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// -*- C++ -*- header.

// Copyright (C) 2008-2015 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

// .

/** @file bits/atomic_base.h

 *  This is an internal header file, included by other library headers.

 *  Do not attempt to use it directly. @headername{atomic}

 */

#ifndef _GLIBCXX_ATOMIC_BASE_H

#define _GLIBCXX_ATOMIC_BASE_H 1

#pragma GCC system_header

#include 

#include 

#include 

#ifndef _GLIBCXX_ALWAYS_INLINE

#define _GLIBCXX_ALWAYS_INLINE inline __attribute__((__always_inline__))

#endif

namespace std _GLIBCXX_VISIBILITY(default)

{

_GLIBCXX_BEGIN_NAMESPACE_VERSION

  /**

   * @defgroup atomics Atomics

   *

   * Components for performing atomic operations.

   * @{

   */

  /// Enumeration for memory_order

  typedef enum memory_order

    {

      memory_order_relaxed,

      memory_order_consume,

      memory_order_acquire,

      memory_order_release,

      memory_order_acq_rel,

      memory_order_seq_cst

    } memory_order;

  enum __memory_order_modifier

    {

      __memory_order_mask          = 0x0ffff,

      __memory_order_modifier_mask = 0xffff0000,

      __memory_order_hle_acquire   = 0x10000,

      __memory_order_hle_release   = 0x20000

    };

  constexpr memory_order

  operator|(memory_order __m, __memory_order_modifier __mod)

  {

    return memory_order(__m | int(__mod));

  }

  constexpr memory_order

  operator&(memory_order __m, __memory_order_modifier __mod)

  {

    return memory_order(__m & int(__mod));

  }

  // Drop release ordering as per [atomics.types.operations.req]/21

  constexpr memory_order

  __cmpexch_failure_order2(memory_order __m) noexcept

  {

    return __m == memory_order_acq_rel ? memory_order_acquire

      : __m == memory_order_release ? memory_order_relaxed : __m;

  }

  constexpr memory_order

  __cmpexch_failure_order(memory_order __m) noexcept

  {

    return memory_order(__cmpexch_failure_order2(__m & __memory_order_mask)

      | (__m & __memory_order_modifier_mask));

  }

  _GLIBCXX_ALWAYS_INLINE void

  atomic_thread_fence(memory_order __m) noexcept

  { __atomic_thread_fence(__m); }

  _GLIBCXX_ALWAYS_INLINE void

  atomic_signal_fence(memory_order __m) noexcept

  { __atomic_signal_fence(__m); }

  /// kill_dependency

  template

    inline _Tp

    kill_dependency(_Tp __y) noexcept

    {

      _Tp __ret(__y);

      return __ret;

    }

  // Base types for atomics.

  template

    struct __atomic_base;

#define ATOMIC_VAR_INIT(_VI) { _VI }

  template

    struct atomic;

  template

    struct atomic<_Tp*>;

    /* The target's "set" value for test-and-set may not be exactly 1.  */

#if __GCC_ATOMIC_TEST_AND_SET_TRUEVAL == 1

    typedef bool __atomic_flag_data_type;

#else

    typedef unsigned char __atomic_flag_data_type;

#endif

  /**

   *  @brief Base type for atomic_flag.

   *

   *  Base type is POD with data, allowing atomic_flag to derive from

   *  it and meet the standard layout type requirement. In addition to

   *  compatibility with a C interface, this allows different

   *  implementations of atomic_flag to use the same atomic operation

   *  functions, via a standard conversion to the __atomic_flag_base

   *  argument.

