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

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** This file is part of the QtCore module of the Qt Toolkit.

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** 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.

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** 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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** $QT_END_LICENSE$

**

** This file implements the generic atomics interface using ARMv6 assembly

** instructions. It is more efficent than the inline versions when Qt is

** built for the THUMB instruction set, as the required instructions are

** only available in ARM state.

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

#include <QtCore/qglobal.h>

#ifdef QT_HAVE_ARMV6

QT_BEGIN_NAMESPACE

QT_USE_NAMESPACE

#ifdef Q_CC_RVCT

#pragma push

#pragma arm

Q_CORE_EXPORT asm

bool QBasicAtomicInt_testAndSetOrdered(volatile int *_q_value, int expectedValue, int newValue)

{

    CODE32

    //R0 = _q_value

    //R1 = expectedValue

    //R2 = newValue

retry_testAndSetOrdered

    LDREX    r3,[r0]        //r3 = *_q_value

    EORS     r3,r3,r1       //if (r3 == expectedValue) {

    STREXEQ  r3,r2,[r0]     //*_q_value = newvalue, r3 = error

    TEQEQ    r3,#1          //if error

    BEQ      retry_testAndSetOrdered          //then goto retry }

    RSBS     r0,r3,#1       //return (r3 == 0)

    MOVCC    r0,#0

    BX       r14

}

Q_CORE_EXPORT asm

int QBasicAtomicInt_fetchAndStoreOrdered(volatile int *_q_value, int newValue)

{

    CODE32

//R0 = _q_value

//R1 = newValue

retry_fetchAndStoreOrdered

    LDREX    r3,[r0]        //r3 = *_q_value

    STREX    r2,r1,[r0]     //*_q_value = newValue, r2 = error

    TEQ      r2,#0          //if error

    BNE      retry_fetchAndStoreOrdered          //then goto retry

    MOV      r0,r3          //return r3

    BX       r14

}

Q_CORE_EXPORT asm

int QBasicAtomicInt_fetchAndAddOrdered(volatile int *_q_value, int valueToAdd)

{

    CODE32

    //R0 = _q_value

    //R1 = valueToAdd

    STMDB    sp!,{r12,lr}

retry_fetchAndAddOrdered

    LDREX    r2,[r0]        //r2 = *_q_value

    ADD      r3,r2,r1       //r3 = r2 + r1

    STREX    r12,r3,[r0]    //*_q_value = r3, r12 = error

    TEQ      r12,#0         //if error

    BNE      retry_fetchAndAddOrdered          //then retry

    MOV      r0,r2          //return r2

    LDMIA    sp!,{r12,pc}

}

Q_CORE_EXPORT asm

bool QBasicAtomicPointer_testAndSetOrdered(void * volatile *_q_value,

                                           void *expectedValue,

                                           void *newValue)

{

    CODE32

    //R0 = _q_value

    //R1 = expectedValue

    //R2 = newValue

retryPointer_testAndSetOrdered

    LDREX    r3,[r0]        //r3 = *_q_value

    EORS     r3,r3,r1       //if (r3 == expectedValue) {

    STREXEQ  r3,r2,[r0]     //*_q_value = newvalue, r3 = error

    TEQEQ    r3,#1          //if error

    BEQ      retryPointer_testAndSetOrdered          //then goto retry }

    RSBS     r0,r3,#1       //return (r3 == 0)

    MOVCC    r0,#0

    BX       r14

}

Q_CORE_EXPORT asm

void *QBasicAtomicPointer_fetchAndStoreOrdered(void * volatile *_q_value, void *newValue)

{

    CODE32

    //R0 = _q_value

    //R1 = newValue

retryPointer_fetchAndStoreOrdered

    LDREX    r3,[r0]        //r3 = *_q_value

    STREX    r2,r1,[r0]     //*_q_value = newValue, r2 = error

    TEQ      r2,#0          //if error

    BNE      retryPointer_fetchAndStoreOrdered          //then goto retry

    MOV      r0,r3          //return r3

    BX       r14

}

Q_CORE_EXPORT asm

void *QBasicAtomicPointer_fetchAndAddOrdered(void * volatile *_q_value, qptrdiff valueToAdd)

{

    CODE32

    //R0 = _q_value

    //R1 = valueToAdd

    STMDB    sp!,{r12,lr}

retryPointer_fetchAndAddOrdered

    LDREX    r2,[r0]        //r2 = *_q_value

    ADD      r3,r2,r1       //r3 = r2 + r1

    STREX    r12,r3,[r0]    //*_q_value = r3, r12 = error

    TEQ      r12,#0         //if error

    BNE      retryPointer_fetchAndAddOrdered          //then retry

    MOV      r0,r2          //return r2

    LDMIA    sp!,{r12,pc}

}

#pragma pop

#elif defined (Q_CC_GCCE)

