atomic_gcc_x86.h

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2011 the Initial Developer.
 *  All Rights Reserved.
 *  
 *  Contributor(s):
 *
 *  Alternatively, the contents of this file may be used under the terms of the 
 *  GNU General Public License Version 2 or later (the GPL), in which case the 
 *  provisions of GPL are applicable instead of those above.  If you wish to allow use
 *  of your version of this file only under the terms of the GPL and not to allow 
 *  others to use your version of this file under the CPAL, indicate your decision by 
 *  deleting the provisions above and replace them with the notice and other 
 *  provisions required by the GPL License. If you do not delete the provisions above,
 *  a recipient may use your version of this file under either the CPAL or the GPL.
 *  
 *  *** END LICENSE INFORMATION ***
 */
 
namespace lass
{
namespace util
{
namespace impl
{
 
template <>
struct AtomicOperations<1>
{
    template <typename T> inline 
    static bool LASS_CALL compareAndSwap(volatile T& dest, T expectedValue, T newValue)
    {
        bool result;
        __asm__ __volatile__(
            "lock; cmpxchgb %2, %0;"
            "sete %1;"
            : "=m"(dest), "=q"(result)
            : "q"(newValue), "a"(expectedValue), "m"(dest)
            : "cc", "memory");
        return result;
    }
 
    template <typename T1, typename T2> inline 
    static bool LASS_CALL compareAndSwap(
            volatile T1& dest1, T1 expected1, T2 expected2, T1 new1, T2 new2)
    {
        bool result;
#if defined(__PIC__) && LASS_ADDRESS_SIZE == 32
        __asm__ __volatile__(
            "pushl %%ebx;"
            "movb %4, %%ah;"
            "movb %%cl, %%dh;"
            "lock; cmpxchgw %%dx, %0;"
            "sete %1;"
            "popl %%ebx;"
            : "=m"(dest1), "=q"(result)
            : "a"(expected1), "d"(expected2), "m"(new1), "c"(new2), "m"(dest1)
            : "cc", "memory");
#else
        __asm__ __volatile__(
            "movb %%bl, %%ah;"
            "movb %%cl, %%dh;"
            "lock; cmpxchgw %%dx, %0;"
            "sete %1;"
            : "=m"(reinterpret_cast<volatile num::Tuint16&>(dest1)), "=q"(result)
            : "a"(expected1), "d"(new1), "b"(expected2), "c"(new2), 
              "m"(reinterpret_cast<volatile num::Tuint16&>(dest1))
            : "cc", "memory");
#endif
        return result;
    }
 
    template <typename T> inline
    static void LASS_CALL increment(volatile T& value)
    {
        __asm__ __volatile__(
            "lock; incb %0;"
            : "=m"(value)
            : "m"(value)
            : "cc", "memory");
    }
 
    template <typename T> inline
    static void LASS_CALL decrement(volatile T& value)
    {
        __asm__ __volatile__(
            "lock; decb %0;"
            : "=m"(value)
            : "m"(value)
            : "cc", "memory");
    }
};
 
 
 
template <>
struct AtomicOperations<2>
{
    template <typename T> inline 
    static bool LASS_CALL compareAndSwap(volatile T& dest, T expectedValue, T newValue)
    {
        bool result;
        __asm__ __volatile__(
            "lock; cmpxchgw %2, %0;"
            "sete %1;"
            : "=m"(dest), "=q"(result)
            : "q"(newValue), "a"(expectedValue), "m"(dest)
            : "cc", "memory");
        return result;
    }
 
    template <typename T1, typename T2> inline 
    static bool LASS_CALL compareAndSwap(
            volatile T1& dest1, T1 expected1, T2 expected2, T1 new1, T2 new2)
    {
        bool result;
        __asm__ __volatile__(
            "shll $16, %%eax;"
            "shll $16, %%edx;"
            "movw %4, %%ax;"
            "movw %5, %%dx;"
            "lock; cmpxchgl %%edx, %0;"
            "sete %1;"
            : "=m"(reinterpret_cast<volatile num::Tuint32&>(dest1)), "=q"(result)
            : "a"(expected2), "d"(new2), "g"(expected1), "g"(new1),
              "m"(reinterpret_cast<volatile num::Tuint32&>(dest1))
            : "cc", "memory");
        return result;  
    }
 
    template <typename T> inline
    static void LASS_CALL increment(volatile T& value)
    {
        __asm__ __volatile__(
            "lock; incw %0;"
            : "=m"(value)
            : "m"(value)
            : "cc", "memory");
    }
 
    template <typename T> inline
    static void LASS_CALL decrement(volatile T& value)
    {
        __asm__ __volatile__(
            "lock; decw %0;"
            : "=m"(value)
            : "m"(value)
            : "cc", "memory");
    }
};
 
 
 
template <>
struct AtomicOperations<4>
{
    template <typename T> inline 
    static bool LASS_CALL compareAndSwap(volatile T& dest, T expectedValue, T newValue)
    {
        bool result;
        __asm__ __volatile__(
            "lock; cmpxchgl %2, %0;"
            "sete %1;"
            : "=m"(dest), "=q"(result)
            : "q"(newValue), "a"(expectedValue), "m"(dest)
            : "cc", "memory");
        return result;
    }
 
    template <typename T1, typename T2> inline 
    static bool LASS_CALL compareAndSwap(
            volatile T1& dest1, T1 expected1, T2 expected2, T1 new1, T2 new2)
    {
        bool result;
 
