MachineBasicBlock.h revision 551ccae044b0ff658fe629dd67edd5ffe75d10e8 
1//===-- llvm/CodeGen/MachineBasicBlock.h ------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Collect the sequence of machine instructions for a basic block.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_CODEGEN_MACHINEBASICBLOCK_H
15#define LLVM_CODEGEN_MACHINEBASICBLOCK_H
16
17#include "llvm/CodeGen/MachineInstr.h"
18#include "llvm/ADT/GraphTraits.h"
19#include "llvm/ADT/ilist"
20#include <iosfwd>
21
22namespace llvm {
23  class MachineFunction;
24
25// ilist_traits
26template <>
27class ilist_traits<MachineInstr> {
28  // this is only set by the MachineBasicBlock owning the ilist
29  friend class MachineBasicBlock;
30  MachineBasicBlock* parent;
31
32public:
33  ilist_traits<MachineInstr>() : parent(0) { }
34
35  static MachineInstr* getPrev(MachineInstr* N) { return N->prev; }
36  static MachineInstr* getNext(MachineInstr* N) { return N->next; }
37
38  static const MachineInstr*
39  getPrev(const MachineInstr* N) { return N->prev; }
40
41  static const MachineInstr*
42  getNext(const MachineInstr* N) { return N->next; }
43
44  static void setPrev(MachineInstr* N, MachineInstr* prev) { N->prev = prev; }
45  static void setNext(MachineInstr* N, MachineInstr* next) { N->next = next; }
46
47  static MachineInstr* createNode();
48  void addNodeToList(MachineInstr* N);
49  void removeNodeFromList(MachineInstr* N);
50  void transferNodesFromList(
51      iplist<MachineInstr, ilist_traits<MachineInstr> >& toList,
52      ilist_iterator<MachineInstr> first,
53      ilist_iterator<MachineInstr> last);
54};
55
56class BasicBlock;
57
58class MachineBasicBlock {
59public:
60  typedef ilist<MachineInstr> Instructions;
61  Instructions Insts;
62  MachineBasicBlock *Prev, *Next;
63  const BasicBlock *BB;
64  std::vector<MachineBasicBlock *> Predecessors;
65  std::vector<MachineBasicBlock *> Successors;
66  int Number;
67  MachineFunction *Parent;
68
69public:
70  MachineBasicBlock(const BasicBlock *bb = 0) : Prev(0), Next(0), BB(bb),
71                                                Number(-1), Parent(0) {
72    Insts.parent = this;
73  }
74
75  ~MachineBasicBlock();
76
77  /// getBasicBlock - Return the LLVM basic block that this instance
78  /// corresponded to originally.
79  ///
80  const BasicBlock *getBasicBlock() const { return BB; }
81
82  /// getParent - Return the MachineFunction containing this basic block.
