+2019-07-11 Jonathan Wakely <jwakely@redhat.com>
+
+ * include/bits/atomic_base.h (__atomic_impl): New namespace for
+ wrappers around atomic built-ins.
+ (__atomic_float, __atomic_ref): New class templates for use as base
+ classes.
+ * include/std/atomic (atomic<float>, atomic<double>)
+ (atomic<long double>): New explicit specializations.
+ (atomic_ref): New class template.
+ (__cpp_lib_atomic_ref): Define.
+ * include/std/version (__cpp_lib_atomic_ref): Define.
+ * testsuite/29_atomics/atomic/60695.cc: Adjust dg-error.
+ * testsuite/29_atomics/atomic_float/1.cc: New test.
+ * testsuite/29_atomics/atomic_float/requirements.cc: New test.
+ * testsuite/29_atomics/atomic_ref/deduction.cc: New test.
+ * testsuite/29_atomics/atomic_ref/float.cc: New test.
+ * testsuite/29_atomics/atomic_ref/generic.cc: New test.
+ * testsuite/29_atomics/atomic_ref/integral.cc: New test.
+ * testsuite/29_atomics/atomic_ref/pointer.cc: New test.
+ * testsuite/29_atomics/atomic_ref/requirements.cc: New test.
+
2019-07-06 Jonathan Wakely <jwakely@redhat.com>
* include/ext/atomicity.h (__exchange_and_add, __atomic_add): Replace
#include <bits/c++config.h>
#include <stdint.h>
#include <bits/atomic_lockfree_defines.h>
+#include <bits/move.h>
#ifndef _GLIBCXX_ALWAYS_INLINE
#define _GLIBCXX_ALWAYS_INLINE inline __attribute__((__always_inline__))
{ return __atomic_fetch_sub(&_M_p, _M_type_size(__d), int(__m)); }
};
+#if __cplusplus > 201703L
+ // Implementation details of atomic_ref and atomic<floating-point>.
+ namespace __atomic_impl
+ {
+ // Remove volatile and create a non-deduced context for value arguments.
+ template<typename _Tp>
+ using _Val = remove_volatile_t<_Tp>;
+
+ // As above, but for difference_type arguments.
+ template<typename _Tp>
+ using _Diff = conditional_t<is_pointer_v<_Tp>, ptrdiff_t, _Val<_Tp>>;
+
+ template<size_t _Size, size_t _Align>
+ _GLIBCXX_ALWAYS_INLINE bool
+ is_lock_free() noexcept
+ {
+ // Produce a fake, minimally aligned pointer.
+ return __atomic_is_lock_free(_Size, reinterpret_cast<void *>(-_Align));
+ }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE void
+ store(_Tp* __ptr, _Val<_Tp> __t, memory_order __m) noexcept
+ { __atomic_store(__ptr, std::__addressof(__t), int(__m)); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ load(_Tp* __ptr, memory_order __m) noexcept
+ {
+ alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
+ _Tp* __dest = reinterpret_cast<_Tp*>(__buf);
+ __atomic_load(__ptr, __dest, int(__m));
+ return *__dest;
+ }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ exchange(_Tp* __ptr, _Val<_Tp> __desired, memory_order __m) noexcept
+ {
+ alignas(_Tp) unsigned char __buf[sizeof(_Tp)];
+ _Tp* __dest = reinterpret_cast<_Tp*>(__buf);
+ __atomic_exchange(__ptr, std::__addressof(__desired), __dest, int(__m));
+ return *__dest;
+ }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE bool
+ compare_exchange_weak(_Tp* __ptr, _Val<_Tp>& __expected,
+ _Val<_Tp> __desired, memory_order __success,
+ memory_order __failure) noexcept
+ {
+ return __atomic_compare_exchange(__ptr, std::__addressof(__expected),
+ std::__addressof(__desired), true,
+ int(__success), int(__failure));
+ }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE bool
+ compare_exchange_strong(_Tp* __ptr, _Val<_Tp>& __expected,
+ _Val<_Tp> __desired, memory_order __success,
+ memory_order __failure) noexcept
+ {
+ return __atomic_compare_exchange(__ptr, std::__addressof(__expected),
+ std::__addressof(__desired), false,
+ int(__success), int(__failure));
+ }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ fetch_add(_Tp* __ptr, _Diff<_Tp> __i, memory_order __m) noexcept
+ { return __atomic_fetch_add(__ptr, __i, int(__m)); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ fetch_sub(_Tp* __ptr, _Diff<_Tp> __i, memory_order __m) noexcept
+ { return __atomic_fetch_sub(__ptr, __i, int(__m)); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ fetch_and(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept
+ { return __atomic_fetch_and(__ptr, __i, int(__m)); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ fetch_or(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept
+ { return __atomic_fetch_or(__ptr, __i, int(__m)); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ fetch_xor(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept
+ { return __atomic_fetch_xor(__ptr, __i, int(__m)); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ __add_fetch(_Tp* __ptr, _Diff<_Tp> __i) noexcept
+ { return __atomic_add_fetch(__ptr, __i, __ATOMIC_SEQ_CST); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ __sub_fetch(_Tp* __ptr, _Diff<_Tp> __i) noexcept
+ { return __atomic_sub_fetch(__ptr, __i, __ATOMIC_SEQ_CST); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ __and_fetch(_Tp* __ptr, _Val<_Tp> __i) noexcept
+ { return __atomic_and_fetch(__ptr, __i, __ATOMIC_SEQ_CST); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ __or_fetch(_Tp* __ptr, _Val<_Tp> __i) noexcept
+ { return __atomic_or_fetch(__ptr, __i, __ATOMIC_SEQ_CST); }
+
+ template<typename _Tp>
+ _GLIBCXX_ALWAYS_INLINE _Tp
+ __xor_fetch(_Tp* __ptr, _Val<_Tp> __i) noexcept
+ { return __atomic_xor_fetch(__ptr, __i, __ATOMIC_SEQ_CST); }
+
+ template<typename _Tp>
+ _Tp
+ __fetch_add_flt(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept
+ {
+ _Val<_Tp> __oldval = load(__ptr, memory_order_relaxed);
+ _Val<_Tp> __newval = __oldval + __i;
+ while (!compare_exchange_weak(__ptr, __oldval, __newval, __m,
+ memory_order_relaxed))
+ __newval = __oldval + __i;
+ return __oldval;
+ }
+
+ template<typename _Tp>
+ _Tp
+ __fetch_sub_flt(_Tp* __ptr, _Val<_Tp> __i, memory_order __m) noexcept
+ {
+ _Val<_Tp> __oldval = load(__ptr, memory_order_relaxed);
+ _Val<_Tp> __newval = __oldval - __i;
+ while (!compare_exchange_weak(__ptr, __oldval, __newval, __m,
+ memory_order_relaxed))
+ __newval = __oldval - __i;
+ return __oldval;
+ }
+
+ template<typename _Tp>
+ _Tp
+ __add_fetch_flt(_Tp* __ptr, _Val<_Tp> __i) noexcept
+ {
+ _Val<_Tp> __oldval = load(__ptr, memory_order_relaxed);
+ _Val<_Tp> __newval = __oldval + __i;
+ while (!compare_exchange_weak(__ptr, __oldval, __newval,
+ memory_order_seq_cst,
+ memory_order_relaxed))
+ __newval = __oldval + __i;
+ return __newval;
+ }
+
+ template<typename _Tp>
+ _Tp
+ __sub_fetch_flt(_Tp* __ptr, _Val<_Tp> __i) noexcept
+ {
+ _Val<_Tp> __oldval = load(__ptr, memory_order_relaxed);
+ _Val<_Tp> __newval = __oldval - __i;
+ while (!compare_exchange_weak(__ptr, __oldval, __newval,
+ memory_order_seq_cst,
+ memory_order_relaxed))
+ __newval = __oldval - __i;
+ return __newval;
+ }
+ } // namespace __atomic_impl
+
+ // base class for atomic<floating-point-type>
+ template<typename _Fp>
+ struct __atomic_float
+ {
+ static_assert(is_floating_point_v<_Fp>);
+
+ static constexpr size_t _S_alignment = __alignof__(_Fp);
+
+ public:
+ using value_type = _Fp;
+ using difference_type = value_type;
+
+ static constexpr bool is_always_lock_free
+ = __atomic_always_lock_free(sizeof(_Fp), 0);
+
+ __atomic_float() = default;
+
+ constexpr
+ __atomic_float(_Fp __t) : _M_fp(__t)
+ { }
+
+ __atomic_float(const __atomic_float&) = delete;
+ __atomic_float& operator=(const __atomic_float&) = delete;
+ __atomic_float& operator=(const __atomic_float&) volatile = delete;
+
+ _Fp
+ operator=(_Fp __t) volatile noexcept
+ {
+ this->store(__t);
+ return __t;
+ }
+
+ _Fp
+ operator=(_Fp __t) noexcept
+ {
+ this->store(__t);
+ return __t;
+ }
+
+ bool
+ is_lock_free() const volatile noexcept
+ { return __atomic_impl::is_lock_free<sizeof(_Fp), _S_alignment>(); }
+
+ bool
+ is_lock_free() const noexcept
+ { return __atomic_impl::is_lock_free<sizeof(_Fp), _S_alignment>(); }
+
+ void
+ store(_Fp __t, memory_order __m = memory_order_seq_cst) volatile noexcept
+ { __atomic_impl::store(&_M_fp, __t, __m); }
+
+ void
+ store(_Fp __t, memory_order __m = memory_order_seq_cst) noexcept
+ { __atomic_impl::store(&_M_fp, __t, __m); }
+
+ _Fp
+ load(memory_order __m = memory_order_seq_cst) const volatile noexcept
+ { return __atomic_impl::load(&_M_fp, __m); }
+
+ _Fp
+ load(memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::load(&_M_fp, __m); }
+
+ operator _Fp() const volatile noexcept { return this->load(); }
+ operator _Fp() const noexcept { return this->load(); }
+
+ _Fp
+ exchange(_Fp __desired,
+ memory_order __m = memory_order_seq_cst) volatile noexcept
+ { return __atomic_impl::exchange(&_M_fp, __desired, __m); }
+
+ _Fp
+ exchange(_Fp __desired,
+ memory_order __m = memory_order_seq_cst) noexcept
+ { return __atomic_impl::exchange(&_M_fp, __desired, __m); }
+
+ bool
+ compare_exchange_weak(_Fp& __expected, _Fp __desired,
+ memory_order __success,
+ memory_order __failure) noexcept
+ {
+ return __atomic_impl::compare_exchange_weak(&_M_fp,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_weak(_Fp& __expected, _Fp __desired,
+ memory_order __success,
+ memory_order __failure) volatile noexcept
+ {
+ return __atomic_impl::compare_exchange_weak(&_M_fp,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_strong(_Fp& __expected, _Fp __desired,
+ memory_order __success,
+ memory_order __failure) noexcept
+ {
+ return __atomic_impl::compare_exchange_strong(&_M_fp,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_strong(_Fp& __expected, _Fp __desired,
+ memory_order __success,
+ memory_order __failure) volatile noexcept
+ {
+ return __atomic_impl::compare_exchange_strong(&_M_fp,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_weak(_Fp& __expected, _Fp __desired,
+ memory_order __order = memory_order_seq_cst)
+ noexcept
+ {
+ return compare_exchange_weak(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ bool
+ compare_exchange_weak(_Fp& __expected, _Fp __desired,
+ memory_order __order = memory_order_seq_cst)
+ volatile noexcept
+ {
+ return compare_exchange_weak(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ bool
+ compare_exchange_strong(_Fp& __expected, _Fp __desired,
+ memory_order __order = memory_order_seq_cst)
+ noexcept
+ {
+ return compare_exchange_strong(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ bool
+ compare_exchange_strong(_Fp& __expected, _Fp __desired,
+ memory_order __order = memory_order_seq_cst)
+ volatile noexcept
+ {
+ return compare_exchange_strong(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ value_type
+ fetch_add(value_type __i,
+ memory_order __m = memory_order_seq_cst) noexcept
+ { return __atomic_impl::__fetch_add_flt(&_M_fp, __i, __m); }
+
+ value_type
+ fetch_add(value_type __i,
+ memory_order __m = memory_order_seq_cst) volatile noexcept
+ { return __atomic_impl::__fetch_add_flt(&_M_fp, __i, __m); }
+
+ value_type
+ fetch_sub(value_type __i,
+ memory_order __m = memory_order_seq_cst) noexcept
+ { return __atomic_impl::__fetch_sub_flt(&_M_fp, __i, __m); }
+
+ value_type
+ fetch_sub(value_type __i,
+ memory_order __m = memory_order_seq_cst) volatile noexcept
+ { return __atomic_impl::__fetch_sub_flt(&_M_fp, __i, __m); }
+
+ value_type
+ operator+=(value_type __i) noexcept
+ { return __atomic_impl::__add_fetch_flt(&_M_fp, __i); }
+
+ value_type
+ operator+=(value_type __i) volatile noexcept
+ { return __atomic_impl::__add_fetch_flt(&_M_fp, __i); }
+
+ value_type
+ operator-=(value_type __i) noexcept
+ { return __atomic_impl::__sub_fetch_flt(&_M_fp, __i); }
+
+ value_type
+ operator-=(value_type __i) volatile noexcept
+ { return __atomic_impl::__sub_fetch_flt(&_M_fp, __i); }
+
+ private:
+ alignas(_S_alignment) _Fp _M_fp;
+ };
+
+ template<typename _Tp,
+ bool = is_integral_v<_Tp>, bool = is_floating_point_v<_Tp>>
+ struct __atomic_ref;
+
+ // base class for non-integral, non-floating-point, non-pointer types
+ template<typename _Tp>
+ struct __atomic_ref<_Tp, false, false>
+ {
+ static_assert(is_trivially_copyable_v<_Tp>);
+
+ // 1/2/4/8/16-byte types must be aligned to at least their size.
