--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr86017.c	Thu Oct 25 07:37:49 2018 +0900
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-store-merging" } */
+
+void f (void*);
+
+void g (void)
+{
+  char a[8];
+  __builtin_memset (a, 0, 8);
+
+  f (a);
+}
+
+void h (void)
+{
+  char a[8];
+  __builtin_memset (a, 0, 1);
+  __builtin_memset (a + 1, 0, 1);
+  __builtin_memset (a + 2, 0, 1);
+  __builtin_memset (a + 3, 0, 1);
+  __builtin_memset (a + 4, 0, 1);
+  __builtin_memset (a + 5, 0, 1);
+  __builtin_memset (a + 6, 0, 1);
+  __builtin_memset (a + 7, 0, 1);
+
+  f (a);
+}
+
+/* { dg-final { scan-tree-dump "Merged into 1 stores" "store-merging" } } */