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- //===-- sanitizer_atomic_clang_other.h --------------------------*- C++ -*-===//
- //
- // 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
- //
- //===----------------------------------------------------------------------===//
- //
- // This file is a part of ThreadSanitizer/AddressSanitizer runtime.
- // Not intended for direct inclusion. Include sanitizer_atomic.h.
- //
- //===----------------------------------------------------------------------===//
- #ifndef SANITIZER_ATOMIC_CLANG_OTHER_H
- #define SANITIZER_ATOMIC_CLANG_OTHER_H
- namespace __sanitizer {
- inline void proc_yield(int cnt) {
- __asm__ __volatile__("" ::: "memory");
- }
- template<typename T>
- inline typename T::Type atomic_load(
- const volatile T *a, memory_order mo) {
- DCHECK(mo & (memory_order_relaxed | memory_order_consume
- | memory_order_acquire | memory_order_seq_cst));
- DCHECK(!((uptr)a % sizeof(*a)));
- typename T::Type v;
- if (sizeof(*a) < 8 || sizeof(void*) == 8) {
- // Assume that aligned loads are atomic.
- if (mo == memory_order_relaxed) {
- v = a->val_dont_use;
- } else if (mo == memory_order_consume) {
- // Assume that processor respects data dependencies
- // (and that compiler won't break them).
- __asm__ __volatile__("" ::: "memory");
- v = a->val_dont_use;
- __asm__ __volatile__("" ::: "memory");
- } else if (mo == memory_order_acquire) {
- __asm__ __volatile__("" ::: "memory");
- v = a->val_dont_use;
- __sync_synchronize();
- } else { // seq_cst
- // E.g. on POWER we need a hw fence even before the store.
- __sync_synchronize();
- v = a->val_dont_use;
- __sync_synchronize();
- }
- } else {
- __atomic_load(const_cast<typename T::Type volatile *>(&a->val_dont_use), &v,
- __ATOMIC_SEQ_CST);
- }
- return v;
- }
- template<typename T>
- inline void atomic_store(volatile T *a, typename T::Type v, memory_order mo) {
- DCHECK(mo & (memory_order_relaxed | memory_order_release
- | memory_order_seq_cst));
- DCHECK(!((uptr)a % sizeof(*a)));
- if (sizeof(*a) < 8 || sizeof(void*) == 8) {
- // Assume that aligned loads are atomic.
- if (mo == memory_order_relaxed) {
- a->val_dont_use = v;
- } else if (mo == memory_order_release) {
- __sync_synchronize();
- a->val_dont_use = v;
- __asm__ __volatile__("" ::: "memory");
- } else { // seq_cst
- __sync_synchronize();
- a->val_dont_use = v;
- __sync_synchronize();
- }
- } else {
- __atomic_store(&a->val_dont_use, &v, __ATOMIC_SEQ_CST);
- }
- }
- } // namespace __sanitizer
- #endif // #ifndef SANITIZER_ATOMIC_CLANG_OTHER_H
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