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-rw-r--r--test/std/atomics/atomics.general/replace_failure_order.pass.cpp43
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diff --git a/test/std/atomics/atomics.general/replace_failure_order.pass.cpp b/test/std/atomics/atomics.general/replace_failure_order.pass.cpp
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+++ b/test/std/atomics/atomics.general/replace_failure_order.pass.cpp
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+//===----------------------------------------------------------------------===//
+//
+// 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;
+}