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Interval.h
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1 //===- llvm/Analysis/Interval.h - Interval Class Declaration ----*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file contains the declaration of the Interval class, which
10 // represents a set of CFG nodes and is a portion of an interval partition.
11 //
12 // Intervals have some interesting and useful properties, including the
13 // following:
14 // 1. The header node of an interval dominates all of the elements of the
15 // interval
16 //
17 //===----------------------------------------------------------------------===//
18 
19 #ifndef LLVM_ANALYSIS_INTERVAL_H
20 #define LLVM_ANALYSIS_INTERVAL_H
21 
22 #include "llvm/ADT/GraphTraits.h"
23 #include <vector>
24 
25 namespace llvm {
26 
27 class BasicBlock;
28 class raw_ostream;
29 
30 //===----------------------------------------------------------------------===//
31 //
32 /// Interval Class - An Interval is a set of nodes defined such that every node
33 /// in the interval has all of its predecessors in the interval (except for the
34 /// header)
35 ///
36 class Interval {
37  /// HeaderNode - The header BasicBlock, which dominates all BasicBlocks in this
38  /// interval. Also, any loops in this interval must go through the HeaderNode.
39  ///
40  BasicBlock *HeaderNode;
41 
42 public:
43  using succ_iterator = std::vector<BasicBlock*>::iterator;
44  using pred_iterator = std::vector<BasicBlock*>::iterator;
45  using node_iterator = std::vector<BasicBlock*>::iterator;
46 
47  inline Interval(BasicBlock *Header) : HeaderNode(Header) {
48  Nodes.push_back(Header);
49  }
50 
51  inline BasicBlock *getHeaderNode() const { return HeaderNode; }
52 
53  /// Nodes - The basic blocks in this interval.
54  std::vector<BasicBlock*> Nodes;
55 
56  /// Successors - List of BasicBlocks that are reachable directly from nodes in
57  /// this interval, but are not in the interval themselves.
58  /// These nodes necessarily must be header nodes for other intervals.
59  std::vector<BasicBlock*> Successors;
60 
61  /// Predecessors - List of BasicBlocks that have this Interval's header block
62  /// as one of their successors.
63  std::vector<BasicBlock*> Predecessors;
64 
65  /// contains - Find out if a basic block is in this interval
66  inline bool contains(BasicBlock *BB) const {
67  for (BasicBlock *Node : Nodes)
68  if (Node == BB)
69  return true;
70  return false;
71  // I don't want the dependency on <algorithm>
72  //return find(Nodes.begin(), Nodes.end(), BB) != Nodes.end();
73  }
74 
75  /// isSuccessor - find out if a basic block is a successor of this Interval
76  inline bool isSuccessor(BasicBlock *BB) const {
77  for (BasicBlock *Successor : Successors)
78  if (Successor == BB)
79  return true;
80  return false;
81  // I don't want the dependency on <algorithm>
82  //return find(Successors.begin(), Successors.end(), BB) != Successors.end();
83  }
84 
85  /// Equality operator. It is only valid to compare two intervals from the
86  /// same partition, because of this, all we have to check is the header node
87  /// for equality.
88  inline bool operator==(const Interval &I) const {
89  return HeaderNode == I.HeaderNode;
90  }
91 
92  /// isLoop - Find out if there is a back edge in this interval...
93  bool isLoop() const;
94 
95  /// print - Show contents in human readable format...
96  void print(raw_ostream &O) const;
97 };
98 
99 /// succ_begin/succ_end - define methods so that Intervals may be used
100 /// just like BasicBlocks can with the succ_* functions, and *::succ_iterator.
101 ///
103  return I->Successors.begin();
104 }
106  return I->Successors.end();
107 }
108 
109 /// pred_begin/pred_end - define methods so that Intervals may be used
110 /// just like BasicBlocks can with the pred_* functions, and *::pred_iterator.
111 ///
113  return I->Predecessors.begin();
114 }
116  return I->Predecessors.end();
117 }
118 
119 template <> struct GraphTraits<Interval*> {
120  using NodeRef = Interval *;
122 
123  static NodeRef getEntryNode(Interval *I) { return I; }
124 
125  /// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
128 };
129 
130 template <> struct GraphTraits<Inverse<Interval*>> {
131  using NodeRef = Interval *;
133 
137 };
138 
139 } // end namespace llvm
140 
141 #endif // LLVM_ANALYSIS_INTERVAL_H
Interval::pred_iterator ChildIteratorType
Definition: Interval.h:132
This class represents lattice values for constants.
Definition: AllocatorList.h:23
bool isLoop() const
isLoop - Find out if there is a back edge in this interval...
Definition: Interval.cpp:26
Various leaf nodes.
Definition: ISDOpcodes.h:59
std::vector< BasicBlock * >::iterator pred_iterator
Definition: Interval.h:44
bool operator==(const Interval &I) const
Equality operator.
Definition: Interval.h:88
Interval Class - An Interval is a set of nodes defined such that every node in the interval has all o...
Definition: Interval.h:36
static ChildIteratorType child_begin(NodeRef N)
nodes_iterator/begin/end - Allow iteration over all nodes in the graph
Definition: Interval.h:126
std::vector< BasicBlock * >::iterator node_iterator
Definition: Interval.h:45
static NodeRef getEntryNode(Inverse< Interval *> G)
Definition: Interval.h:134
std::vector< BasicBlock * >::iterator succ_iterator
Definition: Interval.h:43
static ChildIteratorType child_end(NodeRef N)
Definition: Interval.h:127
Interval::succ_iterator succ_begin(Interval *I)
succ_begin/succ_end - define methods so that Intervals may be used just like BasicBlocks can with the...
Definition: Interval.h:102
static ChildIteratorType child_begin(NodeRef N)
Definition: Interval.h:135
bool contains(BasicBlock *BB) const
contains - Find out if a basic block is in this interval
Definition: Interval.h:66
Interval::succ_iterator succ_end(Interval *I)
Definition: Interval.h:105
BasicBlock * getHeaderNode() const
Definition: Interval.h:51
LLVM Basic Block Representation.
Definition: BasicBlock.h:57
Interval::pred_iterator pred_begin(Interval *I)
pred_begin/pred_end - define methods so that Intervals may be used just like BasicBlocks can with the...
Definition: Interval.h:112
bool isSuccessor(BasicBlock *BB) const
isSuccessor - find out if a basic block is a successor of this Interval
Definition: Interval.h:76
Interval::pred_iterator pred_end(Interval *I)
Definition: Interval.h:115
std::vector< BasicBlock * > Nodes
Nodes - The basic blocks in this interval.
Definition: Interval.h:54
const GraphType & Graph
Definition: GraphTraits.h:96
static NodeRef getEntryNode(Interval *I)
Definition: Interval.h:123
const DataFlowGraph & G
Definition: RDFGraph.cpp:202
std::vector< BasicBlock * > Predecessors
Predecessors - List of BasicBlocks that have this Interval&#39;s header block as one of their successors...
Definition: Interval.h:63
std::vector< BasicBlock * > Successors
Successors - List of BasicBlocks that are reachable directly from nodes in this interval, but are not in the interval themselves.
Definition: Interval.h:59
#define I(x, y, z)
Definition: MD5.cpp:58
#define N
Interval::succ_iterator ChildIteratorType
Definition: Interval.h:121
void print(raw_ostream &O) const
print - Show contents in human readable format...
Definition: Interval.cpp:36
static ChildIteratorType child_end(NodeRef N)
Definition: Interval.h:136
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:45
Interval(BasicBlock *Header)
Definition: Interval.h:47