MachineBasicBlock.h revision 0aef12a7a96968a80c38144dfc0a7ae6a9152db9 
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    assert (std::find (Successors.begin (), Successors.end (), succ)
126            == Successors.end ()
127            && "Trying to addSuccessor a MBB which is already my successor");
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    assert (goner != Successors.end ()
140            && "Trying to removeSuccessor a MBB which isn't my successor");
141    Successors.erase (goner);
142  }
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 push_back(MachineInstr *MI) { Insts.push_back(MI); }
150  template<typename IT>
151  void insert(iterator I, IT S, IT E) { Insts.insert(I, S, E); }
152  iterator insert(iterator I, MachineInstr *M) { return Insts.insert(I, M); }
153
154  // erase - Remove the specified element or range from the instruction list.
155  // These functions delete any instructions removed.
156  //
157  iterator erase(iterator I)             { return Insts.erase(I); }
158  iterator erase(iterator I, iterator E) { return Insts.erase(I, E); }
159  MachineInstr *remove(MachineInstr *I)  { return Insts.remove(I); }
160  void clear()                           { Insts.clear(); }
161
162  // Debugging methods.
163  void dump() const;
164  void print(std::ostream &OS) const;
165
166private:   // Methods used to maintain doubly linked list of blocks...
167  friend class ilist_traits<MachineBasicBlock>;
168
169  MachineBasicBlock *getPrev() const { return Prev; }
170  MachineBasicBlock *getNext() const { return Next; }
171  void setPrev(MachineBasicBlock *P) { Prev = P; }
172  void setNext(MachineBasicBlock *N) { Next = N; }
173
174  // Machine-CFG mutators
175
176  /// addPredecessor - Remove pred as a predecessor of this MachineBasicBlock.
177  /// Don't do this unless you know what you're doing, because it doesn't
178  /// update pred's successors list. Use pred->addSuccessor instead.
179  ///
180  void addPredecessor (MachineBasicBlock *pred) {
181    assert(std::find (Predecessors.begin (), Predecessors.end (), pred)
182           == Predecessors.end ()
183           && "Trying to addPredecessor a MBB which is already my predecessor");
184    Predecessors.push_back (pred);
185  }
186
187  /// removePredecessor - Remove pred as a predecessor of this
188  /// MachineBasicBlock. Don't do this unless you know what you're
189  /// doing, because it doesn't update pred's successors list. Use
190  /// pred->removeSuccessor instead.
191  ///
192  void removePredecessor (MachineBasicBlock *pred) {
193    std::vector<MachineBasicBlock *>::iterator goner =
194      std::find (Predecessors.begin(), Predecessors.end (), pred);
195    assert (goner != Predecessors.end ()
196            && "Trying to removePredecessor a MBB which isn't my predecessor");
197    Predecessors.erase (goner);
198  }
199};
200
201
202//===--------------------------------------------------------------------===//
203// GraphTraits specializations for machine basic block graphs (machine-CFGs)
204//===--------------------------------------------------------------------===//
205
206// Provide specializations of GraphTraits to be able to treat a
207// MachineFunction as a graph of MachineBasicBlocks...
208//
209
210template <> struct GraphTraits<MachineBasicBlock *> {
211  typedef MachineBasicBlock NodeType;
212  typedef MachineBasicBlock::succ_iterator ChildIteratorType;
213
214  static NodeType *getEntryNode(MachineBasicBlock *BB) { return BB; }
215  static inline ChildIteratorType child_begin(NodeType *N) {
216    return N->succ_begin();
217  }
218  static inline ChildIteratorType child_end(NodeType *N) {
219    return N->succ_end();
220  }
221};
222
223template <> struct GraphTraits<const MachineBasicBlock *> {
224  typedef const MachineBasicBlock NodeType;
225  typedef MachineBasicBlock::const_succ_iterator ChildIteratorType;
226
227  static NodeType *getEntryNode(const MachineBasicBlock *BB) { return BB; }
228  static inline ChildIteratorType child_begin(NodeType *N) {
229    return N->succ_begin();
230  }
231  static inline ChildIteratorType child_end(NodeType *N) {
232    return N->succ_end();
233  }
234};
235
236// Provide specializations of GraphTraits to be able to treat a
237// MachineFunction as a graph of MachineBasicBlocks... and to walk it
238// in inverse order.  Inverse order for a function is considered
239// to be when traversing the predecessor edges of a MBB
240// instead of the successor edges.
241//
242template <> struct GraphTraits<Inverse<MachineBasicBlock*> > {
243  typedef MachineBasicBlock NodeType;
244  typedef MachineBasicBlock::pred_iterator ChildIteratorType;
245  static NodeType *getEntryNode(Inverse<MachineBasicBlock *> G) {
246    return G.Graph;
247  }
248  static inline ChildIteratorType child_begin(NodeType *N) {
249    return N->pred_begin();
250  }
251  static inline ChildIteratorType child_end(NodeType *N) {
252    return N->pred_end();
253  }
254};
255
256template <> struct GraphTraits<Inverse<const MachineBasicBlock*> > {
257  typedef const MachineBasicBlock NodeType;
258  typedef MachineBasicBlock::const_pred_iterator ChildIteratorType;
259  static NodeType *getEntryNode(Inverse<const MachineBasicBlock*> G) {
260    return G.Graph;
261  }
262  static inline ChildIteratorType child_begin(NodeType *N) {
263    return N->pred_begin();
264  }
265  static inline ChildIteratorType child_end(NodeType *N) {
266    return N->pred_end();
267  }
268};
269
270} // End llvm namespace
271
272#endif
273