1 files changed, 80 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/strlenopt-10.c b/gcc/testsuite/gcc.dg/strlenopt-10.c
new file mode 100644
index 00000000000..a18c06ae069
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/strlenopt-10.c
@@ -0,0 +1,80 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fdump-tree-strlen" } */
+
+#include "strlenopt.h"
+
+__attribute__((noinline, noclone)) size_t
+fn1 (char *p)
+{
+  char *q;
+  /* This can be optimized into memcpy and the size can be decreased to one,
+     as it is immediately overwritten.  */
+  strcpy (p, "z");
+  q = strchr (p, '\0');
+  *q = 32;
+  /* This strlen can't be optimized away, string length is unknown here.  */
+  return strlen (p);
+}
+
+__attribute__((noinline, noclone)) void
+fn2 (char *p, const char *z, size_t *lp)
+{
+  char *q, *r;
+  char buf[64];
+  size_t l[10];
+  /* The first strlen stays, all the strcpy calls can be optimized
+     into memcpy and all other strlen calls and all strchr calls
+     optimized away.  */
+  l[0] = strlen (z);
+  strcpy (buf, z);
+  strcpy (p, "abcde");
+  q = strchr (p, '\0');
+  strcpy (q, "efghi");
+  r = strchr (q, '\0');
+  strcpy (r, "jkl");
+  l[1] = strlen (p);
+  l[2] = strlen (q);
+  l[3] = strlen (r);
+  strcpy (r, buf);
+  l[4] = strlen (p);
+  l[5] = strlen (q);
+  l[6] = strlen (r);
+  strcpy (r, "mnopqr");
+  l[7] = strlen (p);
+  l[8] = strlen (q);
+  l[9] = strlen (r);
+  memcpy (lp, l, sizeof l);
+}
+
+int
+main ()
+{
+  char buf[64];
+  size_t l[10];
+  const char *volatile z = "ABCDEFG";
+  memset (buf, '\0', sizeof buf);
+  if (fn1 (buf) != 2 || buf[0] != 'z' || buf[1] != 32 || buf[2] != '\0')
+    abort ();
+  fn2 (buf, z, l);
+  if (memcmp (buf, "abcdeefghimnopqr", 17) != 0)
+    abort ();
+  if (l[0] != 7)
+    abort ();
+  if (l[1] != 13 || l[2] != 8 || l[3] != 3)
+    abort ();
+  if (l[4] != 17 || l[5] != 12 || l[6] != 7)
+    abort ();
+  if (l[7] != 16 || l[8] != 11 || l[9] != 6)
+    abort ();
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "strlen \\(" 2 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "memcpy \\(" 8 "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 "\\*q_\[0-9\]* = 32;" 1 "strlen" } } */
+/* { dg-final { scan-tree-dump-times "memcpy \\(\[^\n\r\]*, 1\\)" 1 "strlen" } } */
+/* { dg-final { cleanup-tree-dump "strlen" } } */