MachineBasicBlock.h revision 3dfbb558b5e74554104710ed16807fe74ec220a3 
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
133  /// removeSuccessor - Remove successor from the successors list of this
134  /// MachineBasicBlock. The Predecessors list of succ is automatically updated.
135  ///
136  void removeSuccessor(MachineBasicBlock *succ);
137
138  /// removeSuccessor - Remove specified successor from the successors list of
139  /// this MachineBasicBlock. The Predecessors list of succ is automatically
140  /// updated.
141  ///
142  void removeSuccessor(succ_iterator I);
143
144  /// getFirstTerminator - returns an iterator to the first terminator
145  /// instruction of this basic block. If a terminator does not exist,
146  /// it returns end()
147  iterator getFirstTerminator();
148
149  void pop_front() { Insts.pop_front(); }
150  void pop_back() { Insts.pop_back(); }
151  void push_back(MachineInstr *MI) { Insts.push_back(MI); }
152  template<typename IT>
153  void insert(iterator I, IT S, IT E) { Insts.insert(I, S, E); }
154  iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
155
156  // erase - Remove the specified element or range from the instruction list.
157  // These functions delete any instructions removed.
158  //
159  iterator erase(iterator I)             { return Insts.erase(I); }
160  iterator erase(iterator I, iterator E) { return Insts.erase(I, E); }
161  MachineInstr *remove(MachineInstr *I)  { return Insts.remove(I); }
162  void clear()                           { Insts.clear(); }
163
164  /// splice - Take a block of instructions from MBB 'Other' in the range [From,
165  /// To), and insert them into this MBB right before 'where'.
166  void splice(iterator where, MachineBasicBlock *Other, iterator From,
167              iterator To) {
168    Insts.splice(where, Other->Insts, From, To);
169  }
170
171  // Debugging methods.
172  void dump() const;
173  void print(std::ostream &OS) const;
174
175  /// getNumber - MachineBasicBlocks are uniquely numbered at the function
176  /// level, unless they're not in a MachineFunction yet, in which case this
177  /// will return -1.
178  ///
179  int getNumber() const { return Number; }
180
181private:   // Methods used to maintain doubly linked list of blocks...
182  friend class ilist_traits<MachineBasicBlock>;
183
184  MachineBasicBlock *getPrev() const { return Prev; }
185  MachineBasicBlock *getNext() const { return Next; }
186  void setPrev(MachineBasicBlock *P) { Prev = P; }
187  void setNext(MachineBasicBlock *N) { Next = N; }
188
189  // Machine-CFG mutators
190
191  /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock.
192  /// Don't do this unless you know what you're doing, because it doesn't
193  /// update pred's successors list. Use pred->addSuccessor instead.
194  ///
195  void addPredecessor(MachineBasicBlock *pred);
196
197  /// removePredecessor - Remove pred as a predecessor of this
198  /// MachineBasicBlock. Don't do this unless you know what you're
199  /// doing, because it doesn't update pred's successors list. Use
200  /// pred->removeSuccessor instead.
201  ///
202  void removePredecessor(MachineBasicBlock *pred);
203};
204
205
206
207//===--------------------------------------------------------------------===//
208// GraphTraits specializations for machine basic block graphs (machine-CFGs)
209//===--------------------------------------------------------------------===//
210
211// Provide specializations of GraphTraits to be able to treat a
212// MachineFunction as a graph of MachineBasicBlocks...
213//
214
215template <> struct GraphTraits<MachineBasicBlock *> {
216  typedef MachineBasicBlock NodeType;
217  typedef MachineBasicBlock::succ_iterator ChildIteratorType;
218
219  static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
220  static inline ChildIteratorType child_begin(NodeType *N) {
221    return N->succ_begin();
222  }
223  static inline ChildIteratorType child_end(NodeType *N) {
224    return N->succ_end();
225  }
226};
227
228template <> struct GraphTraits<const MachineBasicBlock *> {
229  typedef const MachineBasicBlock NodeType;
230  typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
231
232  static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
233  static inline ChildIteratorType child_begin(NodeType *N) {
234    return N->succ_begin();
235  }
236  static inline ChildIteratorType child_end(NodeType *N) {
237    return N->succ_end();
238  }
239};
240
241// Provide specializations of GraphTraits to be able to treat a
242// MachineFunction as a graph of MachineBasicBlocks... and to walk it
243// in inverse order.  Inverse order for a function is considered
244// to be when traversing the predecessor edges of a MBB
245// instead of the successor edges.
246//
247template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
248  typedef MachineBasicBlock NodeType;
249  typedef MachineBasicBlock::pred_iterator ChildIteratorType;
250  static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
251    return G.Graph;
252  }
253  static inline ChildIteratorType child_begin(NodeType *N) {
254    return N->pred_begin();
255  }
256  static inline ChildIteratorType child_end(NodeType *N) {
257    return N->pred_end();
258  }
259};
260
261template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > {
262  typedef const MachineBasicBlock NodeType;
263  typedef MachineBasicBlock::const_pred_iterator ChildIteratorType;
264  static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) {
265    return G.Graph;
266  }
267  static inline ChildIteratorType child_begin(NodeType *N) {
268    return N->pred_begin();
269  }
270  static inline ChildIteratorType child_end(NodeType *N) {
271    return N->pred_end();
272  }
273};
274
275} // End llvm namespace
276
277#endif
278