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 bundle_iterator(const bundle_iterator &I) : MII(I.MII) {}
160 bundle_iterator() : MII(0) {}
162 Ty &operator*() const { return *MII; }
163 Ty *operator->() const { return &operator*(); }
165 operator Ty*() const { return MII; }
167 bool operator==(const bundle_iterator &x) const {
170 bool operator!=(const bundle_iterator &x) const {
171 return !operator==(x);
174 // Increment and decrement operators...
175 bundle_iterator &operator--() { // predecrement - Back up
178 } while (MII->isInsideBundle());
181 bundle_iterator &operator++() { // preincrement - Advance
184 } while (MII->isInsideBundle());
187 bundle_iterator operator--(int) { // postdecrement operators...
188 bundle_iterator tmp = *this;
191 } while (MII->isInsideBundle());
194 bundle_iterator operator++(int) { // postincrement operators...
195 bundle_iterator tmp = *this;
198 } while (MII->isInsideBundle());
202 IterTy getInstrIterator() const {
207 typedef Instructions::iterator instr_iterator;
208 typedef Instructions::const_iterator const_instr_iterator;
209 typedef std::reverse_iterator<instr_iterator> reverse_instr_iterator;
211 std::reverse_iterator<const_instr_iterator> const_reverse_instr_iterator;
214 bundle_iterator<MachineInstr,instr_iterator> iterator;
216 bundle_iterator<const MachineInstr,const_instr_iterator> const_iterator;
217 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
218 typedef std::reverse_iterator<iterator> reverse_iterator;
221 unsigned size() const { return (unsigned)Insts.size(); }
222 bool empty() const { return Insts.empty(); }
224 MachineInstr& front() { return Insts.front(); }
225 MachineInstr& back() { return Insts.back(); }
226 const MachineInstr& front() const { return Insts.front(); }
227 const MachineInstr& back() const { return Insts.back(); }
229 instr_iterator instr_begin() { return Insts.begin(); }
230 const_instr_iterator instr_begin() const { return Insts.begin(); }
231 instr_iterator instr_end() { return Insts.end(); }
232 const_instr_iterator instr_end() const { return Insts.end(); }
233 reverse_instr_iterator instr_rbegin() { return Insts.rbegin(); }
234 const_reverse_instr_iterator instr_rbegin() const { return Insts.rbegin(); }
235 reverse_instr_iterator instr_rend () { return Insts.rend(); }
236 const_reverse_instr_iterator instr_rend () const { return Insts.rend(); }
238 iterator begin() { return Insts.begin(); }
239 const_iterator begin() const { return Insts.begin(); }
241 instr_iterator II = instr_end();
242 if (II != instr_begin()) {
243 while (II->isInsideBundle())
248 const_iterator end() const {
249 const_instr_iterator II = instr_end();
250 if (II != instr_begin()) {
251 while (II->isInsideBundle())
256 reverse_iterator rbegin() {
257 reverse_instr_iterator II = instr_rbegin();
258 if (II != instr_rend()) {
259 while (II->isInsideBundle())
264 const_reverse_iterator rbegin() const {
265 const_reverse_instr_iterator II = instr_rbegin();
266 if (II != instr_rend()) {
267 while (II->isInsideBundle())
272 reverse_iterator rend () { return Insts.rend(); }
273 const_reverse_iterator rend () const { return Insts.rend(); }
276 // Machine-CFG iterators
277 typedef std::vector<MachineBasicBlock *>::iterator pred_iterator;
278 typedef std::vector<MachineBasicBlock *>::const_iterator const_pred_iterator;
279 typedef std::vector<MachineBasicBlock *>::iterator succ_iterator;
280 typedef std::vector<MachineBasicBlock *>::const_iterator const_succ_iterator;
281 typedef std::vector<MachineBasicBlock *>::reverse_iterator
282 pred_reverse_iterator;
283 typedef std::vector<MachineBasicBlock *>::const_reverse_iterator
284 const_pred_reverse_iterator;