+ static constexpr int _S_min_alignment
+ = (sizeof(_Tp) & (sizeof(_Tp) - 1)) || sizeof(_Tp) > 16
+ ? 0 : sizeof(_Tp);
+
+ public:
+ using value_type = _Tp;
+
+ static constexpr bool is_always_lock_free
+ = __atomic_always_lock_free(sizeof(_Tp), 0);
+
+ static constexpr size_t required_alignment
+ = _S_min_alignment > alignof(_Tp) ? _S_min_alignment : alignof(_Tp);
+
+ __atomic_ref& operator=(const __atomic_ref&) = delete;
+
+ explicit
+ __atomic_ref(_Tp& __t) : _M_ptr(std::__addressof(__t))
+ { __glibcxx_assert(((uintptr_t)_M_ptr % required_alignment) == 0); }
+
+ __atomic_ref(const __atomic_ref&) noexcept = default;
+
+ _Tp
+ operator=(_Tp __t) const noexcept
+ {
+ this->store(__t);
+ return __t;
+ }
+
+ operator _Tp() const noexcept { return this->load(); }
+
+ bool
+ is_lock_free() const noexcept
+ { return __atomic_impl::is_lock_free<sizeof(_Tp), required_alignment>(); }
+
+ void
+ store(_Tp __t, memory_order __m = memory_order_seq_cst) const noexcept
+ { __atomic_impl::store(_M_ptr, __t, __m); }
+
+ _Tp
+ load(memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::load(_M_ptr, __m); }
+
+ _Tp
+ exchange(_Tp __desired, memory_order __m = memory_order_seq_cst)
+ const noexcept
+ { return __atomic_impl::exchange(_M_ptr, __desired, __m); }
+
+ bool
+ compare_exchange_weak(_Tp& __expected, _Tp __desired,
+ memory_order __success,
+ memory_order __failure) const noexcept
+ {
+ return __atomic_impl::compare_exchange_weak(_M_ptr,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_strong(_Tp& __expected, _Tp __desired,
+ memory_order __success,
+ memory_order __failure) const noexcept
+ {
+ return __atomic_impl::compare_exchange_strong(_M_ptr,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_weak(_Tp& __expected, _Tp __desired,
+ memory_order __order = memory_order_seq_cst)
+ const noexcept
+ {
+ return compare_exchange_weak(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ bool
+ compare_exchange_strong(_Tp& __expected, _Tp __desired,
+ memory_order __order = memory_order_seq_cst)
+ const noexcept
+ {
+ return compare_exchange_strong(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ private:
+ _Tp* _M_ptr;
+ };
+
+ // base class for atomic_ref<integral-type>
+ template<typename _Tp>
+ struct __atomic_ref<_Tp, true, false>
+ {
+ static_assert(is_integral_v<_Tp>);
+
+ public:
+ using value_type = _Tp;
+ using difference_type = value_type;
+
+ static constexpr bool is_always_lock_free
+ = __atomic_always_lock_free(sizeof(_Tp), 0);
+
+ static constexpr size_t required_alignment
+ = sizeof(_Tp) > alignof(_Tp) ? sizeof(_Tp) : alignof(_Tp);
+
+ __atomic_ref() = delete;
+ __atomic_ref& operator=(const __atomic_ref&) = delete;
+
+ explicit
+ __atomic_ref(_Tp& __t) : _M_ptr(&__t)
+ { __glibcxx_assert(((uintptr_t)_M_ptr % required_alignment) == 0); }
+
+ __atomic_ref(const __atomic_ref&) noexcept = default;
+
+ _Tp
+ operator=(_Tp __t) const noexcept
+ {
+ this->store(__t);
+ return __t;
+ }
+
+ operator _Tp() const noexcept { return this->load(); }
+
+ bool
+ is_lock_free() const noexcept
+ {
+ return __atomic_impl::is_lock_free<sizeof(_Tp), required_alignment>();
+ }
+
+ void
+ store(_Tp __t, memory_order __m = memory_order_seq_cst) const noexcept
+ { __atomic_impl::store(_M_ptr, __t, __m); }
+
+ _Tp
+ load(memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::load(_M_ptr, __m); }
+
+ _Tp
+ exchange(_Tp __desired,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::exchange(_M_ptr, __desired, __m); }
+
+ bool
+ compare_exchange_weak(_Tp& __expected, _Tp __desired,
+ memory_order __success,
+ memory_order __failure) const noexcept
+ {
+ return __atomic_impl::compare_exchange_weak(_M_ptr,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_strong(_Tp& __expected, _Tp __desired,
+ memory_order __success,
+ memory_order __failure) const noexcept
+ {
+ return __atomic_impl::compare_exchange_strong(_M_ptr,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_weak(_Tp& __expected, _Tp __desired,
+ memory_order __order = memory_order_seq_cst)
+ const noexcept
+ {
+ return compare_exchange_weak(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ bool
+ compare_exchange_strong(_Tp& __expected, _Tp __desired,
+ memory_order __order = memory_order_seq_cst)
+ const noexcept
+ {
+ return compare_exchange_strong(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ value_type
+ fetch_add(value_type __i,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::fetch_add(_M_ptr, __i, __m); }
+
+ value_type
+ fetch_sub(value_type __i,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::fetch_sub(_M_ptr, __i, __m); }
+
+ value_type
+ fetch_and(value_type __i,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::fetch_and(_M_ptr, __i, __m); }
+
+ value_type
+ fetch_or(value_type __i,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::fetch_or(_M_ptr, __i, __m); }
+
+ value_type
+ fetch_xor(value_type __i,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::fetch_xor(_M_ptr, __i, __m); }
+
+ _GLIBCXX_ALWAYS_INLINE value_type
+ operator++(int) const noexcept
+ { return fetch_add(1); }
+
+ _GLIBCXX_ALWAYS_INLINE value_type
+ operator--(int) const noexcept
+ { return fetch_sub(1); }
+
+ value_type
+ operator++() const noexcept
+ { return __atomic_impl::__add_fetch(_M_ptr, value_type(1)); }
+
+ value_type
+ operator--() const noexcept
+ { return __atomic_impl::__sub_fetch(_M_ptr, value_type(1)); }
+
+ value_type
+ operator+=(value_type __i) const noexcept
+ { return __atomic_impl::__add_fetch(_M_ptr, __i); }
+
+ value_type
+ operator-=(value_type __i) const noexcept
+ { return __atomic_impl::__sub_fetch(_M_ptr, __i); }
+
+ value_type
+ operator&=(value_type __i) const noexcept
+ { return __atomic_impl::__and_fetch(_M_ptr, __i); }
+
+ value_type
+ operator|=(value_type __i) const noexcept
+ { return __atomic_impl::__or_fetch(_M_ptr, __i); }
+
+ value_type
+ operator^=(value_type __i) const noexcept
+ { return __atomic_impl::__xor_fetch(_M_ptr, __i); }
+
+ private:
+ _Tp* _M_ptr;
+ };
+
+ // base class for atomic_ref<floating-point-type>
+ template<typename _Fp>
+ struct __atomic_ref<_Fp, false, true>
+ {
+ static_assert(is_floating_point_v<_Fp>);
+
+ public:
+ using value_type = _Fp;
+ using difference_type = value_type;
+
+ static constexpr bool is_always_lock_free
+ = __atomic_always_lock_free(sizeof(_Fp), 0);
+
+ static constexpr size_t required_alignment = __alignof__(_Fp);
+
+ __atomic_ref() = delete;
+ __atomic_ref& operator=(const __atomic_ref&) = delete;
+
+ explicit
+ __atomic_ref(_Fp& __t) : _M_ptr(&__t)
+ { __glibcxx_assert(((uintptr_t)_M_ptr % required_alignment) == 0); }
+
+ __atomic_ref(const __atomic_ref&) noexcept = default;
+
+ _Fp
+ operator=(_Fp __t) const noexcept
+ {
+ this->store(__t);
+ return __t;
+ }
+
+ operator _Fp() const noexcept { return this->load(); }
+
+ bool
+ is_lock_free() const noexcept
+ {
+ return __atomic_impl::is_lock_free<sizeof(_Fp), required_alignment>();
+ }
+
+ void
+ store(_Fp __t, memory_order __m = memory_order_seq_cst) const noexcept
+ { __atomic_impl::store(_M_ptr, __t, __m); }
+
+ _Fp
+ load(memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::load(_M_ptr, __m); }
+
+ _Fp
+ exchange(_Fp __desired,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::exchange(_M_ptr, __desired, __m); }
+
+ bool
+ compare_exchange_weak(_Fp& __expected, _Fp __desired,
+ memory_order __success,
+ memory_order __failure) const noexcept
+ {
+ return __atomic_impl::compare_exchange_weak(_M_ptr,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_strong(_Fp& __expected, _Fp __desired,
+ memory_order __success,
+ memory_order __failure) const noexcept
+ {
+ return __atomic_impl::compare_exchange_strong(_M_ptr,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_weak(_Fp& __expected, _Fp __desired,
+ memory_order __order = memory_order_seq_cst)
+ const noexcept
+ {
+ return compare_exchange_weak(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ bool
+ compare_exchange_strong(_Fp& __expected, _Fp __desired,
+ memory_order __order = memory_order_seq_cst)
+ const noexcept
+ {
+ return compare_exchange_strong(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ value_type
+ fetch_add(value_type __i,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::__fetch_add_flt(_M_ptr, __i, __m); }
+
+ value_type
+ fetch_sub(value_type __i,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::__fetch_sub_flt(_M_ptr, __i, __m); }
+
+ value_type
+ operator+=(value_type __i) const noexcept
