Changeset 27126 in webkit for trunk/JavaScriptCore/kjs/nodes.h

Timestamp:

Oct 26, 2007, 3:43:03 PM (18 years ago)

Author:

ggaren

Message:

Reviewed by Maciej Stachowiak.

Switched ActivationImp to using a symbol table. For now, though, all
clients take the slow path.

Net .6% speedup on SunSpider.

Slowdowns:

• ActivationImp now mallocs in its constructor
• Local variable hits use an extra level of indirection to retrieve data
• Local variable misses do two lookups

Speedups:

• Fast initialization of local variables upon function entry

• JavaScriptCore.xcodeproj/project.pbxproj: Added SymbolTable.h

• kjs/function.cpp: (KJS::ActivationImp::ActivationImp): Malloc a private structure to hold data that won't fit in a JSCell. (KJS::ActivationImp::argumentsGetter): Use slow symbol table path for lookup. (KJS::ActivationImp::getOwnPropertySlot): ditto (KJS::ActivationImp::deleteProperty): ditto (KJS::ActivationImp::put): ditto (KJS::ActivationImp::createArgumentsObject): ditto

(KJS::ActivationImp::mark): Call JSObject::mark first so that one of
our properties doesn't try to recursively mark us. (This caused a crash
in earlier testing. Not sure why we haven't run into it before.)

• kjs/nodes.cpp: Functions now build a symbol table the first time they're called. (KJS::VarDeclNode::evaluate): (KJS::FunctionBodyNode::FunctionBodyNode): (KJS::FunctionBodyNode::initializeSymbolTable): (KJS::FunctionBodyNode::processDeclarations): (KJS::FunctionBodyNode::processDeclarationsForFunctionCode): (KJS::FunctionBodyNode::processDeclarationsForProgramCode):

• kjs/nodes.h: (KJS::FunctionBodyNode::symbolTable):

• wtf/Forward.h: Added Vector.

File:

• trunk/JavaScriptCore/kjs/nodes.h (modified) (3 diffs)

trunk/JavaScriptCore/kjs/nodes.h

@@ -1235 +1235 @@
 
     virtual Completion execute(ExecState*) KJS_FAST_CALL;
+    
+    SymbolTable& symbolTable() { return m_symbolTable; }
 
     void addParam(const Identifier& ident) KJS_FAST_CALL;
@@ -1242 +1244 @@
     Vector<Identifier>& parameters() KJS_FAST_CALL { return m_parameters; }
     ALWAYS_INLINE void processDeclarations(ExecState*);
-    ALWAYS_INLINE void processDeclarationsFunctionCode(ExecState*);
-    ALWAYS_INLINE void processDeclarationsProgramCode(ExecState*);
+    ALWAYS_INLINE void processDeclarationsForFunctionCode(ExecState*);
+    ALWAYS_INLINE void processDeclarationsForProgramCode(ExecState*);
   private:
     UString m_sourceURL;
@@ -1251 +1253 @@
     bool m_initializedDeclarationStacks;
 
-    // Properties that will go into the ActivationImp's symbol table. (Used for initializing the ActivationImp.)
-    DeclarationStacks::VarStack m_varStack;
-    DeclarationStacks::FunctionStack m_functionStack;
-    Vector<Identifier> m_parameters;
+    void initializesymbolTable();
+    bool m_initializedSymbolTable;
+    
+    // Properties that will go into the ActivationImp's local storage. (Used for initializing the ActivationImp.)
+     DeclarationStacks::VarStack m_varStack;
+     DeclarationStacks::FunctionStack m_functionStack;
+     Vector<Identifier> m_parameters;
+
+    // Mapping from property name -> local storage index. (Used once to transform the AST, and subsequently for residual slow case lookups.)
+    SymbolTable m_symbolTable;
   };