--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/tree-ssa/bit-assoc.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-forwprop1-details -fdump-tree-ccp1-details" } */
+
+int f1(int a, int b){
+  int c = a & b;
+  return c & b;
+}
+int f2(int a, int b){
+  int c = a | b;
+  return b | c;
+}
+int g1(int a, int b, int c){
+  int d = a & b;
+  int e = b & c;
+  return d & e;
+}
+int g2(int a, int b, int c){
+  int d = a | b;
+  int e = c | b;
+  return d | e;
+}
+int g3(int a, int b, int c){
+  int d = a ^ b;
+  int e = b ^ c;
+  return e ^ d;
+}
+
+/* { dg-final { scan-tree-dump-times "Match-and-simplified" 2 "ccp1" } } */
+/* { dg-final { scan-tree-dump-times "gimple_simplified" 3 "forwprop1" } } */