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/* Measure strstr functions.
Copyright (C) 2013-2019 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 MIN_PAGE_SIZE 131072
#define TEST_MAIN
#define TEST_NAME "strstr"
#include "bench-string.h"
static const char input[] =
"This manual is written with the assumption that you are at least "
"somewhat familiar with the C programming language and basic programming "
"concepts. Specifically, familiarity with ISO standard C (*note ISO "
"C::), rather than “traditional” pre-ISO C dialects, is assumed.\n"
" The GNU C Library includes several “header files”, each of which "
"provides definitions and declarations for a group of related facilities; "
"this information is used by the C compiler when processing your program. "
"For example, the header file ‘stdio.h’ declares facilities for "
"performing input and output, and the header file ‘string.h’ declares "
"string processing utilities. The organization of this manual generally "
"follows the same division as the header files.\n"
" If you are reading this manual for the first time, you should read "
"all of the introductory material and skim the remaining chapters. There "
"are a _lot_ of functions in the GNU C Library and it’s not realistic to "
"expect that you will be able to remember exactly _how_ to use each and "
"every one of them. It’s more important to become generally familiar "
"with the kinds of facilities that the library provides, so that when you "
"are writing your programs you can recognize _when_ to make use of "
"library functions, and _where_ in this manual you can find more specific "
"information about them.\n";
/* Simple yet efficient strstr - for needles < 32 bytes it is 2-4 times
faster than the optimized twoway_strstr. */
static char *
basic_strstr (const char *s1, const char *s2)
{
size_t i;
int c = s2[0];
if (c == 0)
return (char*)s1;
for ( ; s1[0] != '\0'; s1++)
{
if (s1[0] != c)
continue;
for (i = 1; s2[i] != 0; i++)
if (s1[i] != s2[i])
break;
if (s2[i] == '\0')
return (char*)s1;
}
return NULL;
}
#define RETURN_TYPE char *
#define AVAILABLE(h, h_l, j, n_l) \
(((j) + (n_l) <= (h_l)) \
|| ((h_l) += __strnlen ((void*)((h) + (h_l)), (n_l) + 512), \
(j) + (n_l) <= (h_l)))
#define CHECK_EOL (1)
#define RET0_IF_0(a) if (!a) goto ret0
#define FASTSEARCH(S,C,N) (void*) strchr ((void*)(S), (C))
#define LONG_NEEDLE_THRESHOLD 32U
#define __strnlen strnlen
#include "string/str-two-way.h"
/* Optimized Two-way implementation from GLIBC 2.29. */
static char *
twoway_strstr (const char *haystack, const char *needle)
{
size_t needle_len; /* Length of NEEDLE. */
size_t haystack_len; /* Known minimum length of HAYSTACK. */
/* Handle empty NEEDLE special case. */
if (needle[0] == '\0')
return (char *) haystack;
/* Skip until we find the first matching char from NEEDLE. */
haystack = strchr (haystack, needle[0]);
if (haystack == NULL || needle[1] == '\0')
return (char *) haystack;
/* Ensure HAYSTACK length is at least as long as NEEDLE length.
Since a match may occur early on in a huge HAYSTACK, use strnlen
and read ahead a few cachelines for improved performance. */
needle_len = strlen (needle);
haystack_len = __strnlen (haystack, needle_len + 256);
if (haystack_len < needle_len)
return NULL;
/* Check whether we have a match. This improves performance since we avoid
the initialization overhead of the two-way algorithm. */
if (memcmp (haystack, needle, needle_len) == 0)
return (char *) haystack;
/* Perform the search. Abstract memory is considered to be an array
of 'unsigned char' values, not an array of 'char' values. See
ISO C 99 section 6.2.6.1. */
if (needle_len < LONG_NEEDLE_THRESHOLD)
return two_way_short_needle ((const unsigned char *) haystack,
haystack_len,
(const unsigned char *) needle, needle_len);
return two_way_long_needle ((const unsigned char *) haystack, haystack_len,
(const unsigned char *) needle, needle_len);
}
typedef char *(*proto_t) (const char *, const char *);
IMPL (strstr, 1)
IMPL (twoway_strstr, 0)
IMPL (basic_strstr, 0)
static void
do_one_test (impl_t *impl, const char *s1, const char *s2, char *exp_result)
{
size_t i, iters = INNER_LOOP_ITERS_SMALL;
timing_t start, stop, cur;
char *res;
TIMING_NOW (start);
for (i = 0; i < iters; ++i)
res = CALL (impl, s1, s2);
TIMING_NOW (stop);
TIMING_DIFF (cur, start, stop);
TIMING_PRINT_MEAN ((double) cur, (double) iters);
if (res != exp_result)
{
error (0, 0, "Wrong result in function %s %s %s", impl->name,
res, exp_result);
ret = 1;
}
}
static void
do_test (size_t align1, size_t align2, size_t len1, size_t len2,
int fail)
{
char *s1 = (char *) (buf1 + align1);
char *s2 = (char *) (buf2 + align2);
size_t size = sizeof (input) - 1;
size_t pos = (len1 + len2) % size;
char *ss2 = s2;
for (size_t l = len2; l > 0; l = l > size ? l - size : 0)
{
size_t t = l > size ? size : l;
if (pos + t <= size)
ss2 = mempcpy (ss2, input + pos, t);
else
{
ss2 = mempcpy (ss2, input + pos, size - pos);
ss2 = mempcpy (ss2, input, t - (size - pos));
}
}
s2[len2] = '\0';
char *ss1 = s1;
for (size_t l = len1; l > 0; l = l > size ? l - size : 0)
{
size_t t = l > size ? size : l;
memcpy (ss1, input, t);
ss1 += t;
}
if (!fail)
memcpy (s1 + len1 - len2, s2, len2);
s1[len1] = '\0';
/* Remove any accidental matches except for the last if !fail. */
for (ss1 = basic_strstr (s1, s2); ss1; ss1 = basic_strstr (ss1 + 1, s2))
if (fail || ss1 != s1 + len1 - len2)
++ss1[len2 / 2];
printf ("Length %4zd/%3zd, alignment %2zd/%2zd, %s:",
len1, len2, align1, align2, fail ? "fail " : "found");
FOR_EACH_IMPL (impl, 0)
do_one_test (impl, s1, s2, fail ? NULL : s1 + len1 - len2);
putchar ('\n');
}
static int
test_main (void)
{
test_init ();
printf ("%23s", "");
FOR_EACH_IMPL (impl, 0)
printf ("\t%s", impl->name);
putchar ('\n');
for (size_t hlen = 64; hlen <= 256; hlen += 32)
for (size_t klen = 1; klen <= 16; klen++)
{
do_test (1, 3, hlen, klen, 0);
do_test (0, 9, hlen, klen, 1);
}
for (size_t hlen = 256; hlen <= 65536; hlen *= 2)
for (size_t klen = 16; klen <= 256; klen *= 2)
{
do_test (1, 11, hlen, klen, 0);
do_test (14, 5, hlen, klen, 1);
}
return ret;
}
#include <support/test-driver.c>
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