  */

  _GLIBCXX_BEGIN_EXTERN_C

  struct __atomic_flag_base

  {

    __atomic_flag_data_type _M_i;

  };

  _GLIBCXX_END_EXTERN_C

#define ATOMIC_FLAG_INIT { 0 }

  /// atomic_flag

  struct atomic_flag : public __atomic_flag_base

  {

    atomic_flag() noexcept = default;

    ~atomic_flag() noexcept = default;

    atomic_flag(const atomic_flag&) = delete;

    atomic_flag& operator=(const atomic_flag&) = delete;

    atomic_flag& operator=(const atomic_flag&) volatile = delete;

    // Conversion to ATOMIC_FLAG_INIT.

    constexpr atomic_flag(bool __i) noexcept

      : __atomic_flag_base{ _S_init(__i) }

    { }

    _GLIBCXX_ALWAYS_INLINE bool

    test_and_set(memory_order __m = memory_order_seq_cst) noexcept

    {

      return __atomic_test_and_set (&_M_i, __m);

    }

    _GLIBCXX_ALWAYS_INLINE bool

    test_and_set(memory_order __m = memory_order_seq_cst) volatile noexcept

    {

      return __atomic_test_and_set (&_M_i, __m);

    }

    _GLIBCXX_ALWAYS_INLINE void

    clear(memory_order __m = memory_order_seq_cst) noexcept

    {

      memory_order __b = __m & __memory_order_mask;

      __glibcxx_assert(__b != memory_order_consume);

      __glibcxx_assert(__b != memory_order_acquire);

      __glibcxx_assert(__b != memory_order_acq_rel);

      __atomic_clear (&_M_i, __m);

    }

    _GLIBCXX_ALWAYS_INLINE void

    clear(memory_order __m = memory_order_seq_cst) volatile noexcept

    {

      memory_order __b = __m & __memory_order_mask;

      __glibcxx_assert(__b != memory_order_consume);

      __glibcxx_assert(__b != memory_order_acquire);

      __glibcxx_assert(__b != memory_order_acq_rel);

      __atomic_clear (&_M_i, __m);

    }

  private:

    static constexpr __atomic_flag_data_type

    _S_init(bool __i)

    { return __i ? __GCC_ATOMIC_TEST_AND_SET_TRUEVAL : 0; }

  };

  /// Base class for atomic integrals.

  //

  // For each of the integral types, define atomic_[integral type] struct

  //

  // atomic_bool     bool

  // atomic_char     char

  // atomic_schar    signed char

  // atomic_uchar    unsigned char

  // atomic_short    short

  // atomic_ushort   unsigned short

  // atomic_int      int

  // atomic_uint     unsigned int

  // atomic_long     long

  // atomic_ulong    unsigned long

  // atomic_llong    long long

  // atomic_ullong   unsigned long long

  // atomic_char16_t char16_t

  // atomic_char32_t char32_t

  // atomic_wchar_t  wchar_t

  //

  // NB: Assuming _ITp is an integral scalar type that is 1, 2, 4, or

  // 8 bytes, since that is what GCC built-in functions for atomic

  // memory access expect.

  template

    struct __atomic_base

    {

    private:

      typedef _ITp 	__int_type;

      static constexpr int _S_alignment =

	sizeof(_ITp) > alignof(_ITp) ? sizeof(_ITp) : alignof(_ITp);

      alignas(_S_alignment) __int_type _M_i;

    public:

      __atomic_base() noexcept = default;

      ~__atomic_base() noexcept = default;

      __atomic_base(const __atomic_base&) = delete;

      __atomic_base& operator=(const __atomic_base&) = delete;

      __atomic_base& operator=(const __atomic_base&) volatile = delete;

      // Requires __int_type convertible to _M_i.

      constexpr __atomic_base(__int_type __i) noexcept : _M_i (__i) { }

      operator __int_type() const noexcept

      { return load(); }

      operator __int_type() const volatile noexcept

      { return load(); }

      __int_type

      operator=(__int_type __i) noexcept

      {

	store(__i);

	return __i;

      }

      __int_type

      operator=(__int_type __i) volatile noexcept

      {

	store(__i);

	return __i;