+ { return __atomic_impl::__add_fetch_flt(_M_ptr, __i); }
+
+ value_type
+ operator-=(value_type __i) const noexcept
+ { return __atomic_impl::__sub_fetch_flt(_M_ptr, __i); }
+
+ private:
+ _Fp* _M_ptr;
+ };
+
+ // base class for atomic_ref<pointer-type>
+ template<typename _Tp>
+ struct __atomic_ref<_Tp*, false, false>
+ {
+ public:
+ using value_type = _Tp*;
+ using difference_type = ptrdiff_t;
+
+ static constexpr bool is_always_lock_free = ATOMIC_POINTER_LOCK_FREE == 2;
+
+ static constexpr size_t required_alignment = __alignof__(_Tp*);
+
+ __atomic_ref() = delete;
+ __atomic_ref& operator=(const __atomic_ref&) = delete;
+
+ explicit
+ __atomic_ref(_Tp*& __t) : _M_ptr(std::__addressof(__t))
+ { __glibcxx_assert(((uintptr_t)_M_ptr % required_alignment) == 0); }
+
+ __atomic_ref(const __atomic_ref&) noexcept = default;
+
+ _Tp*
+ operator=(_Tp* __t) const noexcept
+ {
+ this->store(__t);
+ return __t;
+ }
+
+ operator _Tp*() const noexcept { return this->load(); }
+
+ bool
+ is_lock_free() const noexcept
+ {
+ return __atomic_impl::is_lock_free<sizeof(_Tp*), required_alignment>();
+ }
+
+ void
+ store(_Tp* __t, memory_order __m = memory_order_seq_cst) const noexcept
+ { __atomic_impl::store(_M_ptr, __t, __m); }
+
+ _Tp*
+ load(memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::load(_M_ptr, __m); }
+
+ _Tp*
+ exchange(_Tp* __desired,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::exchange(_M_ptr, __desired, __m); }
+
+ bool
+ compare_exchange_weak(_Tp*& __expected, _Tp* __desired,
+ memory_order __success,
+ memory_order __failure) const noexcept
+ {
+ return __atomic_impl::compare_exchange_weak(_M_ptr,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_strong(_Tp*& __expected, _Tp* __desired,
+ memory_order __success,
+ memory_order __failure) const noexcept
+ {
+ return __atomic_impl::compare_exchange_strong(_M_ptr,
+ __expected, __desired,
+ __success, __failure);
+ }
+
+ bool
+ compare_exchange_weak(_Tp*& __expected, _Tp* __desired,
+ memory_order __order = memory_order_seq_cst)
+ const noexcept
+ {
+ return compare_exchange_weak(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ bool
+ compare_exchange_strong(_Tp*& __expected, _Tp* __desired,
+ memory_order __order = memory_order_seq_cst)
+ const noexcept
+ {
+ return compare_exchange_strong(__expected, __desired, __order,
+ __cmpexch_failure_order(__order));
+ }
+
+ _GLIBCXX_ALWAYS_INLINE value_type
+ fetch_add(difference_type __d,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::fetch_add(_M_ptr, _S_type_size(__d), __m); }
+
+ _GLIBCXX_ALWAYS_INLINE value_type
+ fetch_sub(difference_type __d,
+ memory_order __m = memory_order_seq_cst) const noexcept
+ { return __atomic_impl::fetch_sub(_M_ptr, _S_type_size(__d), __m); }
+
+ value_type
+ operator++(int) const noexcept
+ { return fetch_add(1); }
+
+ value_type
+ operator--(int) const noexcept
+ { return fetch_sub(1); }
+
+ value_type
+ operator++() const noexcept
+ {
+ return __atomic_impl::__add_fetch(_M_ptr, _S_type_size(1));
+ }
+
+ value_type
+ operator--() const noexcept
+ {
+ return __atomic_impl::__sub_fetch(_M_ptr, _S_type_size(1));
+ }
+
+ value_type
+ operator+=(difference_type __d) const noexcept
+ {
+ return __atomic_impl::__add_fetch(_M_ptr, _S_type_size(__d));
+ }
+
+ value_type
+ operator-=(difference_type __d) const noexcept
+ {
+ return __atomic_impl::__sub_fetch(_M_ptr, _S_type_size(__d));
+ }
+
+ private:
+ static constexpr ptrdiff_t
+ _S_type_size(ptrdiff_t __d) noexcept
+ {
+ static_assert(is_object_v<_Tp>);
+ return __d * sizeof(_Tp);
+ }
+
+ _Tp** _M_ptr;
+ };
+
+#endif // C++2a
+
// @} group atomics
_GLIBCXX_END_NAMESPACE_VERSION
#else
#include <bits/atomic_base.h>
-#include <bits/move.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
__atomic_val_t<_ITp> __i) noexcept
{ return atomic_fetch_xor_explicit(__a, __i, memory_order_seq_cst); }
+#if __cplusplus > 201703L
+ template<>
+ struct atomic<float> : __atomic_float<float>
+ {
+ atomic() noexcept = default;
+
+ constexpr
+ atomic(float __fp) noexcept : __atomic_float<float>(__fp)
+ { }
+
+ atomic& operator=(const atomic&) volatile = delete;
+ atomic& operator=(const atomic&) = delete;
+
+ using __atomic_float<float>::operator=;
+ };
+
+ template<>
+ struct atomic<double> : __atomic_float<double>
+ {
+ atomic() noexcept = default;
+
+ constexpr
+ atomic(double __fp) noexcept : __atomic_float<double>(__fp)
+ { }
+
+ atomic& operator=(const atomic&) volatile = delete;
+ atomic& operator=(const atomic&) = delete;
+
+ using __atomic_float<double>::operator=;
+ };
+
+ template<>
+ struct atomic<long double> : __atomic_float<long double>
+ {
+ atomic() noexcept = default;
+
+ constexpr
+ atomic(long double __fp) noexcept : __atomic_float<long double>(__fp)
+ { }
+
+ atomic& operator=(const atomic&) volatile = delete;
+ atomic& operator=(const atomic&) = delete;
+
+ using __atomic_float<long double>::operator=;
+ };
+
+#define __cpp_lib_atomic_ref 201806L
+
+ /// Class template to provide atomic operations on a non-atomic variable.
+ template<typename _Tp>
+ struct atomic_ref : __atomic_ref<_Tp>
+ {
+ explicit
+ atomic_ref(_Tp& __t) noexcept : __atomic_ref<_Tp>(__t)
+ { }
+
+ atomic_ref& operator=(const atomic_ref&) = delete;
+
+ atomic_ref(const atomic_ref&) = default;
+
+ using __atomic_ref<_Tp>::operator=;
+ };
+
+#endif // C++2a
+
// @} group atomics
_GLIBCXX_END_NAMESPACE_VERSION
#if __cplusplus > 201703L
// c++2a
+#define __cpp_lib_atomic_ref 201806L
#define __cpp_lib_bind_front 201902L
#define __cpp_lib_bounded_array_traits 201902L
#if __cpp_impl_destroying_delete
char stuff[0]; // GNU extension, type has zero size
};
-std::atomic<X> a; // { dg-error "not supported" "" { target *-*-* } 194 }
+std::atomic<X> a; // { dg-error "zero-sized types" "" { target *-*-* } 0 }
--- /dev/null
+// Copyright (C) 2019 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+
+#include <atomic>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ const auto mo = std::memory_order_relaxed;
+ bool ok;
+ float expected;
+
+ if constexpr (std::atomic<float>::is_always_lock_free)
+ {
+ std::atomic<float> a0;
+ std::atomic<float> a1(1.0f);
+ ok = a0.is_lock_free();
+ a0 = a1.load();
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( a0.load(mo) == a0.load() );
+ a0.store(0.5f);
+ a1.store(0.5f, mo);
+ VERIFY( a0.load() == a1.load() );
+ auto f0 = a0.exchange(12.5f);
+ auto f1 = a1.exchange(12.5f, mo);
+ VERIFY( a0 == 12.5f );
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( f0 == 0.5f );
+ VERIFY( f0 == f1 );
+
+ expected = 12.5f;
+ while (!a0.compare_exchange_weak(expected, 1.6f, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == 1.6f );
+ VERIFY( expected == 12.5f );
+ expected = 1.5f;
+ ok = a1.compare_exchange_weak(expected, 1.6f, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5f && expected == 12.5f );
+ VERIFY( expected == 12.5f );
+ expected = 1.6f;
+ ok = a0.compare_exchange_strong(expected, 3.2f, mo, mo);
+ VERIFY( ok && a0.load() == 3.2f );
+ VERIFY( expected == 1.6f );
+ expected = 1.5f;
+ ok = a1.compare_exchange_strong(expected, 3.2f, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5f && expected == 12.5f );
+
+ expected = 3.2f;
+ while (!a0.compare_exchange_weak(expected, .64f))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == .64f );
+ expected = 12.5f;
+ while (!a1.compare_exchange_weak(expected, 1.6f, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a1.load() == 1.6f );
+ expected = 0.5f;
+ ok = a0.compare_exchange_weak(expected, 3.2f);
+ VERIFY( !ok && a0.load() == .64f && expected == .64f );
+ expected = 0.5f;
+ ok = a1.compare_exchange_weak(expected, 3.2f, mo);
+ VERIFY( !ok && a1.load() == 1.6f && expected == 1.6f );
+
+ expected = .64f;
+ ok = a0.compare_exchange_strong(expected, 12.8f);
+ VERIFY( ok && a0.load() == 12.8f );
+ expected = 1.6f;
+ ok = a1.compare_exchange_strong(expected, 2.56f, mo);
+ VERIFY( ok && a1.load() == 2.56f );
+ expected = 0.5f;
+ ok = a0.compare_exchange_strong(expected, 3.2f);
+ VERIFY( !ok && a0.load() == 12.8f && expected == 12.8f );
+ expected = 0.5f;
+ ok = a1.compare_exchange_strong(expected, 3.2f, mo);
+ VERIFY( !ok && a1.load() == 2.56f && expected == 2.56f );
+
+ f0 = a0.fetch_add(1.2f);
+ VERIFY( f0 == 12.8f );
+ VERIFY( a0 == 14.0f );
+ f1 = a1.fetch_add(2.4f, mo);
+ VERIFY( f1 == 2.56f );
+ VERIFY( a1 == 4.96f );
+
+ f0 = a0.fetch_sub(1.2f);
+ VERIFY( f0 == 14.0f );
+ VERIFY( a0 == 12.8f );
+ f1 = a1.fetch_sub(3.5f, mo);
+ VERIFY( f1 == 4.96f );
+ VERIFY( a1 == 1.46f );
+
+ f0 = a0 += 1.2f;