285 typedef std::vector<MachineBasicBlock *>::reverse_iterator
286 succ_reverse_iterator;
287 typedef std::vector<MachineBasicBlock *>::const_reverse_iterator
288 const_succ_reverse_iterator;
290 pred_iterator pred_begin() { return Predecessors.begin(); }
291 const_pred_iterator pred_begin() const { return Predecessors.begin(); }
292 pred_iterator pred_end() { return Predecessors.end(); }
293 const_pred_iterator pred_end() const { return Predecessors.end(); }
294 pred_reverse_iterator pred_rbegin()
295 { return Predecessors.rbegin();}
296 const_pred_reverse_iterator pred_rbegin() const
297 { return Predecessors.rbegin();}
298 pred_reverse_iterator pred_rend()
299 { return Predecessors.rend(); }
300 const_pred_reverse_iterator pred_rend() const
301 { return Predecessors.rend(); }
302 unsigned pred_size() const {
303 return (unsigned)Predecessors.size();
305 bool pred_empty() const { return Predecessors.empty(); }
306 succ_iterator succ_begin() { return Successors.begin(); }
307 const_succ_iterator succ_begin() const { return Successors.begin(); }
308 succ_iterator succ_end() { return Successors.end(); }
309 const_succ_iterator succ_end() const { return Successors.end(); }
310 succ_reverse_iterator succ_rbegin()
311 { return Successors.rbegin(); }
312 const_succ_reverse_iterator succ_rbegin() const
313 { return Successors.rbegin(); }
314 succ_reverse_iterator succ_rend()
315 { return Successors.rend(); }
316 const_succ_reverse_iterator succ_rend() const
317 { return Successors.rend(); }
318 unsigned succ_size() const {
319 return (unsigned)Successors.size();
321 bool succ_empty() const { return Successors.empty(); }
323 // LiveIn management methods.
325 /// addLiveIn - Add the specified register as a live in. Note that it
326 /// is an error to add the same register to the same set more than once.
327 void addLiveIn(unsigned Reg) { LiveIns.push_back(Reg); }
329 /// removeLiveIn - Remove the specified register from the live in set.
331 void removeLiveIn(unsigned Reg);
333 /// isLiveIn - Return true if the specified register is in the live in set.
335 bool isLiveIn(unsigned Reg) const;
337 // Iteration support for live in sets. These sets are kept in sorted
338 // order by their register number.
339 typedef std::vector<unsigned>::const_iterator livein_iterator;
340 livein_iterator livein_begin() const { return LiveIns.begin(); }
341 livein_iterator livein_end() const { return LiveIns.end(); }
342 bool livein_empty() const { return LiveIns.empty(); }
344 /// getAlignment - Return alignment of the basic block.
345 /// The alignment is specified as log2(bytes).
347 unsigned getAlignment() const { return Alignment; }
349 /// setAlignment - Set alignment of the basic block.
350 /// The alignment is specified as log2(bytes).
352 void setAlignment(unsigned Align) { Alignment = Align; }
354 /// isLandingPad - Returns true if the block is a landing pad. That is
355 /// this basic block is entered via an exception handler.
356 bool isLandingPad() const { return IsLandingPad; }
358 /// setIsLandingPad - Indicates the block is a landing pad. That is
359 /// this basic block is entered via an exception handler.
360 void setIsLandingPad(bool V = true) { IsLandingPad = V; }
362 /// getLandingPadSuccessor - If this block has a successor that is a landing
363 /// pad, return it. Otherwise return NULL.
364 const MachineBasicBlock *getLandingPadSuccessor() const;
366 // Code Layout methods.
368 /// moveBefore/moveAfter - move 'this' block before or after the specified
369 /// block. This only moves the block, it does not modify the CFG or adjust
370 /// potential fall-throughs at the end of the block.
