glibc/benchtests/bench-memchr.c

/* Measure memchr functions.
   Copyright (C) 2013-2023 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
   <https://www.gnu.org/licenses/>.  */

#ifndef WIDE
# define SMALL_CHAR 127
#else
# define SMALL_CHAR 1273
#endif /* WIDE */

#ifndef USE_AS_MEMRCHR
# define TEST_MAIN
# ifndef WIDE
#  define TEST_NAME "memchr"
# else
#  define TEST_NAME "wmemchr"
# endif /* WIDE */
# include "bench-string.h"

# ifndef WIDE
#  define SIMPLE_MEMCHR simple_memchr
# else
#  define SIMPLE_MEMCHR simple_wmemchr
# 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;
}
#endif /* !USE_AS_MEMRCHR */

#include "json-lib.h"

static void
do_one_test (json_ctx_t *json_ctx, impl_t *impl, const CHAR *s, int c,
	     size_t n)
{
  size_t i, iters = INNER_LOOP_ITERS_LARGE;
  timing_t start, stop, cur;

  TIMING_NOW (start);
  for (i = 0; i < iters; ++i)
    {
      CALL (impl, s, c, n);
    }
  TIMING_NOW (stop);

  TIMING_DIFF (cur, start, stop);

  json_element_double (json_ctx, (double) cur / (double) iters);
}

static void
do_test (json_ctx_t *json_ctx, size_t align, size_t pos, size_t len,
	 int seek_char, int invert_pos)
{
  size_t i;

  align &= getpagesize () - 1;
  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)
    {
      if (invert_pos)
	buf[align + len - pos] = seek_char;
      else
	buf[align + pos] = seek_char;
      buf[align + len] = -seek_char;
    }
  else
    {
      buf[align + len] = seek_char;
    }

  json_element_object_begin (json_ctx);
  json_attr_uint (json_ctx, "align", align);
  json_attr_uint (json_ctx, "pos", pos);
  json_attr_uint (json_ctx, "len", len);
  json_attr_uint (json_ctx, "seek_char", seek_char);
  json_attr_uint (json_ctx, "invert_pos", invert_pos);

  json_array_begin (json_ctx, "timings");

  FOR_EACH_IMPL (impl, 0)
    do_one_test (json_ctx, impl, (CHAR *) (buf + align), seek_char, len);

  json_array_end (json_ctx);
  json_element_object_end (json_ctx);
}

int
test_main (void)
{
  size_t i, j, al, al_max;
  int repeats;
  json_ctx_t json_ctx;
  test_init ();

  json_init (&json_ctx, 0, stdout);

  json_document_begin (&json_ctx);
  json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);

  json_attr_object_begin (&json_ctx, "functions");
  json_attr_object_begin (&json_ctx, TEST_NAME);
  json_attr_string (&json_ctx, "bench-variant", "");

  json_array_begin (&json_ctx, "ifuncs");
  FOR_EACH_IMPL (impl, 0)
    json_element_string (&json_ctx, impl->name);
  json_array_end (&json_ctx);

  json_array_begin (&json_ctx, "results");

  al_max = 0;
#ifdef USE_AS_MEMRCHR
  al_max = getpagesize () / 2;
#endif

  for (repeats = 0; repeats < 2; ++repeats)
    {
      for (al = 0; al <= al_max; al += getpagesize () / 2)
	{
	  for (i = 1; i < 8; ++i)
	    {
	      do_test (&json_ctx, al, 16 << i, 2048, 23, repeats);
	      do_test (&json_ctx, al + i, 64, 256, 23, repeats);
	      do_test (&json_ctx, al, 16 << i, 2048, 0, repeats);
	      do_test (&json_ctx, al + i, 64, 256, 0, repeats);

