4492173466
* stdlib/qsort.c (qswap): Remove hard coded buffer size. Allow swapping of objects of arbitrary size.
81 lines
2.2 KiB
C
81 lines
2.2 KiB
C
/* -*-comment-start: "//";comment-end:""-*-
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* GNU Mes --- Maxwell Equations of Software
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* Copyright © 2017,2018 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
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* Copyright © 2021 Paul Dersey <pdersey@gmail.com>
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*
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* This file is part of GNU Mes.
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*
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* GNU Mes is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or (at
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* your option) any later version.
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*
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* GNU Mes is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU Mes. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <stdlib.h>
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#include <string.h>
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void
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qswap (void *a, void *b, size_t size)
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{
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char *pa = a;
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char *pb = b;
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do
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{
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char tmp = *pa;
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*pa++ = *pb;
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*pb++ = tmp;
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} while (--size > 0);
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}
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size_t
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qpart (void *base, size_t count, size_t size, int (*compare) (void const *, void const *))
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{
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void *p = base + count * size;
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size_t i = 0;
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for (size_t j = 0; j < count; j++)
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{
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int c = compare (base + j * size, p);
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if (c < 0)
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{
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#if 1 //__x86_64__
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qswap (base + i * size, base + j * size, size);
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#else
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int p1 = base + i * size;
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int p2 = base + j * size;
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qswap (p1, p2, size);
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#endif
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i++;
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}
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else if (c == 0)
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i++;
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}
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if (compare (base + count * size, base + i * size) < 0)
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qswap (base + i * size, base + count * size, size);
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return i;
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}
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void
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qsort (void *base, size_t count, size_t size, int (*compare) (void const *, void const *))
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{
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if (count > 1)
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{
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int p = qpart (base, count - 1, size, compare);
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qsort (base, p, size, compare);
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#if 1 //__x86_64__
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qsort (base + p * size, count - p, size, compare);
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#else
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int p1 = base + p * size;
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int p2 = count - p;
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qsort (p1, p2, size, compare);
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#endif
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}
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}
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