+ VERIFY( f0 == 14.0f );
+ VERIFY( a0 == 14.0f );
+
+ f0 = a0 -= 0.8f;
+ VERIFY( f0 == 13.2f );
+ VERIFY( a0 == 13.2f );
+ }
+
+ // Repeat for volatile std::atomic<float>
+ if constexpr (std::atomic<float>::is_always_lock_free)
+ {
+ volatile std::atomic<float> a0;
+ volatile std::atomic<float> a1(1.0f);
+ ok = a0.is_lock_free();
+ a0 = a1.load();
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( a0.load(mo) == a0.load() );
+ a0.store(0.5f);
+ a1.store(0.5f, mo);
+ VERIFY( a0.load() == a1.load() );
+ auto f0 = a0.exchange(12.5f);
+ auto f1 = a1.exchange(12.5f, mo);
+ VERIFY( a0 == 12.5f );
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( f0 == 0.5f );
+ VERIFY( f0 == f1 );
+
+ expected = 12.5f;
+ while (!a0.compare_exchange_weak(expected, 1.6f, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == 1.6f );
+ VERIFY( expected == 12.5f );
+ expected = 1.5f;
+ ok = a1.compare_exchange_weak(expected, 1.6f, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5f && expected == 12.5f );
+ VERIFY( expected == 12.5f );
+ expected = 1.6f;
+ ok = a0.compare_exchange_strong(expected, 3.2f, mo, mo);
+ VERIFY( ok && a0.load() == 3.2f );
+ VERIFY( expected == 1.6f );
+ expected = 1.5f;
+ ok = a1.compare_exchange_strong(expected, 3.2f, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5f && expected == 12.5f );
+
+ expected = 3.2f;
+ while (!a0.compare_exchange_weak(expected, .64f))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == .64f );
+ expected = 12.5f;
+ while (!a1.compare_exchange_weak(expected, 1.6f, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a1.load() == 1.6f );
+ expected = 0.5f;
+ ok = a0.compare_exchange_weak(expected, 3.2f);
+ VERIFY( !ok && a0.load() == .64f && expected == .64f );
+ expected = 0.5f;
+ ok = a1.compare_exchange_weak(expected, 3.2f, mo);
+ VERIFY( !ok && a1.load() == 1.6f && expected == 1.6f );
+
+ expected = .64f;
+ ok = a0.compare_exchange_strong(expected, 12.8f);
+ VERIFY( ok && a0.load() == 12.8f );
+ expected = 1.6f;
+ ok = a1.compare_exchange_strong(expected, 2.56f, mo);
+ VERIFY( ok && a1.load() == 2.56f );
+ expected = 0.5f;
+ ok = a0.compare_exchange_strong(expected, 3.2f);
+ VERIFY( !ok && a0.load() == 12.8f && expected == 12.8f );
+ expected = 0.5f;
+ ok = a1.compare_exchange_strong(expected, 3.2f, mo);
+ VERIFY( !ok && a1.load() == 2.56f && expected == 2.56f );
+
+ f0 = a0.fetch_add(1.2f);
+ VERIFY( f0 == 12.8f );
+ VERIFY( a0 == 14.0f );
+ f1 = a1.fetch_add(2.4f, mo);
+ VERIFY( f1 == 2.56f );
+ VERIFY( a1 == 4.96f );
+
+ f0 = a0.fetch_sub(1.2f);
+ VERIFY( f0 == 14.0f );
+ VERIFY( a0 == 12.8f );
+ f1 = a1.fetch_sub(3.5f, mo);
+ VERIFY( f1 == 4.96f );
+ VERIFY( a1 == 1.46f );
+
+ f0 = a0 += 1.2f;
+ VERIFY( f0 == 14.0f );
+ VERIFY( a0 == 14.0f );
+
+ f0 = a0 -= 0.8f;
+ VERIFY( f0 == 13.2f );
+ VERIFY( a0 == 13.2f );
+ }
+}
+
+void
+test02()
+{
+ const auto mo = std::memory_order_relaxed;
+ bool ok;
+ double expected;
+
+ if constexpr (std::atomic<double>::is_always_lock_free)
+ {
+ std::atomic<double> a0;
+ std::atomic<double> a1(1.0);
+ ok = a0.is_lock_free();
+ a0 = a1.load();
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( a0.load(mo) == a0.load() );
+ a0.store(0.5);
+ a1.store(0.5, mo);
+ VERIFY( a0.load() == a1.load() );
+ auto f0 = a0.exchange(12.5);
+ auto f1 = a1.exchange(12.5, mo);
+ VERIFY( a0 == 12.5 );
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( f0 == 0.5 );
+ VERIFY( f0 == f1 );
+
+ expected = 12.5;
+ while (!a0.compare_exchange_weak(expected, 1.6, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == 1.6 );
+ VERIFY( expected == 12.5 );
+ expected = 1.5;
+ ok = a1.compare_exchange_weak(expected, 1.6, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5 && expected == 12.5 );
+ VERIFY( expected == 12.5 );
+ expected = 1.6;
+ ok = a0.compare_exchange_strong(expected, 3.2, mo, mo);
+ VERIFY( ok && a0.load() == 3.2 );
+ VERIFY( expected == 1.6 );
+ expected = 1.5;
+ ok = a1.compare_exchange_strong(expected, 3.2, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5 && expected == 12.5 );
+
+ expected = 3.2;
+ while (!a0.compare_exchange_weak(expected, .64))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == .64 );
+ expected = 12.5;
+ while (!a1.compare_exchange_weak(expected, 1.6, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a1.load() == 1.6 );
+ expected = 0.5;
+ ok = a0.compare_exchange_weak(expected, 3.2);
+ VERIFY( !ok && a0.load() == .64 && expected == .64 );
+ expected = 0.5;
+ ok = a1.compare_exchange_weak(expected, 3.2, mo);
+ VERIFY( !ok && a1.load() == 1.6 && expected == 1.6 );
+
+ expected = .64;
+ ok = a0.compare_exchange_strong(expected, 12.8);
+ VERIFY( ok && a0.load() == 12.8 );
+ expected = 1.6;
+ ok = a1.compare_exchange_strong(expected, 2.56, mo);
+ VERIFY( ok && a1.load() == 2.56 );
+ expected = 0.5;
+ ok = a0.compare_exchange_strong(expected, 3.2);
+ VERIFY( !ok && a0.load() == 12.8 && expected == 12.8 );
+ expected = 0.5;
+ ok = a1.compare_exchange_strong(expected, 3.2, mo);
+ VERIFY( !ok && a1.load() == 2.56 && expected == 2.56 );
+
+ f0 = a0.fetch_add(1.2);
+ VERIFY( f0 == 12.8 );
+ VERIFY( a0 == 14.0 );
+ f1 = a1.fetch_add(2.4, mo);
+ VERIFY( f1 == 2.56 );
+ VERIFY( a1 == 4.96 );
+
+ f0 = a0.fetch_sub(1.2);
+ VERIFY( f0 == 14.0 );
+ VERIFY( a0 == 12.8 );
+ f1 = a1.fetch_sub(3.5, mo);
+ VERIFY( f1 == 4.96 );
+ VERIFY( a1 == 1.46 );
+
+ f0 = a0 += 1.2;
+ VERIFY( f0 == 14.0 );
+ VERIFY( a0 == 14.0 );
+
+ f0 = a0 -= 0.8;
+ VERIFY( f0 == 13.2 );
+ VERIFY( a0 == 13.2 );
+ }
+
+ // Repeat for volatile std::atomic<double>
+ if constexpr (std::atomic<double>::is_always_lock_free)
+ {
+ volatile std::atomic<double> a0;
+ volatile std::atomic<double> a1(1.0);
+ ok = a0.is_lock_free();
+ a0 = a1.load();
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( a0.load(mo) == a0.load() );
+ a0.store(0.5);
+ a1.store(0.5, mo);
+ VERIFY( a0.load() == a1.load() );
+ auto f0 = a0.exchange(12.5);
+ auto f1 = a1.exchange(12.5, mo);
+ VERIFY( a0 == 12.5 );
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( f0 == 0.5 );
+ VERIFY( f0 == f1 );
+
+ expected = 12.5;
+ while (!a0.compare_exchange_weak(expected, 1.6, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == 1.6 );
+ VERIFY( expected == 12.5 );
+ expected = 1.5;
+ ok = a1.compare_exchange_weak(expected, 1.6, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5 && expected == 12.5 );
+ VERIFY( expected == 12.5 );
+ expected = 1.6;
+ ok = a0.compare_exchange_strong(expected, 3.2, mo, mo);
+ VERIFY( ok && a0.load() == 3.2 );
+ VERIFY( expected == 1.6 );
+ expected = 1.5;
+ ok = a1.compare_exchange_strong(expected, 3.2, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5 && expected == 12.5 );
+
+ expected = 3.2;
+ while (!a0.compare_exchange_weak(expected, .64))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == .64 );
+ expected = 12.5;
+ while (!a1.compare_exchange_weak(expected, 1.6, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a1.load() == 1.6 );
+ expected = 0.5;
+ ok = a0.compare_exchange_weak(expected, 3.2);
+ VERIFY( !ok && a0.load() == .64 && expected == .64 );
+ expected = 0.5;
+ ok = a1.compare_exchange_weak(expected, 3.2, mo);
+ VERIFY( !ok && a1.load() == 1.6 && expected == 1.6 );
+
+ expected = .64;
+ ok = a0.compare_exchange_strong(expected, 12.8);
+ VERIFY( ok && a0.load() == 12.8 );
+ expected = 1.6;
+ ok = a1.compare_exchange_strong(expected, 2.56, mo);
+ VERIFY( ok && a1.load() == 2.56 );
+ expected = 0.5;
+ ok = a0.compare_exchange_strong(expected, 3.2);
+ VERIFY( !ok && a0.load() == 12.8 && expected == 12.8 );
+ expected = 0.5;
+ ok = a1.compare_exchange_strong(expected, 3.2, mo);
+ VERIFY( !ok && a1.load() == 2.56 && expected == 2.56 );
+
+ f0 = a0.fetch_add(1.2);
+ VERIFY( f0 == 12.8 );
+ VERIFY( a0 == 14.0 );
+ f1 = a1.fetch_add(2.4, mo);
+ VERIFY( f1 == 2.56 );
+ VERIFY( a1 == 4.96 );
+
+ f0 = a0.fetch_sub(1.2);
+ VERIFY( f0 == 14.0 );
+ VERIFY( a0 == 12.8 );
+ f1 = a1.fetch_sub(3.5, mo);
+ VERIFY( f1 == 4.96 );
+ VERIFY( a1 == 1.46 );
+
+ f0 = a0 += 1.2;
+ VERIFY( f0 == 14.0 );
+ VERIFY( a0 == 14.0 );
+
+ f0 = a0 -= 0.8;
+ VERIFY( f0 == 13.2 );
+ VERIFY( a0 == 13.2 );
+ }
+}
+
+void
+test03()
+{
+ const auto mo = std::memory_order_relaxed;
+ bool ok;
+ long double expected;
+
+ if constexpr (std::atomic<long double>::is_always_lock_free)
+ {
+ std::atomic<long double> a0;
+ std::atomic<long double> a1(1.0l);
+ ok = a0.is_lock_free();
+ a0 = a1.load();
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( a0.load(mo) == a0.load() );