83  ///
84  const MachineFunction *getParent() const { return Parent; }
85  MachineFunction *getParent() { return Parent; }
86
87  typedef ilist<MachineInstr>::iterator                       iterator;
88  typedef ilist<MachineInstr>::const_iterator           const_iterator;
89  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
90  typedef std::reverse_iterator<iterator>             reverse_iterator;
91
92  unsigned size() const { return Insts.size(); }
93  bool empty() const { return Insts.empty(); }
94
95  MachineInstr& front() { return Insts.front(); }
96  MachineInstr& back()  { return Insts.back(); }
97
98  iterator                begin()       { return Insts.begin();  }
99  const_iterator          begin() const { return Insts.begin();  }
100  iterator                  end()       { return Insts.end();    }
101  const_iterator            end() const { return Insts.end();    }
102  reverse_iterator       rbegin()       { return Insts.rbegin(); }
103  const_reverse_iterator rbegin() const { return Insts.rbegin(); }
104  reverse_iterator       rend  ()       { return Insts.rend();   }
105  const_reverse_iterator rend  () const { return Insts.rend();   }
106
107  // Machine-CFG iterators
108  typedef std::vector<MachineBasicBlock *>::iterator       pred_iterator;
109  typedef std::vector<MachineBasicBlock *>::const_iterator const_pred_iterator;
110  typedef std::vector<MachineBasicBlock *>::iterator       succ_iterator;
111  typedef std::vector<MachineBasicBlock *>::const_iterator const_succ_iterator;
112
113  pred_iterator        pred_begin()       { return Predecessors.begin (); }
114  const_pred_iterator  pred_begin() const { return Predecessors.begin (); }
115  pred_iterator        pred_end()         { return Predecessors.end ();   }
116  const_pred_iterator  pred_end()   const { return Predecessors.end ();   }
117  unsigned             pred_size()  const { return Predecessors.size ();  }
118  bool                 pred_empty() const { return Predecessors.empty();  }
119  succ_iterator        succ_begin()       { return Successors.begin ();   }
120  const_succ_iterator  succ_begin() const { return Successors.begin ();   }
121  succ_iterator        succ_end()         { return Successors.end ();     }
122  const_succ_iterator  succ_end()   const { return Successors.end ();     }
123  unsigned             succ_size()  const { return Successors.size ();    }
124  bool                 succ_empty() const { return Successors.empty();    }
125
126  // Machine-CFG mutators
127
128  /// addSuccessor - Add succ as a successor of this MachineBasicBlock.
129  /// The Predecessors list of succ is automatically updated.
130  ///
131  void addSuccessor(MachineBasicBlock *succ) {
132    Successors.push_back(succ);
133    succ->addPredecessor(this);
134  }
135
136  /// removeSuccessor - Remove successor from the successors list of this
137  /// MachineBasicBlock. The Predecessors list of succ is automatically updated.
138  ///
139  void removeSuccessor(MachineBasicBlock *succ) {
140    succ->removePredecessor(this);
141    succ_iterator I = std::find(Successors.begin(), Successors.end(), succ);
142    assert(I != Successors.end() && "Not a current successor!");
143    Successors.erase(I);
144  }
145
146  /// removeSuccessor - Remove specified successor from the successors list of
147  /// this MachineBasicBlock. The Predecessors list of succ is automatically
148  /// updated.
149  ///
150  void removeSuccessor(succ_iterator I) {
151    assert(I != Successors.end() && "Not a current successor!");
152    (*I)->removePredecessor(this);
153    Successors.erase(I);
154  }
155
156  /// getFirstTerminator - returns an iterator to the first terminator
157  /// instruction of this basic block. If a terminator does not exist,
158  /// it returns end()
159  iterator getFirstTerminator();
160
161  void pop_front() { Insts.pop_front(); }
162  void pop_back() { Insts.pop_back(); }
163  void push_back(MachineInstr *MI) { Insts.push_back(MI); }
164  template<typename IT>
165  void insert(iterator I, IT S, IT E) { Insts.insert(I, S, E); }
166  iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
167
168  // erase - Remove the specified element or range from the instruction list.
169  // These functions delete any instructions removed.
170  //
171  iterator erase(iterator I)             { return Insts.erase(I); }
172  iterator erase(iterator I, iterator E) { return Insts.erase(I, E); }
173  MachineInstr *remove(MachineInstr *I)  { return Insts.remove(I); }
174  void clear()                           { Insts.clear(); }
175
176  /// splice - Take a block of instructions from MBB 'Other' in the range [From,
177  /// To), and insert them into this MBB right before 'where'.
178  void splice(iterator where, MachineBasicBlock *Other, iterator From,
179              iterator To) {
180    Insts.splice(where, Other->Insts, From, To);
181  }
182
183  // Debugging methods.
184  void dump() const;
185  void print(std::ostream &OS) const;
186
187  /// getNumber - MachineBasicBlocks are uniquely numbered at the function
188  /// level, unless they're not in a MachineFunction yet, in which case this
189  /// will return -1.
190  ///
191  int getNumber() const { return Number; }
192
193private:   // Methods used to maintain doubly linked list of blocks...
