QML: Remove internal field padding from QQuickAnchorPrivate.

Don't store QQuickAnchorLine, but store both fields separately in
QQuickAnchorPrivate. This prevents padding of QQuickAnchorLine, saving
48 bytes on x86_64 (or any platform where structs are 8-byte aligned).

On x86_64, this also removes ~180 instructions for each QQuickAnchor
creation/removal, and speeds up the constructor by 25%.

While in the neighborhood, do a drive-by change and merge
QQuickAnchorLine::AnchorLine and QQuickAnchors::Anchor by removing the
former.

Change-Id: I50ab6252b1903f5f1a075174e6185c3048a8f8ec
Reviewed-by: Robin Burchell <robin.burchell@viroteck.net>
Reviewed-by: Shawn Rutledge <shawn.rutledge@theqtcompany.com>

3 files changed, 32 insertions, 20 deletions

diff --git a/tests/auto/quick/qquickanchors/tst_qquickanchors.cpp b/tests/auto/quick/qquickanchors/tst_qquickanchors.cpp
index ab111a6cd3..77fa1292c4 100644
--- a/tests/auto/quick/qquickanchors/tst_qquickanchors.cpp
+++ b/tests/auto/quick/qquickanchors/tst_qquickanchors.cpp
@@ -39,7 +39,6 @@
 #include "../shared/visualtestutil.h"
 
 Q_DECLARE_METATYPE(QQuickAnchors::Anchor)
-Q_DECLARE_METATYPE(QQuickAnchorLine::AnchorLine)
 
 using namespace QQuickVisualTestUtil;
 
@@ -351,14 +350,13 @@ void tst_qquickanchors::illegalSets_data()
 void tst_qquickanchors::reset()
 {
     QFETCH(QString, side);
-    QFETCH(QQuickAnchorLine::AnchorLine, anchorLine);
-    QFETCH(QQuickAnchors::Anchor, usedAnchor);
+    QFETCH(QQuickAnchors::Anchor, anchor);
 
     QQuickItem *baseItem = new QQuickItem;
 
-    QQuickAnchorLine anchor;
-    anchor.item = baseItem;
-    anchor.anchorLine = anchorLine;
+    QQuickAnchorLine anchorLine;
+    anchorLine.item = baseItem;
+    anchorLine.anchorLine = anchor;
 
     QQuickItem *item = new QQuickItem;
     QQuickItemPrivate *itemPrivate = QQuickItemPrivate::get(item);
@@ -366,11 +364,11 @@ void tst_qquickanchors::reset()
     const QMetaObject *meta = itemPrivate->anchors()->metaObject();
     QMetaProperty p = meta->property(meta->indexOfProperty(side.toUtf8().constData()));
 
-    QVERIFY(p.write(itemPrivate->anchors(), qVariantFromValue(anchor)));
-    QCOMPARE(itemPrivate->anchors()->usedAnchors().testFlag(usedAnchor), true);
+    QVERIFY(p.write(itemPrivate->anchors(), qVariantFromValue(anchorLine)));
+    QCOMPARE(itemPrivate->anchors()->usedAnchors().testFlag(anchor), true);
 
     QVERIFY(p.reset(itemPrivate->anchors()));
-    QCOMPARE(itemPrivate->anchors()->usedAnchors().testFlag(usedAnchor), false);
+    QCOMPARE(itemPrivate->anchors()->usedAnchors().testFlag(anchor), false);
 
     delete item;
     delete baseItem;
@@ -379,17 +377,16 @@ void tst_qquickanchors::reset()
 void tst_qquickanchors::reset_data()
 {
     QTest::addColumn<QString>("side");
-    QTest::addColumn<QQuickAnchorLine::AnchorLine>("anchorLine");
-    QTest::addColumn<QQuickAnchors::Anchor>("usedAnchor");
+    QTest::addColumn<QQuickAnchors::Anchor>("anchor");
 
-    QTest::newRow("left") << "left" << QQuickAnchorLine::Left << QQuickAnchors::LeftAnchor;
-    QTest::newRow("top") << "top" << QQuickAnchorLine::Top << QQuickAnchors::TopAnchor;
-    QTest::newRow("right") << "right" << QQuickAnchorLine::Right << QQuickAnchors::RightAnchor;
-    QTest::newRow("bottom") << "bottom" << QQuickAnchorLine::Bottom << QQuickAnchors::BottomAnchor;
+    QTest::newRow("left") << "left" << QQuickAnchors::LeftAnchor;
+    QTest::newRow("top") << "top" << QQuickAnchors::TopAnchor;
+    QTest::newRow("right") << "right" << QQuickAnchors::RightAnchor;
+    QTest::newRow("bottom") << "bottom" << QQuickAnchors::BottomAnchor;
 
