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

/*
 * Copyright (c) 2000-2006 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>

__private_extern__
void
qsort(void *a, size_t n, size_t es, int (*cmp)(const void *, const void *));

static inline char	*med3(char *, char *, char *, int (*)(const void *, const void *));
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); 			\
	TYPE *pi = (TYPE *) (parmi); 			\
	TYPE *pj = (TYPE *) (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, int 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 *)(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(char *a, char *b, char *c, int (*cmp)(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 ));
}

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

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((size_t)(pd - pc), pn - pd - es);
	vecswap(pb, pn - r, r);
	if ((size_t)(r = pb - pa) > es)
		qsort(a, r / es, es, cmp);
	if ((size_t)(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	/*
2d21ac55	2	* Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
5d5c5d0d	3	*
2d21ac55	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
2d21ac55 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.
8f6c56a5	14	*
2d21ac55 A	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
8f6c56a5 A	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
8f6c56a5 A	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
2d21ac55 A	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
	24	* limitations under the License.
8f6c56a5	25	*
2d21ac55	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>
b0d623f7 A	68
	69	__private_extern__
	70	void
	71	qsort(void a, size_t n, size_t es, int (cmp)(const void , const void ));
1c79356b	72
2d21ac55	73	static inline char med3(char , char , char , int ()(const void , const void *));
91447636	74	static inline void swapfunc(char , char , int, int);
1c79356b A	75
	76	#define min(a, b) (a) < (b) ? a : b
	77
	78	/*
	79	* Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
	80	*/
	81	#define swapcode(TYPE, parmi, parmj, n) { \
	82	long i = (n) / sizeof (TYPE); \
2d21ac55 A	83	TYPE pi = (TYPE ) (parmi); \
2d21ac55 A	84	TYPE pj = (TYPE ) (parmj); \
1c79356b	85	do { \
2d21ac55	86	TYPE t = *pi; \
1c79356b A	87	pi++ = pj; \
	88	*pj++ = t; \
	89	} while (--i > 0); \
	90	}
	91
	92	#define SWAPINIT(a, es) swaptype = ((char )a - (char )0) % sizeof(long) \|\| \
	93	es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
	94
	95	static inline void
2d21ac55	96	swapfunc(char a, char b, int n, int swaptype)
1c79356b A	97	{
	98	if(swaptype <= 1)
	99	swapcode(long, a, b, n)
	100	else
	101	swapcode(char, a, b, n)
	102	}
	103
	104	#define swap(a, b) \
	105	if (swaptype == 0) { \
	106	long t = (long )(a); \
	107	(long )(a) = (long )(b); \
	108	(long )(b) = t; \
	109	} else \
	110	swapfunc(a, b, es, swaptype)
	111
	112	#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
	113
	114	static inline char *
2d21ac55	115	med3(char a, char b, char c, int (cmp)(const void , const void ))
1c79356b A	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	123	void
2d21ac55	124	qsort(void a, size_t n, size_t es, int (cmp)(const void , const void ))
1c79356b A	125	{
1c79356b A	126	char pa, pb, pc, pd, pl, pm, *pn;
2d21ac55 A	127	int d, swaptype, swap_cnt;
2d21ac55 A	128	int r;
1c79356b A	129
	130	loop: SWAPINIT(a, es);
	131	swap_cnt = 0;
	132	if (n < 7) {
55e303ae	133	for (pm = (char )a + es; pm < (char ) a + n * es; pm += es)
1c79356b A	134	for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
	135	pl -= es)
	136	swap(pl, pl - es);
	137	return;
	138	}
55e303ae	139	pm = (char )a + (n / 2) es;
1c79356b A	140	if (n > 7) {
1c79356b A	141	pl = a;
55e303ae	142	pn = (char )a + (n - 1) es;
1c79356b A	143	if (n > 40) {
	144	d = (n / 8) * es;
	145	pl = med3(pl, pl + d, pl + 2 * d, cmp);
	146	pm = med3(pm - d, pm, pm + d, cmp);
	147	pn = med3(pn - 2 * d, pn - d, pn, cmp);
	148	}
	149	pm = med3(pl, pm, pn, cmp);
	150	}
	151	swap(a, pm);
55e303ae	152	pa = pb = (char *)a + es;
1c79356b	153
55e303ae	154	pc = pd = (char )a + (n - 1) es;
1c79356b A	155	for (;;) {
	156	while (pb <= pc && (r = cmp(pb, a)) <= 0) {
	157	if (r == 0) {
	158	swap_cnt = 1;
	159	swap(pa, pb);
	160	pa += es;
	161	}
	162	pb += es;
	163	}
	164	while (pb <= pc && (r = cmp(pc, a)) >= 0) {
	165	if (r == 0) {
	166	swap_cnt = 1;
	167	swap(pc, pd);
	168	pd -= es;
	169	}
	170	pc -= es;
	171	}
	172	if (pb > pc)
	173	break;
	174	swap(pb, pc);
	175	swap_cnt = 1;
	176	pb += es;
	177	pc -= es;
	178	}
	179	if (swap_cnt == 0) { /* Switch to insertion sort */
55e303ae	180	for (pm = (char )a + es; pm < (char ) a + n * es; pm += es)
1c79356b A	181	for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
	182	pl -= es)
	183	swap(pl, pl - es);
	184	return;
	185	}
	186
55e303ae	187	pn = (char )a + n es;
1c79356b A	188	r = min(pa - (char *)a, pb - pa);
1c79356b A	189	vecswap(a, pb - r, r);
2d21ac55	190	r = min((size_t)(pd - pc), pn - pd - es);
1c79356b	191	vecswap(pb, pn - r, r);
2d21ac55	192	if ((size_t)(r = pb - pa) > es)
1c79356b	193	qsort(a, r / es, es, cmp);
2d21ac55	194	if ((size_t)(r = pd - pc) > es) {
1c79356b A	195	/* Iterate rather than recurse to save stack space */
	196	a = pn - r;
	197	n = r / es;
	198	goto loop;
	199	}
	200	/* qsort(pn - r, r / es, es, cmp);*/
	201	}