| //===----------------------------------------------------------------------===//// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===//// |
| |
| #ifndef ATOMIC_SUPPORT_H |
| #define ATOMIC_SUPPORT_H |
| |
| #include "__config" |
| #include "memory" // for __libcpp_relaxed_load |
| |
| #if defined(__clang__) && __has_builtin(__atomic_load_n) \ |
| && __has_builtin(__atomic_store_n) \ |
| && __has_builtin(__atomic_add_fetch) \ |
| && __has_builtin(__atomic_exchange_n) \ |
| && __has_builtin(__atomic_compare_exchange_n) \ |
| && defined(__ATOMIC_RELAXED) \ |
| && defined(__ATOMIC_CONSUME) \ |
| && defined(__ATOMIC_ACQUIRE) \ |
| && defined(__ATOMIC_RELEASE) \ |
| && defined(__ATOMIC_ACQ_REL) \ |
| && defined(__ATOMIC_SEQ_CST) |
| # define _LIBCPP_HAS_ATOMIC_BUILTINS |
| #elif defined(_LIBCPP_COMPILER_GCC) |
| # define _LIBCPP_HAS_ATOMIC_BUILTINS |
| #endif |
| |
| #if !defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS) |
| # if defined(_LIBCPP_WARNING) |
| _LIBCPP_WARNING("Building libc++ without __atomic builtins is unsupported") |
| # else |
| # warning Building libc++ without __atomic builtins is unsupported |
| # endif |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| namespace { |
| |
| #if defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS) |
| |
| enum __libcpp_atomic_order { |
| _AO_Relaxed = __ATOMIC_RELAXED, |
| _AO_Consume = __ATOMIC_CONSUME, |
| _AO_Acquire = __ATOMIC_ACQUIRE, |
| _AO_Release = __ATOMIC_RELEASE, |
| _AO_Acq_Rel = __ATOMIC_ACQ_REL, |
| _AO_Seq = __ATOMIC_SEQ_CST |
| }; |
| |
| template <class _ValueType, class _FromType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| void __libcpp_atomic_store(_ValueType* __dest, _FromType __val, |
| int __order = _AO_Seq) |
| { |
| __atomic_store_n(__dest, __val, __order); |
| } |
| |
| template <class _ValueType, class _FromType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val) |
| { |
| __atomic_store_n(__dest, __val, _AO_Relaxed); |
| } |
| |
| template <class _ValueType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| _ValueType __libcpp_atomic_load(_ValueType const* __val, |
| int __order = _AO_Seq) |
| { |
| return __atomic_load_n(__val, __order); |
| } |
| |
| template <class _ValueType, class _AddType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| _ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a, |
| int __order = _AO_Seq) |
| { |
| return __atomic_add_fetch(__val, __a, __order); |
| } |
| |
| template <class _ValueType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| _ValueType __libcpp_atomic_exchange(_ValueType* __target, |
| _ValueType __value, int __order = _AO_Seq) |
| { |
| return __atomic_exchange_n(__target, __value, __order); |
| } |
| |
| template <class _ValueType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| bool __libcpp_atomic_compare_exchange(_ValueType* __val, |
| _ValueType* __expected, _ValueType __after, |
| int __success_order = _AO_Seq, |
| int __fail_order = _AO_Seq) |
| { |
| return __atomic_compare_exchange_n(__val, __expected, __after, true, |
| __success_order, __fail_order); |
| } |
| |
| #else // _LIBCPP_HAS_NO_THREADS |
| |
| enum __libcpp_atomic_order { |
| _AO_Relaxed, |
| _AO_Consume, |
| _AO_Acquire, |
| _AO_Release, |
| _AO_Acq_Rel, |
| _AO_Seq |
| }; |
| |
| template <class _ValueType, class _FromType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| void __libcpp_atomic_store(_ValueType* __dest, _FromType __val, |
| int = 0) |
| { |
| *__dest = __val; |
| } |
| |
| template <class _ValueType, class _FromType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val) |
| { |
| *__dest = __val; |
| } |
| |
| template <class _ValueType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| _ValueType __libcpp_atomic_load(_ValueType const* __val, |
| int = 0) |
| { |
| return *__val; |
| } |
| |
| template <class _ValueType, class _AddType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| _ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a, |
| int = 0) |
| { |
| return *__val += __a; |
| } |
| |
| template <class _ValueType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| _ValueType __libcpp_atomic_exchange(_ValueType* __target, |
| _ValueType __value, int = _AO_Seq) |
| { |
| _ValueType old = *__target; |
| *__target = __value; |
| return old; |
| } |
| |
| template <class _ValueType> |
| inline _LIBCPP_INLINE_VISIBILITY |
| bool __libcpp_atomic_compare_exchange(_ValueType* __val, |
| _ValueType* __expected, _ValueType __after, |
| int = 0, int = 0) |
| { |
| if (*__val == *__expected) { |
| *__val = __after; |
| return true; |
| } |
| *__expected = *__val; |
| return false; |
| } |
| |
| #endif // _LIBCPP_HAS_NO_THREADS |
| |
| } // end namespace |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // ATOMIC_SUPPORT_H |