBranchProbabilityInfo;
34 struct ilist_traits<MachineInstr> : public ilist_default_traits<MachineInstr> {
36 mutable ilist_half_node<MachineInstr> Sentinel;
38 // this is only set by the MachineBasicBlock owning the LiveList
39 friend class MachineBasicBlock;
40 MachineBasicBlock* Parent;
43 MachineInstr *createSentinel() const {
44 return static_cast<MachineInstr*>(&Sentinel);
46 void destroySentinel(MachineInstr *) const {}
48 MachineInstr *provideInitialHead() const { return createSentinel(); }
49 MachineInstr *ensureHead(MachineInstr*) const { return createSentinel(); }
50 static void noteHead(MachineInstr*, MachineInstr*) {}
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);
59 void createNode(const MachineInstr &);
62 class MachineBasicBlock : public ilist_node<MachineBasicBlock> {
63 typedef ilist<MachineInstr> Instructions;
67 MachineFunction *xParent;
69 /// Predecessors/Successors - Keep track of the predecessor / successor
71 std::vector<MachineBasicBlock *> Predecessors;
72 std::vector<MachineBasicBlock *> Successors;
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;
82 /// LiveIns - Keep track of the physical registers that are livein of
84 std::vector<unsigned> LiveIns;
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).
91 /// IsLandingPad - Indicate that this basic block is entered via an
92 /// exception handler.
95 /// AddressTaken - Indicate that this basic block is potentially the
96 /// target of an indirect branch.
99 // Intrusive list support
100 MachineBasicBlock() {}
102 explicit MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb);
104 ~MachineBasicBlock();
106 // MachineBasicBlocks are allocated and owned by MachineFunction.
107 friend class MachineFunction;
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.
114 const BasicBlock *getBasicBlock() const { return BB; }
116 /// getName - Return the name of the corresponding LLVM basic block, or
118 StringRef getName() const;
120 /// getFullName - Return a formatted string to identify this block and its
122 std::string getFullName() const;
124 /// hasAddressTaken - Test whether this block is potentially the target
125 /// of an indirect branch.
126 bool hasAddressTaken() const { return AddressTaken; }
128 /// setHasAddressTaken - Set this block to reflect that it potentially
129 /// is the target of an indirect branch.
130 void setHasAddressTaken() { AddressTaken = true; }
132 /// getParent - Return the MachineFunction containing this basic block.
134 const MachineFunction *getParent() const { return xParent; }
135 MachineFunction *getParent() { return xParent; }
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> {
146 bundle_iterator(IterTy mii) : MII(mii) {
147 assert(!MII->isInsideBundle() &&
148 "It's not legal to initialize bundle_iterator with a bundled MI");
151 bundle_iterator(Ty &mi) : MII(mi) {
152 assert(!mi.isInsideBundle() &&
153 "It's not legal to initialize bundle_iterator with a bundled MI");
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");
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) {}
165 Ty &operator*() const { return *MII; }
166 Ty *operator->() const { return &operator*(); }
168 operator Ty*() const { return MII; }
170 bool operator==(const bundle_iterator &x) const {
173 bool operator!=(const bundle_iterator &x) const {
174 return !operator==(x);
177 // Increment and decrement operators...
178 bundle_iterator &operator--() { // predecrement - Back up
181 } while (MII->isInsideBundle());
184 bundle_iterator &operator++() { // preincrement - Advance
187 } while (MII->isInsideBundle());
190 bundle_iterator operator--(int) { // postdecrement operators...
191 bundle_iterator tmp = *this;
194 } while (MII->isInsideBundle());
197 bundle_iterator operator++(int) { // postincrement operators...
