Changeset 35806 in webkit for trunk/JavaScriptCore

Timestamp:

Aug 17, 2008, 12:57:39 AM (17 years ago)

Author:

[email protected]

Message:

2007-08-16 Geoffrey Garen <​[email protected]>

Reviewed by Oliver Hunt.

Sped up property access for array.length and string.length by adding a
mechanism for returning a temporary value directly instead of returning
a pointer to a function that retrieves the value.

Also removed some unused cruft from PropertySlot.

SunSpider says 0.5% - 1.2% faster.

NOTE: This optimization is not a good idea in general, because it's
actually a pessimization in the case of resolve for assignment,
and it may get in the way of other optimizations in the future.

Location:

trunk/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• JavaScriptCore.exp (modified) (1 diff)
• JavaScriptCore.xcodeproj/project.pbxproj (modified) (1 diff)
• kjs/JSArray.cpp (modified) (2 diffs)
• kjs/JSArray.h (modified) (1 diff)
• kjs/JSString.cpp (modified) (2 diffs)
• kjs/JSString.h (modified) (6 diffs)
• kjs/PropertySlot.cpp (modified) (1 diff)
• kjs/PropertySlot.h (modified) (10 diffs)
• kjs/StringObject.cpp (modified) (1 diff)

trunk/JavaScriptCore/ChangeLog

@@ +1 @@
+2008-08-16  Geoffrey Garen  <[email protected]>
+
+        Reviewed by Oliver Hunt.
+        
+        Sped up property access for array.length and string.length by adding a
+        mechanism for returning a temporary value directly instead of returning
+        a pointer to a function that retrieves the value.
+        
+        Also removed some unused cruft from PropertySlot.
+        
+        SunSpider says 0.5% - 1.2% faster.
+
+        NOTE: This optimization is not a good idea in general, because it's
+        actually a pessimization in the case of resolve for assignment,
+        and it may get in the way of other optimizations in the future.
+        
 2008-08-16  Dan Bernstein  <[email protected]>
 

trunk/JavaScriptCore/JavaScriptCore.exp

@@ -104 +104 @@
 __ZN3KJS12JSGlobalData6createEv
 __ZN3KJS12JSGlobalDataD1Ev
-__ZN3KJS12PropertySlot15undefinedGetterEPNS_9ExecStateERKNS_10IdentifierERKS0_
 __ZN3KJS12SamplingTool4dumpEPNS_9ExecStateE
 __ZN3KJS12SamplingTool4stopEv

trunk/JavaScriptCore/JavaScriptCore.xcodeproj/project.pbxproj

@@ -1626 +1626 @@
                         projectDirPath = "";
                         projectRoot = "";
-                        projectRoots = (
-                                "",
-                        );
                         targets = (
                                 932F5BE30822A1C700736975 /* All */,

trunk/JavaScriptCore/kjs/JSArray.cpp

@@ -174 +174 @@
 }
 
-JSValue* JSArray::lengthGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
-{
-    return jsNumber(exec, static_cast<JSArray*>(slot.slotBase())->m_length);
-}
-
 bool JSArray::getOwnPropertySlot(ExecState* exec, unsigned i, PropertySlot& slot)
 {
@@ -211 +206 @@
 {
     if (propertyName == exec->propertyNames().length) {
-        slot.setCustom(this, lengthGetter);
+        slot.setValue(jsNumber(exec, getLength()));
         return true;
     }

trunk/JavaScriptCore/kjs/JSArray.h

@@ -82 +82 @@
         virtual const ClassInfo* classInfo() const { return &info; }
 
-        static JSValue* lengthGetter(ExecState*, const Identifier&, const PropertySlot&);
-
         bool getOwnPropertySlotSlowCase(ExecState*, unsigned propertyName, PropertySlot&);
         void putSlowCase(ExecState*, unsigned propertyName, JSValue*);

trunk/JavaScriptCore/kjs/JSString.cpp

@@ -83 +83 @@
 }
 
-JSValue* JSString::lengthGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
-{
-    return jsNumber(exec, static_cast<JSString*>(slot.slotBase())->value().size());
-}
-
-JSValue* JSString::indexGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
-{
-    return jsString(exec, static_cast<JSString*>(slot.slotBase())->value().substr(slot.index(), 1));
-}
-
-JSValue* JSString::indexNumericPropertyGetter(ExecState* exec, unsigned index, const PropertySlot& slot)
-{
-    return jsString(exec, static_cast<JSString*>(slot.slotBase())->value().substr(index, 1));
-}
-
 bool JSString::getOwnPropertySlot(ExecState* exec, const Identifier& propertyName, PropertySlot& slot)
 {
@@ -120 +105 @@
     // The semantics here are really getPropertySlot, not getOwnPropertySlot.
     // This function should only be called by JSValue::get.
-    if (getStringPropertySlot(propertyName, slot))
+    if (getStringPropertySlot(exec, propertyName, slot))
         return true;
     return JSString::getOwnPropertySlot(exec, Identifier::from(exec, propertyName), slot);

trunk/JavaScriptCore/kjs/JSString.h

@@ -28 +28 @@
 #include "ExecState.h"
 #include "JSCell.h"
+#include "JSNumberCell.h"
 #include "PropertySlot.h"
 #include "identifier.h"
@@ -51 +52 @@
 
         bool getStringPropertySlot(ExecState*, const Identifier& propertyName, PropertySlot&);
-        bool getStringPropertySlot(unsigned propertyName, PropertySlot&);
+        bool getStringPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
 
         bool canGetIndex(unsigned i) { return i < static_cast<unsigned>(m_value.size()); }
@@ -78 +79 @@
         virtual bool getOwnPropertySlot(ExecState*, unsigned propertyName, PropertySlot&);
 
