[apple/xnu.git] / bsd / kern / qsort.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 *
 *	@(#)qsort.c	8.1 (Berkeley) 6/4/93
 */


#include <sys/types.h>
//#include <stdlib.h>

static inline char	*med3(char *, char *, char *, int (*)());
static inline void	 swapfunc(char *, char *, int, 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) { 		\
	long i = (n) / sizeof (TYPE); 			\
	register TYPE *pi = (TYPE *) (parmi); 		\
	register TYPE *pj = (TYPE *) (parmj); 		\
	do { 						\
		register 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(a, b, n, swaptype)
	char *a, *b;
	int n, 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 *)(a);			\
		*(long *)(a) = *(long *)(b);		\
		*(long *)(b) = t;			\
	} else						\
		swapfunc(a, b, es, swaptype)

#define vecswap(a, b, n) 	if ((n) > 0) swapfunc(a, b, n, swaptype)

static inline char *
med3(a, b, c, cmp)
	char *a, *b, *c;
	int (*cmp)();
{
	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 ));
}

__private_extern__
void
qsort(a, n, es, cmp)
	void *a;
	size_t n, es;
	int (*cmp)();
{
	char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
	int d, r, swaptype, swap_cnt;

loop:	SWAPINIT(a, es);
	swap_cnt = 0;
	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 = 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 && (r = cmp(pb, a)) <= 0) {
			if (r == 0) {
				swap_cnt = 1;
				swap(pa, pb);
				pa += es;
			}
			pb += es;
		}
		while (pb <= pc && (r = cmp(pc, a)) >= 0) {
			if (r == 0) {
				swap_cnt = 1;
				swap(pc, pd);
				pd -= es;
			}
			pc -= es;
		}
		if (pb > pc)
			break;
		swap(pb, pc);
		swap_cnt = 1;
		pb += es;
		pc -= es;
	}
	if (swap_cnt == 0) {  /* Switch to insertion sort */
		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;
	}

