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 * Grabbed from XNU source code with minor modifications:
67 * https://opensource.apple.com/source/xnu/xnu-3248.60.10/bsd/kern/qsort.c
68 */
69 #ifndef CS_QSORT_H
70 #define CS_QSORT_H
71
72 #include <libkern/libkern.h>
73
74 #pragma clang diagnostic push
75 #pragma clang diagnostic ignored "-Wshorten-64-to-32"
76
77 void
78 qsort(void *a, size_t n, size_t es, int (*cmp)(const void *, const void *));
79
80 static inline char *med3(char *, char *, char *, int (*)(const void *, const void *));
81 static inline void swapfunc(char *, char *, int, int);
82
83 #define min(a, b) (a) < (b) ? a : b
84
85 /*
86 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
87 */
88 #define swapcode(TYPE, parmi, parmj, n) { \
89 long i = (n) / sizeof (TYPE); \
90 TYPE *pi = (TYPE *) (parmi); \
91 TYPE *pj = (TYPE *) (parmj); \
92 do { \
93 TYPE t = *pi; \
94 *pi++ = *pj; \
95 *pj++ = t; \
96 } while (--i > 0); \
97 }
98
99 #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
100 es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
101
102 static inline void
swapfunc(char * a,char * b,int n,int swaptype)103 swapfunc(char *a, char *b, int n, int swaptype)
104 {
105 if(swaptype <= 1)
106 swapcode(long, a, b, n)
107 else
108 swapcode(char, a, b, n)
109 }
110
111 #define swap(a, b) \
112 if (swaptype == 0) { \
113 long t = *(long *)(a); \
114 *(long *)(a) = *(long *)(b); \
115 *(long *)(b) = t; \
116 } else \
117 swapfunc(a, b, es, swaptype)
118
119 #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
120
121 static inline char *
med3(char * a,char * b,char * c,int (* cmp)(const void *,const void *))122 med3(char *a, char *b, char *c, int (*cmp)(const void *, const void *))
123 {
124 return cmp(a, b) < 0 ?
125 (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
126 :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
127 }
128
129 void
qsort(void * a,size_t n,size_t es,int (* cmp)(const void *,const void *))130 qsort(void *a, size_t n, size_t es, int (*cmp)(const void *, const void *))
131 {
132 char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
133 int d, swaptype, swap_cnt;
134 int r;
135
136 loop: SWAPINIT(a, es);
137 swap_cnt = 0;
138 if (n < 7) {
139 for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es)
140 for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
141 pl -= es)
142 swap(pl, pl - es);
143 return;
144 }
145 pm = (char *)a + (n / 2) * es;
146 if (n > 7) {
147 pl = a;
148 pn = (char *)a + (n - 1) * es;
149 if (n > 40) {
150 d = (n / 8) * es;
151 pl = med3(pl, pl + d, pl + 2 * d, cmp);
152 pm = med3(pm - d, pm, pm + d, cmp);
153 pn = med3(pn - 2 * d, pn - d, pn, cmp);
154 }
155 pm = med3(pl, pm, pn, cmp);
156 }
157 swap(a, pm);
158 pa = pb = (char *)a + es;
159
160 pc = pd = (char *)a + (n - 1) * es;
161 for (;;) {
162 while (pb <= pc && (r = cmp(pb, a)) <= 0) {
163 if (r == 0) {
164 swap_cnt = 1;
165 swap(pa, pb);
166 pa += es;
167 }
168 pb += es;
169 }
170 while (pb <= pc && (r = cmp(pc, a)) >= 0) {
171 if (r == 0) {
172 swap_cnt = 1;
173 swap(pc, pd);
174 pd -= es;
175 }
176 pc -= es;
177 }
178 if (pb > pc)
179 break;
180 swap(pb, pc);
181 swap_cnt = 1;
182 pb += es;
183 pc -= es;
184 }
185 if (swap_cnt == 0) { /* Switch to insertion sort */
186 for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es)
187 for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
188 pl -= es)
189 swap(pl, pl - es);
190 return;
191 }
192
193 pn = (char *)a + n * es;
194 r = min(pa - (char *)a, pb - pa);
195 vecswap(a, pb - r, r);
196 r = min((size_t)(pd - pc), pn - pd - es);
197 vecswap(pb, pn - r, r);
198 if ((size_t)(r = pb - pa) > es)
199 qsort(a, r / es, es, cmp);
200 if ((size_t)(r = pd - pc) > es) {
201 /* Iterate rather than recurse to save stack space */
202 a = pn - r;
203 n = r / es;
204 goto loop;
205 }
206 /* qsort(pn - r, r / es, es, cmp);*/
207 }
208
209 #pragma clang diagnostic pop
210
211 #endif
212