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 24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 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 34 namespace v8 { 35 namespace 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). 39 class AstLabeler: public AstVisitor { 40 public: AstLabeler()41 AstLabeler() : next_number_(0) {} 42 43 void Label(CompilationInfo* info); 44 45 private: info()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 65 class VarUseMap : public HashMap { 66 public: VarUseMap()67 VarUseMap() : HashMap(VarMatch) {} 68 69 ZoneList<Expression*>* Lookup(Variable* var); 70 71 private: VarMatch(void * key1,void * key2)72 static bool VarMatch(void* key1, void* key2) { return key1 == key2; } 73 }; 74 75 76 class DefinitionInfo : public ZoneObject { 77 public: DefinitionInfo()78 explicit DefinitionInfo() : last_use_(NULL) {} 79 last_use()80 Expression* last_use() { return last_use_; } set_last_use(Expression * expr)81 void set_last_use(Expression* expr) { last_use_ = expr; } 82 83 private: 84 Expression* last_use_; 85 Register location_; 86 }; 87 88 89 class LivenessAnalyzer : public AstVisitor { 90 public: LivenessAnalyzer()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