198 bundle_iterator tmp = *this;
201 } while (MII->isInsideBundle());
205 IterTy getInstrIterator() const {
210 typedef Instructions::iterator instr_iterator;
211 typedef Instructions::const_iterator const_instr_iterator;
212 typedef std::reverse_iterator<instr_iterator> reverse_instr_iterator;
214 std::reverse_iterator<const_instr_iterator> const_reverse_instr_iterator;
217 bundle_iterator<MachineInstr,instr_iterator> iterator;
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;
224 unsigned size() const { return (unsigned)Insts.size(); }
225 bool empty() const { return Insts.empty(); }
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(); }
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(); }
241 iterator begin() { return Insts.begin(); }
242 const_iterator begin() const { return Insts.begin(); }
244 instr_iterator II = instr_end();
245 if (II != instr_begin()) {
246 while (II->isInsideBundle())
251 const_iterator end() const {
252 const_instr_iterator II = instr_end();
253 if (II != instr_begin()) {
254 while (II->isInsideBundle())
259 reverse_iterator rbegin() {
260 reverse_instr_iterator II = instr_rbegin();
261 if (II != instr_rend()) {
262 while (II->isInsideBundle())
267 const_reverse_iterator rbegin() const {
268 const_reverse_instr_iterator II = instr_rbegin();
269 if (II != instr_rend()) {
270 while (II->isInsideBundle())
275 reverse_iterator rend () { return Insts.rend(); }
276 const_reverse_iterator rend () const { return Insts.rend(); }
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;
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();
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();
324 bool succ_empty() const { return Successors.empty(); }
326 // LiveIn management methods.
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); }
332 /// removeLiveIn - Remove the specified register from the live in set.
334 void removeLiveIn(unsigned Reg);
336 /// isLiveIn - Return true if the specified register is in the live in set.
338 bool isLiveIn(unsigned Reg) const;
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(); }
347 /// getAlignment - Return alignment of the basic block.
348 /// The alignment is specified as log2(bytes).
350 unsigned getAlignment() const { return Alignment; }
352 /// setAlignment - Set alignment of the basic block.
353 /// The alignment is specified as log2(bytes).
355 void setAlignment(unsigned Align) { Alignment = Align; }
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; }
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; }
365 /// getLandingPadSuccessor - If this block has a successor that is a landing
366 /// pad, return it. Otherwise return NULL.
367 const MachineBasicBlock *getLandingPadSuccessor() const;
369 // Code Layout methods.
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);
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();
383 // Machine-CFG mutators
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.
390 void addSuccessor(MachineBasicBlock *succ, uint32_t weight = 0);
392 /// removeSuccessor - Remove successor from the successors list of this
393 /// MachineBasicBlock. The Predecessors list of succ is automatically updated.
395 void removeSuccessor(MachineBasicBlock *succ);
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.
401 succ_iterator removeSuccessor(succ_iterator I);
403 /// replaceSuccessor - Replace successor OLD with NEW and update weight info.
405 void replaceSuccessor(MachineBasicBlock *Old, MachineBasicBlock *New);
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);
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);
418 /// isSuccessor - Return true if the specified MBB is a successor of this
420 bool isSuccessor(const MachineBasicBlock *MBB) const;
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;
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();
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();
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);
447 /// getFirstTerminator - returns an iterator to the first terminator
448 /// instruction of this basic block. If a terminator does not exist,
450 iterator getFirstTerminator();
451 const_iterator getFirstTerminator() const;
453 /// getFirstInstrTerminator - Same getFirstTerminator but it ignores bundles
454 /// and return an instr_iterator instead.
455 instr_iterator getFirstInstrTerminator();
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;
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.
466 /// This function updates LiveVariables, MachineDominatorTree, and
467 /// MachineLoopInfo, as applicable.
468 MachineBasicBlock *SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P);
470 void pop_front() { Insts.pop_front(); }
471 void pop_back() { Insts.pop_back(); }
472 void push_back(MachineInstr *MI) { Insts.push_back(MI); }
474 template<typename IT>
475 void insert(instr_iterator I, IT S, IT E) {
476 Insts.insert(I, S, E);
478 instr_iterator insert(instr_iterator I, MachineInstr *M) {
479 return Insts.insert(I, M);
481 instr_iterator insertAfter(instr_iterator I, MachineInstr *M) {
482 return Insts.insertAfter(I, M);
485 template<typename IT>
486 void insert(iterator I, IT S, IT E) {
487 Insts.insert(I.getInstrIterator(), S, E);
489 iterator insert(iterator I, MachineInstr *M) {
490 return Insts.insert(I.getInstrIterator(), M);
492 iterator insertAfter(iterator I, MachineInstr *M) {
493 return Insts.insertAfter(I.getInstrIterator(), M);
496 /// erase - Remove the specified element or range from the instruction list.
