MachineBasicBlock.h revision 20a6d8e63056cc2025e7143a5f7226e079e0bc80 
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 <>
27struct ilist_traits<MachineInstr> {
28protected:
29  // this is only set by the MachineBasicBlock owning the ilist
30  friend class MachineBasicBlock;
31  MachineBasicBlock* parent;
32
33public:
34  ilist_traits<MachineInstr>() : parent(0) { }
35
36  static MachineInstr* getPrev(MachineInstr* N) { return N->prev; }
37  static MachineInstr* getNext(MachineInstr* N) { return N->next; }
38
39  static const MachineInstr*
40  getPrev(const MachineInstr* N) { return N->prev; }
41
42  static const MachineInstr*
43  getNext(const MachineInstr* N) { return N->next; }
44
45  static void setPrev(MachineInstr* N, MachineInstr* prev) { N->prev = prev; }
46  static void setNext(MachineInstr* N, MachineInstr* next) { N->next = next; }
47
48  static MachineInstr* createSentinel();
49  static void destroySentinel(MachineInstr *MI) { delete MI; }
50  void addNodeToList(MachineInstr* N);
51  void removeNodeFromList(MachineInstr* N);
52  void transferNodesFromList(
53      iplist<MachineInstr, ilist_traits<MachineInstr> >& toList,
54      ilist_iterator<MachineInstr> first,
55      ilist_iterator<MachineInstr> last);
56};
57
58class BasicBlock;
59
60class MachineBasicBlock {
61public:
62  typedef ilist<MachineInstr> Instructions;
63  Instructions Insts;
64  MachineBasicBlock *Prev, *Next;
65  const BasicBlock *BB;
66  std::vector<MachineBasicBlock *> Predecessors;
67  std::vector<MachineBasicBlock *> Successors;
68  int Number;
69  MachineFunction *Parent;
70
71public:
72  MachineBasicBlock(const BasicBlock *bb = 0) : Prev(0), Next(0), BB(bb),
73                                                Number(-1), Parent(0) {
74    Insts.parent = this;
75  }
76
77  ~MachineBasicBlock();
78
79  /// getBasicBlock - Return the LLVM basic block that this instance
80  /// corresponded to originally.
81  ///
82  const BasicBlock *getBasicBlock() const { return BB; }
83
84  /// getParent - Return the MachineFunction containing this basic block.
85  ///
86  const MachineFunction *getParent() const { return Parent; }
87  MachineFunction *getParent() { return Parent; }
88
89  typedef ilist<MachineInstr>::iterator                       iterator;
90  typedef ilist<MachineInstr>::const_iterator           const_iterator;
91  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
92  typedef std::reverse_iterator<iterator>             reverse_iterator;
93
94  unsigned size() const { return Insts.size(); }
95  bool empty() const { return Insts.empty(); }
96
97  MachineInstr& front() { return Insts.front(); }
98  MachineInstr& back()  { return Insts.back(); }
99
100  iterator                begin()       { return Insts.begin();  }
101  const_iterator          begin() const { return Insts.begin();  }
102  iterator                  end()       { return Insts.end();    }
103  const_iterator            end() const { return Insts.end();    }
104  reverse_iterator       rbegin()       { return Insts.rbegin(); }
105  const_reverse_iterator rbegin() const { return Insts.rbegin(); }
106  reverse_iterator       rend  ()       { return Insts.rend();   }
107  const_reverse_iterator rend  () const { return Insts.rend();   }
108
109  // Machine-CFG iterators
110  typedef std::vector<MachineBasicBlock *>::iterator       pred_iterator;
111  typedef std::vector<MachineBasicBlock *>::const_iterator const_pred_iterator;
112  typedef std::vector<MachineBasicBlock *>::iterator       succ_iterator;
113  typedef std::vector<MachineBasicBlock *>::const_iterator const_succ_iterator;
114
115  pred_iterator        pred_begin()       { return Predecessors.begin (); }
116  const_pred_iterator  pred_begin() const { return Predecessors.begin (); }
117  pred_iterator        pred_end()         { return Predecessors.end ();   }
118  const_pred_iterator  pred_end()   const { return Predecessors.end ();   }
119  unsigned             pred_size()  const { return Predecessors.size ();  }
120  bool                 pred_empty() const { return Predecessors.empty();  }
121  succ_iterator        succ_begin()       { return Successors.begin ();   }
122  const_succ_iterator  succ_begin() const { return Successors.begin ();   }
123  succ_iterator        succ_end()         { return Successors.end ();     }
124  const_succ_iterator  succ_end()   const { return Successors.end ();     }
125  unsigned             succ_size()  const { return Successors.size ();    }
126  bool                 succ_empty() const { return Successors.empty();    }
127
128  // Machine-CFG mutators
129
130  /// addSuccessor - Add succ as a successor of this MachineBasicBlock.
131  /// The Predecessors list of succ is automatically updated.
132  ///
133  void addSuccessor(MachineBasicBlock *succ);
134
135  /// removeSuccessor - Remove successor from the successors list of this
136  /// MachineBasicBlock. The Predecessors list of succ is automatically updated.
