Speed up arguments object

Don't fully create the arguments object unless required.
In the 95% use case, we can avoid creating any array based
data structures for the arguments object and directly
manipulate the functions arguments. only create the full
data structure for the other 5%.

Speeds up the raytrace test by 50%, gives around 10% overall
on v8-bench.

Change-Id: If727d28b96585e83314f544031a6c3ca1817ea19
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

1 files changed, 8 insertions, 2 deletions

diff --git a/src/qml/jsruntime/qv4argumentsobject_p.h b/src/qml/jsruntime/qv4argumentsobject_p.h
index 7a5b0817a3..7c58c48bcc 100644
--- a/src/qml/jsruntime/qv4argumentsobject_p.h
+++ b/src/qml/jsruntime/qv4argumentsobject_p.h
@@ -74,20 +74,26 @@ struct ArgumentsSetterFunction: FunctionObject
 struct ArgumentsObject: Object {
     Q_MANAGED
     CallContext *context;
+    bool fullyCreated;
     QVector<SafeValue> mappedArguments;
     ArgumentsObject(CallContext *context);
     ~ArgumentsObject() {}
 
+
     enum {
         LengthPropertyIndex = 0,
         CalleePropertyIndex = 1,
         CallerPropertyIndex = 2
     };
     bool defineOwnProperty(ExecutionContext *ctx, uint index, const Property &desc, PropertyAttributes attrs);
-
+    static ReturnedValue getIndexed(Managed *m, uint index, bool *hasProperty);
+    static void putIndexed(Managed *m, uint index, const ValueRef value);
+    static bool deleteIndexedProperty(Managed *m, uint index);
+    static PropertyAttributes queryIndexed(const Managed *m, uint index);
     static void markObjects(Managed *that, ExecutionEngine *e);
-protected:
     static void destroy(Managed *);
+
+    void fullyCreate();
 };
 
 }