Subversion Repositories openrisc_2011-10-31

// Low-level functions for atomic operations: Sparc version  -*- C++ -*-

// Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2009

// Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library is free

// software; you can redistribute it and/or modify it under the

// terms of the GNU General Public License as published by the

// Free Software Foundation; either version 3, or (at your option)

// any later version.

// This library is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional

// permissions described in the GCC Runtime Library Exception, version

// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and

// a copy of the GCC Runtime Library Exception along with this program;

// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

// <http://www.gnu.org/licenses/>.

#include <ext/atomicity.h>

_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

#ifdef __arch64__

  _Atomic_word

  __attribute__ ((__unused__))

  __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()

  {

    _Atomic_word __tmp1, __tmp2;

    _Atomic_word __val_extended = __val;

    __asm__ __volatile__("1:    ldx     [%3], %0\n\t"

                         "      add     %0, %4, %1\n\t"

                         "      casx    [%3], %0, %1\n\t"

                         "      sub     %0, %1, %0\n\t"

                         "      brnz,pn %0, 1b\n\t"

                         "       nop"

                         : "=&r" (__tmp1), "=&r" (__tmp2), "=m" (*__mem)

                         : "r" (__mem), "r" (__val_extended), "m" (*__mem));

    return __tmp2;

  }

  void

  __attribute__ ((__unused__))

  __atomic_add(volatile _Atomic_word* __mem, int __val) throw ()

  {

    _Atomic_word __tmp1, __tmp2;

    _Atomic_word __val_extended = __val;

    __asm__ __volatile__("1:    ldx     [%3], %0\n\t"

                         "      add     %0, %4, %1\n\t"

                         "      casx    [%3], %0, %1\n\t"

                         "      sub     %0, %1, %0\n\t"

                         "      brnz,pn %0, 1b\n\t"

                         "       nop"

                         : "=&r" (__tmp1), "=&r" (__tmp2), "=m" (*__mem)

                         : "r" (__mem), "r" (__val_extended), "m" (*__mem));

  }

#else /* __arch32__ */

  template<int __inst>

    struct _Atomicity_lock

    {

      static unsigned char _S_atomicity_lock;

    };

  template<int __inst>

  unsigned char _Atomicity_lock<__inst>::_S_atomicity_lock = 0;

  template unsigned char _Atomicity_lock<0>::_S_atomicity_lock;

  _Atomic_word

  __attribute__ ((__unused__))

  __exchange_and_add(volatile _Atomic_word* __mem, int __val) throw ()

  {

    _Atomic_word __result, __tmp;

    __asm__ __volatile__("1:    ldstub  [%1], %0\n\t"

                         "      cmp     %0, 0\n\t"

                         "      bne     1b\n\t"

                         "       nop"

                         : "=&r" (__tmp)

                         : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)

                         : "memory");

    __result = *__mem;

    *__mem += __val;

    __asm__ __volatile__("stb   %%g0, [%0]"

                         : /* no outputs */

                         : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)

                         : "memory");

    return __result;

  }

  void

  __attribute__ ((__unused__))

  __atomic_add(volatile _Atomic_word* __mem, int __val) throw ()

  {

    _Atomic_word __tmp;

    __asm__ __volatile__("1:    ldstub  [%1], %0\n\t"

                         "      cmp     %0, 0\n\t"

                         "      bne     1b\n\t"

                         "       nop"

                         : "=&r" (__tmp)

                         : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)

                         : "memory");

    *__mem += __val;

    __asm__ __volatile__("stb   %%g0, [%0]"

                         : /* no outputs */

                         : "r" (&_Atomicity_lock<0>::_S_atomicity_lock)

                         : "memory");

  }

#endif /* __arch32__ */

_GLIBCXX_END_NAMESPACE