aboutsummaryrefslogtreecommitdiffstats
path: root/include/llvm/Analysis/PostDominators.h
blob: aea901374ed770907f2223a5224fd0083464dd96 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
//=- llvm/Analysis/PostDominators.h - Post Dominator Calculation-*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file exposes interfaces to post dominance information.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_ANALYSIS_POST_DOMINATORS_H
#define LLVM_ANALYSIS_POST_DOMINATORS_H

#include "llvm/Analysis/Dominators.h"

namespace llvm {

//===-------------------------------------
/// ImmediatePostDominators Class - Concrete subclass of ImmediateDominatorsBase
/// that is used to compute a normal immediate dominator set.
///
struct ImmediatePostDominators : public ImmediateDominatorsBase {
  ImmediatePostDominators() : ImmediateDominatorsBase(false) {}
  
  virtual bool runOnFunction(Function &F);
  
  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.setPreservesAll();
  }
  
private:
  unsigned DFSPass(BasicBlock *V, InfoRec &VInfo, unsigned N);
  void Compress(BasicBlock *V, InfoRec &VInfo);
  BasicBlock *Eval(BasicBlock *v);
  void Link(BasicBlock *V, BasicBlock *W, InfoRec &WInfo);
};

/// PostDominatorTree Class - Concrete subclass of DominatorTree that is used to
/// compute the a post-dominator tree.
///
struct PostDominatorTree : public DominatorTreeBase {
  PostDominatorTree() : DominatorTreeBase(true) {}

  virtual bool runOnFunction(Function &F) {
    reset();     // Reset from the last time we were run...
    ImmediatePostDominators &IPD = getAnalysis<ImmediatePostDominators>();
    Roots = IPD.getRoots();
    calculate(IPD);
    return false;
  }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.setPreservesAll();
    AU.addRequired<ImmediatePostDominators>();
  }
private:
  void calculate(const ImmediatePostDominators &IPD);
  Node *getNodeForBlock(BasicBlock *BB);
};


/// PostETForest Class - Concrete subclass of ETForestBase that is used to
/// compute a forwards post-dominator ET-Forest.
struct PostETForest : public ETForestBase {
  PostETForest() : ETForestBase(true) {}

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.setPreservesAll();
    AU.addRequired<ImmediatePostDominators>();
  }

  virtual bool runOnFunction(Function &F) {
    reset();     // Reset from the last time we were run...
    ImmediatePostDominators &ID = getAnalysis<ImmediatePostDominators>();
    Roots = ID.getRoots();
    calculate(ID);
    return false;
  }

  void calculate(const ImmediatePostDominators &ID);
  ETNode *getNodeForBlock(BasicBlock *BB);
};


/// PostDominanceFrontier Class - Concrete subclass of DominanceFrontier that is
/// used to compute the a post-dominance frontier.
///
struct PostDominanceFrontier : public DominanceFrontierBase {
  PostDominanceFrontier() : DominanceFrontierBase(true) {}

  virtual bool runOnFunction(Function &) {
    Frontiers.clear();
    PostDominatorTree &DT = getAnalysis<PostDominatorTree>();
    Roots = DT.getRoots();
    if (const DominatorTree::Node *Root = DT.getRootNode())
      calculate(DT, Root);
    return false;
  }

  virtual void getAnalysisUsage(AnalysisUsage &AU) const {
    AU.setPreservesAll();
    AU.addRequired<PostDominatorTree>();
  }

private:
  const DomSetType &calculate(const PostDominatorTree &DT,
                              const DominatorTree::Node *Node);
};

} // End llvm namespace

// Make sure that any clients of this file link in PostDominators.cpp
FORCE_DEFINING_FILE_TO_BE_LINKED(PostDominanceFrontier)

#endif