371 void moveBefore(MachineBasicBlock *NewAfter);
372 void moveAfter(MachineBasicBlock *NewBefore);
374 /// updateTerminator - Update the terminator instructions in block to account
375 /// for changes to the layout. If the block previously used a fallthrough,
376 /// it may now need a branch, and if it previously used branching it may now
377 /// be able to use a fallthrough.
378 void updateTerminator();
380 // Machine-CFG mutators
382 /// addSuccessor - Add succ as a successor of this MachineBasicBlock.
383 /// The Predecessors list of succ is automatically updated. WEIGHT
384 /// parameter is stored in Weights list and it may be used by
385 /// MachineBranchProbabilityInfo analysis to calculate branch probability.
387 void addSuccessor(MachineBasicBlock *succ, uint32_t weight = 0);
389 /// removeSuccessor - Remove successor from the successors list of this
390 /// MachineBasicBlock. The Predecessors list of succ is automatically updated.
392 void removeSuccessor(MachineBasicBlock *succ);
394 /// removeSuccessor - Remove specified successor from the successors list of
395 /// this MachineBasicBlock. The Predecessors list of succ is automatically
396 /// updated. Return the iterator to the element after the one removed.
398 succ_iterator removeSuccessor(succ_iterator I);
400 /// replaceSuccessor - Replace successor OLD with NEW and update weight info.
402 void replaceSuccessor(MachineBasicBlock *Old, MachineBasicBlock *New);
405 /// transferSuccessors - Transfers all the successors from MBB to this
406 /// machine basic block (i.e., copies all the successors fromMBB and
407 /// remove all the successors from fromMBB).
408 void transferSuccessors(MachineBasicBlock *fromMBB);
410 /// transferSuccessorsAndUpdatePHIs - Transfers all the successors, as
411 /// in transferSuccessors, and update PHI operands in the successor blocks
412 /// which refer to fromMBB to refer to this.
413 void transferSuccessorsAndUpdatePHIs(MachineBasicBlock *fromMBB);
415 /// isSuccessor - Return true if the specified MBB is a successor of this
417 bool isSuccessor(const MachineBasicBlock *MBB) const;
419 /// isLayoutSuccessor - Return true if the specified MBB will be emitted
420 /// immediately after this block, such that if this block exits by
421 /// falling through, control will transfer to the specified MBB. Note
422 /// that MBB need not be a successor at all, for example if this block
423 /// ends with an unconditional branch to some other block.
424 bool isLayoutSuccessor(const MachineBasicBlock *MBB) const;
426 /// canFallThrough - Return true if the block can implicitly transfer
427 /// control to the block after it by falling off the end of it. This should
428 /// return false if it can reach the block after it, but it uses an explicit
429 /// branch to do so (e.g., a table jump). True is a conservative answer.
430 bool canFallThrough();
432 /// Returns a pointer to the first instructon in this block that is not a
433 /// PHINode instruction. When adding instruction to the beginning of the
434 /// basic block, they should be added before the returned value, not before
435 /// the first instruction, which might be PHI.
436 /// Returns end() is there's no non-PHI instruction.
437 iterator getFirstNonPHI();
439 /// SkipPHIsAndLabels - Return the first instruction in MBB after I that is
440 /// not a PHI or a label. This is the correct point to insert copies at the
441 /// beginning of a basic block.
442 iterator SkipPHIsAndLabels(iterator I);
444 /// getFirstTerminator - returns an iterator to the first terminator
445 /// instruction of this basic block. If a terminator does not exist,
447 iterator getFirstTerminator();
448 const_iterator getFirstTerminator() const;
450 /// getFirstInstrTerminator - Same getFirstTerminator but it ignores bundles
451 /// and return an instr_iterator instead.
452 instr_iterator getFirstInstrTerminator();
454 /// getLastNonDebugInstr - returns an iterator to the last non-debug
455 /// instruction in the basic block, or end()
456 iterator getLastNonDebugInstr();
457 const_iterator getLastNonDebugInstr() const;
459 /// SplitCriticalEdge - Split the critical edge from this block to the
460 /// given successor block, and return the newly created block, or null
461 /// if splitting is not possible.