      }

      __int_type

      operator++(int) noexcept

      { return fetch_add(1); }

      __int_type

      operator++(int) volatile noexcept

      { return fetch_add(1); }

      __int_type

      operator--(int) noexcept

      { return fetch_sub(1); }

      __int_type

      operator--(int) volatile noexcept

      { return fetch_sub(1); }

      __int_type

      operator++() noexcept

      { return __atomic_add_fetch(&_M_i, 1, memory_order_seq_cst); }

      __int_type

      operator++() volatile noexcept

      { return __atomic_add_fetch(&_M_i, 1, memory_order_seq_cst); }

      __int_type

      operator--() noexcept

      { return __atomic_sub_fetch(&_M_i, 1, memory_order_seq_cst); }

      __int_type

      operator--() volatile noexcept

      { return __atomic_sub_fetch(&_M_i, 1, memory_order_seq_cst); }

      __int_type

      operator+=(__int_type __i) noexcept

      { return __atomic_add_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator+=(__int_type __i) volatile noexcept

      { return __atomic_add_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator-=(__int_type __i) noexcept

      { return __atomic_sub_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator-=(__int_type __i) volatile noexcept

      { return __atomic_sub_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator&=(__int_type __i) noexcept

      { return __atomic_and_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator&=(__int_type __i) volatile noexcept

      { return __atomic_and_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator|=(__int_type __i) noexcept

      { return __atomic_or_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator|=(__int_type __i) volatile noexcept

      { return __atomic_or_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator^=(__int_type __i) noexcept

      { return __atomic_xor_fetch(&_M_i, __i, memory_order_seq_cst); }

      __int_type

      operator^=(__int_type __i) volatile noexcept

      { return __atomic_xor_fetch(&_M_i, __i, memory_order_seq_cst); }

      bool

      is_lock_free() const noexcept

      {

	// Use a fake, minimally aligned pointer.

	return __atomic_is_lock_free(sizeof(_M_i),

	    reinterpret_cast(-__alignof(_M_i)));

      }

      bool

      is_lock_free() const volatile noexcept

      {

	// Use a fake, minimally aligned pointer.

	return __atomic_is_lock_free(sizeof(_M_i),

	    reinterpret_cast(-__alignof(_M_i)));

      }

      _GLIBCXX_ALWAYS_INLINE void

      store(__int_type __i, memory_order __m = memory_order_seq_cst) noexcept

      {

        memory_order __b = __m & __memory_order_mask;

	__glibcxx_assert(__b != memory_order_acquire);

	__glibcxx_assert(__b != memory_order_acq_rel);

	__glibcxx_assert(__b != memory_order_consume);

	__atomic_store_n(&_M_i, __i, __m);

      }

      _GLIBCXX_ALWAYS_INLINE void

      store(__int_type __i,

	    memory_order __m = memory_order_seq_cst) volatile noexcept

      {

        memory_order __b = __m & __memory_order_mask;

	__glibcxx_assert(__b != memory_order_acquire);

	__glibcxx_assert(__b != memory_order_acq_rel);

	__glibcxx_assert(__b != memory_order_consume);

	__atomic_store_n(&_M_i, __i, __m);

      }

      _GLIBCXX_ALWAYS_INLINE __int_type

      load(memory_order __m = memory_order_seq_cst) const noexcept

      {

       memory_order __b = __m & __memory_order_mask;

	__glibcxx_assert(__b != memory_order_release);

	__glibcxx_assert(__b != memory_order_acq_rel);

	return __atomic_load_n(&_M_i, __m);

      }

      _GLIBCXX_ALWAYS_INLINE __int_type

      load(memory_order __m = memory_order_seq_cst) const volatile noexcept

      {

        memory_order __b = __m & __memory_order_mask;

	__glibcxx_assert(__b != memory_order_release);

	__glibcxx_assert(__b != memory_order_acq_rel);

	return __atomic_load_n(&_M_i, __m);

      }

      _GLIBCXX_ALWAYS_INLINE __int_type

      exchange(__int_type __i,

	       memory_order __m = memory_order_seq_cst) noexcept

      {

	return __atomic_exchange_n(&_M_i, __i, __m);

