Add a benchmark for QString::operator==

Reviewed-By: Bradley T. Hughes

2 files changed, 108 insertions, 0 deletions

diff --git a/tests/benchmarks/qstring/main.cpp b/tests/benchmarks/qstring/main.cpp
new file mode 100644
index 0000000..c7962bd
--- /dev/null
+++ b/tests/benchmarks/qstring/main.cpp
@@ -0,0 +1,104 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include <QStringList>
+#include <qtest.h>
+
+class tst_QString: public QObject
+{
+    Q_OBJECT
+private slots:
+    void equals() const;
+    void equals_data() const;
+};
+
+void tst_QString::equals() const
+{
+    QFETCH(QString, a);
+    QFETCH(QString, b);
+
+    QBENCHMARK {
+        a == b;
+    }
+}
+
+void tst_QString::equals_data() const
+{
+    static const struct {
+        ushort data[80];
+        int dummy;              // just to ensure 4-byte alignment
+    } data = {
+        {
+            64, 64, 64, 64,  64, 64, 64, 64,
+            64, 64, 64, 64,  64, 64, 64, 64, // 16
+            64, 64, 64, 64,  64, 64, 64, 64,
+            64, 64, 64, 64,  64, 64, 64, 64, // 32
+            64, 64, 64, 64,  64, 64, 64, 64,
+            64, 64, 64, 64,  64, 64, 64, 64, // 48
+            64, 64, 64, 64,  64, 64, 64, 64,
+            64, 64, 64, 64,  64, 64, 64, 64, // 64
+            64, 64, 64, 64,  64, 64, 64, 64,
+            96, 96, 96, 96,  96, 96, 96, 96  // 80
+        }, 0
+    };
+    const QChar *ptr = reinterpret_cast<const QChar *>(data.data);
+
+    QTest::addColumn<QString>("a");
+    QTest::addColumn<QString>("b");
+    QString base = QString::fromRawData(ptr, 64);
+
+    QTest::newRow("different-length") << base << QString::fromRawData(ptr, 4);
+    QTest::newRow("same-string") << base << base;
+    QTest::newRow("same-data") << base << QString::fromRawData(ptr, 64);
+
+    // don't use length > 64, since that crosses a cache line
+    QTest::newRow("aligned-odd")
+        << QString::fromRawData(ptr, 63) << QString::fromRawData(ptr + 2, 63);
+    QTest::newRow("aligned-even")
+        << QString::fromRawData(ptr, 64) << QString::fromRawData(ptr + 2, 64);
+    QTest::newRow("unaligned-even")
+        << QString::fromRawData(ptr, 63) << QString::fromRawData(ptr + 1, 63);
+    QTest::newRow("unaligned-odd")
+        << QString::fromRawData(ptr, 64) << QString::fromRawData(ptr + 1, 64);
+}
+
+QTEST_MAIN(tst_QString)
+
+#include "main.moc"
diff --git a/tests/benchmarks/qstring/qstring.pro b/tests/benchmarks/qstring/qstring.pro
new file mode 100644
index 0000000..74423e7
--- /dev/null
+++ b/tests/benchmarks/qstring/qstring.pro
@@ -0,0 +1,4 @@
+load(qttest_p4)
+TARGET = tst_qstring
+QT -= gui
+SOURCES += main.cpp