--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/strlenopt-3.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,64 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-strlen -fdump-tree-optimized" } */
+
+#include "strlenopt.h"
+
+__attribute__((noinline, noclone)) size_t
+fn1 (char *p, char *q)
+{
+  size_t s = strlen (q);
+  strcpy (p, q);
+  return s - strlen (p);
+}
+
+__attribute__((noinline, noclone)) size_t
+fn2 (char *p, char *q)
+{
+  size_t s = strlen (q);
+  memcpy (p, q, s + 1);
+  return s - strlen (p);
+}
+
+__attribute__((noinline, noclone)) size_t
+fn3 (char *p)
+{
+  memcpy (p, "abcd", 5);
+  return strlen (p);
+}
+
+__attribute__((noinline, noclone)) size_t
+fn4 (char *p)
+{
+  memcpy (p, "efg\0hij", 6);
+  return strlen (p);
+}
+
+int
+main ()
+{
+  char buf[64];
+  char *volatile p = buf;
+  char *volatile q = "ABCDEF";
+  buf[7] = 'G';
+  if (fn1 (p, q) != 0 || memcmp (buf, "ABCDEF\0G", 8))
+    abort ();
+  q = "HIJ";
+  if (fn2 (p + 1, q) != 0 || memcmp (buf, "AHIJ\0F\0G", 8))
+    abort ();
+  buf[6] = 'K';
+  if (fn3 (p + 1) != 4 || memcmp (buf, "Aabcd\0KG", 8))
+    abort ();
+  if (fn4 (p) != 3 || memcmp (buf, "efg\0hiKG", 8))
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "memcpy \\(" 4 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strcpy \\(" 0 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strcat \\(" 0 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "strchr \\(" 0 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "stpcpy \\(" 0 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "return 0" 3 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "return 4" 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "return 3" 1 "optimized" } } */