Changeset 27126 in webkit for trunk/JavaScriptCore/kjs/function.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/function.h (modified) (4 diffs)

trunk/JavaScriptCore/kjs/function.h

@@ -25 +25 @@
 #define KJS_FUNCTION_H
 
+#include "SymbolTable.h"
 #include "object.h"
 #include <wtf/OwnPtr.h>
@@ -138 +139 @@
   class ActivationImp : public JSObject {
   public:
-    ActivationImp(FunctionImp* function, const List& arguments);
+    struct LocalStorageEntry {
+        LocalStorageEntry()
+        {
+        }
+
+        LocalStorageEntry(JSValue* v, int a)
+            : value(v)
+            , attributes(a)
+        {
+        }
+
+        JSValue* value;
+        int attributes;
+    };
+
+    typedef Vector<LocalStorageEntry, 32> LocalStorage;
+
+  private:
+    struct ActivationImpPrivate {
+        ActivationImpPrivate(FunctionImp* f, const List& a)
+            : function(f)
+            , arguments(a)
+            , argumentsObject(0)
+        {
+            ASSERT(f);
+        }
+        
+        FunctionImp* function;
+        LocalStorage localStorage;
+
+        List arguments;
+        Arguments* argumentsObject;
+    };
+
+  public:
+    ActivationImp::ActivationImp(FunctionImp* function, const List& arguments);
 
     virtual bool getOwnPropertySlot(ExecState*, const Identifier&, PropertySlot&);
@@ -151 +187 @@
     bool isActivation() { return true; }
 
-    void releaseArguments() { _arguments.reset(); }
+    void releaseArguments() { d->arguments.reset(); }
+    
+    LocalStorage& localStorage() { return d->localStorage; };
 
   private:
@@ -157 +195 @@
     static JSValue* argumentsGetter(ExecState*, JSObject*, const Identifier&, const PropertySlot& slot);
     void createArgumentsObject(ExecState*);
-
-    FunctionImp* _function;
-    List _arguments;
-    mutable Arguments* _argumentsObject;
+    
+    OwnPtr<ActivationImpPrivate> d;
+    SymbolTable* symbolTable;
   };