glibc/benchtests/bench-memcmp.c

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/* Measure memcmp functions.
Copyright (C) 2013 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 WIDE
# define TEST_NAME "wmemcmp"
#else
# define TEST_NAME "memcmp"
#endif
#include "bench-string.h"
#ifdef WIDE
# include <inttypes.h>
# include <wchar.h>
# define MEMCMP wmemcmp
# define MEMCPY wmemcpy
# define SIMPLE_MEMCMP simple_wmemcmp
# define CHAR wchar_t
# define UCHAR wchar_t
# define CHARBYTES 4
# define CHAR__MIN WCHAR_MIN
# define CHAR__MAX WCHAR_MAX
int
simple_wmemcmp (const wchar_t *s1, const wchar_t *s2, size_t n)
{
int ret = 0;
/* Warning!
wmemcmp has to use SIGNED comparison for elements.
memcmp has to use UNSIGNED comparison for elemnts.
*/
while (n-- && (ret = *s1 < *s2 ? -1 : *s1 == *s2 ? 0 : 1) == 0) {s1++; s2++;}
return ret;
}
#else
# include <limits.h>
# define MEMCMP memcmp
# define MEMCPY memcpy
# define SIMPLE_MEMCMP simple_memcmp
# define CHAR char
# define MAX_CHAR 255
# define UCHAR unsigned char
# define CHARBYTES 1
# define CHAR__MIN CHAR_MIN
# define CHAR__MAX CHAR_MAX
int
simple_memcmp (const char *s1, const char *s2, size_t n)
{
int ret = 0;
while (n-- && (ret = *(unsigned char *) s1++ - *(unsigned char *) s2++) == 0);
return ret;
}
#endif
typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
IMPL (SIMPLE_MEMCMP, 0)
IMPL (MEMCMP, 1)
static void
do_one_test (impl_t *impl, const CHAR *s1, const CHAR *s2, size_t len,
int exp_result)
{
if (HP_TIMING_AVAIL)
{
hp_timing_t start __attribute ((unused));
hp_timing_t stop __attribute ((unused));
hp_timing_t best_time = ~ (hp_timing_t) 0;
size_t i;
for (i = 0; i < 32; ++i)
{
HP_TIMING_NOW (start);
CALL (impl, s1, s2, len);
HP_TIMING_NOW (stop);
HP_TIMING_BEST (best_time, start, stop);
}
printf ("\t%zd", (size_t) best_time);
}
}
static void
do_test (size_t align1, size_t align2, size_t len, int exp_result)
{
size_t i;
CHAR *s1, *s2;
if (len == 0)
return;
align1 &= 63;
if (align1 + (len + 1) * CHARBYTES >= page_size)
return;
align2 &= 63;
if (align2 + (len + 1) * CHARBYTES >= page_size)
return;
s1 = (CHAR *) (buf1 + align1);
s2 = (CHAR *) (buf2 + align2);
for (i = 0; i < len; i++)
s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % CHAR__MAX;
s1[len] = align1;
s2[len] = align2;
s2[len - 1] -= exp_result;
if (HP_TIMING_AVAIL)
printf ("Length %4zd, alignment %2zd/%2zd:", len, align1, align2);
FOR_EACH_IMPL (impl, 0)
do_one_test (impl, s1, s2, len, exp_result);
if (HP_TIMING_AVAIL)
putchar ('\n');
}
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 = 1; i < 16; ++i)
{
do_test (i * CHARBYTES, i * CHARBYTES, i, 0);
do_test (i * CHARBYTES, i * CHARBYTES, i, 1);
do_test (i * CHARBYTES, i * CHARBYTES, i, -1);
}
for (i = 0; i < 16; ++i)
{
do_test (0, 0, i, 0);
do_test (0, 0, i, 1);
do_test (0, 0, i, -1);
}
for (i = 1; i < 10; ++i)
{
do_test (0, 0, 2 << i, 0);
do_test (0, 0, 2 << i, 1);
do_test (0, 0, 2 << i, -1);
do_test (0, 0, 16 << i, 0);
do_test ((8 - i) * CHARBYTES, (2 * i) * CHARBYTES, 16 << i, 0);
do_test (0, 0, 16 << i, 1);
do_test (0, 0, 16 << i, -1);
}
for (i = 1; i < 8; ++i)
{
do_test (i * CHARBYTES, 2 * (i * CHARBYTES), 8 << i, 0);
do_test (i * CHARBYTES, 2 * (i * CHARBYTES), 8 << i, 1);
do_test (i * CHARBYTES, 2 * (i * CHARBYTES), 8 << i, -1);
}
return ret;
}
#include "../test-skeleton.c"