/*

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 * Copyright (c) 2014, 2019, Red Hat Inc. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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 */

#ifndef OS_CPU_LINUX_AARCH64_ATOMIC_LINUX_AARCH64_HPP

#define OS_CPU_LINUX_AARCH64_ATOMIC_LINUX_AARCH64_HPP

#include "runtime/vm_version.hpp"

// Implementation of class atomic

// Note that memory_order_conservative requires a full barrier after atomic stores.

// See https://patchwork.kernel.org/patch/3575821/

template<size_t byte_size>

struct Atomic::PlatformAdd

  : Atomic::AddAndFetch<Atomic::PlatformAdd<byte_size> >

{

  template<typename I, typename D>

  D add_and_fetch(I add_value, D volatile* dest, atomic_memory_order order) const {

    D res = __atomic_add_fetch(dest, add_value, __ATOMIC_RELEASE);

    FULL_MEM_BARRIER;

    return res;

  }

};

template<size_t byte_size>

template<typename T>

inline T Atomic::PlatformXchg<byte_size>::operator()(T exchange_value,

                                                     T volatile* dest,

                                                     atomic_memory_order order) const {

  STATIC_ASSERT(byte_size == sizeof(T));

  T res = __atomic_exchange_n(dest, exchange_value, __ATOMIC_RELEASE);

  FULL_MEM_BARRIER;

  return res;

}

template<size_t byte_size>

template<typename T>

inline T Atomic::PlatformCmpxchg<byte_size>::operator()(T exchange_value,

                                                        T volatile* dest,

                                                        T compare_value,

                                                        atomic_memory_order order) const {

  STATIC_ASSERT(byte_size == sizeof(T));

  if (order == memory_order_relaxed) {

    T value = compare_value;

    __atomic_compare_exchange(dest, &value, &exchange_value, /*weak*/false,

                              __ATOMIC_RELAXED, __ATOMIC_RELAXED);

    return value;

  } else {

    T value = compare_value;

    FULL_MEM_BARRIER;

    __atomic_compare_exchange(dest, &value, &exchange_value, /*weak*/false,

                              __ATOMIC_RELAXED, __ATOMIC_RELAXED);

    FULL_MEM_BARRIER;

    return value;

  }

}

#endif // OS_CPU_LINUX_AARCH64_ATOMIC_LINUX_AARCH64_HPP