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
34 #include "opal_config.h"
35
36 #if OPAL_HAVE_BROKEN_QSORT
37
38 #include <stdlib.h>
39
40 #include "opal/util/qsort.h"
41
42 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);
45
46 #define min(a, b) (a) < (b) ? a : b
47
48 /*
49 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
50 */
51 #define swapcode(TYPE, parmi, parmj, n) { \
52 long i = (n) / sizeof (TYPE); \
53 TYPE *pi = (TYPE *) (parmi); \
54 TYPE *pj = (TYPE *) (parmj); \
55 do { \
56 TYPE t = *pi; \
57 *pi++ = *pj; \
58 *pj++ = t; \
59 } while (--i > 0); \
60 }
61
62 #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
63 es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
64
65 static inline void
66 swapfunc(a, b, n, swaptype)
67 char *a, *b;
68 int n, swaptype;
69 {
70 if(swaptype <= 1)
71 swapcode(long, a, b, n)
72 else
73 swapcode(char, a, b, n)
74 }
75
76 #define swap(a, b) \
77 if (swaptype == 0) { \
78 long t = *(long *)(a); \
79 *(long *)(a) = *(long *)(b); \
80 *(long *)(b) = t; \
81 } else \
82 swapfunc(a, b, es, swaptype)
83
84 #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
85
86 #define CMP(t, x, y) (cmp((x), (y)))
87
88 static inline char *
89 med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk)
90 {
91 return CMP(thunk, a, b) < 0 ?
92 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a ))
93 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));
94 }
95
96 #define thunk NULL
97 void
98 opal_qsort(void *a, size_t n, size_t es, cmp_t *cmp)
99 {
100 char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
101 int d, r, swaptype, swap_cnt;
102
103 loop: SWAPINIT(a, es);
104 swap_cnt = 0;
105 if (n < 7) {
106 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
107 for (pl = pm;
108 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
109 pl -= es)
110 swap(pl, pl - es);
111 return;
112 }
113 pm = (char *)a + (n / 2) * es;
114 if (n > 7) {
115 pl = a;
116 pn = (char *)a + (n - 1) * es;
117 if (n > 40) {
118 d = (n / 8) * es;
119 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);
120 pm = med3(pm - d, pm, pm + d, cmp, thunk);
121 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk);
122 }
123 pm = med3(pl, pm, pn, cmp, thunk);
124 }
125 swap(a, pm);
126 pa = pb = (char *)a + es;
127
128 pc = pd = (char *)a + (n - 1) * es;
129 for (;;) {
130 while (pb <= pc && (r = CMP(thunk, pb, a)) <= 0) {
131 if (r == 0) {
132 swap_cnt = 1;
133 swap(pa, pb);
134 pa += es;
135 }
136 pb += es;
137 }
138 while (pb <= pc && (r = CMP(thunk, pc, a)) >= 0) {
139 if (r == 0) {
140 swap_cnt = 1;
141 swap(pc, pd);
142 pd -= es;
143 }
144 pc -= es;
145 }
146 if (pb > pc)
147 break;
148 swap(pb, pc);
149 swap_cnt = 1;
150 pb += es;
151 pc -= es;
152 }
153 if (swap_cnt == 0) { /* Switch to insertion sort */
154 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
155 for (pl = pm;
156 pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
157 pl -= es)
158 swap(pl, pl - es);
159 return;
160 }
161
162 pn = (char *)a + n * es;
163 r = (int) min(pa - (char *)a, pb - pa);
164 vecswap(a, pb - r, r);
165 r = (int) (min((char*) (pd - pc), (char*) (pn - pd - es)));
166 vecswap(pb, pn - r, r);
167 if ((size_t) (r = pb - pa) > es)
168 opal_qsort(a, r / es, es, cmp);
169 if ((size_t) (r = pd - pc) > es) {
170 /* Iterate rather than recurse to save stack space */
171 a = pn - r;
172 n = r / es;
173 goto loop;
174 }
175 /* qsort(pn - r, r / es, es, cmp);*/
176 }
177
178 #endif /* OPAL_HAVE_BROKEN_QSORT */