MachineBasicBlock.h revision cd5bad37112ba22f4c546e5443714570b4104bb6 
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  /// isSuccessor - Return true if the specified MBB is a successor of this
147  /// block.
148  bool isSuccessor(MachineBasicBlock *MBB) const {
149    for (const_succ_iterator I = succ_begin(), E = succ_end(); I != E; ++I)
150      if (*I == MBB)
151        return true;
152    return false;
153  }
154
155  /// getFirstTerminator - returns an iterator to the first terminator
156  /// instruction of this basic block. If a terminator does not exist,
157  /// it returns end()
158  iterator getFirstTerminator();
159
160  void pop_front() { Insts.pop_front(); }
161  void pop_back() { Insts.pop_back(); }
162  void push_back(MachineInstr *MI) { Insts.push_back(MI); }
163  template<typename IT>
164  void insert(iterator I, IT S, IT E) { Insts.insert(I, S, E); }
165  iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
166
167  // erase - Remove the specified element or range from the instruction list.
168  // These functions delete any instructions removed.
169  //
170  iterator erase(iterator I)             { return Insts.erase(I); }
171  iterator erase(iterator I, iterator E) { return Insts.erase(I, E); }
172  MachineInstr *remove(MachineInstr *I)  { return Insts.remove(I); }
173  void clear()                           { Insts.clear(); }
174
175  /// splice - Take a block of instructions from MBB 'Other' in the range [From,
176  /// To), and insert them into this MBB right before 'where'.
177  void splice(iterator where, MachineBasicBlock *Other, iterator From,
178              iterator To) {
179    Insts.splice(where, Other->Insts, From, To);
180  }
181
182  // Debugging methods.
183  void dump() const;
184  void print(std::ostream &OS) const;
185
186  /// getNumber - MachineBasicBlocks are uniquely numbered at the function
187  /// level, unless they're not in a MachineFunction yet, in which case this
188  /// will return -1.
189  ///
190  int getNumber() const { return Number; }
191  void setNumber(int N) { Number = N; }
192
193private:   // Methods used to maintain doubly linked list of blocks...
194  friend struct 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
209  /// removePredecessor - Remove pred as a predecessor of this
210  /// MachineBasicBlock. Don't do this unless you know what you're
211  /// doing, because it doesn't update pred's successors list. Use
212  /// pred->removeSuccessor instead.
213  ///
214  void removePredecessor(MachineBasicBlock *pred);
215};
216
217
218
219//===--------------------------------------------------------------------===//
220// GraphTraits specializations for machine basic block graphs (machine-CFGs)
221//===--------------------------------------------------------------------===//
222
223// Provide specializations of GraphTraits to be able to treat a
224// MachineFunction as a graph of MachineBasicBlocks...
225//
226
227template <> struct GraphTraits<MachineBasicBlock *> {
228  typedef MachineBasicBlock NodeType;
229  typedef MachineBasicBlock::succ_iterator ChildIteratorType;
230
231  static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
232  static inline ChildIteratorType child_begin(NodeType *N) {
233    return N->succ_begin();
234  }
235  static inline ChildIteratorType child_end(NodeType *N) {
236    return N->succ_end();
237  }
238};
239
240template <> struct GraphTraits<const MachineBasicBlock *> {
241  typedef const MachineBasicBlock NodeType;
242  typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
243
244  static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
245  static inline ChildIteratorType child_begin(NodeType *N) {
246    return N->succ_begin();
247  }
248  static inline ChildIteratorType child_end(NodeType *N) {
249    return N->succ_end();
250  }
251};
252
253// Provide specializations of GraphTraits to be able to treat a
254// MachineFunction as a graph of MachineBasicBlocks... and to walk it
255// in inverse order.  Inverse order for a function is considered
256// to be when traversing the predecessor edges of a MBB
257// instead of the successor edges.
258//
259template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
260  typedef MachineBasicBlock NodeType;
261  typedef MachineBasicBlock::pred_iterator ChildIteratorType;
262  static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
263    return G.Graph;
264  }
265  static inline ChildIteratorType child_begin(NodeType *N) {
266    return N->pred_begin();
267  }
268  static inline ChildIteratorType child_end(NodeType *N) {
269    return N->pred_end();
270  }
271};
272
273template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > {
274  typedef const MachineBasicBlock NodeType;
275  typedef MachineBasicBlock::const_pred_iterator ChildIteratorType;
276  static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) {
277    return G.Graph;
278  }
279  static inline ChildIteratorType child_begin(NodeType *N) {
280    return N->pred_begin();
281  }
282  static inline ChildIteratorType child_end(NodeType *N) {
283    return N->pred_end();
284  }
285};
286
287} // End llvm namespace
288
289#endif
290