Re-add some inline property storage

It turns out that not using any inline property storage
comes at a relatively high price in terms of memory
consumption, as we always need to also create a
memberData for any object.

This avoids the memberData creation in quite a few
cases, as we use the additional padding we have up
to the 32 byte boundary given by the memory manager
to store some property data.

This complicates property access somewhat. To avoid
performance regressions because of this, add specialized
QV4::Lookup functions that optimize for properties that
are inline or in the memberData struct.

Change seems to be performance neutral on v8-bench on
x86_64, but reduces peak memory usage when running the
benchmark by around 20%.

Change-Id: I0127d31a2d6038aaa540c4c4a1156f45ca3b7464
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
Reviewed-by: Robin Burchell <robin.burchell@crimson.no>

1 files changed, 9 insertions, 4 deletions

diff --git a/src/qml/jsruntime/qv4lookup_p.h b/src/qml/jsruntime/qv4lookup_p.h
index 2ffb43cce9..5a67c203ce 100644
--- a/src/qml/jsruntime/qv4lookup_p.h
+++ b/src/qml/jsruntime/qv4lookup_p.h
@@ -102,11 +102,15 @@ struct Lookup {
     static ReturnedValue getterTwoClasses(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getterFallback(Lookup *l, ExecutionEngine *engine, const Value &object);
 
-    static ReturnedValue getter0(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getter0Inline(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getter1(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getter2(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getter0getter0(Lookup *l, ExecutionEngine *engine, const Value &object);
-    static ReturnedValue getter0getter1(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getter0Inlinegetter0Inline(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getter0Inlinegetter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getter0MemberDatagetter0MemberData(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getter0Inlinegetter1(Lookup *l, ExecutionEngine *engine, const Value &object);
+    static ReturnedValue getter0MemberDatagetter1(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getter1getter1(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getterAccessor0(Lookup *l, ExecutionEngine *engine, const Value &object);
     static ReturnedValue getterAccessor1(Lookup *l, ExecutionEngine *engine, const Value &object);
@@ -120,7 +124,8 @@ struct Lookup {
     static ReturnedValue arrayLengthGetter(Lookup *l, ExecutionEngine *engine, const Value &object);
 
     static ReturnedValue globalGetterGeneric(Lookup *l, ExecutionEngine *engine);
-    static ReturnedValue globalGetter0(Lookup *l, ExecutionEngine *engine);
+    static ReturnedValue globalGetter0Inline(Lookup *l, ExecutionEngine *engine);
+    static ReturnedValue globalGetter0MemberData(Lookup *l, ExecutionEngine *engine);
     static ReturnedValue globalGetter1(Lookup *l, ExecutionEngine *engine);
     static ReturnedValue globalGetter2(Lookup *l, ExecutionEngine *engine);
     static ReturnedValue globalGetterAccessor0(Lookup *l, ExecutionEngine *engine);