MachineBasicBlock.h revision 3ec4f261d287002c2b6b5241dafef52b03142c1a 
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
67public:
68  MachineBasicBlock(const BasicBlock *bb = 0) : Prev(0), Next(0), BB(bb) {
69    Insts.parent = this;
70  }
71  ~MachineBasicBlock() {}
72
73  /// getBasicBlock - Return the LLVM basic block that this instance
74  /// corresponded to originally.
75  ///
76  const BasicBlock *getBasicBlock() const { return BB; }
77
78  /// getParent - Return the MachineFunction containing this basic block.
79  ///
80  const MachineFunction *getParent() const;
81
82  typedef ilist<MachineInstr>::iterator                       iterator;
83  typedef ilist<MachineInstr>::const_iterator           const_iterator;
84  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
85  typedef std::reverse_iterator<iterator>             reverse_iterator;
86
87  unsigned size() const { return Insts.size(); }
88  bool empty() const { return Insts.empty(); }
89
90  MachineInstr& front() { return Insts.front(); }
91  MachineInstr& back()  { return Insts.back(); }
92
93  iterator                begin()       { return Insts.begin();  }
94  const_iterator          begin() const { return Insts.begin();  }
95  iterator                  end()       { return Insts.end();    }
96  const_iterator            end() const { return Insts.end();    }
97  reverse_iterator       rbegin()       { return Insts.rbegin(); }
98  const_reverse_iterator rbegin() const { return Insts.rbegin(); }
99  reverse_iterator       rend  ()       { return Insts.rend();   }
100  const_reverse_iterator rend  () const { return Insts.rend();   }
101
102  // Machine-CFG iterators
103  typedef std::vector<MachineBasicBlock *>::iterator       pred_iterator;
104  typedef std::vector<MachineBasicBlock *>::const_iterator const_pred_iterator;
105  typedef std::vector<MachineBasicBlock *>::iterator       succ_iterator;
106  typedef std::vector<MachineBasicBlock *>::const_iterator const_succ_iterator;
107
108  pred_iterator        pred_begin()       { return Predecessors.begin (); }
109  const_pred_iterator  pred_begin() const { return Predecessors.begin (); }
110  pred_iterator        pred_end()         { return Predecessors.end ();   }
111  const_pred_iterator  pred_end()   const { return Predecessors.end ();   }
112  unsigned             pred_size()  const { return Predecessors.size ();  }
113  succ_iterator        succ_begin()       { return Successors.begin ();   }
114  const_succ_iterator  succ_begin() const { return Successors.begin ();   }
115  succ_iterator        succ_end()         { return Successors.end ();     }
116  const_succ_iterator  succ_end()   const { return Successors.end ();     }
117  unsigned             succ_size()  const { return Successors.size ();    }
118
119  // Machine-CFG mutators
120
121  /// addSuccessor - Add succ as a successor of this MachineBasicBlock.
122  /// The Predecessors list of succ is automatically updated.
123  ///
124  void addSuccessor (MachineBasicBlock *succ) {
125    Successors.push_back (succ);
126    succ->addPredecessor (this);
127  }
128
129  /// removeSuccessor - Remove succ from the successors list of this
130  /// MachineBasicBlock. The Predecessors list of succ is automatically updated.
131  ///
132  void removeSuccessor (MachineBasicBlock *succ) {
133    succ->removePredecessor (this);
134    std::vector<MachineBasicBlock *>::iterator goner =
135      std::find (Successors.begin(), Successors.end (), succ);
136    Successors.erase (goner);
137  }
138
139  /// getFirstTerminator - returns an iterator to the first terminator
140  /// instruction of this basic block. If a terminator does not exist,
141  /// it returns end()
142  iterator getFirstTerminator();
143
144  void push_back(MachineInstr *MI) { Insts.push_back(MI); }
145  template<typename IT>
146  void insert(iterator I, IT S, IT E) { Insts.insert(I, S, E); }
147  iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
148
149  // erase - Remove the specified element or range from the instruction list.