-    QTest::newRow("hcenter") << "horizontalCenter" << QQuickAnchorLine::HCenter << QQuickAnchors::HCenterAnchor;
-    QTest::newRow("vcenter") << "verticalCenter" << QQuickAnchorLine::VCenter << QQuickAnchors::VCenterAnchor;
-    QTest::newRow("baseline") << "baseline" << QQuickAnchorLine::Baseline << QQuickAnchors::BaselineAnchor;
+    QTest::newRow("hcenter") << "horizontalCenter" << QQuickAnchors::HCenterAnchor;
+    QTest::newRow("vcenter") << "verticalCenter" << QQuickAnchors::VCenterAnchor;
+    QTest::newRow("baseline") << "baseline" << QQuickAnchors::BaselineAnchor;
 }
 
 void tst_qquickanchors::resetConvenience()
diff --git a/tests/auto/quick/qquickstates/tst_qquickstates.cpp b/tests/auto/quick/qquickstates/tst_qquickstates.cpp
index 562d53bceb..9b152b0676 100644
--- a/tests/auto/quick/qquickstates/tst_qquickstates.cpp
+++ b/tests/auto/quick/qquickstates/tst_qquickstates.cpp
@@ -698,7 +698,7 @@ void tst_qquickstates::anchorChanges()
     rectPrivate->setState("right");
     QCOMPARE(innerRect->x(), qreal(150));
     QCOMPARE(aChanges->object(), qobject_cast<QQuickItem*>(innerRect));
-    QCOMPARE(QQuickItemPrivate::get(aChanges->object())->anchors()->left().anchorLine, QQuickAnchorLine::Invalid);  //### was reset (how do we distinguish from not set at all)
+    QCOMPARE(QQuickItemPrivate::get(aChanges->object())->anchors()->left().anchorLine, QQuickAnchors::InvalidAnchor);  //### was reset (how do we distinguish from not set at all)
     QCOMPARE(QQuickItemPrivate::get(aChanges->object())->anchors()->right().item, rectPrivate->right().item);
     QCOMPARE(QQuickItemPrivate::get(aChanges->object())->anchors()->right().anchorLine, rectPrivate->right().anchorLine);
 
@@ -891,7 +891,7 @@ void tst_qquickstates::anchorChangesRTL()
     rectPrivate->setState("right");
     QCOMPARE(innerRect->x(), offsetRTL(rect, innerRect) - qreal(150));
     QCOMPARE(aChanges->object(), qobject_cast<QQuickItem*>(innerRect));
-    QCOMPARE(QQuickItemPrivate::get(aChanges->object())->anchors()->left().anchorLine, QQuickAnchorLine::Invalid);  //### was reset (how do we distinguish from not set at all)
+    QCOMPARE(QQuickItemPrivate::get(aChanges->object())->anchors()->left().anchorLine, QQuickAnchors::InvalidAnchor);  //### was reset (how do we distinguish from not set at all)
     QCOMPARE(QQuickItemPrivate::get(aChanges->object())->anchors()->right().item, rectPrivate->right().item);
     QCOMPARE(QQuickItemPrivate::get(aChanges->object())->anchors()->right().anchorLine, rectPrivate->right().anchorLine);
 
diff --git a/tests/benchmarks/qml/creation/tst_creation.cpp b/tests/benchmarks/qml/creation/tst_creation.cpp
index e126cdae7e..7b00eabc28 100644
--- a/tests/benchmarks/qml/creation/tst_creation.cpp
+++ b/tests/benchmarks/qml/creation/tst_creation.cpp
@@ -68,6 +68,7 @@ private slots:
     void itemtests_qml_data();
     void itemtests_qml();
 
+    void anchors_creation();
     void anchors_heightChange();
 
 private:
@@ -375,6 +376,20 @@ void tst_creation::itemtests_qml()
     QBENCHMARK { delete component.create(); }
 }
 
+void tst_creation::anchors_creation()
+{
+    QQmlComponent component(&engine);
+    component.setData("import QtQuick 2.0\nItem { Item { anchors.bottom: parent.bottom } }", QUrl());
+
+    QObject *obj = component.create();
+    delete obj;
+
+    QBENCHMARK {
+        QObject *obj = component.create();
+        delete obj;
+    }
+}
+
 void tst_creation::anchors_heightChange()
 {
     QQmlComponent component(&engine);