diff --git a/ap/libc/glibc/glibc-2.23/string/test-memchr.c b/ap/libc/glibc/glibc-2.23/string/test-memchr.c
new file mode 100644
index 0000000..449a19a
--- /dev/null
+++ b/ap/libc/glibc/glibc-2.23/string/test-memchr.c
@@ -0,0 +1,196 @@
+/* Test memchr functions.
+   Copyright (C) 1999-2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Written by Jakub Jelinek <jakub@redhat.com>, 1999.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define TEST_MAIN
+#ifndef WIDE
+# define TEST_NAME "memchr"
+#else
+# define TEST_NAME "wmemchr"
+#endif /* WIDE */
+#include "test-string.h"
+
+#ifndef WIDE
+# define MEMCHR memchr
+# define CHAR char
+# define UCHAR unsigned char
+# define SIMPLE_MEMCHR simple_memchr
+# define BIG_CHAR CHAR_MAX
+# define SMALL_CHAR 127
+#else
+# include <wchar.h>
+# define MEMCHR wmemchr
+# define CHAR wchar_t
+# define UCHAR wchar_t
+# define SIMPLE_MEMCHR simple_wmemchr
+# define BIG_CHAR WCHAR_MAX
+# define SMALL_CHAR 1273
+#endif /* WIDE */
+
+typedef CHAR *(*proto_t) (const CHAR *, int, size_t);
+CHAR *SIMPLE_MEMCHR (const CHAR *, int, size_t);
+
+IMPL (SIMPLE_MEMCHR, 0)
+IMPL (MEMCHR, 1)
+
+CHAR *
+SIMPLE_MEMCHR (const CHAR *s, int c, size_t n)
+{
+  while (n--)
+    if (*s++ == (CHAR) c)
+      return (CHAR *) s - 1;
+  return NULL;
+}
+
+static void
+do_one_test (impl_t *impl, const CHAR *s, int c, size_t n, CHAR *exp_res)
+{
+  CHAR *res = CALL (impl, s, c, n);
+  if (res != exp_res)
+    {
+      error (0, 0, "Wrong result in function %s %p %p", impl->name,
+	     res, exp_res);
+      ret = 1;
+      return;
+    }
+}
+
+static void
+do_test (size_t align, size_t pos, size_t len, int seek_char)
+{
+  size_t i;
+  CHAR *result;
+
+  align &= 7;
+  if ((align + len) * sizeof (CHAR) >= page_size)
+    return;
+
+  CHAR *buf = (CHAR *) (buf1);
+
+  for (i = 0; i < len; ++i)
+    {
+      buf[align + i] = 1 + 23 * i % SMALL_CHAR;
+      if (buf[align + i] == seek_char)
+	buf[align + i] = seek_char + 1;
+    }
+  buf[align + len] = 0;
+
+  if (pos < len)
+    {
+      buf[align + pos] = seek_char;
+      buf[align + len] = -seek_char;
+      result = (CHAR *) (buf + align + pos);
+    }
+  else
+    {
+      result = NULL;
+      buf[align + len] = seek_char;
+    }
+
+  FOR_EACH_IMPL (impl, 0)
+    do_one_test (impl, (CHAR *) (buf + align), seek_char, len, result);
+}
+
+static void
+do_random_tests (void)
+{
+  size_t i, j, n, align, pos, len;
+  int seek_char;
+  CHAR *result;
+  UCHAR *p = (UCHAR *) (buf1 + page_size) - 512;
+
+  for (n = 0; n < ITERATIONS; n++)
+    {
+      align = random () & 15;
+      pos = random () & 511;
+      if (pos + align >= 512)
+	pos = 511 - align - (random () & 7);
+      len = random () & 511;
+      if (pos >= len)
+	len = pos + (random () & 7);
+      if (len + align >= 512)
+	len = 512 - align - (random () & 7);
+      seek_char = random () & BIG_CHAR;
+      j = len + align + 64;
+      if (j > 512)
+	j = 512;
+
+      for (i = 0; i < j; i++)
+	{
+	  if (i == pos + align)
+	    p[i] = seek_char;
+	  else
+	    {
+	      p[i] = random () & BIG_CHAR;
+	      if (i < pos + align && p[i] == seek_char)
+		p[i] = seek_char + 13;
+	    }
+	}
+
+      if (pos < len)
+	{
+	  size_t r = random ();
+	  if ((r & 31) == 0)
+	    len = ~(uintptr_t) (p + align) - ((r >> 5) & 31);
+	  result = (CHAR *) (p + pos + align);
+	}
+      else
+	result = NULL;
+
+      FOR_EACH_IMPL (impl, 1)
+	if (CALL (impl, (CHAR *) (p + align), seek_char, len) != result)
+	  {
+	    error (0, 0, "Iteration %zd - wrong result in function %s (%zd, %d, %zd, %zd) %p != %p, p %p",
+		   n, impl->name, align, seek_char, len, pos,
+		   CALL (impl, (CHAR *) (p + align), seek_char, len),
+		   result, p);
+	    ret = 1;
+	  }
+    }
+}
+
+int
+test_main (void)
+{
+  size_t i;
+
+  test_init ();
+
+  printf ("%20s", "");
+  FOR_EACH_IMPL (impl, 0)
+    printf ("\t%s", impl->name);
+  putchar ('\n');
+
+  for (i = 1; i < 8; ++i)
+    {
+      do_test (0, 16 << i, 2048, 23);
+      do_test (i, 64, 256, 23);
+      do_test (0, 16 << i, 2048, 0);
+      do_test (i, 64, 256, 0);
+    }
+  for (i = 1; i < 32; ++i)
+    {
+      do_test (0, i, i + 1, 23);
+      do_test (0, i, i + 1, 0);
+    }
+
+  do_random_tests ();
+  return ret;
+}
+
+#include "../test-skeleton.c"