1 files changed, 27 insertions, 0 deletions
diff --git a/lib/libcompiler_rt/atomic_flag_clear.c b/lib/libcompiler_rt/atomic_flag_clear.c
new file mode 100644
index 00000000000..da912af6431
--- /dev/null
+++ b/lib/libcompiler_rt/atomic_flag_clear.c
@@ -0,0 +1,27 @@
+/*===-- atomic_flag_clear.c -------------------------------------------------===
+ *
+ *                     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.
+ *
+ *===------------------------------------------------------------------------===
+ *
+ * This file implements atomic_flag_clear from C11's stdatomic.h.
+ *
+ *===------------------------------------------------------------------------===
+ */
+
+#ifndef __has_include
+#define __has_include(inc) 0
+#endif
+
+#if __has_include(<stdatomic.h>)
+
+#include <stdatomic.h>
+#undef atomic_flag_clear
+void atomic_flag_clear(volatile atomic_flag *object) {
+  __c11_atomic_store(&(object)->_Value, 0, __ATOMIC_SEQ_CST);
+}
+
+#endif