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1/*
2 * Copyright (c) 1999-2003 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * Portions Copyright (c) 1999-2003 Apple Computer, Inc. All Rights
7 * Reserved. This file contains Original Code and/or Modifications of
8 * Original Code as defined in and that are subject to the Apple Public
9 * Source License Version 2.0 (the "License"). You may not use this file
10 * except in compliance with the License. Please obtain a copy of the
11 * License at http://www.apple.com/publicsource and read it before using
12 * this file.
13 *
14 * The Original Code and all software distributed under the License are
15 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
16 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT. Please see the
19 * License for the specific language governing rights and limitations
20 * under the License.
21 *
22 * @APPLE_LICENSE_HEADER_END@
23 */
24/*
25 * Copyright (c) 1992, 1993
26 *The Regents of the University of California. All rights reserved.
27 *
28 * Redistribution and use in source and binary forms, with or without
29 * modification, are permitted provided that the following conditions
30 * are met:
31 * 1. Redistributions of source code must retain the above copyright
32 * notice, this list of conditions and the following disclaimer.
33 * 2. Redistributions in binary form must reproduce the above copyright
34 * notice, this list of conditions and the following disclaimer in the
35 * documentation and/or other materials provided with the distribution.
36 * 3. All advertising materials mentioning features or use of this software
37 * must display the following acknowledgement:
38 *This product includes software developed by the University of
39 *California, Berkeley and its contributors.
40 * 4. Neither the name of the University nor the names of its contributors
41 * may be used to endorse or promote products derived from this software
42 * without specific prior written permission.
43 *
44 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
45 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
46 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
47 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
48 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
49 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
50 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
51 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
52 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
53 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
54 * SUCH DAMAGE.
55 */
56
57
58#include <sys/types.h>
59#include <stdlib.h>
60#include <sys/param.h>
61
62static inline char*med3 __P((char *, char *, char *, int (*)()));
63static inline void swapfunc __P((char *, char *, int, int));
64
65/*
66 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
67 */
68#define swapcode(TYPE, parmi, parmj, n) { \
69long i = (n) / sizeof (TYPE); \
70register TYPE *pi = (TYPE *) (parmi); \
71register TYPE *pj = (TYPE *) (parmj); \
72do { \
73register TYPEt = *pi;\
74*pi++ = *pj;\
75*pj++ = t;\
76 } while (--i > 0);\
77}
78
79#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
80es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
81
82static inline void
83swapfunc(a, b, n, swaptype)
84char *a, *b;
85int n, swaptype;
86{
87if(swaptype <= 1)
88swapcode(long, a, b, n)
89else
90swapcode(char, a, b, n)
91}
92
93#define swap(a, b)\
94if (swaptype == 0) {\
95long t = *(long *)(a);\
96*(long *)(a) = *(long *)(b);\
97*(long *)(b) = t;\
98} else\
99swapfunc(a, b, es, swaptype)
100
101#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
102
103static inline char *
104med3(a, b, c, cmp)
105char *a, *b, *c;
106int (*cmp)();
107{
108return cmp(a, b) < 0 ?
109 (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
110 :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
111}
112
113void
114qsort(a, n, es, cmp)
115void *a;
116size_t n, es;
117int (*cmp)();
118{
119char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
120int d, r, swaptype, swap_cnt;
121
122loop:SWAPINIT(a, es);
123swap_cnt = 0;
124if (n < 7) {
125for (pm = a + es; pm < (char *) a + n * es; pm += es)
126for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
127 pl -= es)
128swap(pl, pl - es);
129return;
130}
131pm = a + (n / 2) * es;
132if (n > 7) {
133pl = a;
134pn = a + (n - 1) * es;
135if (n > 40) {
136d = (n / 8) * es;
137pl = med3(pl, pl + d, pl + 2 * d, cmp);
138pm = med3(pm - d, pm, pm + d, cmp);
139pn = med3(pn - 2 * d, pn - d, pn, cmp);
140}
141pm = med3(pl, pm, pn, cmp);
142}
143swap(a, pm);
144pa = pb = a + es;
145
146pc = pd = a + (n - 1) * es;
147for (;;) {
148while (pb <= pc && (r = cmp(pb, a)) <= 0) {
149if (r == 0) {
150swap_cnt = 1;
151swap(pa, pb);
152pa += es;
153}
154pb += es;
155}
156while (pb <= pc && (r = cmp(pc, a)) >= 0) {
157if (r == 0) {
158swap_cnt = 1;
159swap(pc, pd);
160pd -= es;
161}
162pc -= es;
163}
164if (pb > pc)
165break;
166swap(pb, pc);
167swap_cnt = 1;
168pb += es;
169pc -= es;
170}
171if (swap_cnt == 0) { /* Switch to insertion sort */
172for (pm = a + es; pm < (char *) a + n * es; pm += es)
173for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
174 pl -= es)
175swap(pl, pl - es);
176return;
177}
178
179pn = a + n * es;
180r = MIN(pa - (char *)a, pb - pa);
181vecswap(a, pb - r, r);
182r = MIN(pd - pc, (pn - pd) - (int)es);
183vecswap(pb, pn - r, r);
184if ((r = pb - pa) > (int)es)
185qsort(a, r / es, es, cmp);
186if ((r = pd - pc) > (int)es) {
187/* Iterate rather than recurse to save stack space */
188a = pn - r;
189n = r / es;
190goto loop;
191}
192/*qsort(pn - r, r / es, es, cmp);*/
193}
194

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