glibc/benchtests/bench-memmove.c

/* Measure memmove functions.
   Copyright (C) 2013-2017 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
#ifdef TEST_BCOPY
# define TEST_NAME "bcopy"
#else
# define TEST_NAME "memmove"
#endif
#include "bench-string.h"

char *simple_memmove (char *, const char *, size_t);

#ifdef TEST_BCOPY
typedef void (*proto_t) (const char *, char *, size_t);
void simple_bcopy (const char *, char *, size_t);

IMPL (simple_bcopy, 0)
IMPL (bcopy, 1)

void
simple_bcopy (const char *src, char *dst, size_t n)
{
  simple_memmove (dst, src, n);
}
#else
typedef char *(*proto_t) (char *, const char *, size_t);

IMPL (simple_memmove, 0)
IMPL (memmove, 1)
#endif

char *
inhibit_loop_to_libcall
simple_memmove (char *dst, const char *src, size_t n)
{
  char *ret = dst;
  if (src < dst)
    {
      dst += n;
      src += n;
      while (n--)
	*--dst = *--src;
    }
  else
    while (n--)
      *dst++ = *src++;
  return ret;
}

static void
do_one_test (impl_t *impl, char *dst, char *src, const char *orig_src,
	     size_t len)
{
  size_t i, iters = INNER_LOOP_ITERS;
  timing_t start, stop, cur;

  TIMING_NOW (start);
  for (i = 0; i < iters; ++i)
    {
#ifdef TEST_BCOPY
      CALL (impl, src, dst, len);
#else
      CALL (impl, dst, src, len);
#endif
    }
  TIMING_NOW (stop);

  TIMING_DIFF (cur, start, stop);

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

static void
do_test (size_t align1, size_t align2, size_t len)
{
  size_t i, j;
  char *s1, *s2;

  align1 &= 63;
  if (align1 + len >= page_size)
    return;

  align2 &= 63;
  if (align2 + len >= page_size)
    return;

  s1 = (char *) (buf1 + align1);
  s2 = (char *) (buf2 + align2);

  for (i = 0, j = 1; i < len; i++, j += 23)
    s1[i] = j;

  printf ("Length %4zd, alignment %2zd/%2zd:", len, align1, align2);

  FOR_EACH_IMPL (impl, 0)
    do_one_test (impl, s2, (char *) (buf2 + align1), s1, len);

  putchar ('\n');
}

static 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 < 14; ++i)
    {
      do_test (0, 32, 1 << i);
      do_test (32, 0, 1 << i);
      do_test (0, i, 1 << i);
      do_test (i, 0, 1 << i);
    }

  for (i = 0; i < 32; ++i)
    {
      do_test (0, 32, i);
      do_test (32, 0, i);
      do_test (0, i, i);
      do_test (i, 0, i);
    }

  for (i = 3; i < 32; ++i)
    {
      if ((i & (i - 1)) == 0)
	continue;
      do_test (0, 32, 16 * i);
      do_test (32, 0, 16 * i);
      do_test (0, i, 16 * i);
      do_test (i, 0, 16 * i);
    }

  for (i = 32; i < 64; ++i)
    {
      do_test (0, 0, 32 * i);
      do_test (i, 0, 32 * i);
      do_test (0, i, 32 * i);
      do_test (i, i, 32 * i);
    }

  return ret;
}

#include <support/test-driver.c>