194  friend class ilist_traits<MachineBasicBlock>;
195
196  MachineBasicBlock *getPrev() const { return Prev; }
197  MachineBasicBlock *getNext() const { return Next; }
198  void setPrev(MachineBasicBlock *P) { Prev = P; }
199  void setNext(MachineBasicBlock *N) { Next = N; }
200
201  // Machine-CFG mutators
202
203  /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock.
204  /// Don't do this unless you know what you're doing, because it doesn't
205  /// update pred's successors list. Use pred->addSuccessor instead.
206  ///
207  void addPredecessor (MachineBasicBlock *pred) {
208    Predecessors.push_back (pred);
209  }
210
211  /// removePredecessor - Remove pred as a predecessor of this
212  /// MachineBasicBlock. Don't do this unless you know what you're
213  /// doing, because it doesn't update pred's successors list. Use
214  /// pred->removeSuccessor instead.
215  ///
216  void removePredecessor (MachineBasicBlock *pred) {
217    std::vector<MachineBasicBlock *>::iterator goner =
218      std::find (Predecessors.begin(), Predecessors.end (), pred);
219    Predecessors.erase (goner);
220  }
221};
222
223// This is useful when building DenseMaps keyed on MachineBasicBlocks
224struct MachineBasicBlock2IndexFunctor
225  : std::unary_function<const MachineBasicBlock*, unsigned> {
226  unsigned operator()(const MachineBasicBlock* MBB) const {
227    assert(MBB->getNumber() != -1 &&
228           "MachineBasicBlock does not belong to a MachineFunction");
229    return MBB->getNumber();
230  }
231};
232
233
234//===--------------------------------------------------------------------===//
235// GraphTraits specializations for machine basic block graphs (machine-CFGs)
236//===--------------------------------------------------------------------===//
237
238// Provide specializations of GraphTraits to be able to treat a
239// MachineFunction as a graph of MachineBasicBlocks...
240//
241
242template <> struct GraphTraits<MachineBasicBlock *> {
243  typedef MachineBasicBlock NodeType;
244  typedef MachineBasicBlock::succ_iterator ChildIteratorType;
245
246  static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
247  static inline ChildIteratorType child_begin(NodeType *N) {
248    return N->succ_begin();
249  }
250  static inline ChildIteratorType child_end(NodeType *N) {
251    return N->succ_end();
252  }
253};
254
255template <> struct GraphTraits<const MachineBasicBlock *> {
256  typedef const MachineBasicBlock NodeType;
257  typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
258
259  static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
260  static inline ChildIteratorType child_begin(NodeType *N) {
261    return N->succ_begin();
262  }
263  static inline ChildIteratorType child_end(NodeType *N) {
264    return N->succ_end();
265  }
266};
267
268// Provide specializations of GraphTraits to be able to treat a
269// MachineFunction as a graph of MachineBasicBlocks... and to walk it
270// in inverse order.  Inverse order for a function is considered
271// to be when traversing the predecessor edges of a MBB
272// instead of the successor edges.
273//
274template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
275  typedef MachineBasicBlock NodeType;
276  typedef MachineBasicBlock::pred_iterator ChildIteratorType;
277  static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
278    return G.Graph;
279  }
280  static inline ChildIteratorType child_begin(NodeType *N) {
281    return N->pred_begin();
282  }
283  static inline ChildIteratorType child_end(NodeType *N) {
284    return N->pred_end();
285  }
286};
287
288template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > {
289  typedef const MachineBasicBlock NodeType;
290  typedef MachineBasicBlock::const_pred_iterator ChildIteratorType;
291  static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) {
292    return G.Graph;
293  }
294  static inline ChildIteratorType child_begin(NodeType *N) {
295    return N->pred_begin();
296  }
297  static inline ChildIteratorType child_end(NodeType *N) {
298    return N->pred_end();
299  }
300};
301
302} // End llvm namespace
303
304#endif
305