/****************************************************************************
**
** Copyright (C) 2021 The Qt Company Ltd.
** 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 <QVector>
#include <QDebug>
#include <QTest>

#include "qrawvector.h"

#include <vector>

/*

Code generated by g++ 4.3.3.  The lines marked with '!' are the ones that get
executed inside the loop. Using the external 's' causes some load making the
loop resembling a 'simple inner loop' in 'real' applications.


qvector_mutable_read_access:

.L166:
!       movl    -16(%ebp), %edx
!       movl    (%edx), %eax
!       subl    $1, %eax
!       je      .L165
            movl    4(%edx), %eax
            movl    %eax, 8(%esp)
            movl    8(%edx), %eax
            movl    %esi, (%esp)
            movl    %eax, 4(%esp)
            call    _ZN4myns7QVectorIdE7reallocEii
.L165:
!       movl    -16(%ebp), %eax
!       fldl    s
!       faddl   16(%eax,%ebx,8)
!       addl    $1, %ebx
!       cmpl    $10000, %ebx
!       fstpl   s
!       jne     .L166


qvector_const_read_access:

        movl    -16(%ebp), %edx
        xorl    %eax, %eax
.L183:
!       fldl    s
!       faddl   16(%edx,%eax,8)
!       addl    $1, %eax
!       cmpl    $10000, %eax
!       fstpl   s
!       jne     .L183


stdvector_const_read_access and stdvector_mutable_read_access and
qrawvector_const_read_access and qrawvector_mutable_read_access:

        xorl    %eax, %eax
.L64:
!       fldl    s
!       faddl   (%ebx,%eax,8)
!       addl    $1, %eax
!       cmpl    $10000, %eax
!       fstpl   s
!       jne     .L64



Behaviour varies with small modifications, but total is more or
less stable:

qrawvector_mutable_read_access, using  size() instead of N:

.L145:
!       faddl   (%edx,%eax,8)
!       addl    $1, %eax
!       cmpl    %ecx, %eax
!       fstl    s
!       jne     .L145
!       fstp    %st(0)


qrawvector_mutable_read_access, counting backward:

.L145:
!       faddl   (%edx,%eax,8)
!       subl    $1, %eax
!       cmpl    $-1, %eax
!       fstl    s
!       jne     .L145


qrawvector_mutable_read_access, counting backward, using size():

.L146:
!       faddl   (%edx)
!       addl    $1, %eax
!       subl    $8, %edx
!       cmpl    %ecx, %eax
!       fstl    s
!       jne     .L146



*/


/*

////////////////////////////////////////////////////////////////////

time ./tst_vector qvector_const_read_access
real    0m12.912s
user    0m12.401s
sys     0m0.016s

time ./tst_vector qvector_mutable_read_access
real    0m38.566s
user    0m36.754s
sys     0m0.008s


time ./tst_vector stdvector_mutable_read_access
real    0m12.736s
user    0m12.665s
sys     0m0.004s


////////////////////////////////////////////////////////////////////

time ./tst_vector qvector_fill_and_return
real    0m28.778s
user    0m28.522s
sys     0m0.012s

time ./tst_vector stdvector_fill_and_return
real    0m26.675s
user    0m26.558s
sys     0m0.012s

time ./tst_vector qrawvector_fill_and_return
real    0m23.370s
user    0m23.269s
sys     0m0.008s



*/



#define TEST_RETURN 1
#if TEST_RETURN
/* QRawVector::mutateToVector() hacks a semblance of a Qt 5 QVector.

   However, Qt 6's QVector is Qt 6's QList and completely different in internal
   layout.  The QTypedArrayData inside it is also completely rearranged.  Until
   QRawVector can be rewritten to do whatever it's supposed to do in a
   Qt6-compatible way, this test is suppressed, see QTBUG-95061.
*/
#define TEST_RAW 0
#endif

// For some reason, both 'plain' and '-callgrind' create strange results
// (like varying instruction count for the same assembly code)
// So replace it by a plain loop and measure wall clock time.
//#undef QBENCHMARK
//#define QBENCHMARK for (int j = 0; j != 10000; ++j)

class tst_QVector: public QObject
{
    Q_OBJECT

private slots:
    void calibration();

    // Pure Qt solution
    void qvector_separator() { qWarning() << "QVector results: "; }
    void qvector_const_read_access();
    void qvector_mutable_read_access();
    void qvector_pop_back();
    #ifdef TEST_RETURN
    void qvector_fill_and_return();
    #endif

    // Purre Standard solution
    void stdvector() { qWarning() << "std::vector results: "; }
    void stdvector_const_read_access();
    void stdvector_mutable_read_access();
    void stdvector_pop_back();

