nataraid(4): Add devstat support.
[dragonfly.git] / sys / libkern / qsort.c
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1/*-
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: src/sys/libkern/qsort.c,v 1.10 1999/08/28 00:46:35 peter Exp $
e93690c2 34 * $DragonFly: src/sys/libkern/qsort.c,v 1.6 2006/12/13 21:58:51 dillon Exp $
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35 */
36
37#include <sys/libkern.h>
38
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39typedef int cmp_t(const void *, const void *);
40static __inline char *med3(char *, char *, char *, cmp_t *);
41static __inline void swapfunc(char *, char *, int, int);
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42
43#define min(a, b) (a) < (b) ? a : b
44
45/*
46 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
47 */
48#define swapcode(TYPE, parmi, parmj, n) { \
49 long i = (n) / sizeof (TYPE); \
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50 TYPE *pi = (TYPE *) (parmi); \
51 TYPE *pj = (TYPE *) (parmj); \
984263bc 52 do { \
0e99e805 53 TYPE t = *pi; \
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54 *pi++ = *pj; \
55 *pj++ = t; \
56 } while (--i > 0); \
57}
58
59#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
60 es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
61
62static __inline void
e73e0a5e 63swapfunc(char *a, char *b, int n, int swaptype)
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64{
65 if(swaptype <= 1)
66 swapcode(long, a, b, n)
67 else
68 swapcode(char, a, b, n)
69}
70
71#define swap(a, b) \
72 if (swaptype == 0) { \
73 long t = *(long *)(a); \
74 *(long *)(a) = *(long *)(b); \
75 *(long *)(b) = t; \
76 } else \
77 swapfunc(a, b, es, swaptype)
78
79#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
80
81static __inline char *
e73e0a5e 82med3(char *a, char *b, char *c, cmp_t *cmp)
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83{
84 return cmp(a, b) < 0 ?
85 (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
86 :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
87}
88
89void
e93690c2 90kqsort(void *a, size_t n, size_t es, cmp_t *cmp)
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91{
92 char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
93 int d, r, swaptype, swap_cnt;
94
95loop: SWAPINIT(a, es);
96 swap_cnt = 0;
97 if (n < 7) {
98 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
99 for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0;
100 pl -= es)
101 swap(pl, pl - es);
102 return;
103 }
104 pm = (char *)a + (n / 2) * es;
105 if (n > 7) {
106 pl = a;
107 pn = (char *)a + (n - 1) * es;
108 if (n > 40) {
109 d = (n / 8) * es;
110 pl = med3(pl, pl + d, pl + 2 * d, cmp);
111 pm = med3(pm - d, pm, pm + d, cmp);
112 pn = med3(pn - 2 * d, pn - d, pn, cmp);
113 }
114 pm = med3(pl, pm, pn, cmp);
115 }
116 swap(a, pm);
117 pa = pb = (char *)a + es;
118
119 pc = pd = (char *)a + (n - 1) * es;
120 for (;;) {
121 while (pb <= pc && (r = cmp(pb, a)) <= 0) {
122 if (r == 0) {
123 swap_cnt = 1;
124 swap(pa, pb);
125 pa += es;
126 }
127 pb += es;
128 }
129 while (pb <= pc && (r = cmp(pc, a)) >= 0) {
130 if (r == 0) {
131 swap_cnt = 1;
132 swap(pc, pd);
133 pd -= es;
134 }
135 pc -= es;
136 }
137 if (pb > pc)
138 break;
139 swap(pb, pc);
140 swap_cnt = 1;
141 pb += es;
142 pc -= es;
143 }
144 if (swap_cnt == 0) { /* Switch to insertion sort */
145 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
146 for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0;
147 pl -= es)
148 swap(pl, pl - es);
149 return;
150 }
151
152 pn = (char *)a + n * es;
153 r = min(pa - (char *)a, pb - pa);
154 vecswap(a, pb - r, r);
155 r = min(pd - pc, pn - pd - es);
156 vecswap(pb, pn - r, r);
157 if ((r = pb - pa) > es)
e93690c2 158 kqsort(a, r / es, es, cmp);
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159 if ((r = pd - pc) > es) {
160 /* Iterate rather than recurse to save stack space */
161 a = pn - r;
162 n = r / es;
163 goto loop;
164 }
e93690c2 165/* kqsort(pn - r, r / es, es, cmp);*/
984263bc 166}