      }

      _GLIBCXX_ALWAYS_INLINE __int_type

      exchange(__int_type __i,

	       memory_order __m = memory_order_seq_cst) volatile noexcept

      {

	return __atomic_exchange_n(&_M_i, __i, __m);

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_weak(__int_type& __i1, __int_type __i2,

			    memory_order __m1, memory_order __m2) noexcept

      {

       memory_order __b2 = __m2 & __memory_order_mask;

       memory_order __b1 = __m1 & __memory_order_mask;

	__glibcxx_assert(__b2 != memory_order_release);

	__glibcxx_assert(__b2 != memory_order_acq_rel);

	__glibcxx_assert(__b2 <= __b1);

	return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, __m1, __m2);

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_weak(__int_type& __i1, __int_type __i2,

			    memory_order __m1,

			    memory_order __m2) volatile noexcept

      {

       memory_order __b2 = __m2 & __memory_order_mask;

       memory_order __b1 = __m1 & __memory_order_mask;

	__glibcxx_assert(__b2 != memory_order_release);

	__glibcxx_assert(__b2 != memory_order_acq_rel);

	__glibcxx_assert(__b2 <= __b1);

	return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 1, __m1, __m2);

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_weak(__int_type& __i1, __int_type __i2,

			    memory_order __m = memory_order_seq_cst) noexcept

      {

	return compare_exchange_weak(__i1, __i2, __m,

				     __cmpexch_failure_order(__m));

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_weak(__int_type& __i1, __int_type __i2,

		   memory_order __m = memory_order_seq_cst) volatile noexcept

      {

	return compare_exchange_weak(__i1, __i2, __m,

				     __cmpexch_failure_order(__m));

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_strong(__int_type& __i1, __int_type __i2,

			      memory_order __m1, memory_order __m2) noexcept

      {

        memory_order __b2 = __m2 & __memory_order_mask;

        memory_order __b1 = __m1 & __memory_order_mask;

	__glibcxx_assert(__b2 != memory_order_release);

	__glibcxx_assert(__b2 != memory_order_acq_rel);

	__glibcxx_assert(__b2 <= __b1);

	return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, __m1, __m2);

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_strong(__int_type& __i1, __int_type __i2,

			      memory_order __m1,

			      memory_order __m2) volatile noexcept

      {

        memory_order __b2 = __m2 & __memory_order_mask;

        memory_order __b1 = __m1 & __memory_order_mask;

	__glibcxx_assert(__b2 != memory_order_release);

	__glibcxx_assert(__b2 != memory_order_acq_rel);

	__glibcxx_assert(__b2 <= __b1);

	return __atomic_compare_exchange_n(&_M_i, &__i1, __i2, 0, __m1, __m2);

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_strong(__int_type& __i1, __int_type __i2,

			      memory_order __m = memory_order_seq_cst) noexcept

      {

	return compare_exchange_strong(__i1, __i2, __m,

				       __cmpexch_failure_order(__m));

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_strong(__int_type& __i1, __int_type __i2,

		 memory_order __m = memory_order_seq_cst) volatile noexcept

      {

	return compare_exchange_strong(__i1, __i2, __m,

				       __cmpexch_failure_order(__m));

      }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_add(__int_type __i,

		memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_add(&_M_i, __i, __m); }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_add(__int_type __i,

		memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_add(&_M_i, __i, __m); }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_sub(__int_type __i,

		memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_sub(&_M_i, __i, __m); }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_sub(__int_type __i,

		memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_sub(&_M_i, __i, __m); }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_and(__int_type __i,

		memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_and(&_M_i, __i, __m); }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_and(__int_type __i,

		memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_and(&_M_i, __i, __m); }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_or(__int_type __i,

	       memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_or(&_M_i, __i, __m); }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_or(__int_type __i,

	       memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_or(&_M_i, __i, __m); }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_xor(__int_type __i,

		memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_xor(&_M_i, __i, __m); }

      _GLIBCXX_ALWAYS_INLINE __int_type

      fetch_xor(__int_type __i,

		memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_xor(&_M_i, __i, __m); }

    };

