1 /*
2 * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
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
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
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>
67 #include <sys/kpi_private.h>
68 #include <kern/qsort.h>
69
70 static inline char *med3(char *, char *, char *, int (*)(const void *, const void *));
71 static inline void swapfunc(char *, char *, long, int);
72
73 #define min(a, b) ((a) < (b) ? (a) : (b))
74
75 /*
76 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
77 */
78 #define swapcode(TYPE, parmi, parmj, n) \
79 long i = (n) / sizeof (TYPE); \
80 TYPE *pi = (TYPE *) (parmi); \
81 TYPE *pj = (TYPE *) (parmj); \
82 do { \
83 TYPE t = *pi; \
84 *pi++ = *pj; \
85 *pj++ = t; \
86 } while (--i > 0);
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
swapfunc(char * a,char * b,long n,int swaptype)92 swapfunc(char *a, char *b, long n, int swaptype)
93 {
94 if (swaptype <= 1) {
95 swapcode(long, a, b, n);
96 } else {
97 swapcode(char, a, b, n);
98 }
99 }
100
101 #define swap(a, b) \
102 if (swaptype == 0) { \
103 long t = *(long *)(a); \
104 *(long *)(a) = *(long *)(b); \
105 *(long *)(b) = t; \
106 } else \
107 swapfunc(a, b, es, swaptype)
108
109 #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
110
111 static inline char *
med3(char * a,char * b,char * c,int (* cmp)(const void *,const void *))112 med3(char *a, char *b, char *c, int (*cmp)(const void *, const void *))
113 {
114 return cmp(a, b) < 0 ?
115 (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a))
116 :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c));
117 }
118
119 __private_extern__
120 void
qsort(void * a,size_t n,size_t es,int (* cmp)(const void *,const void *))121 qsort(void *a, size_t n, size_t es, int (*cmp)(const void *, const void *))
122 {
123 char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
124 int swaptype, swap_cnt;
125 long d, r;
126
127 loop: SWAPINIT(a, es);
128 swap_cnt = 0;
129 if (n < 7) {
130 for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es) {
131 for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
132 pl -= es) {
133 swap(pl, (char *)(pl - es));
134 }
135 }
136 return;
137 }
138 pm = (char *)a + (n / 2) * es;
139 if (n > 7) {
140 pl = a;
141 pn = (char *)a + (n - 1) * es;
142 if (n > 40) {
143 d = (n / 8) * es;
144 pl = med3(pl, pl + d, pl + 2 * d, cmp);
145 pm = med3(pm - d, pm, pm + d, cmp);
146 pn = med3(pn - 2 * d, pn - d, pn, cmp);
147 }
148 pm = med3(pl, pm, pn, cmp);
149 }
150 swap(a, pm);
151 pa = pb = (char *)a + es;
152
153 pc = pd = (char *)a + (n - 1) * es;
154 for (;;) {
155 while (pb <= pc && (r = cmp(pb, a)) <= 0) {
156 if (r == 0) {
157 swap_cnt = 1;
158 swap(pa, pb);
159 pa += es;
160 }
161 pb += es;
162 }
163 while (pb <= pc && (r = cmp(pc, a)) >= 0) {
164 if (r == 0) {
165 swap_cnt = 1;
166 swap(pc, pd);
167 pd -= es;
168 }
169 pc -= es;
170 }
171 if (pb > pc) {
172 break;
173 }
174 swap(pb, pc);
175 swap_cnt = 1;
176 pb += es;
177 pc -= es;
178 }
179 if (swap_cnt == 0) { /* Switch to insertion sort */
180 for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es) {
181 for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
182 pl -= es) {
183 swap(pl, pl - es);
184 }
185 }
186 return;
187 }
188
189 pn = (char *)a + n * es;
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 ((size_t)(r = pb - pa) > es) {
195 qsort(a, r / es, es, cmp);
196 }
197 if ((size_t)(r = pd - pc) > es) {
198 /* Iterate rather than recurse to save stack space */
199 a = pn - r;
200 n = r / es;
201 goto loop;
202 }
203 /* qsort(pn - r, r / es, es, cmp);*/
204 }
205
206 /* private KPI */
207 void
kx_qsort(void * array,size_t nm,size_t member_size,int (* cmpf)(const void *,const void *))208 kx_qsort(void *array, size_t nm, size_t member_size, int (*cmpf)(const void *, const void *))
209 {
210 qsort(array, nm, member_size, cmpf);
211 }
212