+ a0.store(0.5l);
+ a1.store(0.5l, mo);
+ VERIFY( a0.load() == a1.load() );
+ auto f0 = a0.exchange(12.5l);
+ auto f1 = a1.exchange(12.5l, mo);
+ VERIFY( a0 == 12.5l );
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( f0 == 0.5l );
+ VERIFY( f0 == f1 );
+
+ expected = 12.5l;
+ while (!a0.compare_exchange_weak(expected, 1.6l, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == 1.6l );
+ VERIFY( expected == 12.5l );
+ expected = 1.5l;
+ ok = a1.compare_exchange_weak(expected, 1.6l, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5l && expected == 12.5l );
+ VERIFY( expected == 12.5l );
+ expected = 1.6l;
+ ok = a0.compare_exchange_strong(expected, 3.2l, mo, mo);
+ VERIFY( ok && a0.load() == 3.2l );
+ VERIFY( expected == 1.6l );
+ expected = 1.5l;
+ ok = a1.compare_exchange_strong(expected, 3.2l, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5l && expected == 12.5l );
+
+ expected = 3.2l;
+ while (!a0.compare_exchange_weak(expected, .64l))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == .64l );
+ expected = 12.5l;
+ while (!a1.compare_exchange_weak(expected, 1.6l, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a1.load() == 1.6l );
+ expected = 0.5l;
+ ok = a0.compare_exchange_weak(expected, 3.2l);
+ VERIFY( !ok && a0.load() == .64l && expected == .64l );
+ expected = 0.5l;
+ ok = a1.compare_exchange_weak(expected, 3.2l, mo);
+ VERIFY( !ok && a1.load() == 1.6l && expected == 1.6l );
+
+ expected = .64l;
+ ok = a0.compare_exchange_strong(expected, 12.8l);
+ VERIFY( ok && a0.load() == 12.8l );
+ expected = 1.6l;
+ ok = a1.compare_exchange_strong(expected, 2.56l, mo);
+ VERIFY( ok && a1.load() == 2.56l );
+ expected = 0.5l;
+ ok = a0.compare_exchange_strong(expected, 3.2l);
+ VERIFY( !ok && a0.load() == 12.8l && expected == 12.8l );
+ expected = 0.5l;
+ ok = a1.compare_exchange_strong(expected, 3.2l, mo);
+ VERIFY( !ok && a1.load() == 2.56l && expected == 2.56l );
+
+ f0 = a0.fetch_add(1.2l);
+ VERIFY( f0 == 12.8l );
+ VERIFY( a0 == 14.0l );
+ f1 = a1.fetch_add(2.4l, mo);
+ VERIFY( f1 == 2.56l );
+ VERIFY( a1 == 4.96l );
+
+ f0 = a0.fetch_sub(1.2l);
+ VERIFY( f0 == 14.0l );
+ VERIFY( a0 == 12.8l );
+ f1 = a1.fetch_sub(3.5l, mo);
+ VERIFY( f1 == 4.96l );
+ VERIFY( a1 == 1.46l );
+
+ f0 = a0 += 1.2l;
+ VERIFY( f0 == 14.0l );
+ VERIFY( a0 == 14.0l );
+
+ f0 = a0 -= 0.8l;
+ VERIFY( f0 == 13.2l );
+ VERIFY( a0 == 13.2l );
+ }
+
+ // Repeat for volatile std::atomic<double>
+ if constexpr (std::atomic<long double>::is_always_lock_free)
+ {
+ volatile std::atomic<long double> a0;
+ volatile std::atomic<long double> a1(1.0l);
+ ok = a0.is_lock_free();
+ a0 = a1.load();
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( a0.load(mo) == a0.load() );
+ a0.store(0.5l);
+ a1.store(0.5l, mo);
+ VERIFY( a0.load() == a1.load() );
+ auto f0 = a0.exchange(12.5l);
+ auto f1 = a1.exchange(12.5l, mo);
+ VERIFY( a0 == 12.5l );
+ VERIFY( a0.load() == a1.load() );
+ VERIFY( f0 == 0.5l );
+ VERIFY( f0 == f1 );
+
+ expected = 12.5l;
+ while (!a0.compare_exchange_weak(expected, 1.6l, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == 1.6l );
+ VERIFY( expected == 12.5l );
+ expected = 1.5l;
+ ok = a1.compare_exchange_weak(expected, 1.6l, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5l && expected == 12.5l );
+ VERIFY( expected == 12.5l );
+ expected = 1.6l;
+ ok = a0.compare_exchange_strong(expected, 3.2l, mo, mo);
+ VERIFY( ok && a0.load() == 3.2l );
+ VERIFY( expected == 1.6l );
+ expected = 1.5l;
+ ok = a1.compare_exchange_strong(expected, 3.2l, mo, mo);
+ VERIFY( !ok && a1.load() == 12.5l && expected == 12.5l );
+
+ expected = 3.2l;
+ while (!a0.compare_exchange_weak(expected, .64l))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a0.load() == .64l );
+ expected = 12.5l;
+ while (!a1.compare_exchange_weak(expected, 1.6l, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a1.load() == 1.6l );
+ expected = 0.5l;
+ ok = a0.compare_exchange_weak(expected, 3.2l);
+ VERIFY( !ok && a0.load() == .64l && expected == .64l );
+ expected = 0.5l;
+ ok = a1.compare_exchange_weak(expected, 3.2l, mo);
+ VERIFY( !ok && a1.load() == 1.6l && expected == 1.6l );
+
+ expected = .64l;
+ ok = a0.compare_exchange_strong(expected, 12.8l);
+ VERIFY( ok && a0.load() == 12.8l );
+ expected = 1.6l;
+ ok = a1.compare_exchange_strong(expected, 2.56l, mo);
+ VERIFY( ok && a1.load() == 2.56l );
+ expected = 0.5l;
+ ok = a0.compare_exchange_strong(expected, 3.2l);
+ VERIFY( !ok && a0.load() == 12.8l && expected == 12.8l );
+ expected = 0.5l;
+ ok = a1.compare_exchange_strong(expected, 3.2l, mo);
+ VERIFY( !ok && a1.load() == 2.56l && expected == 2.56l );
+
+ f0 = a0.fetch_add(1.2l);
+ VERIFY( f0 == 12.8l );
+ VERIFY( a0 == 14.0l );
+ f1 = a1.fetch_add(2.4l, mo);
+ VERIFY( f1 == 2.56l );
+ VERIFY( a1 == 4.96l );
+
+ f0 = a0.fetch_sub(1.2l);
+ VERIFY( f0 == 14.0l );
+ VERIFY( a0 == 12.8l );
+ f1 = a1.fetch_sub(3.5l, mo);
+ VERIFY( f1 == 4.96l );
+ VERIFY( a1 == 1.46l );
+
+ f0 = a0 += 1.2l;
+ VERIFY( f0 == 14.0l );
+ VERIFY( a0 == 14.0l );
+
+ f0 = a0 -= 0.8l;
+ VERIFY( f0 == 13.2l );
+ VERIFY( a0 == 13.2l );
+ }
+}
+
+int
+main()
+{
+ test01();
+ test02();
+ test03();
+}
--- /dev/null
+// Copyright (C) 2019 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <atomic>
+
+void
+test01()
+{
+ using A = std::atomic<float>;
+ static_assert( std::is_standard_layout_v<A> );
+ static_assert( std::is_trivially_default_constructible_v<A> );
+ static_assert( std::is_trivially_destructible_v<A> );
+ static_assert( std::is_same_v<A::value_type, float> );
+ static_assert( std::is_same_v<A::difference_type, A::value_type> );
+ static_assert( !std::is_copy_constructible_v<A> );
+ static_assert( !std::is_move_constructible_v<A> );
+ static_assert( !std::is_copy_assignable_v<A> );
+ static_assert( !std::is_move_assignable_v<A> );
+ static_assert( !std::is_assignable_v<volatile A&, const A&> );
+}
+
+void
+test02()
+{
+ using A = std::atomic<double>;
+ static_assert( std::is_standard_layout_v<A> );
+ static_assert( std::is_trivially_default_constructible_v<A> );
+ static_assert( std::is_trivially_destructible_v<A> );
+ static_assert( std::is_same_v<A::value_type, double> );
+ static_assert( std::is_same_v<A::difference_type, A::value_type> );
+ static_assert( !std::is_copy_constructible_v<A> );
+ static_assert( !std::is_move_constructible_v<A> );
+ static_assert( !std::is_copy_assignable_v<A> );
+ static_assert( !std::is_move_assignable_v<A> );
+ static_assert( !std::is_assignable_v<volatile A&, const A&> );
+}
+
+void
+test03()
+{
+ using A = std::atomic<long double>;
+ static_assert( std::is_standard_layout_v<A> );
+ static_assert( std::is_trivially_default_constructible_v<A> );
+ static_assert( std::is_trivially_destructible_v<A> );
+ static_assert( std::is_same_v<A::value_type, long double> );
+ static_assert( std::is_same_v<A::difference_type, A::value_type> );
+ static_assert( !std::is_copy_constructible_v<A> );
+ static_assert( !std::is_move_constructible_v<A> );
+ static_assert( !std::is_copy_assignable_v<A> );
+ static_assert( !std::is_move_assignable_v<A> );
+ static_assert( !std::is_assignable_v<volatile A&, const A&> );
+}
--- /dev/null
+// Copyright (C) 2019 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <atomic>
+
+void
+test01()
+{
+ int i = 0;
+ std::atomic_ref a0(i);
+ static_assert(std::is_same_v<decltype(a0), std::atomic_ref<int>>);
+
+ float f = 1.0f;
+ std::atomic_ref a1(f);
+ static_assert(std::is_same_v<decltype(a1), std::atomic_ref<float>>);
+
+ int* p = &i;
+ std::atomic_ref a2(p);
+ static_assert(std::is_same_v<decltype(a2), std::atomic_ref<int*>>);
+
+ struct X { } x;
+ std::atomic_ref a3(x);
+ static_assert(std::is_same_v<decltype(a3), std::atomic_ref<X>>);
+}
--- /dev/null
+// Copyright (C) 2019 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+
+#include <atomic>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ float value;
+ if constexpr (std::atomic_ref<float>::is_always_lock_free)
+ {
+ const auto mo = std::memory_order_relaxed;
+ std::atomic_ref<float> a(value);
+ bool ok = a.is_lock_free();
+ if constexpr (std::atomic_ref<float>::is_always_lock_free)
+ VERIFY( ok );
+ a = 1.6f;
+ VERIFY( a.load() == 1.6f );
+ a.store(0.8f);
+ VERIFY( a.load(mo) == 0.8f );
+ a.store(3.2f, mo);
+ VERIFY( a.load() == 3.2f );
+ auto v = a.exchange(6.4f);
+ VERIFY( a == 6.4f );
+ VERIFY( v == 3.2f );
+ v = a.exchange(1.28f, mo);
+ VERIFY( a == 1.28f );
+ VERIFY( v == 6.4f );
+
+ auto expected = a.load();
