1//===-- sanitizer_atomic_clang.h --------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file is a part of ThreadSanitizer/AddressSanitizer runtime.
10// Not intended for direct inclusion. Include sanitizer_atomic.h.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef SANITIZER_ATOMIC_CLANG_H
15#define SANITIZER_ATOMIC_CLANG_H
16
17namespace __sanitizer {
18
19// We use the compiler builtin atomic operations for loads and stores, which
20// generates correct code for all architectures, but may require libatomic
21// on platforms where e.g. 64-bit atomics are not supported natively.
22
23// See http://www.cl.cam.ac.uk/~pes20/cpp/cpp0xmappings.html
24// for mappings of the memory model to different processors.
25
26inline void atomic_signal_fence(memory_order mo) { __atomic_signal_fence(mo); }
27
28inline void atomic_thread_fence(memory_order mo) { __atomic_thread_fence(mo); }
29
30inline void proc_yield(int cnt) {
31 __asm__ __volatile__("" ::: "memory");
32#if defined(__i386__) || defined(__x86_64__)
33 for (int i = 0; i < cnt; i++) __asm__ __volatile__("pause");
34 __asm__ __volatile__("" ::: "memory");
35#endif
36}
37
38template <typename T>
39inline typename T::Type atomic_load(const volatile T *a, memory_order mo) {
40 DCHECK(mo == memory_order_relaxed || mo == memory_order_consume ||
41 mo == memory_order_acquire || mo == memory_order_seq_cst);
42 DCHECK(!((uptr)a % sizeof(*a)));
43 return __atomic_load_n(&a->val_dont_use, mo);
44}
45
46template <typename T>
47inline void atomic_store(volatile T *a, typename T::Type v, memory_order mo) {
48 DCHECK(mo == memory_order_relaxed || mo == memory_order_release ||
49 mo == memory_order_seq_cst);
50 DCHECK(!((uptr)a % sizeof(*a)));
51 __atomic_store_n(&a->val_dont_use, v, mo);
52}
53
54template <typename T>
55inline typename T::Type atomic_fetch_add(volatile T *a, typename T::Type v,
56 memory_order mo) {
57 DCHECK(!((uptr)a % sizeof(*a)));
58 return __atomic_fetch_add(&a->val_dont_use, v, mo);
59}
60
61template <typename T>
62inline typename T::Type atomic_fetch_sub(volatile T *a, typename T::Type v,
63 memory_order mo) {
64 (void)mo;
65 DCHECK(!((uptr)a % sizeof(*a)));
66 return __atomic_fetch_sub(&a->val_dont_use, v, mo);
67}
68
69template <typename T>
70inline typename T::Type atomic_exchange(volatile T *a, typename T::Type v,
71 memory_order mo) {
72 DCHECK(!((uptr)a % sizeof(*a)));
73 return __atomic_exchange_n(&a->val_dont_use, v, mo);
74}
75
76template <typename T>
77inline bool atomic_compare_exchange_strong(volatile T *a, typename T::Type *cmp,
78 typename T::Type xchg,
79 memory_order mo) {
80 // Transitioned from __sync_val_compare_and_swap to support targets like
81 // SPARC V8 that cannot inline atomic cmpxchg. __atomic_compare_exchange
82 // can then be resolved from libatomic. __ATOMIC_SEQ_CST is used to best
83 // match the __sync builtin memory order.
84 return __atomic_compare_exchange(&a->val_dont_use, cmp, &xchg, false,
85 __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST);
86}
87
88template <typename T>
89inline bool atomic_compare_exchange_weak(volatile T *a, typename T::Type *cmp,
90 typename T::Type xchg,
91 memory_order mo) {
92 return atomic_compare_exchange_strong(a, cmp, xchg, mo);
93}
94
95} // namespace __sanitizer
96
97#undef ATOMIC_ORDER
98
99#endif // SANITIZER_ATOMIC_CLANG_H
100

source code of compiler-rt/lib/sanitizer_common/sanitizer_atomic_clang.h