-        static JSValue* lengthGetter(ExecState*, const Identifier&, const PropertySlot&);
-        static JSValue* indexGetter(ExecState*, const Identifier&, const PropertySlot&);
-        static JSValue* indexNumericPropertyGetter(ExecState*, unsigned, const PropertySlot&);
-
         UString m_value;
     };
@@ -96 +93 @@
     {
         if (propertyName == exec->propertyNames().length) {
-            slot.setCustom(this, lengthGetter);
+            slot.setValue(jsNumber(exec, value().size()));
             return true;
         }
@@ -103 +100 @@
         unsigned i = propertyName.toStrictUInt32(&isStrictUInt32);
         if (isStrictUInt32 && i < static_cast<unsigned>(m_value.size())) {
-            slot.setCustomIndex(this, i, indexGetter);
+            slot.setValue(jsString(exec, value().substr(i, 1)));
             return true;
         }
@@ -110 +107 @@
     }
         
-    ALWAYS_INLINE bool JSString::getStringPropertySlot(unsigned propertyName, PropertySlot& slot)
+    ALWAYS_INLINE bool JSString::getStringPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
     {
         if (propertyName < static_cast<unsigned>(m_value.size())) {
-            slot.setCustomNumeric(this, indexNumericPropertyGetter);
+            slot.setValue(jsString(exec, value().substr(propertyName, 1)));
             return true;
         }

trunk/JavaScriptCore/kjs/PropertySlot.cpp

@@ -28 +28 @@
 namespace KJS {
 
-JSValue* PropertySlot::undefinedGetter(ExecState*, const Identifier&, const PropertySlot&)
-{
-    return jsUndefined();
-}
-
 JSValue* PropertySlot::functionGetter(ExecState* exec, const Identifier&, const PropertySlot& slot)
 {

trunk/JavaScriptCore/kjs/PropertySlot.h

@@ -35 +35 @@
 #define KJS_VALUE_SLOT_MARKER 0
 #define KJS_REGISTER_SLOT_MARKER reinterpret_cast<GetValueFunc>(1)
-#define KJS_NUMERIC_PROPERTY_NAME_SLOT_MARKER reinterpret_cast<GetValueFunc>(2)
 
     class PropertySlot {
@@ -42 +41 @@
         {
             clearBase();
+            clearValue();
         }
 
@@ -47 +47 @@
             : m_slotBase(base)
         {
+            clearValue();
         }
 
         typedef JSValue* (*GetValueFunc)(ExecState*, const Identifier&, const PropertySlot&);
-        typedef JSValue* (*GetValueNumericFunc)(ExecState*, unsigned index, const PropertySlot&);
 
         JSValue* getValue(ExecState* exec, const Identifier& propertyName) const
@@ -58 +58 @@
             if (m_getValue == KJS_REGISTER_SLOT_MARKER)
                 return (*m_data.registerSlot).jsValue(exec);
-            ASSERT(m_getValue != KJS_NUMERIC_PROPERTY_NAME_SLOT_MARKER);
             return m_getValue(exec, propertyName, *this);
         }
@@ -66 +65 @@
             if (m_getValue == KJS_VALUE_SLOT_MARKER)
                 return *m_data.valueSlot;
-            if (m_getValue == KJS_NUMERIC_PROPERTY_NAME_SLOT_MARKER)
-                return m_data.numericFunc(exec, propertyName, *this);
             if (m_getValue == KJS_REGISTER_SLOT_MARKER)
                 return (*m_data.registerSlot).jsValue(exec);
@@ -91 +88 @@
         }
         
+        void setValue(JSValue* value)
+        {
+            ASSERT(value);
+            m_getValue = KJS_VALUE_SLOT_MARKER;
+            clearBase();
+            m_value = value;
+            m_data.valueSlot = &m_value;
+        }
+
         void setRegisterSlot(Register* registerSlot)
         {
@@ -126 +132 @@
         }
         
-        void setCustomNumeric(JSValue* slotBase, GetValueNumericFunc getValue)
-        {
-            ASSERT(slotBase);
-            ASSERT(getValue);
-            m_slotBase = slotBase;
-            m_getValue = KJS_NUMERIC_PROPERTY_NAME_SLOT_MARKER;
-            m_data.numericFunc = getValue;
-        }
-        
         void setGetterSlot(JSObject* getterFunc)
         {
@@ -145 +142 @@
         {
             clearBase();
-            m_getValue = undefinedGetter;
+            setValue(jsUndefined());
         }
 
@@ -168 +165 @@
         }
 
+        void clearValue()
+        {
+#ifndef NDEBUG
+            m_value = 0;
+#endif
+        }
+
         const HashEntry* staticEntry() const { return m_data.staticEntry; }
         unsigned index() const { return m_data.index; }
 
     private:
-        static JSValue* undefinedGetter(ExecState*, const Identifier&, const PropertySlot&);
         static JSValue* functionGetter(ExecState*, const Identifier&, const PropertySlot&);
 
         GetValueFunc m_getValue;
+        
+        JSValue* m_value;
 
         JSValue* m_slotBase;
@@ -184 +189 @@
             const HashEntry* staticEntry;
             unsigned index;
-            GetValueNumericFunc numericFunc;
         } m_data;
     };

trunk/JavaScriptCore/kjs/StringObject.cpp

@@ -55 +55 @@
 bool StringObject::getOwnPropertySlot(ExecState* exec, unsigned propertyName, PropertySlot& slot)
 {
-    if (internalValue()->getStringPropertySlot(propertyName, slot))
+    if (internalValue()->getStringPropertySlot(exec, propertyName, slot))
         return true;    
     return JSObject::getOwnPropertySlot(exec, Identifier::from(exec, propertyName), slot);