2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include <sys/param.h>
34 #include <sys/libkern.h>
37 typedef int cmp_t(void *, const void *, const void *);
39 typedef int cmp_t(const void *, const void *);
41 static inline char *med3(char *, char *, char *, cmp_t *, void *);
42 static inline void swapfunc(char *, char *, size_t, int, int);
45 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
47 #define swapcode(TYPE, parmi, parmj, n) { \
48 size_t i = (n) / sizeof (TYPE); \
49 TYPE *pi = (TYPE *) (parmi); \
50 TYPE *pj = (TYPE *) (parmj); \
58 #define SWAPINIT(TYPE, a, es) swaptype_ ## TYPE = \
59 ((char *)a - (char *)0) % sizeof(TYPE) || \
60 es % sizeof(TYPE) ? 2 : es == sizeof(TYPE) ? 0 : 1;
63 swapfunc(char *a, char *b, size_t n, int swaptype_long, int swaptype_int)
65 if (swaptype_long <= 1)
66 swapcode(long, a, b, n)
67 else if (swaptype_int <= 1)
68 swapcode(int, a, b, n)
70 swapcode(char, a, b, n)
74 if (swaptype_long == 0) { \
75 long t = *(long *)(a); \
76 *(long *)(a) = *(long *)(b); \
78 } else if (swaptype_int == 0) { \
79 int t = *(int *)(a); \
80 *(int *)(a) = *(int *)(b); \
83 swapfunc(a, b, es, swaptype_long, swaptype_int)
85 #define vecswap(a, b, n) \
86 if ((n) > 0) swapfunc(a, b, n, swaptype_long, swaptype_int)
89 #define CMP(t, x, y) (cmp((t), (x), (y)))
91 #define CMP(t, x, y) (cmp((x), (y)))
95 med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk
101 return CMP(thunk, a, b) < 0 ?
102 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a ))
103 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));
108 qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
112 qsort(void *a, size_t n, size_t es, cmp_t *cmp)
115 char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
118 int swaptype_long, swaptype_int, swap_cnt;
120 loop: SWAPINIT(long, a, es);
121 SWAPINIT(int, a, es);
124 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
126 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
131 pm = (char *)a + (n / 2) * es;
134 pn = (char *)a + (n - 1) * es;
136 size_t d = (n / 8) * es;
138 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);
139 pm = med3(pm - d, pm, pm + d, cmp, thunk);
140 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk);
142 pm = med3(pl, pm, pn, cmp, thunk);
145 pa = pb = (char *)a + es;
147 pc = pd = (char *)a + (n - 1) * es;
149 while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) {
150 if (cmp_result == 0) {
157 while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) {
158 if (cmp_result == 0) {
172 if (swap_cnt == 0) { /* Switch to insertion sort */
173 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
175 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
181 pn = (char *)a + n * es;
182 d1 = MIN(pa - (char *)a, pb - pa);
183 vecswap(a, pb - d1, d1);
184 d1 = MIN(pd - pc, pn - pd - es);
185 vecswap(pb, pn - d1, d1);
190 /* Recurse on left partition, then iterate on right partition */
193 qsort_r(a, d1 / es, es, thunk, cmp);
195 qsort(a, d1 / es, es, cmp);
199 /* Iterate rather than recurse to save stack space */
200 /* qsort(pn - d2, d2 / es, es, cmp); */
206 /* Recurse on right partition, then iterate on left partition */
209 qsort_r(pn - d2, d2 / es, es, thunk, cmp);
211 qsort(pn - d2, d2 / es, es, cmp);
215 /* Iterate rather than recurse to save stack space */
216 /* qsort(a, d1 / es, es, cmp); */