  /// Partial specialization for pointer types.

  template

    struct __atomic_base<_PTp*>

    {

    private:

      typedef _PTp* 	__pointer_type;

      __pointer_type 	_M_p;

      // Factored out to facilitate explicit specialization.

      constexpr ptrdiff_t

      _M_type_size(ptrdiff_t __d) const { return __d * sizeof(_PTp); }

      constexpr ptrdiff_t

      _M_type_size(ptrdiff_t __d) const volatile { return __d * sizeof(_PTp); }

    public:

      __atomic_base() noexcept = default;

      ~__atomic_base() noexcept = default;

      __atomic_base(const __atomic_base&) = delete;

      __atomic_base& operator=(const __atomic_base&) = delete;

      __atomic_base& operator=(const __atomic_base&) volatile = delete;

      // Requires __pointer_type convertible to _M_p.

      constexpr __atomic_base(__pointer_type __p) noexcept : _M_p (__p) { }

      operator __pointer_type() const noexcept

      { return load(); }

      operator __pointer_type() const volatile noexcept

      { return load(); }

      __pointer_type

      operator=(__pointer_type __p) noexcept

      {

	store(__p);

	return __p;

      }

      __pointer_type

      operator=(__pointer_type __p) volatile noexcept

      {

	store(__p);

	return __p;

      }

      __pointer_type

      operator++(int) noexcept

      { return fetch_add(1); }

      __pointer_type

      operator++(int) volatile noexcept

      { return fetch_add(1); }

      __pointer_type

      operator--(int) noexcept

      { return fetch_sub(1); }

      __pointer_type

      operator--(int) volatile noexcept

      { return fetch_sub(1); }

      __pointer_type

      operator++() noexcept

      { return __atomic_add_fetch(&_M_p, _M_type_size(1),

				  memory_order_seq_cst); }

      __pointer_type

      operator++() volatile noexcept

      { return __atomic_add_fetch(&_M_p, _M_type_size(1),

				  memory_order_seq_cst); }

      __pointer_type

      operator--() noexcept

      { return __atomic_sub_fetch(&_M_p, _M_type_size(1),

				  memory_order_seq_cst); }

      __pointer_type

      operator--() volatile noexcept

      { return __atomic_sub_fetch(&_M_p, _M_type_size(1),

				  memory_order_seq_cst); }

      __pointer_type

      operator+=(ptrdiff_t __d) noexcept

      { return __atomic_add_fetch(&_M_p, _M_type_size(__d),

				  memory_order_seq_cst); }

      __pointer_type

      operator+=(ptrdiff_t __d) volatile noexcept

      { return __atomic_add_fetch(&_M_p, _M_type_size(__d),

				  memory_order_seq_cst); }

      __pointer_type

      operator-=(ptrdiff_t __d) noexcept

      { return __atomic_sub_fetch(&_M_p, _M_type_size(__d),

				  memory_order_seq_cst); }

      __pointer_type

      operator-=(ptrdiff_t __d) volatile noexcept

      { return __atomic_sub_fetch(&_M_p, _M_type_size(__d),

				  memory_order_seq_cst); }

      bool

      is_lock_free() const noexcept

      {

	// Produce a fake, minimally aligned pointer.

	return __atomic_is_lock_free(sizeof(_M_p),

	    reinterpret_cast(-__alignof(_M_p)));

      }

      bool

      is_lock_free() const volatile noexcept

      {

	// Produce a fake, minimally aligned pointer.

	return __atomic_is_lock_free(sizeof(_M_p),

	    reinterpret_cast(-__alignof(_M_p)));

      }

      _GLIBCXX_ALWAYS_INLINE void

      store(__pointer_type __p,

	    memory_order __m = memory_order_seq_cst) noexcept

      {

        memory_order __b = __m & __memory_order_mask;

