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 
11 // Adding "-fsanitize=thread" directly causes many platforms to fail (because
12 // they don't support tsan), and causes other sanitizer builds to fail (e.g.
13 // asan and tsan don't mix). Instead, require the tsan feature.
14 // REQUIRES: tsan
15 
16 // This test verifies behavior specified by [atomics.types.operations.req]/21:
17 //
18 //     When only one memory_order argument is supplied, the value of success is
19 //     order, and the value of failure is order except that a value of
20 //     memory_order_acq_rel shall be replaced by the value memory_order_acquire
21 //     and a value of memory_order_release shall be replaced by the value
22 //     memory_order_relaxed.
23 //
24 // This test mirrors replace_failure_order.pass.cpp. However, we also want to
25 // verify the codegen is correct. This verifies a bug where memory_order_acq_rel
26 // was not being replaced with memory_order_acquire in external
27 // TSAN-instrumented tests.
28 
29 // RUN: %{cxx} -c %s %{flags} %{compile_flags} -O2 -stdlib=libc++ -S -emit-llvm -o %t.ll
30 
31 #include <atomic>
32 
33 // Note: libc++ tests do not use on FileCheck.
34 // RUN: grep -E "call i32 @__tsan_atomic32_compare_exchange_val\(.*, i32 1, i32 4, i32 2\)" %t.ll
35 bool strong_memory_order_acq_rel(std::atomic<int>* a, int cmp) {
36   return a->compare_exchange_strong(cmp, 1, std::memory_order_acq_rel);
37 }
38