--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/atomic-compare-exchange-3.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,86 @@
+/* Test __atomic routines for existence and proper execution on 4 byte 
+   values with each valid memory model.  */
+/* { dg-do run } */
+/* { dg-require-effective-target sync_int_long } */
+
+/* Test the execution of the __atomic_compare_exchange_n builtin for an int.  */
+
+extern void abort(void);
+
+int v = 0;
+int expected = 0;
+int max = ~0;
+int desired = ~0;
+int zero = 0;
+
+#define STRONG 0
+#define WEAK 1
+
+int
+main ()
+{
+
+  if (!__atomic_compare_exchange_n (&v, &expected, max, STRONG , __ATOMIC_RELAXED, __ATOMIC_RELAXED)) 
+    abort ();
+  if (expected != 0)
+    abort ();
+
+  if (__atomic_compare_exchange_n (&v, &expected, 0, STRONG , __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) 
+    abort ();
+  if (expected != max)
+    abort ();
+
+  if (!__atomic_compare_exchange_n (&v, &expected, 0, STRONG , __ATOMIC_RELEASE, __ATOMIC_ACQUIRE)) 
+    abort ();
+  if (expected != max)
+    abort ();
+  if (v != 0)
+    abort ();
+
+  if (__atomic_compare_exchange_n (&v, &expected, desired, WEAK, __ATOMIC_ACQ_REL, __ATOMIC_ACQUIRE)) 
+    abort ();
+  if (expected != 0)
+    abort ();
+
+  if (!__atomic_compare_exchange_n (&v, &expected, desired, STRONG , __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) 
+    abort ();
+  if (expected != 0)
+    abort ();
+  if (v != max)
+    abort ();
+
+  /* Now test the generic version.  */
+
+  v = 0;
+
+  if (!__atomic_compare_exchange (&v, &expected, &max, STRONG, __ATOMIC_RELAXED, __ATOMIC_RELAXED))
+    abort ();
+  if (expected != 0)
+    abort ();
+
+  if (__atomic_compare_exchange (&v, &expected, &zero, STRONG , __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) 
+    abort ();
+  if (expected != max)
+    abort ();
+
+  if (!__atomic_compare_exchange (&v, &expected, &zero, STRONG , __ATOMIC_RELEASE, __ATOMIC_ACQUIRE)) 
+    abort ();
+  if (expected != max)
+    abort ();
+  if (v != 0)
+    abort ();
+
+  if (__atomic_compare_exchange (&v, &expected, &desired, WEAK, __ATOMIC_ACQ_REL, __ATOMIC_ACQUIRE)) 
+    abort ();
+  if (expected != 0)
+    abort ();
+
+  if (!__atomic_compare_exchange (&v, &expected, &desired, STRONG , __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) 
+    abort ();
+  if (expected != 0)
+    abort ();
+  if (v != max)
+    abort ();
+
+  return 0;
+}