/****************************************************************************
**
** Copyright (C) 1992-2005 Trolltech AS. All rights reserved.
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 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 GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
** http://www.trolltech.com/products/qt/licensing.html or contact the
** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#ifndef I386_QATOMIC_H
#define I386_QATOMIC_H

#include <QtCore/qglobal.h>

#if defined(Q_CC_GNU) || defined(Q_CC_INTEL)

inline int q_atomic_test_and_set_int(volatile int *ptr, int expected, int newval)
{
    unsigned char ret;
    asm volatile("lock\n"
                 "cmpxchgl %2,%3\n"
                 "sete %1\n"
                 : "=a" (newval), "=qm" (ret)
                 : "r" (newval), "m" (*ptr), "0" (expected)
                 : "memory");
    return static_cast<int>(ret);
}

inline int q_atomic_test_and_set_ptr(volatile void *ptr, void *expected, void *newval)
{
    return q_atomic_test_and_set_int(reinterpret_cast<volatile int *>(ptr),
                                     reinterpret_cast<int>(expected),
                                     reinterpret_cast<int>(newval));
}

inline int q_atomic_increment(volatile int *ptr)
{
    unsigned char ret;
    asm volatile("lock\n"
                 "incl %0\n"
                 "setne %1"
                 : "=m" (*ptr), "=qm" (ret)
                 : "m" (*ptr)
                 : "memory");
    return static_cast<int>(ret);
}

inline int q_atomic_decrement(volatile int *ptr)
{
    unsigned char ret;
    asm volatile("lock\n" 
                 "decl %0\n"
                 "setne %1"
                 : "=m" (*ptr), "=qm" (ret)
                 : "m" (*ptr)
                 : "memory");
    return static_cast<int>(ret);
}

inline int q_atomic_set_int(volatile int *ptr, int newval)
{
    asm volatile("xchgl %0,%1"
                 : "=r" (newval)
                 : "m" (*ptr), "0" (newval)
                 : "memory");
    return newval;
}

inline void *q_atomic_set_ptr(volatile void *ptr, void *newval)
{
    return reinterpret_cast<void *>(q_atomic_set_int(reinterpret_cast<volatile int *>(ptr),
                                                     reinterpret_cast<int>(newval)));
}

#else

extern "C" {
    Q_CORE_EXPORT int q_atomic_test_and_set_int(volatile int *ptr, int expected, int newval);
    Q_CORE_EXPORT int q_atomic_test_and_set_ptr(volatile void *ptr, void *expected, void *newval);
    Q_CORE_EXPORT int q_atomic_increment(volatile int *ptr);
    Q_CORE_EXPORT int q_atomic_decrement(volatile int *ptr);
    Q_CORE_EXPORT int q_atomic_set_int(volatile int *ptr, int newval);
    Q_CORE_EXPORT void *q_atomic_set_ptr(volatile void *ptr, void *newval);
} // extern "C"

#endif

#endif // I386_QATOMIC_H
