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950891b5e7
Optimize the bsearch() function to improve binary search performance. Although the code size grew by 8 bytes, the new implementation achieves a 15% reduction in execution time on my x86 machine, according to the bench-bsearch benchmark results. Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com> Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com> Reviewed-by: DJ Delorie <dj@redhat.com>
51 lines
1.5 KiB
C
51 lines
1.5 KiB
C
/* Perform binary search - inline version.
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Copyright (C) 1991-2024 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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__extern_inline void *
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bsearch (const void *__key, const void *__base, size_t __nmemb, size_t __size,
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__compar_fn_t __compar)
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{
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const void *__p;
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int __comparison;
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while (__nmemb)
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{
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__p = (const void *) (((const char *) __base) + ((__nmemb >> 1) * __size));
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__comparison = (*__compar) (__key, __p);
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if (__comparison == 0)
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{
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#if __GNUC_PREREQ(4, 6)
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# pragma GCC diagnostic push
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# pragma GCC diagnostic ignored "-Wcast-qual"
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#endif
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return (void *) __p;
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#if __GNUC_PREREQ(4, 6)
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# pragma GCC diagnostic pop
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#endif
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}
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if (__comparison > 0)
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{
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__base = ((const char *) __p) + __size;
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--__nmemb;
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}
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__nmemb >>= 1;
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}
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return NULL;
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}
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