1 //===----------------------------------------------------------------------===//// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===//// 9 10 #ifndef ATOMIC_SUPPORT_H 11 #define ATOMIC_SUPPORT_H 12 13 #include "__config" 14 #include "memory" // for __libcpp_relaxed_load 15 16 #if defined(__clang__) && __has_builtin(__atomic_load_n) \ 17 && __has_builtin(__atomic_store_n) \ 18 && __has_builtin(__atomic_add_fetch) \ 19 && __has_builtin(__atomic_compare_exchange_n) \ 20 && defined(__ATOMIC_RELAXED) \ 21 && defined(__ATOMIC_CONSUME) \ 22 && defined(__ATOMIC_ACQUIRE) \ 23 && defined(__ATOMIC_RELEASE) \ 24 && defined(__ATOMIC_ACQ_REL) \ 25 && defined(__ATOMIC_SEQ_CST) 26 # define _LIBCPP_HAS_ATOMIC_BUILTINS 27 #elif !defined(__clang__) && defined(_GNUC_VER) && _GNUC_VER >= 407 28 # define _LIBCPP_HAS_ATOMIC_BUILTINS 29 #endif 30 31 #if !defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS) 32 # if defined(_LIBCPP_MSVC) 33 _LIBCPP_WARNING("Building libc++ without __atomic builtins is unsupported") 34 # else 35 # warning Building libc++ without __atomic builtins is unsupported 36 # endif 37 #endif 38 39 _LIBCPP_BEGIN_NAMESPACE_STD 40 41 namespace { 42 43 #if defined(_LIBCPP_HAS_ATOMIC_BUILTINS) && !defined(_LIBCPP_HAS_NO_THREADS) 44 45 enum __libcpp_atomic_order { 46 _AO_Relaxed = __ATOMIC_RELAXED, 47 _AO_Consume = __ATOMIC_CONSUME, 48 _AO_Acquire = __ATOMIC_ACQUIRE, 49 _AO_Release = __ATOMIC_RELEASE, 50 _AO_Acq_Rel = __ATOMIC_ACQ_REL, 51 _AO_Seq = __ATOMIC_SEQ_CST 52 }; 53 54 template <class _ValueType, class _FromType> 55 inline _LIBCPP_INLINE_VISIBILITY 56 void __libcpp_atomic_store(_ValueType* __dest, _FromType __val, 57 int __order = _AO_Seq) 58 { 59 __atomic_store_n(__dest, __val, __order); 60 } 61 62 template <class _ValueType, class _FromType> 63 inline _LIBCPP_INLINE_VISIBILITY 64 void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val) 65 { 66 __atomic_store_n(__dest, __val, _AO_Relaxed); 67 } 68 69 template <class _ValueType> 70 inline _LIBCPP_INLINE_VISIBILITY 71 _ValueType __libcpp_atomic_load(_ValueType const* __val, 72 int __order = _AO_Seq) 73 { 74 return __atomic_load_n(__val, __order); 75 } 76 77 template <class _ValueType, class _AddType> 78 inline _LIBCPP_INLINE_VISIBILITY 79 _ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a, 80 int __order = _AO_Seq) 81 { 82 return __atomic_add_fetch(__val, __a, __order); 83 } 84 85 template <class _ValueType> 86 inline _LIBCPP_INLINE_VISIBILITY 87 bool __libcpp_atomic_compare_exchange(_ValueType* __val, 88 _ValueType* __expected, _ValueType __after, 89 int __success_order = _AO_Seq, 90 int __fail_order = _AO_Seq) 91 { 92 return __atomic_compare_exchange_n(__val, __expected, __after, true, 93 __success_order, __fail_order); 94 } 95 96 #else // _LIBCPP_HAS_NO_THREADS 97 98 enum __libcpp_atomic_order { 99 _AO_Relaxed, 100 _AO_Consume, 101 _AO_Acquire, 102 _AO_Release, 103 _AO_Acq_Rel, 104 _AO_Seq 105 }; 106 107 template <class _ValueType, class _FromType> 108 inline _LIBCPP_INLINE_VISIBILITY 109 void __libcpp_atomic_store(_ValueType* __dest, _FromType __val, 110 int = 0) 111 { 112 *__dest = __val; 113 } 114 115 template <class _ValueType, class _FromType> 116 inline _LIBCPP_INLINE_VISIBILITY 117 void __libcpp_relaxed_store(_ValueType* __dest, _FromType __val) 118 { 119 *__dest = __val; 120 } 121 122 template <class _ValueType> 123 inline _LIBCPP_INLINE_VISIBILITY 124 _ValueType __libcpp_atomic_load(_ValueType const* __val, 125 int = 0) 126 { 127 return *__val; 128 } 129 130 template <class _ValueType, class _AddType> 131 inline _LIBCPP_INLINE_VISIBILITY 132 _ValueType __libcpp_atomic_add(_ValueType* __val, _AddType __a, 133 int = 0) 134 { 135 return *__val += __a; 136 } 137 138 template <class _ValueType> 139 inline _LIBCPP_INLINE_VISIBILITY 140 bool __libcpp_atomic_compare_exchange(_ValueType* __val, 141 _ValueType* __expected, _ValueType __after, 142 int = 0, int = 0) 143 { 144 if (*__val == *__expected) { 145 *__val = __after; 146 return true; 147 } 148 *__expected = *__val; 149 return false; 150 } 151 152 #endif // _LIBCPP_HAS_NO_THREADS 153 154 } // end namespace 155 156 _LIBCPP_END_NAMESPACE_STD 157 158 #endif // ATOMIC_SUPPORT_H 159