	      do_test (&json_ctx, al + getpagesize () - 15, 64, 256, 0,
		       repeats);
#ifdef USE_AS_MEMRCHR
	      /* Also test the position close to the beginning for memrchr.  */
	      do_test (&json_ctx, al, i, 256, 23, repeats);
	      do_test (&json_ctx, al, i, 256, 0, repeats);
	      do_test (&json_ctx, al + i, i, 256, 23, repeats);
	      do_test (&json_ctx, al + i, i, 256, 0, repeats);
#endif
	    }
	  for (i = 1; i < 8; ++i)
	    {
	      do_test (&json_ctx, al + i, i << 5, 192, 23, repeats);
	      do_test (&json_ctx, al + i, i << 5, 192, 0, repeats);
	      do_test (&json_ctx, al + i, i << 5, 256, 23, repeats);
	      do_test (&json_ctx, al + i, i << 5, 256, 0, repeats);
	      do_test (&json_ctx, al + i, i << 5, 512, 23, repeats);
	      do_test (&json_ctx, al + i, i << 5, 512, 0, repeats);

	      do_test (&json_ctx, al + getpagesize () - 15, i << 5, 256, 23,
		       repeats);
	    }
	}

      for (i = 1; i < 32; ++i)
	{
	  do_test (&json_ctx, 0, i, i + 1, 23, repeats);
	  do_test (&json_ctx, 0, i, i + 1, 0, repeats);
	  do_test (&json_ctx, i, i, i + 1, 23, repeats);
	  do_test (&json_ctx, i, i, i + 1, 0, repeats);
	  do_test (&json_ctx, 0, i, i - 1, 23, repeats);
	  do_test (&json_ctx, 0, i, i - 1, 0, repeats);
	  do_test (&json_ctx, i, i, i - 1, 23, repeats);
	  do_test (&json_ctx, i, i, i - 1, 0, repeats);

	  do_test (&json_ctx, getpagesize () / 2, i, i + 1, 23, repeats);
	  do_test (&json_ctx, getpagesize () / 2, i, i + 1, 0, repeats);
	  do_test (&json_ctx, getpagesize () / 2 + i, i, i + 1, 23, repeats);
	  do_test (&json_ctx, getpagesize () / 2 + i, i, i + 1, 0, repeats);
	  do_test (&json_ctx, getpagesize () / 2, i, i - 1, 23, repeats);
	  do_test (&json_ctx, getpagesize () / 2, i, i - 1, 0, repeats);
	  do_test (&json_ctx, getpagesize () / 2 + i, i, i - 1, 23, repeats);
	  do_test (&json_ctx, getpagesize () / 2 + i, i, i - 1, 0, repeats);

	  do_test (&json_ctx, getpagesize () - 15, i, i - 1, 23, repeats);
	  do_test (&json_ctx, getpagesize () - 15, i, i - 1, 0, repeats);

	  do_test (&json_ctx, getpagesize () - 15, i, i + 1, 23, repeats);
	  do_test (&json_ctx, getpagesize () - 15, i, i + 1, 0, repeats);

#ifdef USE_AS_MEMRCHR
	  do_test (&json_ctx, 0, 1, i + 1, 23, repeats);
	  do_test (&json_ctx, 0, 2, i + 1, 0, repeats);
#endif
	}
      for (al = 0; al <= al_max; al += getpagesize () / 2)
	{
	  for (i = (16 / sizeof (CHAR)); i <= (8192 / sizeof (CHAR)); i += i)
	    {
	      for (j = 0; j <= (384 / sizeof (CHAR));
		   j += (32 / sizeof (CHAR)))
		{
		  do_test (&json_ctx, al, i + j, i, 23, repeats);
		  do_test (&json_ctx, al, i, i + j, 23, repeats);
		  if (j < i)
		    {
		      do_test (&json_ctx, al, i - j, i, 23, repeats);
		      do_test (&json_ctx, al, i, i - j, 23, repeats);
		    }
		}
	    }
	}

#ifndef USE_AS_MEMRCHR
      break;
#endif
    }

  json_array_end (&json_ctx);
  json_attr_object_end (&json_ctx);
  json_attr_object_end (&json_ctx);
  json_document_end (&json_ctx);

  return ret;
}

#include <support/test-driver.c>