re PR middle-end/54261 (reverse sync/atomic operators when only…

re PR middle-end/54261 (reverse sync/atomic operators when only sync_compare_and_swap_optab libfuncs implemented)

	PR middle-end/54261
	* gcc.dg/torture/pr54261-1.c: New test.

From-SVN: r190455

gcc/testsuite/ChangeLog

+2012-08-17  Hans-Peter Nilsson  <hp@axis.com>
+
+	PR middle-end/54261
+	* gcc.dg/torture/pr54261-1.c: New test.
+
 2012-08-15  Janus Weil  <janus@gcc.gnu.org>
 
 	PR fortran/54243

gcc/testsuite/gcc.dg/torture/pr54261-1.c

+/* { dg-do run } */
+/* { dg-additional-options "-DSYNC_FALLBACK" { target { ! cas_int } } } */
+
+#ifdef SYNC_FALLBACK
+/* The SYNC_FALLBACK code is just so we don't have to restrict this test
+   to any subset of targets.  For targets with no atomics support at
+   all, the cas_int effective-target is false and the fallback provides
+   a PASS.  Where the bug trigs (at the time this test-case was added),
+   cas_int is also false but the fallback isn't used.  */
+__attribute__((__noinline__, __noclone__))
+int
+# if __INT_MAX__ == 0x7fff
+ __sync_fetch_and_add_2
+# else
+ __sync_fetch_and_add_4
+# endif
+ (int *at, int val)
+{
+  int tmp = *at;
+  asm ("");
+  *at = tmp + val;
+  return tmp;
+}
+#endif
+
+__attribute__((__noinline__, __noclone__))
+void g (int *at, int val)
+{
+  asm ("");
+  __sync_fetch_and_add (at, val);
+}
+
+int main(void)
+{
+  int x = 41;
+  int a = 1;
+  g (&x, a);
+
+  if (x != 42)
+    __builtin_abort ();
+  __builtin_exit (0);
+}