150  // These functions delete any instructions removed.
151  //
152  iterator erase(iterator I)             { return Insts.erase(I); }
153  iterator erase(iterator I, iterator E) { return Insts.erase(I, E); }
154  MachineInstr *remove(MachineInstr *I)  { return Insts.remove(I); }
155  void clear()                           { Insts.clear(); }
156
157  // Debugging methods.
158  void dump() const;
159  void print(std::ostream &OS) const;
160
161private:   // Methods used to maintain doubly linked list of blocks...
162  friend class ilist_traits<MachineBasicBlock>;
163
164  MachineBasicBlock *getPrev() const { return Prev; }
165  MachineBasicBlock *getNext() const { return Next; }
166  void setPrev(MachineBasicBlock *P) { Prev = P; }
167  void setNext(MachineBasicBlock *N) { Next = N; }
168
169  // Machine-CFG mutators
170
171  /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock.
172  /// Don't do this unless you know what you're doing, because it doesn't
173  /// update pred's successors list. Use pred->addSuccessor instead.
174  ///
175  void addPredecessor (MachineBasicBlock *pred) {
176    Predecessors.push_back (pred);
177  }
178
179  /// removePredecessor - Remove pred as a predecessor of this
180  /// MachineBasicBlock. Don't do this unless you know what you're
181  /// doing, because it doesn't update pred's successors list. Use
182  /// pred->removeSuccessor instead.
183  ///
184  void removePredecessor (MachineBasicBlock *pred) {
185    std::vector<MachineBasicBlock *>::iterator goner =
186      std::find (Predecessors.begin(), Predecessors.end (), pred);
187    Predecessors.erase (goner);
188  }
189};
190
191
192//===--------------------------------------------------------------------===//
193// GraphTraits specializations for machine basic block graphs (machine-CFGs)
194//===--------------------------------------------------------------------===//
195
196// Provide specializations of GraphTraits to be able to treat a
197// MachineFunction as a graph of MachineBasicBlocks...
198//
199
200template <> struct GraphTraits<MachineBasicBlock *> {
201  typedef MachineBasicBlock NodeType;
202  typedef MachineBasicBlock::succ_iterator ChildIteratorType;
203
204  static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
205  static inline ChildIteratorType child_begin(NodeType *N) {
206    return N->succ_begin();
207  }
208  static inline ChildIteratorType child_end(NodeType *N) {
209    return N->succ_end();
210  }
211};
212
213template <> struct GraphTraits<const MachineBasicBlock *> {
214  typedef const MachineBasicBlock NodeType;
215  typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
216
217  static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
218  static inline ChildIteratorType child_begin(NodeType *N) {
219    return N->succ_begin();
220  }
221  static inline ChildIteratorType child_end(NodeType *N) {
222    return N->succ_end();
223  }
224};
225
226// Provide specializations of GraphTraits to be able to treat a
227// MachineFunction as a graph of MachineBasicBlocks... and to walk it
228// in inverse order.  Inverse order for a function is considered
229// to be when traversing the predecessor edges of a MBB
230// instead of the successor edges.
231//
232template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
233  typedef MachineBasicBlock NodeType;
234  typedef MachineBasicBlock::pred_iterator ChildIteratorType;
235  static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
236    return G.Graph;
237  }
238  static inline ChildIteratorType child_begin(NodeType *N) {
239    return N->pred_begin();
240  }
241  static inline ChildIteratorType child_end(NodeType *N) {
242    return N->pred_end();
243  }
244};
245
246template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > {
247  typedef const MachineBasicBlock NodeType;
248  typedef MachineBasicBlock::const_pred_iterator ChildIteratorType;
249  static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) {
250    return G.Graph;
251  }
252  static inline ChildIteratorType child_begin(NodeType *N) {
253    return N->pred_begin();
254  }
255  static inline ChildIteratorType child_end(NodeType *N) {
256    return N->pred_end();
257  }
258};
259
260} // End llvm namespace
261
262#endif
263