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1 /*
2  * Code adapted from uClibc-0.9.30.3
3  *
4  * It is therefore covered by the GNU LESSER GENERAL PUBLIC LICENSE
5  * Version 2.1, February 1999
6  *
7  * Wolfgang Denk <wd@denx.de>
8  */
9
10 /* This code is derived from a public domain shell sort routine by
11  * Ray Gardner and found in Bob Stout's snippets collection.  The
12  * original code is included below in an #if 0/#endif block.
13  *
14  * I modified it to avoid the possibility of overflow in the wgap
15  * calculation, as well as to reduce the generated code size with
16  * bcc and gcc. */
17
18 #include <linux/types.h>
19 #include <common.h>
20 #include <exports.h>
21
22 void qsort(void  *base,
23            size_t nel,
24            size_t width,
25            int (*comp)(const void *, const void *))
26 {
27         size_t wgap, i, j, k;
28         char tmp;
29
30         if ((nel > 1) && (width > 0)) {
31                 assert(nel <= ((size_t)(-1)) / width); /* check for overflow */
32                 wgap = 0;
33                 do {
34                         wgap = 3 * wgap + 1;
35                 } while (wgap < (nel-1)/3);
36                 /* From the above, we know that either wgap == 1 < nel or */
37                 /* ((wgap-1)/3 < (int) ((nel-1)/3) <= (nel-1)/3 ==> wgap <  nel. */
38                 wgap *= width;                  /* So this can not overflow if wnel doesn't. */
39                 nel *= width;                   /* Convert nel to 'wnel' */
40                 do {
41                         i = wgap;
42                         do {
43                                 j = i;
44                                 do {
45                                         register char *a;
46                                         register char *b;
47
48                                         j -= wgap;
49                                         a = j + ((char *)base);
50                                         b = a + wgap;
51                                         if ((*comp)(a, b) <= 0) {
52                                                 break;
53                                         }
54                                         k = width;
55                                         do {
56                                                 tmp = *a;
57                                                 *a++ = *b;
58                                                 *b++ = tmp;
59                                         } while (--k);
60                                 } while (j >= wgap);
61                                 i += width;
62                         } while (i < nel);
63                         wgap = (wgap - width)/3;
64                 } while (wgap);
65         }
66 }
67
68 int strcmp_compar(const void *p1, const void *p2)
69 {
70         return strcmp(*(const char **)p1, *(const char **)p2);
71 }