Don't move any property slots in Objects anymore

Until now, changing an existing property into an accessor
property would cause the slots in the object to get re-arranged
to make space for the additional setter required.

Change this by dropping the requirement that getter and setter
slot have to be next to each other. This has the advantage, that
any slot we define to be at a certain position in the internal
class/object will stay there and we can use that assumption to
optimize accesses to the slot.

Change-Id: Ib37c2a49fc6aae42ea4b2da36ac1dc3036540c12
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

1 files changed, 7 insertions, 2 deletions

diff --git a/src/qml/jsruntime/qv4internalclass_p.h b/src/qml/jsruntime/qv4internalclass_p.h
index febc1561f9..2d60a0048f 100644
--- a/src/qml/jsruntime/qv4internalclass_p.h
+++ b/src/qml/jsruntime/qv4internalclass_p.h
@@ -76,6 +76,7 @@ struct PropertyHash
     struct Entry {
         PropertyKey identifier;
         uint index;
+        uint setterIndex;
     };
 
     PropertyHashData *d;
@@ -377,7 +378,7 @@ struct InternalClass : Base {
         PropertyHash::Entry *e = propertyTable.lookup(id);
         if (e && e->index < size) {
             PropertyAttributes a = propertyData.at(e->index);
-            return { e->index, (a.isAccessor() ? e->index + 1 : UINT_MAX), a };
+            return { e->index, e->setterIndex, a };
         }
 
         return { UINT_MAX, UINT_MAX, Attr_Invalid };
@@ -407,7 +408,11 @@ struct InternalClass : Base {
         PropertyHash::Entry *e = propertyTable.lookup(id);
         if (e && e->index < size) {
             PropertyAttributes a = propertyData.at(e->index);
-            return { a.isAccessor() ? e->index + 1 : e->index, a };
+            if (a.isAccessor()) {
+                Q_ASSERT(e->setterIndex != UINT_MAX);
+                return { e->setterIndex, a };
+            }
+            return { e->index, a };
         }
 
         return { UINT_MAX, Attr_Invalid };