MachineBasicBlock.h revision da86bdc75c8d36cb7b1f4e785a3749d7c8f8e638 
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 "Support/GraphTraits.h"
19#include "Support/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
68public:
69  MachineBasicBlock(const BasicBlock *bb = 0) : Prev(0), Next(0), BB(bb),
70                                                Number(-1) {
71    Insts.parent = this;
72  }
73  ~MachineBasicBlock() {}
74
75  /// getBasicBlock - Return the LLVM basic block that this instance
76  /// corresponded to originally.
77  ///
78  const BasicBlock *getBasicBlock() const { return BB; }
79
80  /// getParent - Return the MachineFunction containing this basic block.
81  ///
82  const MachineFunction *getParent() const;
83        MachineFunction *getParent();
84
85  typedef ilist<MachineInstr>::iterator                       iterator;
86  typedef ilist<MachineInstr>::const_iterator           const_iterator;
87  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
88  typedef std::reverse_iterator<iterator>             reverse_iterator;
89
90  unsigned size() const { return Insts.size(); }
91  bool empty() const { return Insts.empty(); }
92
93  MachineInstr& front() { return Insts.front(); }
94  MachineInstr& back()  { return Insts.back(); }
95
96  iterator                begin()       { return Insts.begin();  }
97  const_iterator          begin() const { return Insts.begin();  }
98  iterator                  end()       { return Insts.end();    }
99  const_iterator            end() const { return Insts.end();    }
100  reverse_iterator       rbegin()       { return Insts.rbegin(); }
101  const_reverse_iterator rbegin() const { return Insts.rbegin(); }
102  reverse_iterator       rend  ()       { return Insts.rend();   }
103  const_reverse_iterator rend  () const { return Insts.rend();   }
104
105  // Machine-CFG iterators
106  typedef std::vector<MachineBasicBlock *>::iterator       pred_iterator;
107  typedef std::vector<MachineBasicBlock *>::const_iterator const_pred_iterator;
108  typedef std::vector<MachineBasicBlock *>::iterator       succ_iterator;
109  typedef std::vector<MachineBasicBlock *>::const_iterator const_succ_iterator;
110
111  pred_iterator        pred_begin()       { return Predecessors.begin (); }
112  const_pred_iterator  pred_begin() const { return Predecessors.begin (); }
113  pred_iterator        pred_end()         { return Predecessors.end ();   }
114  const_pred_iterator  pred_end()   const { return Predecessors.end ();   }
115  unsigned             pred_size()  const { return Predecessors.size ();  }
116  succ_iterator        succ_begin()       { return Successors.begin ();   }
117  const_succ_iterator  succ_begin() const { return Successors.begin ();   }
118  succ_iterator        succ_end()         { return Successors.end ();     }
119  const_succ_iterator  succ_end()   const { return Successors.end ();     }
120  unsigned             succ_size()  const { return Successors.size ();    }
121
122  // Machine-CFG mutators
123
124  /// addSuccessor - Add succ as a successor of this MachineBasicBlock.
125  /// The Predecessors list of succ is automatically updated.
126  ///
127  void addSuccessor (MachineBasicBlock *succ) {
128    Successors.push_back (succ);
129    succ->addPredecessor (this);
130  }
131
132  /// removeSuccessor - Remove succ from the successors list of this
133  /// MachineBasicBlock. The Predecessors list of succ is automatically updated.
134  ///
135  void removeSuccessor (MachineBasicBlock *succ) {
136    succ->removePredecessor (this);
137    std::vector<MachineBasicBlock *>::iterator goner =
138      std::find (Successors.begin(), Successors.end (), succ);
139    Successors.erase (goner);
140  }
141
142  /// getFirstTerminator - returns an iterator to the first terminator
143  /// instruction of this basic block. If a terminator does not exist,
144  /// it returns end()
145  iterator getFirstTerminator();
146
147  void push_back(MachineInstr *MI) { Insts.push_back(MI); }
148  template<typename IT>
149  void insert(iterator I, IT S, IT E) { Insts.insert(I, S, E); }
150  iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
151
152  // erase - Remove the specified element or range from the instruction list.
153  // These functions delete any instructions removed.
