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glibc/sysdeps/tile/tilegx/strcasestr.c

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tilegx: provide optimized strnlen, strstr, and strcasestr strnlen() is based on the existing tile strlen() with length checking added. It speeds up by up to 5x, but on average across the benchtest corpus by around 35%. No regressions are seen. strstr() does 8-byte aligned loads and compares using a 2-byte filter on the first two bytes of the needle and then testing the remaining bytes in needle using memcmp(). It speeds up about 5x in the best case (for "found" needles), about 2x looking at benchtest as a whole, with some slowdowns as much as 45%. on a few cases (including the "fail" case for 128KB search). strcasestr() is based on strstr() but uses a SIMD tolower routine to convert 8-bytes to lower case in 5 instructions. It also uses a 2-byte filter and then strncasecmp() for the remaining bytes. strncasecmp() is not optimized for SIMD, so there is futher room for improvement. However, it is still up to 16x faster for "found" needles, averaging 2x faster on the whole corpus of benchtests. It does slow down by up to 35% on a few cases, similarly to strstr().
2014-09-16 00:10:18 +00:00
/* Return the offset of one string within another.
tile: fix copyright header blocks in just-committed files I accidentally committed versions not following the conventions.
2014-10-06 17:47:02 +00:00
Copyright (C) 1994-2014 Free Software Foundation, Inc.
tilegx: provide optimized strnlen, strstr, and strcasestr strnlen() is based on the existing tile strlen() with length checking added. It speeds up by up to 5x, but on average across the benchtest corpus by around 35%. No regressions are seen. strstr() does 8-byte aligned loads and compares using a 2-byte filter on the first two bytes of the needle and then testing the remaining bytes in needle using memcmp(). It speeds up about 5x in the best case (for "found" needles), about 2x looking at benchtest as a whole, with some slowdowns as much as 45%. on a few cases (including the "fail" case for 128KB search). strcasestr() is based on strstr() but uses a SIMD tolower routine to convert 8-bytes to lower case in 5 instructions. It also uses a 2-byte filter and then strncasecmp() for the remaining bytes. strncasecmp() is not optimized for SIMD, so there is futher room for improvement. However, it is still up to 16x faster for "found" needles, averaging 2x faster on the whole corpus of benchtests. It does slow down by up to 35% on a few cases, similarly to strstr().
2014-09-16 00:10:18 +00:00
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
tile: fix copyright header blocks in just-committed files I accidentally committed versions not following the conventions.
2014-10-06 17:47:02 +00:00
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
tilegx: provide optimized strnlen, strstr, and strcasestr strnlen() is based on the existing tile strlen() with length checking added. It speeds up by up to 5x, but on average across the benchtest corpus by around 35%. No regressions are seen. strstr() does 8-byte aligned loads and compares using a 2-byte filter on the first two bytes of the needle and then testing the remaining bytes in needle using memcmp(). It speeds up about 5x in the best case (for "found" needles), about 2x looking at benchtest as a whole, with some slowdowns as much as 45%. on a few cases (including the "fail" case for 128KB search). strcasestr() is based on strstr() but uses a SIMD tolower routine to convert 8-bytes to lower case in 5 instructions. It also uses a 2-byte filter and then strncasecmp() for the remaining bytes. strncasecmp() is not optimized for SIMD, so there is futher room for improvement. However, it is still up to 16x faster for "found" needles, averaging 2x faster on the whole corpus of benchtests. It does slow down by up to 35% on a few cases, similarly to strstr().
2014-09-16 00:10:18 +00:00
#if HAVE_CONFIG_H
# include <config.h>
#endif
/* Specification. */
#include <string.h>
#include <ctype.h>
#include <stdbool.h>
#include <strings.h>
#define USE_AS_STRCASESTR
#define STRSTR __strcasestr
#define STRSTR2 strcasestr2
#define STRCHR strcasechr
#define STRSTR_SCAN strcasestr_scan
#undef strcasestr
#undef __strcasestr
#ifndef STRCASESTR
#define STRCASESTR __strcasestr
#endif
#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
#define CANON_ELEMENT(c) TOLOWER (c)
#define CMP_FUNC(p1, p2, l) \
__strncasecmp ((const char *) (p1), (const char *) (p2), l)
#include "strstr.c"
#ifndef NO_ALIAS
weak_alias (__strcasestr, strcasestr)
#endif
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