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glibc/sysdeps/x86_64/multiarch/strstr.c

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Add strstr with unaligned loads. Fixes bug 12100. A sse42 version of strstr used pcmpistr instruction which is quite ineffective. A faster way is look for pairs of characters which is uses sse2, is faster than pcmpistr and for real strings a pairs we look for are relatively rare. For linear time complexity we use buy or rent technique which switches to two-way algorithm when superlinear behaviour is detected.
2013-12-14 18:33:56 +00:00
/* Multiple versions of strstr.
All versions must be listed in ifunc-impl-list.c.
Update copyright dates with scripts/update-copyrights.
2015-01-02 16:28:19 +00:00
Copyright (C) 2012-2015 Free Software Foundation, Inc.
SSE4.2 strstr/strcasestr for x86-64. This patch implements SSE4.2 strstr/strcasestr, using Knuth-Morris-Pratt string searching algorithm.
2009-07-21 04:06:50 +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
Replace FSF snail mail address with URLs.
2012-02-09 23:18:22 +00:00
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
SSE4.2 strstr/strcasestr for x86-64. This patch implements SSE4.2 strstr/strcasestr, using Knuth-Morris-Pratt string searching algorithm.
2009-07-21 04:06:50 +00:00
Add strstr with unaligned loads. Fixes bug 12100. A sse42 version of strstr used pcmpistr instruction which is quite ineffective. A faster way is look for pairs of characters which is uses sse2, is faster than pcmpistr and for real strings a pairs we look for are relatively rare. For linear time complexity we use buy or rent technique which switches to two-way algorithm when superlinear behaviour is detected.
2013-12-14 18:33:56 +00:00
/* Redefine strstr so that the compiler won't complain about the type
mismatch with the IFUNC selector in strong_alias, below. */
#undef strstr
#define strstr __redirect_strstr
#include <string.h>
#undef strstr
#define STRSTR __strstr_sse2
#ifdef SHARED
# undef libc_hidden_builtin_def
# define libc_hidden_builtin_def(name) \
__hidden_ver1 (__strstr_sse2, __GI_strstr, __strstr_sse2);
SSE4.2 strstr/strcasestr for x86-64. This patch implements SSE4.2 strstr/strcasestr, using Knuth-Morris-Pratt string searching algorithm.
2009-07-21 04:06:50 +00:00
#endif
Add strstr with unaligned loads. Fixes bug 12100. A sse42 version of strstr used pcmpistr instruction which is quite ineffective. A faster way is look for pairs of characters which is uses sse2, is faster than pcmpistr and for real strings a pairs we look for are relatively rare. For linear time complexity we use buy or rent technique which switches to two-way algorithm when superlinear behaviour is detected.
2013-12-14 18:33:56 +00:00
#include "string/strstr.c"
SSE4.2 strstr/strcasestr for x86-64. This patch implements SSE4.2 strstr/strcasestr, using Knuth-Morris-Pratt string searching algorithm.
2009-07-21 04:06:50 +00:00
Add strstr with unaligned loads. Fixes bug 12100. A sse42 version of strstr used pcmpistr instruction which is quite ineffective. A faster way is look for pairs of characters which is uses sse2, is faster than pcmpistr and for real strings a pairs we look for are relatively rare. For linear time complexity we use buy or rent technique which switches to two-way algorithm when superlinear behaviour is detected.
2013-12-14 18:33:56 +00:00
extern __typeof (__redirect_strstr) __strstr_sse2_unaligned attribute_hidden;
extern __typeof (__redirect_strstr) __strstr_sse2 attribute_hidden;
SSE4.2 strstr/strcasestr for x86-64. This patch implements SSE4.2 strstr/strcasestr, using Knuth-Morris-Pratt string searching algorithm.
2009-07-21 04:06:50 +00:00
Add strstr with unaligned loads. Fixes bug 12100. A sse42 version of strstr used pcmpistr instruction which is quite ineffective. A faster way is look for pairs of characters which is uses sse2, is faster than pcmpistr and for real strings a pairs we look for are relatively rare. For linear time complexity we use buy or rent technique which switches to two-way algorithm when superlinear behaviour is detected.
2013-12-14 18:33:56 +00:00
#include "init-arch.h"
Minor cleanups in x86-64 strstr.
2009-07-21 14:52:12 +00:00
Add strstr with unaligned loads. Fixes bug 12100. A sse42 version of strstr used pcmpistr instruction which is quite ineffective. A faster way is look for pairs of characters which is uses sse2, is faster than pcmpistr and for real strings a pairs we look for are relatively rare. For linear time complexity we use buy or rent technique which switches to two-way algorithm when superlinear behaviour is detected.
2013-12-14 18:33:56 +00:00
/* Avoid DWARF definition DIE on ifunc symbol so that GDB can handle
ifunc symbol properly. */
extern __typeof (__redirect_strstr) __libc_strstr;
libc_ifunc (__libc_strstr, HAS_FAST_UNALIGNED_LOAD ? __strstr_sse2_unaligned : __strstr_sse2)
SSE4.2 strstr/strcasestr for x86-64. This patch implements SSE4.2 strstr/strcasestr, using Knuth-Morris-Pratt string searching algorithm.
2009-07-21 04:06:50 +00:00
Add strstr with unaligned loads. Fixes bug 12100. A sse42 version of strstr used pcmpistr instruction which is quite ineffective. A faster way is look for pairs of characters which is uses sse2, is faster than pcmpistr and for real strings a pairs we look for are relatively rare. For linear time complexity we use buy or rent technique which switches to two-way algorithm when superlinear behaviour is detected.
2013-12-14 18:33:56 +00:00
#undef strstr
strong_alias (__libc_strstr, strstr)
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