463 /// This function updates LiveVariables, MachineDominatorTree, and
464 /// MachineLoopInfo, as applicable.
465 MachineBasicBlock *SplitCriticalEdge(MachineBasicBlock *Succ, Pass *P);
467 void pop_front() { Insts.pop_front(); }
468 void pop_back() { Insts.pop_back(); }
469 void push_back(MachineInstr *MI) { Insts.push_back(MI); }
471 template<typename IT>
472 void insert(instr_iterator I, IT S, IT E) {
473 Insts.insert(I, S, E);
475 instr_iterator insert(instr_iterator I, MachineInstr *M) {
476 return Insts.insert(I, M);
478 instr_iterator insertAfter(instr_iterator I, MachineInstr *M) {
479 return Insts.insertAfter(I, M);
482 template<typename IT>
483 void insert(iterator I, IT S, IT E) {
484 Insts.insert(I.getInstrIterator(), S, E);
486 iterator insert(iterator I, MachineInstr *M) {
487 return Insts.insert(I.getInstrIterator(), M);
489 iterator insertAfter(iterator I, MachineInstr *M) {
490 return Insts.insertAfter(I.getInstrIterator(), M);
493 /// erase - Remove the specified element or range from the instruction list.
494 /// These functions delete any instructions removed.
496 instr_iterator erase(instr_iterator I) {
497 return Insts.erase(I);
499 instr_iterator erase(instr_iterator I, instr_iterator E) {
500 return Insts.erase(I, E);
502 instr_iterator erase_instr(MachineInstr *I) {
503 instr_iterator MII(I);
507 iterator erase(iterator I);
508 iterator erase(iterator I, iterator E) {
509 return Insts.erase(I.getInstrIterator(), E.getInstrIterator());
511 iterator erase(MachineInstr *I) {
516 /// remove - Remove the instruction from the instruction list. This function
517 /// does not delete the instruction. WARNING: Note, if the specified
518 /// instruction is a bundle this function will remove all the bundled
519 /// instructions as well. It is up to the caller to keep a list of the
520 /// bundled instructions and re-insert them if desired. This function is
521 /// *not recommended* for manipulating instructions with bundles. Use
523 MachineInstr *remove(MachineInstr *I);
528 /// splice - Take an instruction from MBB 'Other' at the position From,
529 /// and insert it into this MBB right before 'where'.
530 void splice(instr_iterator where, MachineBasicBlock *Other,
531 instr_iterator From) {
532 Insts.splice(where, Other->Insts, From);
534 void splice(iterator where, MachineBasicBlock *Other, iterator From);
536 /// splice - Take a block of instructions from MBB 'Other' in the range [From,
537 /// To), and insert them into this MBB right before 'where'.
538 void splice(instr_iterator where, MachineBasicBlock *Other, instr_iterator From,
540 Insts.splice(where, Other->Insts, From, To);
542 void splice(iterator where, MachineBasicBlock *Other, iterator From,
544 Insts.splice(where.getInstrIterator(), Other->Insts,
545 From.getInstrIterator(), To.getInstrIterator());
548 /// removeFromParent - This method unlinks 'this' from the containing
549 /// function, and returns it, but does not delete it.
550 MachineBasicBlock *removeFromParent();
552 /// eraseFromParent - This method unlinks 'this' from the containing
553 /// function and deletes it.
554 void eraseFromParent();
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);
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,
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());
577 // Debugging methods.
579 void print(raw_ostream &OS, SlotIndexes* = 0) const;
581 /// getNumber - MachineBasicBlocks are uniquely numbered at the function
582 /// level, unless they're not in a MachineFunction yet, in which case this
585 int getNumber() const { return Number; }
586 void setNumber(int N) { Number = N; }
588 /// getSymbol - Return the MCSymbol for this basic block.
