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 * 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.
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
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
43 typedef int cmp_t(void *, const void *, const void *);
45 typedef int cmp_t(const void *, const void *);
47 static inline char *med3(char *, char *, char *, cmp_t *, void *);
48 static inline void swapfunc(char *, char *, int, int);
50 #define min(a, b) (a) < (b) ? a : b
53 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
55 #define swapcode(TYPE, parmi, parmj, n) { \
56 long i = (n) / sizeof (TYPE); \
57 TYPE *pi = (TYPE *) (parmi); \
58 TYPE *pj = (TYPE *) (parmj); \
66 #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
67 es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
70 swapfunc(a, b, n, swaptype)
75 swapcode(long, a, b, n)
77 swapcode(char, a, b, n)
81 if (swaptype == 0) { \
82 long t = *(long *)(a); \
83 *(long *)(a) = *(long *)(b); \
86 swapfunc(a, b, es, swaptype)
88 #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
91 #define CMP(t, x, y) (cmp((t), (x), (y)))
93 #define CMP(t, x, y) (cmp((x), (y)))
97 med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk
103 return CMP(thunk, a, b) < 0 ?
104 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a ))
105 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));
110 qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
114 qsort(void *a, size_t n, size_t es, cmp_t *cmp)
117 char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
118 int d, r, swaptype, swap_cnt;
120 loop: SWAPINIT(a, es);
123 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
125 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
130 pm = (char *)a + (n / 2) * es;
133 pn = (char *)a + (n - 1) * es;
136 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);
137 pm = med3(pm - d, pm, pm + d, cmp, thunk);
138 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk);
140 pm = med3(pl, pm, pn, cmp, thunk);
143 pa = pb = (char *)a + es;
145 pc = pd = (char *)a + (n - 1) * es;
147 while (pb <= pc && (r = CMP(thunk, pb, a)) <= 0) {
155 while (pb <= pc && (r = CMP(thunk, pc, a)) >= 0) {
170 if (swap_cnt == 0) { /* Switch to insertion sort */
171 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
173 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
179 pn = (char *)a + n * es;
180 r = min(pa - (char *)a, pb - pa);
181 vecswap(a, pb - r, r);
182 r = min(pd - pc, pn - pd - es);
183 vecswap(pb, pn - r, r);
184 if ((r = pb - pa) > es)
186 qsort_r(a, r / es, es, thunk, cmp);
188 qsort(a, r / es, es, cmp);
190 if ((r = pd - pc) > es) {
191 /* Iterate rather than recurse to save stack space */
196 /* qsort(pn - r, r / es, es, cmp);*/