154  //
155  iterator erase(iterator I)             { return Insts.erase(I); }
156  iterator erase(iterator I, iterator E) { return Insts.erase(I, E); }
157  MachineInstr *remove(MachineInstr *I)  { return Insts.remove(I); }
158  void clear()                           { Insts.clear(); }
159
160  // Debugging methods.
161  void dump() const;
162  void print(std::ostream &OS) const;
163
164  /// getNumber - MachineBasicBlocks are uniquely numbered at the function
165  /// level, unless they're not in a MachineFunction yet, in which case this
166  /// will return -1.
167  ///
168  int getNumber() const { return Number; }
169
170private:   // Methods used to maintain doubly linked list of blocks...
171  friend class ilist_traits<MachineBasicBlock>;
172
173  MachineBasicBlock *getPrev() const { return Prev; }
174  MachineBasicBlock *getNext() const { return Next; }
175  void setPrev(MachineBasicBlock *P) { Prev = P; }
176  void setNext(MachineBasicBlock *N) { Next = N; }
177
178  // Machine-CFG mutators
179
180  /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock.
181  /// Don't do this unless you know what you're doing, because it doesn't
182  /// update pred's successors list. Use pred->addSuccessor instead.
183  ///
184  void addPredecessor (MachineBasicBlock *pred) {
185    Predecessors.push_back (pred);
186  }
187
188  /// removePredecessor - Remove pred as a predecessor of this
189  /// MachineBasicBlock. Don't do this unless you know what you're
190  /// doing, because it doesn't update pred's successors list. Use
191  /// pred->removeSuccessor instead.
192  ///
193  void removePredecessor (MachineBasicBlock *pred) {
194    std::vector<MachineBasicBlock *>::iterator goner =
195      std::find (Predecessors.begin(), Predecessors.end (), pred);
196    Predecessors.erase (goner);
197  }
198};
199
200
201//===--------------------------------------------------------------------===//
202// GraphTraits specializations for machine basic block graphs (machine-CFGs)
203//===--------------------------------------------------------------------===//
204
205// Provide specializations of GraphTraits to be able to treat a
206// MachineFunction as a graph of MachineBasicBlocks...
207//
208
209template <> struct GraphTraits<MachineBasicBlock *> {
210  typedef MachineBasicBlock NodeType;
211  typedef MachineBasicBlock::succ_iterator ChildIteratorType;
212
213  static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
214  static inline ChildIteratorType child_begin(NodeType *N) {
215    return N->succ_begin();
216  }
217  static inline ChildIteratorType child_end(NodeType *N) {
218    return N->succ_end();
219  }
220};
221
222template <> struct GraphTraits<const MachineBasicBlock *> {
223  typedef const MachineBasicBlock NodeType;
224  typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
225
226  static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
227  static inline ChildIteratorType child_begin(NodeType *N) {
228    return N->succ_begin();
229  }
230  static inline ChildIteratorType child_end(NodeType *N) {
231    return N->succ_end();
232  }
233};
234
235// Provide specializations of GraphTraits to be able to treat a
236// MachineFunction as a graph of MachineBasicBlocks... and to walk it
237// in inverse order.  Inverse order for a function is considered
238// to be when traversing the predecessor edges of a MBB
239// instead of the successor edges.
240//
241template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
242  typedef MachineBasicBlock NodeType;
243  typedef MachineBasicBlock::pred_iterator ChildIteratorType;
244  static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
245    return G.Graph;
246  }
247  static inline ChildIteratorType child_begin(NodeType *N) {
248    return N->pred_begin();
249  }
250  static inline ChildIteratorType child_end(NodeType *N) {
251    return N->pred_end();
252  }
253};
254
255template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > {
256  typedef const MachineBasicBlock NodeType;
257  typedef MachineBasicBlock::const_pred_iterator ChildIteratorType;
258  static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) {
259    return G.Graph;
260  }
261  static inline ChildIteratorType child_begin(NodeType *N) {
262    return N->pred_begin();
263  }
264  static inline ChildIteratorType child_end(NodeType *N) {
265    return N->pred_end();
266  }
267};
268
269} // End llvm namespace
270
271#endif
272