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54c6977e WD |
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 <[email protected]> | |
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 | ||
f7ae49fc | 18 | #include <log.h> |
54c6977e | 19 | #include <linux/types.h> |
42c4a23a | 20 | #include <common.h> |
560d424b | 21 | #include <exports.h> |
8bef79bf | 22 | #include <sort.h> |
54c6977e WD |
23 | |
24 | void qsort(void *base, | |
071bc923 WD |
25 | size_t nel, |
26 | size_t width, | |
27 | int (*comp)(const void *, const void *)) | |
54c6977e WD |
28 | { |
29 | size_t wgap, i, j, k; | |
30 | char tmp; | |
31 | ||
32 | if ((nel > 1) && (width > 0)) { | |
33 | assert(nel <= ((size_t)(-1)) / width); /* check for overflow */ | |
34 | wgap = 0; | |
35 | do { | |
36 | wgap = 3 * wgap + 1; | |
37 | } while (wgap < (nel-1)/3); | |
38 | /* From the above, we know that either wgap == 1 < nel or */ | |
39 | /* ((wgap-1)/3 < (int) ((nel-1)/3) <= (nel-1)/3 ==> wgap < nel. */ | |
40 | wgap *= width; /* So this can not overflow if wnel doesn't. */ | |
41 | nel *= width; /* Convert nel to 'wnel' */ | |
42 | do { | |
43 | i = wgap; | |
44 | do { | |
45 | j = i; | |
46 | do { | |
47 | register char *a; | |
48 | register char *b; | |
49 | ||
50 | j -= wgap; | |
51 | a = j + ((char *)base); | |
52 | b = a + wgap; | |
53 | if ((*comp)(a, b) <= 0) { | |
54 | break; | |
55 | } | |
56 | k = width; | |
57 | do { | |
58 | tmp = *a; | |
59 | *a++ = *b; | |
60 | *b++ = tmp; | |
61 | } while (--k); | |
62 | } while (j >= wgap); | |
63 | i += width; | |
64 | } while (i < nel); | |
65 | wgap = (wgap - width)/3; | |
66 | } while (wgap); | |
67 | } | |
68 | } | |
560d424b MF |
69 | |
70 | int strcmp_compar(const void *p1, const void *p2) | |
71 | { | |
72 | return strcmp(*(const char **)p1, *(const char **)p2); | |
73 | } |