--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/c-c++-common/pr85822.c	Thu Oct 25 07:37:49 2018 +0900
@@ -0,0 +1,27 @@
+/* { dg-options "-O2" } */
+/* { dg-do run } */
+
+static const long long int TagTypeNumber = 0xffff000000000000ll;
+
+long long int x;
+
+void foo(void)
+{
+  x = TagTypeNumber + 1;
+}
+
+int main(int argc, char **argv)
+{
+  if (argc > 0)
+    foo ();
+
+  if ((x & TagTypeNumber) == TagTypeNumber)
+  {
+    unsigned y = (unsigned)x;
+    __builtin_printf ("v: %u\n", y);
+    if (y != 1)
+      __builtin_abort ();
+  }
+
+  return 0;
+}