497 /// These functions delete any instructions removed.
499 instr_iterator erase(instr_iterator I) {
500 return Insts.erase(I);
502 instr_iterator erase(instr_iterator I, instr_iterator E) {
503 return Insts.erase(I, E);
505 instr_iterator erase_instr(MachineInstr *I) {
506 instr_iterator MII(I);
510 iterator erase(iterator I);
511 iterator erase(iterator I, iterator E) {
512 return Insts.erase(I.getInstrIterator(), E.getInstrIterator());
514 iterator erase(MachineInstr *I) {
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
526 MachineInstr *remove(MachineInstr *I);
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);
537 void splice(iterator where, MachineBasicBlock *Other, iterator From);
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,
543 Insts.splice(where, Other->Insts, From, To);
545 void splice(iterator where, MachineBasicBlock *Other, iterator From,
547 Insts.splice(where.getInstrIterator(), Other->Insts,
548 From.getInstrIterator(), To.getInstrIterator());
551 /// removeFromParent - This method unlinks 'this' from the containing
552 /// function, and returns it, but does not delete it.
553 MachineBasicBlock *removeFromParent();
555 /// eraseFromParent - This method unlinks 'this' from the containing
556 /// function and deletes it.
557 void eraseFromParent();
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);
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,
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());
580 // Debugging methods.
582 void print(raw_ostream &OS, SlotIndexes* = 0) const;
584 /// getNumber - MachineBasicBlocks are uniquely numbered at the function
585 /// level, unless they're not in a MachineFunction yet, in which case this
588 int getNumber() const { return Number; }
589 void setNumber(int N) { Number = N; }
591 /// getSymbol - Return the MCSymbol for this basic block.
593 MCSymbol *getSymbol() const;
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;
602 friend class MachineBranchProbabilityInfo;
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;
610 // Methods used to maintain doubly linked list of blocks...
611 friend struct ilist_traits<MachineBasicBlock>;
613 // Machine-CFG mutators
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.
619 void addPredecessor(MachineBasicBlock *pred);
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.
626 void removePredecessor(MachineBasicBlock *pred);
629 raw_ostream& operator<<(raw_ostream &OS, const MachineBasicBlock &MBB);
631 void WriteAsOperand(raw_ostream &, const MachineBasicBlock*, bool t);
633 // This is useful when building IndexedMaps keyed on basic block pointers.
634 struct MBB2NumberFunctor :
635 public std::unary_function<const MachineBasicBlock*, unsigned> {
636 unsigned operator()(const MachineBasicBlock *MBB) const {
637 return MBB->getNumber();
641 //===--------------------------------------------------------------------===//
642 // GraphTraits specializations for machine basic block graphs (machine-CFGs)
643 //===--------------------------------------------------------------------===//
645 // Provide specializations of GraphTraits to be able to treat a
646 // MachineFunction as a graph of MachineBasicBlocks...
649 template <> struct GraphTraits<MachineBasicBlock *> {
650 typedef MachineBasicBlock NodeType;
651 typedef MachineBasicBlock::succ_iterator ChildIteratorType;
653 static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
654 static inline ChildIteratorType child_begin(NodeType *N) {
655 return N->succ_begin();
657 static inline ChildIteratorType child_end(NodeType *N) {
658 return N->succ_end();
662 template <> struct GraphTraits<const MachineBasicBlock *> {
663 typedef const MachineBasicBlock NodeType;
664 typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
666 static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
667 static inline ChildIteratorType child_begin(NodeType *N) {
668 return N->succ_begin();
670 static inline ChildIteratorType child_end(NodeType *N) {
671 return N->succ_end();
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.
681 template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
682 typedef MachineBasicBlock NodeType;
683 typedef MachineBasicBlock::pred_iterator ChildIteratorType;
684 static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
687 static inline ChildIteratorType child_begin(NodeType *N) {
688 return N->pred_begin();
690 static inline ChildIteratorType child_end(NodeType *N) {
691 return N->pred_end();
695 template <> 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) {
701 static inline ChildIteratorType child_begin(NodeType *N) {
702 return N->pred_begin();
704 static inline ChildIteratorType child_end(NodeType *N) {
705 return N->pred_end();
709 } // End llvm namespace