1 //===----------------------------------------------------------------------===// 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 // REQUIRES: clang 10 // UNSUPPORTED: libcpp-has-no-threads 11 12 // Adding "-fsanitize=thread" directly causes many platforms to fail (because 13 // they don't support tsan), and causes other sanitizer builds to fail (e.g. 14 // asan and tsan don't mix). Instead, require the tsan feature. 15 // REQUIRES: tsan 16 17 // This test verifies behavior specified by [atomics.types.operations.req]/21: 18 // 19 // When only one memory_order argument is supplied, the value of success is 20 // order, and the value of failure is order except that a value of 21 // memory_order_acq_rel shall be replaced by the value memory_order_acquire 22 // and a value of memory_order_release shall be replaced by the value 23 // memory_order_relaxed. 24 // 25 // This test mirrors replace_failure_order.pass.cpp. However, we also want to 26 // verify the codegen is correct. This verifies a bug where memory_order_acq_rel 27 // was not being replaced with memory_order_acquire in external 28 // TSAN-instrumented tests. 29 30 // RUN: %{cxx} -c %s %{flags} %{compile_flags} -O2 -stdlib=libc++ -S -emit-llvm -o %t.ll 31 32 #include <atomic> 33 34 // Note: libc++ tests do not use on FileCheck. 35 // RUN: grep -E "call i32 @__tsan_atomic32_compare_exchange_val\(.*, i32 1, i32 4, i32 2\)" %t.ll 36 bool strong_memory_order_acq_rel(std::atomic<int>* a, int cmp) { 37 return a->compare_exchange_strong(cmp, 1, std::memory_order_acq_rel); 38 } 39