172 lines
4.8 KiB
C
172 lines
4.8 KiB
C
/* $NetBSD: qsort.c,v 1.20 2009/06/01 06:37:40 yamt Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 1992, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
#if 0
|
|
static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93";
|
|
#else
|
|
__RCSID("$NetBSD: qsort.c,v 1.20 2009/06/01 06:37:40 yamt Exp $");
|
|
#endif
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <assert.h>
|
|
#include <errno.h>
|
|
#include <stdlib.h>
|
|
|
|
static inline char *med3 __P((char *, char *, char *,
|
|
int (*)(const void *, const void *)));
|
|
static inline void swapfunc __P((char *, char *, size_t, int));
|
|
|
|
#define min(a, b) (a) < (b) ? a : b
|
|
|
|
/*
|
|
* Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
|
|
*/
|
|
#define swapcode(TYPE, parmi, parmj, n) { \
|
|
size_t i = (n) / sizeof (TYPE); \
|
|
TYPE *pi = (TYPE *)(void *)(parmi); \
|
|
TYPE *pj = (TYPE *)(void *)(parmj); \
|
|
do { \
|
|
TYPE t = *pi; \
|
|
*pi++ = *pj; \
|
|
*pj++ = t; \
|
|
} while (--i > 0); \
|
|
}
|
|
|
|
#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
|
|
es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
|
|
|
|
static inline void
|
|
swapfunc(char *a, char *b, size_t n, int swaptype)
|
|
{
|
|
|
|
if (swaptype <= 1)
|
|
swapcode(long, a, b, n)
|
|
else
|
|
swapcode(char, a, b, n)
|
|
}
|
|
|
|
#define swap(a, b) \
|
|
if (swaptype == 0) { \
|
|
long t = *(long *)(void *)(a); \
|
|
*(long *)(void *)(a) = *(long *)(void *)(b); \
|
|
*(long *)(void *)(b) = t; \
|
|
} else \
|
|
swapfunc(a, b, es, swaptype)
|
|
|
|
#define vecswap(a, b, n) if ((n) > 0) swapfunc((a), (b), (size_t)(n), swaptype)
|
|
|
|
static inline char *
|
|
med3(char *a, char *b, char *c,
|
|
int (*cmp) __P((const void *, const void *)))
|
|
{
|
|
|
|
return cmp(a, b) < 0 ?
|
|
(cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
|
|
:(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
|
|
}
|
|
|
|
void
|
|
qsort(void *a, size_t n, size_t es,
|
|
int (*cmp) __P((const void *, const void *)))
|
|
{
|
|
char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
|
|
size_t d, r;
|
|
int swaptype, cmp_result;
|
|
|
|
_DIAGASSERT(a != NULL);
|
|
_DIAGASSERT(cmp != NULL);
|
|
|
|
loop: SWAPINIT(a, es);
|
|
if (n < 7) {
|
|
for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
|
|
for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
|
|
pl -= es)
|
|
swap(pl, pl - es);
|
|
return;
|
|
}
|
|
pm = (char *) a + (n / 2) * es;
|
|
if (n > 7) {
|
|
pl = (char *) a;
|
|
pn = (char *) a + (n - 1) * es;
|
|
if (n > 40) {
|
|
d = (n / 8) * es;
|
|
pl = med3(pl, pl + d, pl + 2 * d, cmp);
|
|
pm = med3(pm - d, pm, pm + d, cmp);
|
|
pn = med3(pn - 2 * d, pn - d, pn, cmp);
|
|
}
|
|
pm = med3(pl, pm, pn, cmp);
|
|
}
|
|
swap(a, pm);
|
|
pa = pb = (char *) a + es;
|
|
|
|
pc = pd = (char *) a + (n - 1) * es;
|
|
for (;;) {
|
|
while (pb <= pc && (cmp_result = cmp(pb, a)) <= 0) {
|
|
if (cmp_result == 0) {
|
|
swap(pa, pb);
|
|
pa += es;
|
|
}
|
|
pb += es;
|
|
}
|
|
while (pb <= pc && (cmp_result = cmp(pc, a)) >= 0) {
|
|
if (cmp_result == 0) {
|
|
swap(pc, pd);
|
|
pd -= es;
|
|
}
|
|
pc -= es;
|
|
}
|
|
if (pb > pc)
|
|
break;
|
|
swap(pb, pc);
|
|
pb += es;
|
|
pc -= es;
|
|
}
|
|
|
|
pn = (char *) a + n * es;
|
|
r = min(pa - (char *) a, pb - pa);
|
|
vecswap(a, pb - r, r);
|
|
r = min((size_t)(pd - pc), pn - pd - es);
|
|
vecswap(pb, pn - r, r);
|
|
if ((r = pb - pa) > es)
|
|
qsort(a, r / es, es, cmp);
|
|
if ((r = pd - pc) > es) {
|
|
/* Iterate rather than recurse to save stack space */
|
|
a = pn - r;
|
|
n = r / es;
|
|
goto loop;
|
|
}
|
|
/* qsort(pn - r, r / es, es, cmp);*/
|
|
}
|