137  ///
138  void removeSuccessor(MachineBasicBlock *succ);
139
140  /// removeSuccessor - Remove specified successor from the successors list of
141  /// this MachineBasicBlock. The Predecessors list of succ is automatically
142  /// updated.
143  ///
144  void removeSuccessor(succ_iterator I);
145
146  /// getFirstTerminator - returns an iterator to the first terminator
147  /// instruction of this basic block. If a terminator does not exist,
148  /// it returns end()
149  iterator getFirstTerminator();
150
151  void pop_front() { Insts.pop_front(); }
152  void pop_back() { Insts.pop_back(); }
153  void push_back(MachineInstr *MI) { Insts.push_back(MI); }
154  template<typename IT>
155  void insert(iterator I, IT S, IT E) { Insts.insert(I, S, E); }
156  iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
157
158  // erase - Remove the specified element or range from the instruction list.
159  // These functions delete any instructions removed.
160  //
161  iterator erase(iterator I)             { return Insts.erase(I); }
162  iterator erase(iterator I, iterator E) { return Insts.erase(I, E); }
163  MachineInstr *remove(MachineInstr *I)  { return Insts.remove(I); }
164  void clear()                           { Insts.clear(); }
165
166  /// splice - Take a block of instructions from MBB 'Other' in the range [From,
167  /// To), and insert them into this MBB right before 'where'.
168  void splice(iterator where, MachineBasicBlock *Other, iterator From,
169              iterator To) {
170    Insts.splice(where, Other->Insts, From, To);
171  }
172
173  // Debugging methods.
174  void dump() const;
175  void print(std::ostream &OS) const;
176
177  /// getNumber - MachineBasicBlocks are uniquely numbered at the function
178  /// level, unless they're not in a MachineFunction yet, in which case this
179  /// will return -1.
180  ///
181  int getNumber() const { return Number; }
182  void setNumber(int N) { Number = N; }
183
184private:   // Methods used to maintain doubly linked list of blocks...
185  friend struct ilist_traits<MachineBasicBlock>;
186
187  MachineBasicBlock *getPrev() const { return Prev; }
188  MachineBasicBlock *getNext() const { return Next; }
189  void setPrev(MachineBasicBlock *P) { Prev = P; }
190  void setNext(MachineBasicBlock *N) { Next = N; }
191
192  // Machine-CFG mutators
193
194  /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock.
195  /// Don't do this unless you know what you're doing, because it doesn't
196  /// update pred's successors list. Use pred->addSuccessor instead.
197  ///
198  void addPredecessor(MachineBasicBlock *pred);
199
200  /// removePredecessor - Remove pred as a predecessor of this
201  /// MachineBasicBlock. Don't do this unless you know what you're
202  /// doing, because it doesn't update pred's successors list. Use
203  /// pred->removeSuccessor instead.
204  ///
205  void removePredecessor(MachineBasicBlock *pred);
206};
207
208
209
210//===--------------------------------------------------------------------===//
211// GraphTraits specializations for machine basic block graphs (machine-CFGs)
212//===--------------------------------------------------------------------===//
213
214// Provide specializations of GraphTraits to be able to treat a
215// MachineFunction as a graph of MachineBasicBlocks...
216//
217
218template <> struct GraphTraits<MachineBasicBlock *> {
219  typedef MachineBasicBlock NodeType;
220  typedef MachineBasicBlock::succ_iterator ChildIteratorType;
221
222  static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
223  static inline ChildIteratorType child_begin(NodeType *N) {
224    return N->succ_begin();
225  }
226  static inline ChildIteratorType child_end(NodeType *N) {
227    return N->succ_end();
228  }
229};
230
231template <> struct GraphTraits<const MachineBasicBlock *> {
232  typedef const MachineBasicBlock NodeType;
233  typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
234
235  static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
236  static inline ChildIteratorType child_begin(NodeType *N) {
237    return N->succ_begin();
238  }
239  static inline ChildIteratorType child_end(NodeType *N) {
240    return N->succ_end();
241  }
242};
243
244// Provide specializations of GraphTraits to be able to treat a
245// MachineFunction as a graph of MachineBasicBlocks... and to walk it
246// in inverse order.  Inverse order for a function is considered
247// to be when traversing the predecessor edges of a MBB
248// instead of the successor edges.
249//
250template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
251  typedef MachineBasicBlock NodeType;
252  typedef MachineBasicBlock::pred_iterator ChildIteratorType;
253  static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
254    return G.Graph;
255  }
256  static inline ChildIteratorType child_begin(NodeType *N) {
257    return N->pred_begin();
258  }
259  static inline ChildIteratorType child_end(NodeType *N) {
260    return N->pred_end();
261  }
262};
263
264template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > {
265  typedef const MachineBasicBlock NodeType;
266  typedef MachineBasicBlock::const_pred_iterator ChildIteratorType;
267  static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) {
268    return G.Graph;
269  }
270  static inline ChildIteratorType child_begin(NodeType *N) {
271    return N->pred_begin();
272  }
273  static inline ChildIteratorType child_end(NodeType *N) {
274    return N->pred_end();
275  }
276};
277
278} // End llvm namespace
279
280#endif
281