--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/pr86271.c	Thu Oct 25 07:37:49 2018 +0900
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int main ()
+{
+  int i;
+  foobar (i, &i); /* { dg-warning "implicit declaration" } */
+}
+
+int foobar (int a, long long b)
+{
+  int c;
+
+  c = a % b;
+  a = a / b;
+  return a + b;
+}