/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtCore module 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 Technology Preview License Agreement accompanying

** this package.

**

** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

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** $QT_END_LICENSE$

**

****************************************************************************/

#include "qsimd_p.h"

#include <QByteArray>

#if defined(Q_OS_WINCE)

#include <windows.h>

#endif

QT_BEGIN_NAMESPACE

uint qDetectCPUFeatures()

{

    static uint features = 0xffffffff;

    if (features != 0xffffffff)

        return features;

#if defined (Q_OS_WINCE)

#if defined (ARM)

    if (IsProcessorFeaturePresent(PF_ARM_INTEL_WMMX)) {

        features = IWMMXT;

        return features;

    }

#elif defined(_X86_)

    features = 0;

#if defined QT_HAVE_MMX

    if (IsProcessorFeaturePresent(PF_MMX_INSTRUCTIONS_AVAILABLE))

        features |= MMX;

#endif

#if defined QT_HAVE_3DNOW

    if (IsProcessorFeaturePresent(PF_3DNOW_INSTRUCTIONS_AVAILABLE))

        features |= MMX3DNOW;

#endif

    return features;

#endif

    features = 0;

    return features;

#elif defined(QT_HAVE_IWMMXT)

    // runtime detection only available when running as a previlegied process

    static const bool doIWMMXT = !qgetenv("QT_NO_IWMMXT").toInt();

    features = doIWMMXT ? IWMMXT : 0;

    return features;

#elif defined(QT_HAVE_NEON)

    static const bool doNEON = !qgetenv("QT_NO_NEON").toInt();

    features = doNEON ? NEON : 0;

    return features;

#else

    features = 0;

#if defined(__x86_64__) || defined(Q_OS_WIN64)

    features = MMX|SSE|SSE2|CMOV;

#elif defined(__ia64__)

    features = MMX|SSE|SSE2;

#elif defined(__i386__) || defined(_M_IX86)

    unsigned int extended_result = 0;

    uint result = 0;

    /* see p. 118 of amd64 instruction set manual Vol3 */

#if defined(Q_CC_GNU)

    asm ("push %%ebx\n"

         "pushf\n"

         "pop %%eax\n"

         "mov %%eax, %%ebx\n"

         "xor $0x00200000, %%eax\n"

         "push %%eax\n"

         "popf\n"

         "pushf\n"

         "pop %%eax\n"

         "xor %%edx, %%edx\n"

         "xor %%ebx, %%eax\n"

         "jz 1f\n"

         "mov $0x00000001, %%eax\n"

         "cpuid\n"

         "1:\n"

         "pop %%ebx\n"

         "mov %%edx, %0\n"

        : "=r" (result)

        :

        : "%eax", "%ecx", "%edx"

        );

    asm ("push %%ebx\n"

         "pushf\n"

         "pop %%eax\n"

         "mov %%eax, %%ebx\n"

         "xor $0x00200000, %%eax\n"

         "push %%eax\n"

         "popf\n"

         "pushf\n"

         "pop %%eax\n"

         "xor %%edx, %%edx\n"

         "xor %%ebx, %%eax\n"

         "jz 2f\n"

         "mov $0x80000000, %%eax\n"

         "cpuid\n"

         "cmp $0x80000000, %%eax\n"

         "jbe 2f\n"

         "mov $0x80000001, %%eax\n"

         "cpuid\n"

         "2:\n"

         "pop %%ebx\n"

         "mov %%edx, %0\n"

        : "=r" (extended_result)

        :

        : "%eax", "%ecx", "%edx"

        );

#elif defined (Q_OS_WIN)

    _asm {

        push eax

        push ebx

        push ecx

        push edx

        pushfd

        pop eax

        mov ebx, eax

        xor eax, 00200000h

        push eax

        popfd

        pushfd

        pop eax

        mov edx, 0

        xor eax, ebx

        jz skip

        mov eax, 1

        cpuid

        mov result, edx

    skip:

        pop edx

        pop ecx

        pop ebx

        pop eax

    }

    _asm {

        push eax

        push ebx

        push ecx

        push edx

        pushfd

        pop eax

        mov ebx, eax

        xor eax, 00200000h

        push eax

        popfd

        pushfd

        pop eax

        mov edx, 0

        xor eax, ebx

        jz skip2

        mov eax, 80000000h

        cpuid

        cmp eax, 80000000h

        jbe skip2

        mov eax, 80000001h

        cpuid

        mov extended_result, edx

    skip2:

        pop edx

        pop ecx

        pop ebx

        pop eax

    }

#endif

    // result now contains the standard feature bits

    if (result & (1u << 15))

        features |= CMOV;

    if (result & (1u << 23))

        features |= MMX;

    if (extended_result & (1u << 22))

        features |= MMXEXT;

    if (extended_result & (1u << 31))

        features |= MMX3DNOW;

    if (extended_result & (1u << 30))

        features |= MMX3DNOWEXT;

    if (result & (1u << 25))

        features |= SSE;

    if (result & (1u << 26))

        features |= SSE2;

#endif // i386

#if defined(QT_HAVE_MMX)

    if (qgetenv("QT_NO_MMX").toInt())

        features ^= MMX;

#endif

    if (qgetenv("QT_NO_MMXEXT").toInt())

        features ^= MMXEXT;

#if defined(QT_HAVE_3DNOW)

    if (qgetenv("QT_NO_3DNOW").toInt())

        features ^= MMX3DNOW;

#endif

    if (qgetenv("QT_NO_3DNOWEXT").toInt())

        features ^= MMX3DNOWEXT;

#if defined(QT_HAVE_SSE)

    if (qgetenv("QT_NO_SSE").toInt())

        features ^= SSE;

#endif

#if defined(QT_HAVE_SSE2)

    if (qgetenv("QT_NO_SSE2").toInt())

        features ^= SSE2;

#endif

    return features;

#endif

}

QT_END_NAMESPACE