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. 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 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
39 typedef int cmp_t(void *, const void *, const void *);
41 typedef int cmp_t(const void *, const void *);
43 static inline char *med3(char *, char *, char *, cmp_t *, void *);
44 static inline void swapfunc(char *, char *, int, int, int);
46 #define MIN(a, b) ((a) < (b) ? a : b)
49 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
51 #define swapcode(TYPE, parmi, parmj, n) { \
52 long i = (n) / sizeof (TYPE); \
53 TYPE *pi = (TYPE *) (parmi); \
54 TYPE *pj = (TYPE *) (parmj); \
62 #define SWAPINIT(TYPE, a, es) swaptype_ ## TYPE = \
63 ((char *)a - (char *)0) % sizeof(TYPE) || \
64 es % sizeof(TYPE) ? 2 : es == sizeof(TYPE) ? 0 : 1;
67 swapfunc(a, b, n, swaptype_long, swaptype_int)
69 int n, swaptype_long, swaptype_int;
71 if (swaptype_long <= 1)
72 swapcode(long, a, b, n)
73 else if (swaptype_int <= 1)
74 swapcode(int, a, b, n)
76 swapcode(char, a, b, n)
80 if (swaptype_long == 0) { \
81 long t = *(long *)(a); \
82 *(long *)(a) = *(long *)(b); \
84 } else if (swaptype_int == 0) { \
85 int t = *(int *)(a); \
86 *(int *)(a) = *(int *)(b); \
89 swapfunc(a, b, es, swaptype_long, swaptype_int)
91 #define vecswap(a, b, n) \
92 if ((n) > 0) swapfunc(a, b, n, swaptype_long, swaptype_int)
95 #define CMP(t, x, y) (cmp((t), (x), (y)))
97 #define CMP(t, x, y) (cmp((x), (y)))
101 med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk
107 return CMP(thunk, a, b) < 0 ?
108 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a ))
109 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));
114 qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
118 qsort(void *a, size_t n, size_t es, cmp_t *cmp)
121 char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
124 int swaptype_long, swaptype_int, swap_cnt;
126 loop: SWAPINIT(long, a, es);
127 SWAPINIT(int, a, es);
130 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
132 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
137 pm = (char *)a + (n / 2) * es;
140 pn = (char *)a + (n - 1) * es;
143 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);
144 pm = med3(pm - d, pm, pm + d, cmp, thunk);
145 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk);
147 pm = med3(pl, pm, pn, cmp, thunk);
150 pa = pb = (char *)a + es;
152 pc = pd = (char *)a + (n - 1) * es;
154 while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) {
155 if (cmp_result == 0) {
162 while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) {
163 if (cmp_result == 0) {
177 if (swap_cnt == 0) { /* Switch to insertion sort */
178 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
180 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
186 pn = (char *)a + n * es;
187 r = MIN(pa - (char *)a, pb - pa);
188 vecswap(a, pb - r, r);
189 r = MIN(pd - pc, pn - pd - es);
190 vecswap(pb, pn - r, r);
191 if ((r = pb - pa) > es)
193 qsort_r(a, r / es, es, thunk, cmp);
195 qsort(a, r / es, es, cmp);
197 if ((r = pd - pc) > es) {
198 /* Iterate rather than recurse to save stack space */
203 /* qsort(pn - r, r / es, es, cmp);*/