QProperty: micro optimizations

- Ensure that the allocateDependencyObserver fast path is inlined.
- Use addObserver instead of observerProperty; we know that a freshly
  allocated observer does not have its prev pointer set. If prev weren't
  a private member, we could simply use Q_ASSUME(ptr->prev == nullptr),
  but making it public or befriending the class seems like a bad idea,
  as it grants too much access to the internals.

Change-Id: Ia845f2807c70512563f7b9e1ecb85fe82b66208c
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
(cherry picked from commit 5d0095b1c2e60ecfb492c1910df70021128d663c)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/corelib/kernel/qproperty.cpp b/src/corelib/kernel/qproperty.cpp
index db202ad725..5e9dfb0e2d 100644
--- a/src/corelib/kernel/qproperty.cpp
+++ b/src/corelib/kernel/qproperty.cpp
@@ -540,7 +540,7 @@ void QPropertyBindingData::registerWithCurrentlyEvaluatingBinding_helper(Binding
 
     QPropertyObserverPointer dependencyObserver = currentState->binding->allocateDependencyObserver();
     dependencyObserver.setBindingToNotify(currentState->binding);
-    dependencyObserver.observeProperty(d);
+    d.addObserver(dependencyObserver.ptr);
 }
 
 void QPropertyBindingData::notifyObservers(QUntypedPropertyData *propertyDataPtr) const