    #ifdef TEST_RETURN
    void stdvector_fill_and_return();
    #endif

    // Build using std, pass as QVector
    void mixedvector() { qWarning() << "mixed results: "; }
    #ifdef TEST_RETURN
    void mixedvector_fill_and_return();
    #endif

    // Alternative implementation
    void qrawvector_separator() { qWarning() << "QRawVector results: "; }
    void qrawvector_const_read_access();
    void qrawvector_mutable_read_access();
#if TEST_RAW
    void qrawvector_fill_and_return();
#endif
};

const int N = 1000000;
extern double s;

void tst_QVector::calibration()
{
    QVector<double> v(N);
    for (int i = 0; i != N; ++i)
        v[i] = i;
    QBENCHMARK {
        for (int i = 0; i != N; ++i)
            s += i;
    }
}

///////////////////// QVector /////////////////////

void tst_QVector::qvector_const_read_access()
{
    QVector<double> v(N);
    for (int i = 0; i != N; ++i)
        v[i] = i;

    const QVector<double> &vc = v;
    QBENCHMARK {
        for (int i = 0; i != N; ++i)
            s += vc[i];
    }
}

void tst_QVector::qvector_mutable_read_access()
{
    QVector<double> v(N);
    for (int i = 0; i != N; ++i)
        v[i] = i;

    QBENCHMARK {
        for (int i = 0; i != N; ++i)
            s += v[i];
    }
}

#ifdef TEST_RETURN
extern QVector<double> qvector_fill_and_return_helper();

void tst_QVector::qvector_fill_and_return()
{
    QBENCHMARK {
        QVector<double> v = qvector_fill_and_return_helper();
        s += v[1];
    }
}

#endif


///////////////////// QRawVector /////////////////////

void tst_QVector::qrawvector_const_read_access()
{
    QRawVector<double> v(N);
    for (int i = 0; i != N; ++i)
        v[i] = i;

    const QRawVector<double> &vc = v;
    QBENCHMARK {
        for (int i = vc.size(); --i >= 0;)
            s += vc[i];
    }
}

void tst_QVector::qrawvector_mutable_read_access()
{
    QRawVector<double> v(N);
    for (int i = 0; i != N; ++i)
        v[i] = i;

    QBENCHMARK {
        for (int i = 0; i != N; ++i)
            s += v[i];
    }
}

void tst_QVector::qvector_pop_back()
{
    const int c1 = 100000;
    QVERIFY(N % c1 == 0);

    QVector<int> v;
    v.resize(N);

    QBENCHMARK {
        for (int i = 0; i < c1; ++i)
            v.pop_back();
        if (v.size() == 0)
            v.resize(N);
    }
}

#if TEST_RAW
extern QVector<double> qrawvector_fill_and_return_helper();

void tst_QVector::qrawvector_fill_and_return()
{
    QBENCHMARK {
        QVector<double> v = qrawvector_fill_and_return_helper();
        s += v[1];
    }
}

#endif


///////////////////// std::vector /////////////////////

void tst_QVector::stdvector_const_read_access()
{
    std::vector<double> v(N);
    for (int i = 0; i != N; ++i)
        v[i] = i;

    const std::vector<double> &vc = v;
    QBENCHMARK {
        for (int i = 0; i != N; ++i)
            s += vc[i];
    }
}

void tst_QVector::stdvector_mutable_read_access()
{
    std::vector<double> v(N);
    for (int i = 0; i != N; ++i)
        v[i] = i;

    QBENCHMARK {
        for (int i = 0; i != N; ++i)
            s += v[i];
    }
}

void tst_QVector::stdvector_pop_back()
{
    const int c1 = 100000;
    QVERIFY(N % c1 == 0);

    std::vector<int> v;
    v.resize(N);

    QBENCHMARK {
        for (int i = 0; i < c1; ++i)
            v.pop_back();
        if (v.size() == 0)
            v.resize(N);
    }
}

#ifdef TEST_RETURN
extern std::vector<double> stdvector_fill_and_return_helper();

void tst_QVector::stdvector_fill_and_return()
{
    QBENCHMARK {
        std::vector<double> v = stdvector_fill_and_return_helper();
        s += v[1];
    }
}

#endif

///////////////////// mixed vector /////////////////////


#ifdef TEST_RETURN
extern QVector<double> mixedvector_fill_and_return_helper();

void tst_QVector::mixedvector_fill_and_return()
{
    QBENCHMARK {
        std::vector<double> v = stdvector_fill_and_return_helper();
        s += v[1];
    }
}

#endif

QTEST_MAIN(tst_QVector)

#include "main.moc"
