--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr83198.c	Thu Oct 25 07:37:49 2018 +0900
@@ -0,0 +1,27 @@
+/* PR tree-optimization/83198 */
+/* { dg-do compile { target __float128 } } */
+/* { dg-options "-O2 -fprintf-return-value -Wno-format -fdump-tree-optimized" } */
+/* { dg-add-options __float128 } */
+
+void bar (void);
+void link_error (void);
+
+void
+foo (char *x, double y)
+{
+  /* The expected result should not be constant but rather that
+     of the %f directive with an unknown argument, i.e., at least
+     [3, 317] (but in reality [3, 322] when taking into account
+     that the decimal point can be up to MB_LEN_MAX bytes long).  */
+  int a = __builtin_sprintf (x, "%f", 1.0Q);
+  if (a < 3)
+    link_error ();
+  if (a > 13)
+    bar ();
+  if (a > 322)
+    link_error ();
+}
+
+/* Verify we don't optimize return value to [3, 13].  */
+/* { dg-final { scan-tree-dump-not "link_error \\(\\);" "optimized" } } */
+/* { dg-final { scan-tree-dump "bar \\(\\);" "optimized" } } */