--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/pr80776-1.c	Thu Oct 25 07:37:49 2018 +0900
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wformat-overflow" } */
+
+extern __inline __attribute__ ((__always_inline__)) __attribute__ ((__gnu_inline__)) __attribute__ ((__artificial__)) int
+__attribute__ ((__nothrow__ , __leaf__)) sprintf (char *__restrict __s, const char *__restrict __fmt, ...)
+{
+  return __builtin___sprintf_chk (__s, 2 - 1,
+				  __builtin_object_size (__s, 2 > 1), __fmt, __builtin_va_arg_pack ());
+}
+char number[sizeof "999999"];
+int somerandom (void);
+void
+Foo (void)
+{
+  int i = somerandom ();
+  if (! (0 <= i))
+    __builtin_unreachable ();
+  if (! (0 <= i && i <= 999999))
+    __builtin_unreachable ();
+  /* The correctness bits for [E]VRP cannot handle chained conditionals
+     when deciding to ignore a unreachable branch for setting SSA range info. */
+  sprintf (number, "%d", i); /* { dg-bogus "writing" "" { xfail *-*-* } } */
+}