1 //===- llvm/Analysis/Interval.h - Interval Class Declaration ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declaration of the Interval class, which
11 // represents a set of CFG nodes and is a portion of an interval partition.
13 // Intervals have some interesting and useful properties, including the
15 // 1. The header node of an interval dominates all of the elements of the
18 //===----------------------------------------------------------------------===//
20 #ifndef LLVM_ANALYSIS_INTERVAL_H
21 #define LLVM_ANALYSIS_INTERVAL_H
23 #include "llvm/ADT/GraphTraits.h"
31 //===----------------------------------------------------------------------===//
33 /// Interval Class - An Interval is a set of nodes defined such that every node
34 /// in the interval has all of its predecessors in the interval (except for the
38 /// HeaderNode - The header BasicBlock, which dominates all BasicBlocks in this
39 /// interval. Also, any loops in this interval must go through the HeaderNode.
41 BasicBlock *HeaderNode;
44 using succ_iterator = std::vector<BasicBlock*>::iterator;
45 using pred_iterator = std::vector<BasicBlock*>::iterator;
46 using node_iterator = std::vector<BasicBlock*>::iterator;
48 inline Interval(BasicBlock *Header) : HeaderNode(Header) {
49 Nodes.push_back(Header);
52 inline BasicBlock *getHeaderNode() const { return HeaderNode; }
54 /// Nodes - The basic blocks in this interval.
55 std::vector<BasicBlock*> Nodes;
57 /// Successors - List of BasicBlocks that are reachable directly from nodes in
58 /// this interval, but are not in the interval themselves.
59 /// These nodes necessarily must be header nodes for other intervals.
60 std::vector<BasicBlock*> Successors;
62 /// Predecessors - List of BasicBlocks that have this Interval's header block
63 /// as one of their successors.
64 std::vector<BasicBlock*> Predecessors;
66 /// contains - Find out if a basic block is in this interval
67 inline bool contains(BasicBlock *BB) const {
68 for (BasicBlock *Node : Nodes)
72 // I don't want the dependency on <algorithm>
73 //return find(Nodes.begin(), Nodes.end(), BB) != Nodes.end();
76 /// isSuccessor - find out if a basic block is a successor of this Interval
77 inline bool isSuccessor(BasicBlock *BB) const {
78 for (BasicBlock *Successor : Successors)
82 // I don't want the dependency on <algorithm>
83 //return find(Successors.begin(), Successors.end(), BB) != Successors.end();
86 /// Equality operator. It is only valid to compare two intervals from the
87 /// same partition, because of this, all we have to check is the header node
89 inline bool operator==(const Interval &I) const {
90 return HeaderNode == I.HeaderNode;
93 /// isLoop - Find out if there is a back edge in this interval...
96 /// print - Show contents in human readable format...
97 void print(raw_ostream &O) const;
100 /// succ_begin/succ_end - define methods so that Intervals may be used
101 /// just like BasicBlocks can with the succ_* functions, and *::succ_iterator.
103 inline Interval::succ_iterator succ_begin(Interval *I) {
104 return I->Successors.begin();
106 inline Interval::succ_iterator succ_end(Interval *I) {
107 return I->Successors.end();
110 /// pred_begin/pred_end - define methods so that Intervals may be used
111 /// just like BasicBlocks can with the pred_* functions, and *::pred_iterator.
113 inline Interval::pred_iterator pred_begin(Interval *I) {
114 return I->Predecessors.begin();
116 inline Interval::pred_iterator pred_end(Interval *I) {
117 return I->Predecessors.end();
120 template <> struct GraphTraits<Interval*> {
121 using NodeRef = Interval *;
122 using ChildIteratorType = Interval::succ_iterator;
124 static NodeRef getEntryNode(Interval *I) { return I; }
126 /// nodes_iterator/begin/end - Allow iteration over all nodes in the graph
127 static ChildIteratorType child_begin(NodeRef N) { return succ_begin(N); }
128 static ChildIteratorType child_end(NodeRef N) { return succ_end(N); }
131 template <> struct GraphTraits<Inverse<Interval*>> {
132 using NodeRef = Interval *;
133 using ChildIteratorType = Interval::pred_iterator;
135 static NodeRef getEntryNode(Inverse<Interval *> G) { return G.Graph; }
136 static ChildIteratorType child_begin(NodeRef N) { return pred_begin(N); }
137 static ChildIteratorType child_end(NodeRef N) { return pred_end(N); }
140 } // end namespace llvm
142 #endif // LLVM_ANALYSIS_INTERVAL_H