Q_CORE_EXPORT __declspec( naked )

bool QBasicAtomicInt_testAndSetOrdered(volatile int *_q_value, int expectedValue, int newValue)

{

    //R0 = _q_value

    //R1 = expectedValue

    //R2 = newValue

    asm("retry_testAndSetOrdered:");

    asm("    LDREX    r3,[r0]");        //r3 = *_q_value

    asm("    EORS     r3,r3,r1");       //if (r3 == expectedValue) {

    asm("    STREXEQ  r3,r2,[r0]");     //*_q_value = newvalue, r3 = error

    asm("    TEQEQ    r3,#1");          //if error

    asm("    BEQ      retry_testAndSetOrdered");          //then goto retry }

    asm("    RSBS     r0,r3,#1");       //return (r3 == 0)

    asm("    MOVCC    r0,#0");

    asm("    BX       r14");

}

Q_CORE_EXPORT __declspec( naked )

int QBasicAtomicInt_fetchAndStoreOrdered(volatile int *_q_value, int newValue)

{

//R0 = _q_value

//R1 = newValue

    asm("retry_fetchAndStoreOrdered:");

    asm("    LDREX    r3,[r0]");        //r3 = *_q_value

    asm("    STREX    r2,r1,[r0]");     //*_q_value = newValue, r2 = error

    asm("    TEQ      r2,#0");          //if error

    asm("    BNE      retry_fetchAndStoreOrdered");          //then goto retry

    asm("    MOV      r0,r3");          //return r3

    asm("    BX       r14");

}

Q_CORE_EXPORT __declspec( naked )

int QBasicAtomicInt_fetchAndAddOrdered(volatile int *_q_value, int valueToAdd)

{

    //R0 = _q_value

    //R1 = valueToAdd

    asm("    STMDB    sp!,{r12,lr}");

    asm("retry_fetchAndAddOrdered:");

    asm("    LDREX    r2,[r0]");        //r2 = *_q_value

    asm("    ADD      r3,r2,r1 ");      //r3 = r2 + r1

    asm("    STREX    r12,r3,[r0]");    //*_q_value = r3, r12 = error

    asm("    TEQ      r12,#0");         //if error

    asm("    BNE      retry_fetchAndAddOrdered");          //then retry

    asm("    MOV      r0,r2");          //return r2

    asm("    LDMIA    sp!,{r12,pc}");

}

Q_CORE_EXPORT __declspec( naked )

bool QBasicAtomicPointer_testAndSetOrdered(void * volatile *_q_value,

                                           void *expectedValue,

                                           void *newValue)

{

    //R0 = _q_value

    //R1 = expectedValue

    //R2 = newValue

    asm("retryPointer_testAndSetOrdered:");

    asm("    LDREX    r3,[r0]");        //r3 = *_q_value

    asm("    EORS     r3,r3,r1");       //if (r3 == expectedValue) {

    asm("    STREXEQ  r3,r2,[r0]");     //*_q_value = newvalue, r3 = error

    asm("    TEQEQ    r3,#1");          //if error

    asm("    BEQ      retryPointer_testAndSetOrdered");          //then goto retry }

    asm("    RSBS     r0,r3,#1");       //return (r3 == 0)

    asm("    MOVCC    r0,#0");

    asm("    BX       r14");

}

Q_CORE_EXPORT __declspec( naked )

void *QBasicAtomicPointer_fetchAndStoreOrdered(void * volatile *_q_value, void *newValue)

{

    //R0 = _q_value

    //R1 = newValue

    asm("retryPointer_fetchAndStoreOrdered:");

    asm("    LDREX    r3,[r0]");        //r3 = *_q_value

    asm("    STREX    r2,r1,[r0]");     //*_q_value = newValue, r2 = error

    asm("    TEQ      r2,#0");          //if error

    asm("    BNE      retryPointer_fetchAndStoreOrdered");          //then goto retry

    asm("    MOV      r0,r3");          //return r3

    asm("    BX       r14");

}

Q_CORE_EXPORT __declspec( naked )

void *QBasicAtomicPointer_fetchAndAddOrdered(void * volatile *_q_value, qptrdiff valueToAdd)

{

    //R0 = _q_value

    //R1 = valueToAdd

    asm("    STMDB    sp!,{r12,lr}");

    asm("retryPointer_fetchAndAddOrdered:");

    asm("    LDREX    r2,[r0]");        //r2 = *_q_value

    asm("    ADD      r3,r2,r1");       //r3 = r2 + r1

    asm("    STREX    r12,r3,[r0]");    //*_q_value = r3, r12 = error

    asm("    TEQ      r12,#0");         //if error

    asm("    BNE      retryPointer_fetchAndAddOrdered");          //then retry

    asm("    MOV      r0,r2");          //return r2

    asm("    LDMIA    sp!,{r12,pc}");

}

#else

#error unknown arm compiler

#endif

QT_END_NAMESPACE

#endif