--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/fold-minus-6.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,42 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-cddce1" } */
+
+int
+fn1 (int x)
+{
+  return 42L - (42 / x) * x;
+}
+
+long
+fn2 (int x)
+{
+  return 42L - (42 / x) * x;
+}
+
+int
+fn3 (long int x)
+{
+  return 42L - (42 / x) * x;
+}
+
+int
+fn4 (unsigned int a, int b)
+{
+  return a - (unsigned) ((a / b) * b);
+}
+
+int
+fn5 (int a, unsigned int b)
+{
+  return a - ((a / b) * b);
+}
+
+unsigned int
+fn6 (int a, int b)
+{
+  return a - ((a / b) * b);
+}
+
+/* { dg-final { scan-tree-dump-not " / " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " - " "cddce1" } } */
+/* { dg-final { scan-tree-dump-not " \\+ " "cddce1" } } */