usr/klibc/qsort.c

/*
 * qsort.c
 *
 * This is actually combsort.  It's an O(n log n) algorithm with
 * simplicity/small code size being its main virtue.
 */

#include <stddef.h>
#include <stdlib.h>
#include <string.h>

static inline size_t newgap(size_t gap)
{
	gap = (gap * 10) / 13;
	if (gap == 9 || gap == 10)
		gap = 11;

	if (gap < 1)
		gap = 1;
	return gap;
}

void qsort(void *base, size_t nmemb, size_t size,
	   int (*compar) (const void *, const void *))
{
	size_t gap = nmemb;
	size_t i, j;
	char *p1, *p2;
	int swapped;

	if (!nmemb)
		return;

	do {
		gap = newgap(gap);
		swapped = 0;

		for (i = 0, p1 = base; i < nmemb - gap; i++, p1 += size) {
			j = i + gap;
			if (compar(p1, p2 = (char *)base + j * size) > 0) {
				memswap(p1, p2, size);
				swapped = 1;
			}
		}
	} while (gap > 1 || swapped);
}
1	/*
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	#include <stdlib.h>
10	#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	}