1// Copyright 2010 the V8 project authors. All rights reserved.
2// Redistribution and use in source and binary forms, with or without
3// modification, are permitted provided that the following conditions are
4// met:
5//
6//     * Redistributions of source code must retain the above copyright
7//       notice, this list of conditions and the following disclaimer.
8//     * Redistributions in binary form must reproduce the above
9//       copyright notice, this list of conditions and the following
10//       disclaimer in the documentation and/or other materials provided
11//       with the distribution.
12//     * Neither the name of Google Inc. nor the names of its
13//       contributors may be used to endorse or promote products derived
14//       from this software without specific prior written permission.
15//
16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
28#ifndef V8_DATAFLOW_H_
29#define V8_DATAFLOW_H_
30
31#include "ast.h"
32#include "compiler.h"
33
34namespace v8 {
35namespace internal {
36
37// This class is used to number all expressions in the AST according to
38// their evaluation order (post-order left-to-right traversal).
39class AstLabeler: public AstVisitor {
40 public:
41  AstLabeler() : next_number_(0) {}
42
43  void Label(CompilationInfo* info);
44
45 private:
46  CompilationInfo* info() { return info_; }
47
48  void VisitDeclarations(ZoneList<Declaration*>* decls);
49  void VisitStatements(ZoneList<Statement*>* stmts);
50
51  // AST node visit functions.
52#define DECLARE_VISIT(type) virtual void Visit##type(type* node);
53  AST_NODE_LIST(DECLARE_VISIT)
54#undef DECLARE_VISIT
55
56  // Traversal number for labelling AST nodes.
57  int next_number_;
58
59  CompilationInfo* info_;
60
61  DISALLOW_COPY_AND_ASSIGN(AstLabeler);
62};
63
64
65class VarUseMap : public HashMap {
66 public:
67  VarUseMap() : HashMap(VarMatch) {}
68
69  ZoneList<Expression*>* Lookup(Variable* var);
70
71 private:
72  static bool VarMatch(void* key1, void* key2) { return key1 == key2; }
73};
74
75
76class DefinitionInfo : public ZoneObject {
77 public:
78  explicit DefinitionInfo() : last_use_(NULL) {}
79
80  Expression* last_use() { return last_use_; }
81  void set_last_use(Expression* expr) { last_use_ = expr; }
82
83 private:
84  Expression* last_use_;
85  Register location_;
86};
87
88
89class LivenessAnalyzer : public AstVisitor {
90 public:
91  LivenessAnalyzer() {}
92
93  void Analyze(FunctionLiteral* fun);
94
95 private:
96  void VisitStatements(ZoneList<Statement*>* stmts);
97
98  void RecordUse(Variable* var, Expression* expr);
99  void RecordDef(Variable* var, Expression* expr);
100
101
102  // AST node visit functions.
103#define DECLARE_VISIT(type) virtual void Visit##type(type* node);
104  AST_NODE_LIST(DECLARE_VISIT)
105#undef DECLARE_VISIT
106
107  // Map for tracking the live variables.
108  VarUseMap live_vars_;
109
110  DISALLOW_COPY_AND_ASSIGN(LivenessAnalyzer);
111};
112
113
114} }  // namespace v8::internal
115
116
117#endif  // V8_DATAFLOW_H_
118