        // cmpxchg8b and PIC mode don't play nice.  Push ebx before use!
        // see http://www.technovelty.org/code/arch/pic-cas.html
        //
#if defined(__PIC__) && LASS_ADDRESS_SIZE == 32
        __asm__ __volatile__(
            "pushl %%ebx;"
            "movl %4,%%ebx;"
            "lock; cmpxchg8b %0;"
            "sete %1;"
            "popl %%ebx;"
            : "=m"(dest1), "=q"(result)
            : "a"(expected1), "d"(expected2), "m"(new1), "c"(new2), "m"(dest1)
            : "cc", "memory");
#else
        __asm__ __volatile__(
            "lock; cmpxchg8b %0;"
            "sete %1;"
            : "=m"(dest1), "=q"(result)
            : "a"(expected1), "d"(expected2), "b"(new1), "c"(new2), "m"(dest1)
            : "cc", "memory");
#endif
        return result;
    }
 
    template <typename T> inline
    static void LASS_CALL increment(volatile T& value)
    {
        __asm__ __volatile__(
            "lock; incl %0;"
            : "=m"(value)
            : "m"(value)
            : "cc", "memory");
    }
 
    template <typename T> inline
    static void LASS_CALL decrement(volatile T& value)
    {
        __asm__ __volatile__(
            "lock; decl %0;"
            : "=m"(value)
            : "m"(value)
            : "cc", "memory");
    }
};
 
 
 
template <>
struct AtomicOperations<8>
{
    template <typename T> inline 
    static bool LASS_CALL compareAndSwap(volatile T& dest, T expectedValue, T newValue)
    {
        bool result;
#if LASS_ADDRESS_SIZE == 32
        // cmpxchg8b and PIC mode don't play nice.  Push ebx before use!
        // see http://www.technovelty.org/code/arch/pic-cas.html
        //
#   ifdef __PIC__
        __asm__ __volatile__(
            "pushl %%ebx;"
            "movl (%%ecx),%%ebx;"
            "movl 4(%%ecx),%%ecx;"
            "lock; cmpxchg8b %0;"
            "sete %1;"
            "pop %%ebx;"
            : "=m"(dest), "=q"(result)
            : "m"(dest),
              "a"(reinterpret_cast<volatile num::Tuint32*>((void*)&expectedValue)[0]), 
              "d"(reinterpret_cast<volatile num::Tuint32*>((void*)&expectedValue)[1]),  
              "c"(&newValue)
            : "cc", "memory");
#   else
        __asm__ __volatile__(
            "lock; cmpxchg8b %0;"
            "sete %1;"
            : "=m"(dest), "=q"(result)
            : "m"(dest),
              "a"(reinterpret_cast<volatile num::Tuint32*>((void*)&expectedValue)[0]), 
              "d"(reinterpret_cast<volatile num::Tuint32*>((void*)&expectedValue)[1]),  
              "b"(reinterpret_cast<volatile num::Tuint32*>((void*)&newValue)[0]), 
              "c"(reinterpret_cast<volatile num::Tuint32*>((void*)&newValue)[1])    
            : "cc", "memory");
#   endif
#else
        __asm__ __volatile__(
            "lock; cmpxchgq %2, %0;"
            "sete %1;"
            : "=m"(dest), "=q"(result)
            : "q"(newValue), "a"(expectedValue), "m"(dest)
            : "cc", "memory");
#endif
        return result;
    }
 
#if LASS_ADDRESS_SIZE != 32
    template <typename T1, typename T2> inline 
    static bool LASS_CALL compareAndSwap(
            volatile T1& dest1, T1 expected1, T2 expected2, T1 new1, T2 new2)
    {
        LASS_ASSERT((reinterpret_cast<num::Tuint64>(&dest1) & 0xf) == 0); // dest needs to be 16-byte aligned.
        bool result;
        __asm__ __volatile__(
            "lock; cmpxchg16b %0;"
            "sete %1;"
            : "=m"(dest1), "=q"(result)
            : "a"(expected1), "d"(expected2), "b"(new1), "c"(new2), "m"(dest1)
            : "cc", "memory");
        return result;
    }
#endif
    
    template <typename T> inline
    static void LASS_CALL increment(volatile T& value)
    {
#if LASS_ADDRESS_SIZE == 32
        // not knowing any better, we emulate incq with cas loop
        T old, fresh;
        do
        {
            old = value;
            fresh = old + 1;
        }
        while (!atomicCompareAndSwap(value, old, fresh));       
#else
        __asm__ __volatile__(
            "lock; incq %0;"
            : "=m"(value)
            : "m"(value)
            : "cc", "memory");
#endif      
    }
 
    template <typename T> inline
    static void LASS_CALL decrement(volatile T& value)
    {
#if LASS_ADDRESS_SIZE == 32
        // not knowing any better, we emulate decq with cas loop
        T old, fresh;
        do
        {
            old = value;
            fresh = old - 1;
        }
        while (!atomicCompareAndSwap(value, old, fresh));
#else
        __asm__ __volatile__(
            "lock; decq %0;"
            : "=m"(value)
            : "m"(value)
            : "cc", "memory");
#endif
    }
};
 
}
}
}
 
// EOF