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 <log.h>
19 #include <linux/types.h>
20 #include <common.h>
21 #include <exports.h>
22 #include <sort.h>
23 
qsort(void * base,size_t nel,size_t width,int (* comp)(const void *,const void *))24 void qsort(void  *base,
25 	   size_t nel,
26 	   size_t width,
27 	   int (*comp)(const void *, const void *))
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 }
69 
strcmp_compar(const void * p1,const void * p2)70 int strcmp_compar(const void *p1, const void *p2)
71 {
72 	return strcmp(*(const char **)p1, *(const char **)p2);
73 }
74