	__glibcxx_assert(__b != memory_order_acquire);

	__glibcxx_assert(__b != memory_order_acq_rel);

	__glibcxx_assert(__b != memory_order_consume);

	__atomic_store_n(&_M_p, __p, __m);

      }

      _GLIBCXX_ALWAYS_INLINE void

      store(__pointer_type __p,

	    memory_order __m = memory_order_seq_cst) volatile noexcept

      {

        memory_order __b = __m & __memory_order_mask;

	__glibcxx_assert(__b != memory_order_acquire);

	__glibcxx_assert(__b != memory_order_acq_rel);

	__glibcxx_assert(__b != memory_order_consume);

	__atomic_store_n(&_M_p, __p, __m);

      }

      _GLIBCXX_ALWAYS_INLINE __pointer_type

      load(memory_order __m = memory_order_seq_cst) const noexcept

      {

        memory_order __b = __m & __memory_order_mask;

	__glibcxx_assert(__b != memory_order_release);

	__glibcxx_assert(__b != memory_order_acq_rel);

	return __atomic_load_n(&_M_p, __m);

      }

      _GLIBCXX_ALWAYS_INLINE __pointer_type

      load(memory_order __m = memory_order_seq_cst) const volatile noexcept

      {

        memory_order __b = __m & __memory_order_mask;

	__glibcxx_assert(__b != memory_order_release);

	__glibcxx_assert(__b != memory_order_acq_rel);

	return __atomic_load_n(&_M_p, __m);

      }

      _GLIBCXX_ALWAYS_INLINE __pointer_type

      exchange(__pointer_type __p,

	       memory_order __m = memory_order_seq_cst) noexcept

      {

	return __atomic_exchange_n(&_M_p, __p, __m);

      }

      _GLIBCXX_ALWAYS_INLINE __pointer_type

      exchange(__pointer_type __p,

	       memory_order __m = memory_order_seq_cst) volatile noexcept

      {

	return __atomic_exchange_n(&_M_p, __p, __m);

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,

			      memory_order __m1,

			      memory_order __m2) noexcept

      {

        memory_order __b2 = __m2 & __memory_order_mask;

        memory_order __b1 = __m1 & __memory_order_mask;

	__glibcxx_assert(__b2 != memory_order_release);

	__glibcxx_assert(__b2 != memory_order_acq_rel);

	__glibcxx_assert(__b2 <= __b1);

	return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 0, __m1, __m2);

      }

      _GLIBCXX_ALWAYS_INLINE bool

      compare_exchange_strong(__pointer_type& __p1, __pointer_type __p2,

			      memory_order __m1,

			      memory_order __m2) volatile noexcept

      {

        memory_order __b2 = __m2 & __memory_order_mask;

        memory_order __b1 = __m1 & __memory_order_mask;

	__glibcxx_assert(__b2 != memory_order_release);

	__glibcxx_assert(__b2 != memory_order_acq_rel);

	__glibcxx_assert(__b2 <= __b1);

	return __atomic_compare_exchange_n(&_M_p, &__p1, __p2, 0, __m1, __m2);

      }

      _GLIBCXX_ALWAYS_INLINE __pointer_type

      fetch_add(ptrdiff_t __d,

		memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_add(&_M_p, _M_type_size(__d), __m); }

      _GLIBCXX_ALWAYS_INLINE __pointer_type

      fetch_add(ptrdiff_t __d,

		memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_add(&_M_p, _M_type_size(__d), __m); }

      _GLIBCXX_ALWAYS_INLINE __pointer_type

      fetch_sub(ptrdiff_t __d,

		memory_order __m = memory_order_seq_cst) noexcept

      { return __atomic_fetch_sub(&_M_p, _M_type_size(__d), __m); }

      _GLIBCXX_ALWAYS_INLINE __pointer_type

      fetch_sub(ptrdiff_t __d,

		memory_order __m = memory_order_seq_cst) volatile noexcept

      { return __atomic_fetch_sub(&_M_p, _M_type_size(__d), __m); }

    };

  // @} group atomics

_GLIBCXX_END_NAMESPACE_VERSION

} // namespace std

#endif