Annotation of /trunk/mkinitrd-magellan/klibc/usr/klibc/qsort.c
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Revision 815 -
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Fri Apr 24 18:32:46 2009 UTC (15 years, 1 month ago) by niro
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Fri Apr 24 18:32:46 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 800 byte(s)
-updated to klibc-1.5.15
1 | niro | 532 | /* |
2 | * qsort.c | ||
3 | * | ||
4 | * This is actually combsort. It's an O(n log n) algorithm with | ||
5 | * simplicity/small code size being its main virtue. | ||
6 | */ | ||
7 | |||
8 | #include <stddef.h> | ||
9 | niro | 815 | #include <stdlib.h> |
10 | niro | 532 | #include <string.h> |
11 | |||
12 | static inline size_t newgap(size_t gap) | ||
13 | { | ||
14 | gap = (gap * 10) / 13; | ||
15 | if (gap == 9 || gap == 10) | ||
16 | gap = 11; | ||
17 | |||
18 | if (gap < 1) | ||
19 | gap = 1; | ||
20 | return gap; | ||
21 | } | ||
22 | |||
23 | void qsort(void *base, size_t nmemb, size_t size, | ||
24 | int (*compar) (const void *, const void *)) | ||
25 | { | ||
26 | size_t gap = nmemb; | ||
27 | size_t i, j; | ||
28 | char *p1, *p2; | ||
29 | int swapped; | ||
30 | |||
31 | if (!nmemb) | ||
32 | return; | ||
33 | |||
34 | do { | ||
35 | gap = newgap(gap); | ||
36 | swapped = 0; | ||
37 | |||
38 | for (i = 0, p1 = base; i < nmemb - gap; i++, p1 += size) { | ||
39 | j = i + gap; | ||
40 | if (compar(p1, p2 = (char *)base + j * size) > 0) { | ||
41 | memswap(p1, p2, size); | ||
42 | swapped = 1; | ||
43 | } | ||
44 | } | ||
45 | } while (gap > 1 || swapped); | ||
46 | } |