590 MCSymbol *getSymbol() const;
594 /// getWeightIterator - Return weight iterator corresponding to the I
595 /// successor iterator.
596 weight_iterator getWeightIterator(succ_iterator I);
597 const_weight_iterator getWeightIterator(const_succ_iterator I) const;
599 friend class MachineBranchProbabilityInfo;
601 /// getSuccWeight - Return weight of the edge from this block to MBB. This
602 /// method should NOT be called directly, but by using getEdgeWeight method
603 /// from MachineBranchProbabilityInfo class.
604 uint32_t getSuccWeight(const MachineBasicBlock *succ) const;
607 // Methods used to maintain doubly linked list of blocks...
608 friend struct ilist_traits<MachineBasicBlock>;
610 // Machine-CFG mutators
612 /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock.
613 /// Don't do this unless you know what you're doing, because it doesn't
614 /// update pred's successors list. Use pred->addSuccessor instead.
616 void addPredecessor(MachineBasicBlock *pred);
618 /// removePredecessor - Remove pred as a predecessor of this
619 /// MachineBasicBlock. Don't do this unless you know what you're
620 /// doing, because it doesn't update pred's successors list. Use
621 /// pred->removeSuccessor instead.
623 void removePredecessor(MachineBasicBlock *pred);
626 raw_ostream& operator<<(raw_ostream &OS, const MachineBasicBlock &MBB);
628 void WriteAsOperand(raw_ostream &, const MachineBasicBlock*, bool t);
630 // This is useful when building IndexedMaps keyed on basic block pointers.
631 struct MBB2NumberFunctor :
632 public std::unary_function<const MachineBasicBlock*, unsigned> {
633 unsigned operator()(const MachineBasicBlock *MBB) const {
634 return MBB->getNumber();
638 //===--------------------------------------------------------------------===//
639 // GraphTraits specializations for machine basic block graphs (machine-CFGs)
640 //===--------------------------------------------------------------------===//
642 // Provide specializations of GraphTraits to be able to treat a
643 // MachineFunction as a graph of MachineBasicBlocks...
646 template <> struct GraphTraits<MachineBasicBlock *> {
647 typedef MachineBasicBlock NodeType;
648 typedef MachineBasicBlock::succ_iterator ChildIteratorType;
650 static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
651 static inline ChildIteratorType child_begin(NodeType *N) {
652 return N->succ_begin();
654 static inline ChildIteratorType child_end(NodeType *N) {
655 return N->succ_end();
659 template <> struct GraphTraits<const MachineBasicBlock *> {
660 typedef const MachineBasicBlock NodeType;
661 typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
663 static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
664 static inline ChildIteratorType child_begin(NodeType *N) {
665 return N->succ_begin();
667 static inline ChildIteratorType child_end(NodeType *N) {
668 return N->succ_end();
672 // Provide specializations of GraphTraits to be able to treat a
673 // MachineFunction as a graph of MachineBasicBlocks... and to walk it
674 // in inverse order. Inverse order for a function is considered
675 // to be when traversing the predecessor edges of a MBB
676 // instead of the successor edges.
678 template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
679 typedef MachineBasicBlock NodeType;
680 typedef MachineBasicBlock::pred_iterator ChildIteratorType;
681 static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
684 static inline ChildIteratorType child_begin(NodeType *N) {
685 return N->pred_begin();
687 static inline ChildIteratorType child_end(NodeType *N) {
688 return N->pred_end();
692 template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > {
693 typedef const MachineBasicBlock NodeType;
694 typedef MachineBasicBlock::const_pred_iterator ChildIteratorType;
695 static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) {
698 static inline ChildIteratorType child_begin(NodeType *N) {
699 return N->pred_begin();
701 static inline ChildIteratorType child_end(NodeType *N) {
702 return N->pred_end();
706 } // End llvm namespace