	pn = (char *)a + n * es;
	r = min(pa - (char *)a, pb - pa);
	vecswap(a, pb - r, r);
	r = min(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);*/
}
Commit	Line	Data
1c79356b	1	/*
5d5c5d0d A	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
5d5c5d0d A	3	*
8f6c56a5	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
8f6c56a5 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
8ad349bb	24	* limitations under the License.
8f6c56a5 A	25	*
8f6c56a5 A	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/*
	29	* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
	30	*
	31	* Copyright (c) 1992, 1993
	32	* The Regents of the University of California. All rights reserved.
	33	*
	34	* Redistribution and use in source and binary forms, with or without
	35	* modification, are permitted provided that the following conditions
	36	* are met:
	37	* 1. Redistributions of source code must retain the above copyright
	38	* notice, this list of conditions and the following disclaimer.
	39	* 2. Redistributions in binary form must reproduce the above copyright
	40	* notice, this list of conditions and the following disclaimer in the
	41	* documentation and/or other materials provided with the distribution.
	42	* 3. All advertising materials mentioning features or use of this software
	43	* must display the following acknowledgement:
	44	* This product includes software developed by the University of
	45	* California, Berkeley and its contributors.
	46	* 4. Neither the name of the University nor the names of its contributors
	47	* may be used to endorse or promote products derived from this software
	48	* without specific prior written permission.
	49	*
	50	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	51	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	52	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	53	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	54	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	55	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	56	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	57	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	58	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	59	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	60	* SUCH DAMAGE.
	61	*
	62	* @(#)qsort.c 8.1 (Berkeley) 6/4/93
	63	*/
	64
	65
	66	#include <sys/types.h>
b4c24cb9	67	//#include <stdlib.h>
1c79356b	68
91447636 A	69	static inline char med3(char , char , char , int (*)());
91447636 A	70	static inline void swapfunc(char , char , int, int);
1c79356b A	71
	72	#define min(a, b) (a) < (b) ? a : b
	73
	74	/*
	75	* Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
	76	*/
	77	#define swapcode(TYPE, parmi, parmj, n) { \
	78	long i = (n) / sizeof (TYPE); \
	79	register TYPE pi = (TYPE ) (parmi); \
	80	register TYPE pj = (TYPE ) (parmj); \
	81	do { \
	82	register TYPE t = *pi; \
	83	pi++ = pj; \
	84	*pj++ = t; \
	85	} while (--i > 0); \
	86	}
	87
	88	#define SWAPINIT(a, es) swaptype = ((char )a - (char )0) % sizeof(long) \|\| \
	89	es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
	90
	91	static inline void
	92	swapfunc(a, b, n, swaptype)
	93	char a, b;
	94	int n, swaptype;
	95	{
	96	if(swaptype <= 1)
	97	swapcode(long, a, b, n)
	98	else
	99	swapcode(char, a, b, n)
	100	}
	101
	102	#define swap(a, b) \
	103	if (swaptype == 0) { \
	104	long t = (long )(a); \
	105	(long )(a) = (long )(b); \
	106	(long )(b) = t; \
	107	} else \
	108	swapfunc(a, b, es, swaptype)
	109
	110	#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
	111
	112	static inline char *
	113	med3(a, b, c, cmp)
	114	char a, b, *c;
	115	int (*cmp)();
	116	{
	117	return cmp(a, b) < 0 ?
	118	(cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
	119	:(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
	120	}
	121
b4c24cb9	122	__private_extern__
1c79356b A	123	void
	124	qsort(a, n, es, cmp)
	125	void *a;
	126	size_t n, es;
	127	int (*cmp)();
	128	{
	129	char pa, pb, pc, pd, pl, pm, *pn;
	130	int d, r, swaptype, swap_cnt;
	131
	132	loop: SWAPINIT(a, es);
	133	swap_cnt = 0;
	134	if (n < 7) {
55e303ae	135	for (pm = (char )a + es; pm < (char ) a + n * es; pm += es)
1c79356b A	136	for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
	137	pl -= es)
	138	swap(pl, pl - es);
	139	return;
	140	}
55e303ae	141	pm = (char )a + (n / 2) es;
1c79356b A	142	if (n > 7) {
1c79356b A	143	pl = a;
55e303ae	144	pn = (char )a + (n - 1) es;
1c79356b A	145	if (n > 40) {
	146	d = (n / 8) * es;
	147	pl = med3(pl, pl + d, pl + 2 * d, cmp);
	148	pm = med3(pm - d, pm, pm + d, cmp);
	149	pn = med3(pn - 2 * d, pn - d, pn, cmp);
	150	}
	151	pm = med3(pl, pm, pn, cmp);
	152	}
	153	swap(a, pm);
55e303ae	154	pa = pb = (char *)a + es;
1c79356b	155
55e303ae	156	pc = pd = (char )a + (n - 1) es;
1c79356b A	157	for (;;) {
	158	while (pb <= pc && (r = cmp(pb, a)) <= 0) {
	159	if (r == 0) {
	160	swap_cnt = 1;
	161	swap(pa, pb);
	162	pa += es;
	163	}
	164	pb += es;
	165	}
	166	while (pb <= pc && (r = cmp(pc, a)) >= 0) {
	167	if (r == 0) {
	168	swap_cnt = 1;
	169	swap(pc, pd);
	170	pd -= es;
	171	}
	172	pc -= es;
	173	}
	174	if (pb > pc)
	175	break;
	176	swap(pb, pc);
	177	swap_cnt = 1;
	178	pb += es;
	179	pc -= es;
	180	}
	181	if (swap_cnt == 0) { /* Switch to insertion sort */
55e303ae	182	for (pm = (char )a + es; pm < (char ) a + n * es; pm += es)
1c79356b A	183	for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
	184	pl -= es)
	185	swap(pl, pl - es);
	186	return;
	187	}
	188
55e303ae	189	pn = (char )a + n es;
1c79356b A	190	r = min(pa - (char *)a, pb - pa);
	191	vecswap(a, pb - r, r);
	192	r = min(pd - pc, pn - pd - es);
	193	vecswap(pb, pn - r, r);
	194	if ((r = pb - pa) > es)
	195	qsort(a, r / es, es, cmp);
	196	if ((r = pd - pc) > es) {
	197	/* Iterate rather than recurse to save stack space */
	198	a = pn - r;
	199	n = r / es;
	200	goto loop;
	201	}
	202	/* qsort(pn - r, r / es, es, cmp);*/
	203	}