+ while (!a.compare_exchange_weak(expected, 25.6f, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 25.6f );
+ VERIFY( expected == 1.28f );
+ expected = 3.2f;
+ ok = a.compare_exchange_weak(expected, 51.2f, mo, mo);
+ VERIFY( !ok && a.load() == 25.6f && expected == 25.6f );
+ ok = a.compare_exchange_strong(expected, 51.2f, mo, mo);
+ VERIFY( ok && a.load() == 51.2f && expected == 25.6f );
+ expected = 0.0f;
+ ok = a.compare_exchange_strong(expected, 1.28f, mo, mo);
+ VERIFY( !ok && a.load() == 51.2f && expected == 51.2f );
+
+ while (!a.compare_exchange_weak(expected, 25.6f))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 25.6f && expected == 51.2f );
+ expected = a.load();
+ while (!a.compare_exchange_weak(expected, 10.24f, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 10.24f && expected == 25.6f );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, 40.96f);
+ VERIFY( !ok && a.load() == 10.24f && expected == 10.24f );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, 40.96f, mo);
+ VERIFY( !ok && a.load() == 10.24f && expected == 10.24f );
+
+ ok = a.compare_exchange_strong(expected, 1.024f);
+ VERIFY( ok && a.load() == 1.024f && expected == 10.24f );
+ expected = a.load();
+ ok = a.compare_exchange_strong(expected, 204.8f, mo);
+ VERIFY( ok && a.load() == 204.8f && expected == 1.024f );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 6.4f);
+ VERIFY( !ok && a.load() == 204.8f && expected == 204.8f );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 6.4f, mo);
+ VERIFY( !ok && a.load() == 204.8f && expected == 204.8f );
+
+ v = a.fetch_add(3.2f);
+ VERIFY( v == 204.8f );
+ VERIFY( a == 208.0f );
+ v = a.fetch_add(-8.5f, mo);
+ VERIFY( v == 208.0f );
+ VERIFY( a == 199.5f );
+
+ v = a.fetch_sub(109.5f);
+ VERIFY( v == 199.5f );
+ VERIFY( a == 90.0f );
+ v = a.fetch_sub(2, mo);
+ VERIFY( v == 90.0f );
+ VERIFY( a == 88.0f );
+
+ v = a += 5.0f;
+ VERIFY( v == 93.0f );
+ VERIFY( a == 93.0f );
+
+ v = a -= 6.5f;
+ VERIFY( v == 86.5f );
+ VERIFY( a == 86.5f );
+ }
+
+ if constexpr (std::atomic_ref<float>::is_always_lock_free)
+ VERIFY( value == 86.5f );
+}
+
+void
+test02()
+{
+ double value;
+ if constexpr (std::atomic_ref<double>::is_always_lock_free)
+ {
+ const auto mo = std::memory_order_relaxed;
+ std::atomic_ref<double> a(value);
+ bool ok = a.is_lock_free();
+ if constexpr (std::atomic_ref<double>::is_always_lock_free)
+ VERIFY( ok );
+ a = 1.6;
+ VERIFY( a.load() == 1.6 );
+ a.store(0.8);
+ VERIFY( a.load(mo) == 0.8 );
+ a.store(3.2, mo);
+ VERIFY( a.load() == 3.2 );
+ auto v = a.exchange(6.4);
+ VERIFY( a == 6.4 );
+ VERIFY( v == 3.2 );
+ v = a.exchange(1.28, mo);
+ VERIFY( a == 1.28 );
+ VERIFY( v == 6.4 );
+
+ auto expected = a.load();
+ while (!a.compare_exchange_weak(expected, 25.6, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 25.6 );
+ VERIFY( expected == 1.28 );
+ expected = 3.2;
+ ok = a.compare_exchange_weak(expected, 51.2, mo, mo);
+ VERIFY( !ok && a.load() == 25.6 && expected == 25.6 );
+ ok = a.compare_exchange_strong(expected, 51.2, mo, mo);
+ VERIFY( ok && a.load() == 51.2 && expected == 25.6 );
+ expected = 0.0;
+ ok = a.compare_exchange_strong(expected, 1.28, mo, mo);
+ VERIFY( !ok && a.load() == 51.2 && expected == 51.2 );
+
+ while (!a.compare_exchange_weak(expected, 25.6))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 25.6 && expected == 51.2 );
+ expected = a.load();
+ while (!a.compare_exchange_weak(expected, 10.24, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 10.24 && expected == 25.6 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, 40.96);
+ VERIFY( !ok && a.load() == 10.24 && expected == 10.24 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, 40.96, mo);
+ VERIFY( !ok && a.load() == 10.24 && expected == 10.24 );
+
+ ok = a.compare_exchange_strong(expected, 1.024);
+ VERIFY( ok && a.load() == 1.024 && expected == 10.24 );
+ expected = a.load();
+ ok = a.compare_exchange_strong(expected, 204.8, mo);
+ VERIFY( ok && a.load() == 204.8 && expected == 1.024 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 6.4);
+ VERIFY( !ok && a.load() == 204.8 && expected == 204.8 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 6.4, mo);
+ VERIFY( !ok && a.load() == 204.8 && expected == 204.8 );
+
+ v = a.fetch_add(3.2);
+ VERIFY( v == 204.8 );
+ VERIFY( a == 208.0 );
+ v = a.fetch_add(-8.5, mo);
+ VERIFY( v == 208.0 );
+ VERIFY( a == 199.5 );
+
+ v = a.fetch_sub(109.5);
+ VERIFY( v == 199.5 );
+ VERIFY( a == 90.0 );
+ v = a.fetch_sub(2, mo);
+ VERIFY( v == 90.0 );
+ VERIFY( a == 88.0 );
+
+ v = a += 5.0;
+ VERIFY( v == 93.0 );
+ VERIFY( a == 93.0 );
+
+ v = a -= 6.5;
+ VERIFY( v == 86.5 );
+ VERIFY( a == 86.5 );
+ }
+
+ if constexpr (std::atomic_ref<double>::is_always_lock_free)
+ VERIFY( value == 86.5 );
+}
+
+void
+test03()
+{
+ long double value;
+ if constexpr (std::atomic_ref<long double>::is_always_lock_free)
+ {
+ const auto mo = std::memory_order_relaxed;
+ std::atomic_ref<long double> a(value);
+ bool ok = a.is_lock_free();
+ if constexpr (std::atomic_ref<long double>::is_always_lock_free)
+ VERIFY( ok );
+ a = 1.6l;
+ VERIFY( a.load() == 1.6l );
+ a.store(0.8l);
+ VERIFY( a.load(mo) == 0.8l );
+ a.store(3.2l, mo);
+ VERIFY( a.load() == 3.2l );
+ auto v = a.exchange(6.4l);
+ VERIFY( a == 6.4l );
+ VERIFY( v == 3.2l );
+ v = a.exchange(1.28l, mo);
+ VERIFY( a == 1.28l );
+ VERIFY( v == 6.4l );
+
+ auto expected = a.load();
+ while (!a.compare_exchange_weak(expected, 25.6l, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 25.6l );
+ VERIFY( expected == 1.28l );
+ expected = 3.2l;
+ ok = a.compare_exchange_weak(expected, 51.2l, mo, mo);
+ VERIFY( !ok && a.load() == 25.6l && expected == 25.6l );
+ ok = a.compare_exchange_strong(expected, 51.2l, mo, mo);
+ VERIFY( ok && a.load() == 51.2l && expected == 25.6l );
+ expected = 0.0l;
+ ok = a.compare_exchange_strong(expected, 1.28l, mo, mo);
+ VERIFY( !ok && a.load() == 51.2l && expected == 51.2l );
+
+ while (!a.compare_exchange_weak(expected, 25.6l))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 25.6l && expected == 51.2l );
+ expected = a.load();
+ while (!a.compare_exchange_weak(expected, 10.24l, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 10.24l && expected == 25.6l );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, 40.96l);
+ VERIFY( !ok && a.load() == 10.24l && expected == 10.24l );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, 40.96l, mo);
+ VERIFY( !ok && a.load() == 10.24l && expected == 10.24l );
+
+ ok = a.compare_exchange_strong(expected, 1.024l);
+ VERIFY( ok && a.load() == 1.024l && expected == 10.24l );
+ expected = a.load();
+ ok = a.compare_exchange_strong(expected, 204.8l, mo);
+ VERIFY( ok && a.load() == 204.8l && expected == 1.024l );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 6.4l);
+ VERIFY( !ok && a.load() == 204.8l && expected == 204.8l );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 6.4l, mo);
+ VERIFY( !ok && a.load() == 204.8l && expected == 204.8l );
+
+ v = a.fetch_add(3.2l);
+ VERIFY( v == 204.8l );
+ VERIFY( a == 208.0l );
+ v = a.fetch_add(-8.5l, mo);
+ VERIFY( v == 208.0l );
+ VERIFY( a == 199.5l );
+
+ v = a.fetch_sub(109.5l);
+ VERIFY( v == 199.5l );
+ VERIFY( a == 90.0l );
+ v = a.fetch_sub(2, mo);
+ VERIFY( v == 90.0l );
+ VERIFY( a == 88.0l );
+
+ v = a += 5.0l;
+ VERIFY( v == 93.0l );
+ VERIFY( a == 93.0l );
+
+ v = a -= 6.5l;
+ VERIFY( v == 86.5l );
+ VERIFY( a == 86.5l );
+ }
+
+ if constexpr (std::atomic_ref<long double>::is_always_lock_free)
+ VERIFY( value == 86.5l );
+}
+
+void
+test04()
+{
+ if constexpr (std::atomic_ref<float>::is_always_lock_free)
+ {
+ float i = 0;
+ float* ptr = 0;
+ std::atomic_ref<float*> a0(ptr);
+ std::atomic_ref<float*> a1(ptr);
+ std::atomic_ref<float*> a2(a0);
+ a0 = &i;
+ VERIFY( a1 == &i );
+ VERIFY( a2 == &i );
+ }
+}
+
+int
+main()
+{
+ test01();
+ test02();
+ test03();
+ test04();
+}
--- /dev/null
+// Copyright (C) 2019 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+// { dg-add-options libatomic }
+
+#include <atomic>
+#include <limits.h>
+#include <testsuite_hooks.h>
+
+struct X
+{
+ X() = default;
+ X(int i) : i(i) { }
+ bool operator==(int rhs) const { return i == rhs; }
+ int i;
+};
+
+void
+test01()
+{
+ X value;
+
+ {
+ const auto mo = std::memory_order_relaxed;
+ std::atomic_ref<X> a(value);
+ bool ok = a.is_lock_free();
+ if constexpr (std::atomic_ref<X>::is_always_lock_free)
+ VERIFY( ok );
+ a = X{};
+ VERIFY( a.load() == 0 );
+ VERIFY( a.load(mo) == 0 );
+ a.store(1);
+ VERIFY( a.load() == 1 );
