diff options
Diffstat (limited to 'test/std/atomics/atomics.general/replace_failure_order.pass.cpp')
-rw-r--r-- | test/std/atomics/atomics.general/replace_failure_order.pass.cpp | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/test/std/atomics/atomics.general/replace_failure_order.pass.cpp b/test/std/atomics/atomics.general/replace_failure_order.pass.cpp new file mode 100644 index 0000000000000..cd0683d6887d5 --- /dev/null +++ b/test/std/atomics/atomics.general/replace_failure_order.pass.cpp @@ -0,0 +1,43 @@ +//===----------------------------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +// UNSUPPORTED: libcpp-has-no-threads + +// This test verifies behavior specified by [atomics.types.operations.req]/21: +// +// When only one memory_order argument is supplied, the value of success is +// order, and the value of failure is order except that a value of +// memory_order_acq_rel shall be replaced by the value memory_order_acquire +// and a value of memory_order_release shall be replaced by the value +// memory_order_relaxed. +// +// Clang's atomic intrinsics do this for us, but GCC's do not. We don't actually +// have visibility to see what these memory orders are lowered to, but we can at +// least check that they are lowered at all (otherwise there is a compile +// failure with GCC). + +#include <atomic> + +int main() { + std::atomic<int> i; + volatile std::atomic<int> v; + int exp = 0; + + i.compare_exchange_weak(exp, 0, std::memory_order_acq_rel); + i.compare_exchange_weak(exp, 0, std::memory_order_release); + i.compare_exchange_strong(exp, 0, std::memory_order_acq_rel); + i.compare_exchange_strong(exp, 0, std::memory_order_release); + + v.compare_exchange_weak(exp, 0, std::memory_order_acq_rel); + v.compare_exchange_weak(exp, 0, std::memory_order_release); + v.compare_exchange_strong(exp, 0, std::memory_order_acq_rel); + v.compare_exchange_strong(exp, 0, std::memory_order_release); + + return 0; +} |