Add benchmark for QMetaEnum

Change-Id: If57f00b14713f2083260a00fd833da62d6f1cd57
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

tests/benchmarks/corelib/kernel/CMakeLists.txt

@@ -6,6 +6,7 @@ add_subdirectory(qvariant)
 add_subdirectory(qcoreapplication)
 add_subdirectory(qtimer_vs_qmetaobject)
 add_subdirectory(qproperty)
+add_subdirectory(qmetaenum)
 if(TARGET Qt::Widgets)
     add_subdirectory(qmetaobject)
     add_subdirectory(qobject)

tests/benchmarks/corelib/kernel/qmetaenum/CMakeLists.txt

@@ -0,0 +1,7 @@
+qt_internal_add_benchmark(tst_bench_qmetaenum
+    SOURCES
+        tst_bench_qmetaenum.cpp
+    PUBLIC_LIBRARIES
+        Qt::Core
+        Qt::Test
+)

tests/benchmarks/corelib/kernel/qmetaenum/tst_bench_qmetaenum.cpp

@@ -0,0 +1,80 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Marc Mutz <marc.mutz@kdab.com>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QMetaEnum>
+#include <QTest>
+
+class tst_QMetaEnum: public QObject
+{
+    Q_OBJECT
+public:
+    using QObject::QObject;
+
+private Q_SLOTS:
+    void valueToKeys_data();
+    void valueToKeys();
+    void keysToValue_data() { valueToKeys_data(); }
+    void keysToValue();
+};
+
+void tst_QMetaEnum::valueToKeys_data()
+{
+    QTest::addColumn<int>("buttons");
+    QTest::addColumn<QByteArray>("string");
+    // Qt::MouseButtons has at least 24 enumerators, so it's a good performance test
+    const auto me = QMetaEnum::fromType<Qt::MouseButtons>();
+    int accu = 0;
+    for (int i = 0; i < std::min(31, me.keyCount()); ++i) {
+        accu <<= 1;
+        accu |= 1;
+        QTest::addRow("%d bits set", i) << accu << me.valueToKeys(accu);
+    }
+}
+
+void tst_QMetaEnum::valueToKeys()
+{
+    QFETCH(const int, buttons);
+    const auto me = QMetaEnum::fromType<Qt::MouseButtons>();
+    QBENCHMARK {
+        [[maybe_unused]] auto r = me.valueToKeys(buttons);
+    }
+}
+
+void tst_QMetaEnum::keysToValue()
+{
+    QFETCH(const QByteArray, string);
+    const auto me = QMetaEnum::fromType<Qt::MouseButtons>();
+    bool ok;
+    QBENCHMARK {
+        [[maybe_unused]] auto r = me.keysToValue(string.data(), &ok);
+    }
+}
+
+QTEST_MAIN(tst_QMetaEnum)
+
+#include "tst_bench_qmetaenum.moc"