+ auto v = a.exchange(2);
+ VERIFY( a.load() == 2 );
+ VERIFY( v == 1 );
+ v = a.exchange(3, mo);
+ VERIFY( a.load() == 3 );
+ VERIFY( v == 2 );
+
+ auto expected = a.load();
+ while (!a.compare_exchange_weak(expected, 4, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 4 );
+ VERIFY( expected == 3 );
+ expected = 1;
+ ok = a.compare_exchange_weak(expected, 5, mo, mo);
+ VERIFY( !ok && a.load() == 4 && expected == 4 );
+ ok = a.compare_exchange_strong(expected, 5, mo, mo);
+ VERIFY( ok && a.load() == 5 && expected == 4 );
+ expected = 0;
+ ok = a.compare_exchange_strong(expected, 3, mo, mo);
+ VERIFY( !ok && a.load() == 5 && expected == 5 );
+
+ while (!a.compare_exchange_weak(expected, 4))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 4 && expected == 5 );
+ expected = a.load();
+ while (!a.compare_exchange_weak(expected, 6, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 6 && expected == 4 );
+ expected = a.load();
+ expected.i += 1;
+ ok = a.compare_exchange_weak(expected, -8);
+ VERIFY( !ok && a.load() == 6 && expected == 6 );
+ expected = a.load();
+ expected.i += 1;
+ ok = a.compare_exchange_weak(expected, 8, mo);
+ VERIFY( !ok && a.load() == 6 && expected == 6 );
+
+ ok = a.compare_exchange_strong(expected, -6);
+ VERIFY( ok && a.load() == -6 && expected == 6 );
+ expected = a.load();
+ ok = a.compare_exchange_strong(expected, 7, mo);
+ VERIFY( ok && a.load() == 7 && expected == -6 );
+ expected = a.load();
+ expected.i += 1;
+ ok = a.compare_exchange_strong(expected, 2);
+ VERIFY( !ok && a.load() == 7 && expected == 7 );
+ expected = a.load();
+ expected.i += 1;
+ ok = a.compare_exchange_strong(expected, 2, mo);
+ VERIFY( !ok && a.load() == 7 && expected == 7 );
+ }
+
+ VERIFY( value == 7 );
+}
+
+void
+test02()
+{
+ X i;
+ std::atomic_ref<X> a0(i);
+ std::atomic_ref<X> a1(i);
+ std::atomic_ref<X> a2(a0);
+ a0 = 42;
+ VERIFY( a1.load() == 42 );
+ VERIFY( a2.load() == 42 );
+}
+
+int
+main()
+{
+ test01();
+ test02();
+}
--- /dev/null
+// Copyright (C) 2019 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+// { dg-add-options libatomic }
+
+#include <atomic>
+#include <limits.h>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ int value;
+
+ {
+ const auto mo = std::memory_order_relaxed;
+ std::atomic_ref<int> a(value);
+ bool ok = a.is_lock_free();
+ if constexpr (std::atomic_ref<int>::is_always_lock_free)
+ VERIFY( ok );
+ a = 0;
+ VERIFY( a.load() == 0 );
+ VERIFY( a.load(mo) == 0 );
+ a.store(1);
+ VERIFY( a.load() == 1 );
+ auto v = a.exchange(2);
+ VERIFY( a == 2 );
+ VERIFY( v == 1 );
+ v = a.exchange(3, mo);
+ VERIFY( a == 3 );
+ VERIFY( v == 2 );
+
+ auto expected = a.load();
+ while (!a.compare_exchange_weak(expected, 4, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 4 );
+ VERIFY( expected == 3 );
+ expected = 1;
+ ok = a.compare_exchange_weak(expected, 5, mo, mo);
+ VERIFY( !ok && a.load() == 4 && expected == 4 );
+ ok = a.compare_exchange_strong(expected, 5, mo, mo);
+ VERIFY( ok && a.load() == 5 && expected == 4 );
+ expected = 0;
+ ok = a.compare_exchange_strong(expected, 3, mo, mo);
+ VERIFY( !ok && a.load() == 5 && expected == 5 );
+
+ while (!a.compare_exchange_weak(expected, 4))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 4 && expected == 5 );
+ expected = a.load();
+ while (!a.compare_exchange_weak(expected, 6, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 6 && expected == 4 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, -8);
+ VERIFY( !ok && a.load() == 6 && expected == 6 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, 8, mo);
+ VERIFY( !ok && a.load() == 6 && expected == 6 );
+
+ ok = a.compare_exchange_strong(expected, -6);
+ VERIFY( ok && a.load() == -6 && expected == 6 );
+ expected = a.load();
+ ok = a.compare_exchange_strong(expected, 7, mo);
+ VERIFY( ok && a.load() == 7 && expected == -6 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 2);
+ VERIFY( !ok && a.load() == 7 && expected == 7 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 2, mo);
+ VERIFY( !ok && a.load() == 7 && expected == 7 );
+
+ v = a.fetch_add(2);
+ VERIFY( v == 7 );
+ VERIFY( a == 9 );
+ v = a.fetch_add(-30, mo);
+ VERIFY( v == 9 );
+ VERIFY( a == -21 );
+
+ v = a.fetch_sub(3);
+ VERIFY( v == -21 );
+ VERIFY( a == -24 );
+ v = a.fetch_sub(-41, mo);
+ VERIFY( v == -24 );
+ VERIFY( a == 17 );
+
+ v = a.fetch_and(0x101);
+ VERIFY( v == 17 );
+ VERIFY( a == 1 );
+ a = 0x17;
+ v = a.fetch_and(0x23, mo);
+ VERIFY( v == 0x17 );
+ VERIFY( a == 3 );
+
+ v = a.fetch_or(0x101);
+ VERIFY( v == 3 );
+ VERIFY( a == 0x103 );
+ v = a.fetch_or(0x23, mo);
+ VERIFY( v == 0x103 );
+ VERIFY( a == 0x123 );
+
+ v = a.fetch_xor(0x101);
+ VERIFY( v == 0x123 );
+ VERIFY( a == 0x022 );
+ v = a.fetch_xor(0x123, mo);
+ VERIFY( v == 0x022 );
+ VERIFY( a == 0x101 );
+
+ v = a++;
+ VERIFY( v == 0x101 );
+ VERIFY( a == 0x102 );
+ v = a--;
+ VERIFY( v == 0x102 );
+ VERIFY( a == 0x101 );
+ v = ++a;
+ VERIFY( v == 0x102 );
+ VERIFY( a == 0x102 );
+ v = --a;
+ VERIFY( v == 0x101 );
+ VERIFY( a == 0x101 );
+
+ v = a += -10;
+ VERIFY( v == 247 );
+ VERIFY( a == 247 );
+
+ v = a -= 250;
+ VERIFY( v == -3 );
+ VERIFY( a == -3 );
+
+ a = 0x17;
+ v = a &= 0x102;
+ VERIFY( v == 2 );
+ VERIFY( a == 2 );
+
+ v = a |= 0x101;
+ VERIFY( v == 0x103 );
+ VERIFY( a == 0x103 );
+
+ v = a ^= 0x121;
+ VERIFY( v == 0x022 );
+ VERIFY( a == 0x022 );
+ }
+
+ VERIFY( value == 0x022 );
+}
+
+void
+test02()
+{
+ unsigned short value;
+
+ {
+ const auto mo = std::memory_order_relaxed;
+ std::atomic_ref<unsigned short> a(value);
+ bool ok = a.is_lock_free();
+ if constexpr (std::atomic_ref<unsigned short>::is_always_lock_free)
+ VERIFY( ok );
+ a = 0;
+ VERIFY( a.load() == 0 );
+ VERIFY( a.load(mo) == 0 );
+ a.store(1);
+ VERIFY( a.load() == 1 );
+ auto v = a.exchange(2);
+ VERIFY( a == 2 );
+ VERIFY( v == 1 );
+ v = a.exchange(3, mo);
+ VERIFY( a == 3 );
+ VERIFY( v == 2 );
+
+ auto expected = a.load();
+ while (!a.compare_exchange_weak(expected, 4, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 4 );
+ VERIFY( expected == 3 );
+ expected = 1;
+ ok = a.compare_exchange_weak(expected, 5, mo, mo);
+ VERIFY( !ok && a.load() == 4 && expected == 4 );
+ ok = a.compare_exchange_strong(expected, 5, mo, mo);
+ VERIFY( ok && a.load() == 5 && expected == 4 );
+ expected = 0;
+ ok = a.compare_exchange_strong(expected, 3, mo, mo);
+ VERIFY( !ok && a.load() == 5 && expected == 5 );
+
+ while (!a.compare_exchange_weak(expected, 4))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 4 && expected == 5 );
+ expected = a.load();
+ while (!a.compare_exchange_weak(expected, 6, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == 6 && expected == 4 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, -8);
+ VERIFY( !ok && a.load() == 6 && expected == 6 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, 8, mo);
+ VERIFY( !ok && a.load() == 6 && expected == 6 );
+
+ ok = a.compare_exchange_strong(expected, -6);
+ VERIFY( ok && a.load() == (unsigned short)-6 && expected == 6 );
+ expected = a.load();
+ ok = a.compare_exchange_strong(expected, 7, mo);
+ VERIFY( ok && a.load() == 7 && expected == (unsigned short)-6 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 2);
+ VERIFY( !ok && a.load() == 7 && expected == 7 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, 2, mo);
+ VERIFY( !ok && a.load() == 7 && expected == 7 );
+
+ v = a.fetch_add(2);
+ VERIFY( v == 7 );
+ VERIFY( a == 9 );
+ v = a.fetch_add(-30, mo);
+ VERIFY( v == 9 );
+ VERIFY( a == (unsigned short)-21 );
+
+ v = a.fetch_sub(3);
+ VERIFY( v == (unsigned short)-21 );
+ VERIFY( a == (unsigned short)-24 );
+ v = a.fetch_sub((unsigned short)-41, mo);
+ VERIFY( v == (unsigned short)-24 );
+ VERIFY( a == 17 );
+
+ v = a.fetch_and(0x21);
+ VERIFY( v == 17 );
+ VERIFY( a == 1 );
+ a = 0x17;
+ v = a.fetch_and(0x23, mo);
+ VERIFY( v == 0x17 );
+ VERIFY( a == 3 );
+
+ v = a.fetch_or(0x21);
+ VERIFY( v == 3 );
+ VERIFY( a == 0x23 );
+ v = a.fetch_or(0x44, mo);
+ VERIFY( v == 0x23 );
+ VERIFY( a == 0x67 );
+
+ v = a.fetch_xor(0x21);
+ VERIFY( v == 0x67 );
+ VERIFY( a == 0x46 );
+ v = a.fetch_xor(0x12, mo);
+ VERIFY( v == 0x46 );
+ VERIFY( a == 0x54 );
+
+ v = a++;
+ VERIFY( v == 0x54 );
+ VERIFY( a == 0x55 );
+ v = a--;
+ VERIFY( v == 0x55 );
+ VERIFY( a == 0x54 );
+ v = ++a;
+ VERIFY( v == 0x55 );
+ VERIFY( a == 0x55 );
+ v = --a;
+ VERIFY( v == 0x54 );
+ VERIFY( a == 0x54 );
+
+ v = a += -10;
+ VERIFY( v == 0x4a );
+ VERIFY( a == 0x4a );
+
+ v = a -= 15;
