/* Measure memmem functions.

   Copyright (C) 2013-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   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

#define TEST_NAME "memmem"

#define BUF1PAGES 20

#define ITERATIONS 500

#include "bench-string.h"

typedef char *(*proto_t) (const void *, size_t, const void *, size_t);

void *simple_memmem (const void *, size_t, const void *, size_t);

IMPL (simple_memmem, 0)

IMPL (memmem, 1)

void *

simple_memmem (const void *haystack, size_t haystack_len, const void *needle,

	       size_t needle_len)

{

  const char *begin;

  const char *const last_possible

    = (const char *) haystack + haystack_len - needle_len;

  if (needle_len == 0)

    /* The first occurrence of the empty string is deemed to occur at

       the beginning of the string.  */

    return (void *) haystack;

  /* Sanity check, otherwise the loop might search through the whole

     memory.  */

  if (__glibc_unlikely (haystack_len < needle_len))

    return NULL;

  for (begin = (const char *) haystack; begin <= last_possible; ++begin)

    if (begin[0] == ((const char *) needle)[0] &&

	!memcmp ((const void *) &begin[1],

		 (const void *) ((const char *) needle + 1),

		 needle_len - 1))

      return (void *) begin;

  return NULL;

}

static void

do_one_test (impl_t *impl, const void *haystack, size_t haystack_len,

	     const void *needle, size_t needle_len, const void *expected)

{

  size_t i, iters = INNER_LOOP_ITERS;

  timing_t start, stop, cur;

  TIMING_NOW (start);

  for (i = 0; i < iters; ++i)

    {

      CALL (impl, haystack, haystack_len, needle, needle_len);

    }

  TIMING_NOW (stop);

  TIMING_DIFF (cur, start, stop);

  TIMING_PRINT_MEAN ((double) cur, (double) iters);

}

static void

do_test (const char *str, size_t len, size_t idx)

{

  char tmpbuf[len];

  memcpy (tmpbuf, buf1 + idx, len);

  memcpy (buf1 + idx, str, len);

  printf ("String %s, offset %zd:", str, idx);

  FOR_EACH_IMPL (impl, 0)

    do_one_test (impl, buf1, BUF1PAGES * page_size, str, len, buf1 + idx);

  memcpy (buf1 + idx, tmpbuf, len);

  putchar ('\n');

}

static void

do_random_tests (void)

{

  for (size_t n = 0; n < ITERATIONS; ++n)

    {

      char tmpbuf[32];

      size_t shift = random () % 11;

      size_t rel = random () % ((2 << (shift + 1)) * 64);

      size_t idx = MIN ((2 << shift) * 64 + rel, BUF1PAGES * page_size - 2);

      size_t len = random () % (sizeof (tmpbuf) - 1) + 1;

      len = MIN (len, BUF1PAGES * page_size - idx - 1);

      memcpy (tmpbuf, buf1 + idx, len);

      for (size_t i = random () % len / 2 + 1; i > 0; --i)

	{

	  size_t off = random () % len;

	  char ch = '0' + random () % 10;

	  buf1[idx + off] = ch;

	}

      printf ("String %.*s, offset %zd:", (int) len, buf1 + idx, idx);

      FOR_EACH_IMPL (impl, 0)

	do_one_test (impl, buf1, BUF1PAGES * page_size, buf1 + idx, len,

		     buf1 + idx);

      putchar ('\n');

      memcpy (buf1 + idx, tmpbuf, len);

    }

}

static const char *const strs[] =

  {

    "00000", "00112233", "0123456789", "0000111100001111",

    "00000111110000022222", "012345678901234567890",

    "abc0", "aaaa0", "abcabc0"

  };

int

test_main (void)

{

  size_t i;

  test_init ();

  printf ("%23s", "");

  FOR_EACH_IMPL (impl, 0)

    printf ("\t%s", impl->name);

  putchar ('\n');

  for (i = 0; i < BUF1PAGES * page_size; ++i)

    buf1[i] = 60 + random () % 32;

  for (i = 0; i < sizeof (strs) / sizeof (strs[0]); ++i)

    for (size_t j = 0; j < 120; j += 7)

      {

	size_t len = strlen (strs[i]);

	do_test (strs[i], len, j);

      }

  do_random_tests ();

  return ret;

}

#include <support/test-driver.c>