ReactOS 0.4.15-dev-8116-gf69e256
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 * 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.
16 *
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
27 * SUCH DAMAGE.
28 */
29
30#include <stdlib.h>
31#include <search.h>
32
33#define long intptr_t
34
35#define min(a, b) (a) < (b) ? (a) : (b)
36
37/*
38 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
39 */
40#define swapcode(TYPE, parmi, parmj, n) { \
41 long i = (n) / sizeof (TYPE); \
42 register TYPE *pi = (TYPE *) (parmi); \
43 register TYPE *pj = (TYPE *) (parmj); \
44 do { \
45 register TYPE t = *pi; \
46 *pi++ = *pj; \
47 *pj++ = t; \
48 } while (--i > 0); \
49}
50
51#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
52 es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
53
54static __inline void
55swapfunc(char *a, char *b, intptr_t n, int swaptype)
56{
57 if(swaptype <= 1)
58 swapcode(long, a, b, n)
59 else
60 swapcode(char, a, b, n)
61}
62
63#define swap(a, b) \
64 if (swaptype == 0) { \
65 long t = *(long *)(a); \
66 *(long *)(a) = *(long *)(b); \
67 *(long *)(b) = t; \
68 } else \
69 swapfunc(a, b, es, swaptype)
70
71#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
72
73#define CMP(x, y) (cmp((x), (y)))
74
75static __inline char *
76med3(char *a, char *b, char *c, int (__cdecl *cmp)(const void*, const void*))
77{
78 return CMP(a, b) < 0 ?
79 (CMP(b, c) < 0 ? b : (CMP(a, c) < 0 ? c : a ))
80 :(CMP(b, c) > 0 ? b : (CMP(a, c) < 0 ? a : c ));
81}
82
83/*
84 * qsort:
85 * First, set up some global parameters for qst to share. Then, quicksort
86 * with qst(), and then a cleanup insertion sort ourselves. Sound simple?
87 * It's not...
88 *
89 * @implemented
90 */
91void
93qsort(void *a, size_t n, size_t es, int (__cdecl *cmp)(const void*, const void*))
94{
95 char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
96 int swaptype, swap_cnt;
97 intptr_t d, r;
98
99loop: SWAPINIT(a, es);
100 swap_cnt = 0;
101 if (n < 7) {
102 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
103 for (pl = pm; pl > (char *)a && CMP(pl - es, pl) > 0;
104 pl -= es)
105 swap(pl, pl - es);
106 return;
107 }
108 pm = (char *)a + (n / 2) * es;
109 if (n > 7) {
110 pl = a;
111 pn = (char *)a + (n - 1) * es;
112 if (n > 40) {
113 d = (n / 8) * es;
114 pl = med3(pl, pl + d, pl + 2 * d, cmp);
115 pm = med3(pm - d, pm, pm + d, cmp);
116 pn = med3(pn - 2 * d, pn - d, pn, cmp);
117 }
118 pm = med3(pl, pm, pn, cmp);
119 }
120 swap(a, pm);
121 pa = pb = (char *)a + es;
122
123 pc = pd = (char *)a + (n - 1) * es;
124 for (;;) {
125 while (pb <= pc && (r = CMP(pb, a)) <= 0) {
126 if (r == 0) {
127 swap_cnt = 1;
128 swap(pa, pb);
129 pa += es;
130 }
131 pb += es;
132 }
133 while (pb <= pc && (r = CMP(pc, a)) >= 0) {
134 if (r == 0) {
135 swap_cnt = 1;
136 swap(pc, pd);
137 pd -= es;
138 }
139 pc -= es;
140 }
141 if (pb > pc)
142 break;
143 swap(pb, pc);
144 swap_cnt = 1;
145 pb += es;
146 pc -= es;
147 }
148 if (swap_cnt == 0) { /* Switch to insertion sort */
149 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
150 for (pl = pm; pl > (char *)a && CMP(pl - es, pl) > 0;
151 pl -= es)
152 swap(pl, pl - es);
153 return;
154 }
155
156 pn = (char *)a + n * es;
157 r = min(pa - (char *)a, pb - pa);
158 vecswap(a, pb - r, r);
159 r = min(pd - pc, pn - pd - es);
160 vecswap(pb, pn - r, r);
161 if ((r = pb - pa) > es)
162 qsort(a, r / es, es, cmp);
163 if ((r = pd - pc) > es) {
164 /* Iterate rather than recurse to save stack space */
165 a = pn - r;
166 n = r / es;
167 goto loop;
168 }
169}
#define __cdecl
Definition: accygwin.h:79
int intptr_t
Definition: crtdefs.h:304
GLdouble GLdouble GLdouble r
Definition: gl.h:2055
GLdouble n
Definition: glext.h:7729
const GLubyte * c
Definition: glext.h:8905
GLboolean GLboolean GLboolean b
Definition: glext.h:6204
GLboolean GLboolean GLboolean GLboolean a
Definition: glext.h:6204
#define es
Definition: i386-dis.c:440
#define d
Definition: ke_i.h:81
#define a
Definition: ke_i.h:78
#define c
Definition: ke_i.h:80
#define b
Definition: ke_i.h:79
static LPMONITOREX pm
Definition: localmon.c:45
#define cmp(status, error)
Definition: error.c:114
static int pints_t pn[]
Definition: server.c:129
static int ** pa
Definition: server.c:126
void __cdecl qsort(void *a, size_t n, size_t es, int(__cdecl *cmp)(const void *, const void *))
Definition: qsort.c:93
#define swap(a, b)
Definition: qsort.c:63
static __inline void swapfunc(char *a, char *b, intptr_t n, int swaptype)
Definition: qsort.c:55
static __inline char * med3(char *a, char *b, char *c, int(__cdecl *cmp)(const void *, const void *))
Definition: qsort.c:76
#define vecswap(a, b, n)
Definition: qsort.c:71
#define swapcode(TYPE, parmi, parmj, n)
Definition: qsort.c:40
#define min(a, b)
Definition: qsort.c:35
#define SWAPINIT(a, es)
Definition: qsort.c:51
#define CMP(x, y)
Definition: qsort.c:73