+ VERIFY( v == 0x3b );
+ VERIFY( a == 0x3b );
+
+ a = 0x17;
+ v = a &= 0x12;
+ VERIFY( v == 0x12 );
+ VERIFY( a == 0x12 );
+
+ v = a |= 0x34;
+ VERIFY( v == 0x36 );
+ VERIFY( a == 0x36 );
+
+ v = a ^= 0x12;
+ VERIFY( v == 0x24 );
+ VERIFY( a == 0x24 );
+ }
+
+ VERIFY( value == 0x24 );
+}
+void
+test03()
+{
+ int i = 0;
+ std::atomic_ref<int> a0(i);
+ std::atomic_ref<int> a1(i);
+ std::atomic_ref<int> a2(a0);
+ a0 = 42;
+ VERIFY( a1 == 42 );
+ VERIFY( a2 == 42 );
+}
+
+void
+test04()
+{
+ int i = INT_MIN;
+ std::atomic_ref<int> a(i);
+ --a;
+ VERIFY( a == INT_MAX );
+ ++a;
+ VERIFY( a == INT_MIN );
+ a |= INT_MAX;
+ VERIFY( a == -1 );
+}
+
+int
+main()
+{
+ test01();
+ test02();
+ test03();
+ test04();
+}
--- /dev/null
+// Copyright (C) 2019 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do run { target c++2a } }
+// { dg-add-options libatomic }
+
+#include <atomic>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+ long arr[10] = { };
+ long* value;
+
+ {
+ const auto mo = std::memory_order_relaxed;
+ std::atomic_ref<long*> a(value);
+ bool ok = a.is_lock_free();
+ if constexpr (std::atomic_ref<long*>::is_always_lock_free)
+ VERIFY( ok );
+ a = arr;
+ VERIFY( a.load() == arr );
+ VERIFY( a.load(mo) == arr );
+ a.store(arr+1);
+ VERIFY( a.load() == arr+1 );
+ auto v = a.exchange(arr+2);
+ VERIFY( a == arr+2 );
+ VERIFY( v == arr+1 );
+ v = a.exchange(arr+3, mo);
+ VERIFY( a == arr+3 );
+ VERIFY( v == arr+2 );
+
+ auto expected = a.load();
+ while (!a.compare_exchange_weak(expected, arr+4, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == arr+4 );
+ VERIFY( expected == arr+3 );
+ expected = arr+1;
+ ok = a.compare_exchange_weak(expected, arr+5, mo, mo);
+ VERIFY( !ok && a.load() == arr+4 && expected == arr+4 );
+ ok = a.compare_exchange_strong(expected, arr+5, mo, mo);
+ VERIFY( ok && a.load() == arr+5 && expected == arr+4 );
+ expected = nullptr;
+ ok = a.compare_exchange_strong(expected, arr+3, mo, mo);
+ VERIFY( !ok && a.load() == arr+5 && expected == arr+5 );
+
+ while (!a.compare_exchange_weak(expected, arr+4))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == arr+4 && expected == arr+5 );
+ expected = a.load();
+ while (!a.compare_exchange_weak(expected, arr+6, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == arr+6 && expected == arr+4 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, arr+8);
+ VERIFY( !ok && a.load() == arr+6 && expected == arr+6 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, arr+8, mo);
+ VERIFY( !ok && a.load() == arr+6 && expected == arr+6 );
+
+ ok = a.compare_exchange_strong(expected, arr+5);
+ VERIFY( ok && a.load() == arr+5 && expected == arr+6 );
+ expected = a.load();
+ ok = a.compare_exchange_strong(expected, arr+7, mo);
+ VERIFY( ok && a.load() == arr+7 && expected == arr+5 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, arr+2);
+ VERIFY( !ok && a.load() == arr+7 && expected == arr+7 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, arr+2, mo);
+ VERIFY( !ok && a.load() == arr+7 && expected == arr+7 );
+
+ v = a.fetch_add(2);
+ VERIFY( v == arr+7 );
+ VERIFY( a == arr+9 );
+ v = a.fetch_add(-3, mo);
+ VERIFY( v == arr+9 );
+ VERIFY( a == arr+6 );
+
+ v = a.fetch_sub(3);
+ VERIFY( v == arr+6 );
+ VERIFY( a == arr+3 );
+ v = a.fetch_sub(2, mo);
+ VERIFY( v == arr+3 );
+ VERIFY( a == arr+1 );
+
+ v = a += 5;
+ VERIFY( v == arr+6 );
+ VERIFY( a == arr+6 );
+
+ v = a -= 5;
+ VERIFY( v == arr+1 );
+ VERIFY( a == arr+1 );
+ }
+
+ VERIFY( value == arr+1 );
+}
+
+void
+test02()
+{
+ char arr[10] = { };
+ char* value;
+
+ {
+ const auto mo = std::memory_order_relaxed;
+ std::atomic_ref<char*> a(value);
+ bool ok = a.is_lock_free();
+ if constexpr (std::atomic_ref<char*>::is_always_lock_free)
+ VERIFY( ok );
+ a = arr;
+ VERIFY( a.load() == arr );
+ a.store(arr+3);
+ VERIFY( a.load(mo) == arr+3 );
+ a.store(arr+1, mo);
+ VERIFY( a.load() == arr+1 );
+ auto v = a.exchange(arr+2);
+ VERIFY( a == arr+2 );
+ VERIFY( v == arr+1 );
+ v = a.exchange(arr+3, mo);
+ VERIFY( a == arr+3 );
+ VERIFY( v == arr+2 );
+
+ auto expected = a.load();
+ while (!a.compare_exchange_weak(expected, arr+4, mo, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == arr+4 );
+ VERIFY( expected == arr+3 );
+ expected = arr+1;
+ ok = a.compare_exchange_weak(expected, arr+5, mo, mo);
+ VERIFY( !ok && a.load() == arr+4 && expected == arr+4 );
+ ok = a.compare_exchange_strong(expected, arr+5, mo, mo);
+ VERIFY( ok && a.load() == arr+5 && expected == arr+4 );
+ expected = nullptr;
+ ok = a.compare_exchange_strong(expected, arr+3, mo, mo);
+ VERIFY( !ok && a.load() == arr+5 && expected == arr+5 );
+
+ while (!a.compare_exchange_weak(expected, arr+4))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == arr+4 && expected == arr+5 );
+ expected = a.load();
+ while (!a.compare_exchange_weak(expected, arr+6, mo))
+ { /* weak form can fail spuriously */ }
+ VERIFY( a.load() == arr+6 && expected == arr+4 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, arr+8);
+ VERIFY( !ok && a.load() == arr+6 && expected == arr+6 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_weak(expected, arr+8, mo);
+ VERIFY( !ok && a.load() == arr+6 && expected == arr+6 );
+
+ ok = a.compare_exchange_strong(expected, arr+5);
+ VERIFY( ok && a.load() == arr+5 && expected == arr+6 );
+ expected = a.load();
+ ok = a.compare_exchange_strong(expected, arr+7, mo);
+ VERIFY( ok && a.load() == arr+7 && expected == arr+5 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, arr+2);
+ VERIFY( !ok && a.load() == arr+7 && expected == arr+7 );
+ expected = a.load() + 1;
+ ok = a.compare_exchange_strong(expected, arr+2, mo);
+ VERIFY( !ok && a.load() == arr+7 && expected == arr+7 );
+
+ v = a.fetch_add(2);
+ VERIFY( v == arr+7 );
+ VERIFY( a == arr+9 );
+ v = a.fetch_add(-3, mo);
+ VERIFY( v == arr+9 );
+ VERIFY( a == arr+6 );
+
+ v = a.fetch_sub(3);
+ VERIFY( v == arr+6 );
+ VERIFY( a == arr+3 );
+ v = a.fetch_sub(2, mo);
+ VERIFY( v == arr+3 );
+ VERIFY( a == arr+1 );
+
+ v = a += 5;
+ VERIFY( v == arr+6 );
+ VERIFY( a == arr+6 );
+
+ v = a -= 5;
+ VERIFY( v == arr+1 );
+ VERIFY( a == arr+1 );
+ }
+
+ VERIFY( value == arr+1 );
+}
+
+void
+test03()
+{
+ int i = 0;
+ int* ptr = 0;
+ std::atomic_ref<int*> a0(ptr);
+ std::atomic_ref<int*> a1(ptr);
+ std::atomic_ref<int*> a2(a0);
+ a0 = &i;
+ VERIFY( a1 == &i );
+ VERIFY( a2 == &i );
+}
+
+int
+main()
+{
+ test01();
+ test02();
+ test03();
+}
--- /dev/null
+// Copyright (C) 2019 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.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++2a" }
+// { dg-do compile { target c++2a } }
+
+#include <atomic>
+
+void
+test01()
+{
+ struct X { int c; };
+ using A = std::atomic_ref<X>;
+ static_assert( std::is_standard_layout_v<A> );
+ static_assert( std::is_nothrow_copy_constructible_v<A> );
+ static_assert( std::is_trivially_destructible_v<A> );
+ static_assert( std::is_same_v<A::value_type, X> );
+ static_assert( !std::is_copy_assignable_v<A> );
+ static_assert( !std::is_move_assignable_v<A> );
+}
+
+void
+test02()
+{
+ using A = std::atomic_ref<int>;
+ static_assert( std::is_standard_layout_v<A> );
+ static_assert( std::is_nothrow_copy_constructible_v<A> );
+ static_assert( std::is_trivially_destructible_v<A> );
+ static_assert( std::is_same_v<A::value_type, int> );
+ static_assert( std::is_same_v<A::difference_type, A::value_type> );
+ static_assert( !std::is_copy_assignable_v<A> );
+ static_assert( !std::is_move_assignable_v<A> );
+}
+
+void
+test03()
+{
+ using A = std::atomic_ref<double>;
+ static_assert( std::is_standard_layout_v<A> );
+ static_assert( std::is_nothrow_copy_constructible_v<A> );
+ static_assert( std::is_trivially_destructible_v<A> );
+ static_assert( std::is_same_v<A::value_type, double> );
+ static_assert( std::is_same_v<A::difference_type, A::value_type> );
+ static_assert( !std::is_copy_assignable_v<A> );
+ static_assert( !std::is_move_assignable_v<A> );
+}
+
+void
+test04()
+{
+ using A = std::atomic_ref<int*>;
+ static_assert( std::is_standard_layout_v<A> );
+ static_assert( std::is_nothrow_copy_constructible_v<A> );
+ static_assert( std::is_trivially_destructible_v<A> );
+ static_assert( std::is_same_v<A::value_type, int*> );
+ static_assert( std::is_same_v<A::difference_type, std::ptrdiff_t> );
+ static_assert( std::is_nothrow_copy_constructible_v<A> );
+ static_assert( !std::is_copy_assignable_v<A> );
+ static_assert( !std::is_move_assignable_v<A> );
+}
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