2
* Copyright (c) 1992, 1993
3
* The Regents of the University of California. All rights reserved.
5
* SPDX-License-Identifier: BSD-3-Clause
9
/* #include <linux/string.h> */
12
* Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
14
#define swapcode(TYPE, parmi, parmj, n) do { \
15
long i = (n) / sizeof(TYPE); \
16
register TYPE *pi = (TYPE *) (parmi); \
17
register TYPE *pj = (TYPE *) (parmj); \
19
register TYPE t = *pi; \
25
#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
26
es % sizeof(long) ? 2 : es == sizeof(long) ? 0 : 1;
29
swapfunc(char *a, char *b, int n, int swaptype)
32
swapcode(long, a, b, n);
34
swapcode(char, a, b, n);
37
#define yswap(a, b) do { \
38
if (swaptype == 0) { \
39
long t = *(long *)(a); \
40
*(long *)(a) = *(long *)(b); \
43
swapfunc(a, b, es, swaptype); \
46
#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
49
med3(char *a, char *b, char *c, int (*cmp)(const void *, const void *))
51
return cmp(a, b) < 0 ?
52
(cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a))
53
: (cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c));
57
#define min(a, b) (((a) < (b)) ? (a) : (b))
61
yaffs_qsort(void *aa, size_t n, size_t es,
62
int (*cmp)(const void *, const void *))
64
char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
65
int d, r, swaptype, swap_cnt;
66
register char *a = aa;
68
loop: SWAPINIT(a, es);
71
for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es)
72
for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
77
pm = (char *)a + (n / 2) * es;
80
pn = (char *)a + (n - 1) * es;
83
pl = med3(pl, pl + d, pl + 2 * d, cmp);
84
pm = med3(pm - d, pm, pm + d, cmp);
85
pn = med3(pn - 2 * d, pn - d, pn, cmp);
87
pm = med3(pl, pm, pn, cmp);
90
pa = pb = (char *)a + es;
92
pc = pd = (char *)a + (n - 1) * es;
94
while (pb <= pc && (r = cmp(pb, a)) <= 0) {
102
while (pb <= pc && (r = cmp(pc, a)) >= 0) {
117
if (swap_cnt == 0) { /* Switch to insertion sort */
118
for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
119
for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
125
pn = (char *)a + n * es;
126
r = min(pa - (char *)a, pb - pa);
127
vecswap(a, pb - r, r);
128
r = min((long)(pd - pc), (long)(pn - pd - es));
129
vecswap(pb, pn - r, r);
132
yaffs_qsort(a, r / es, es, cmp);
135
/* Iterate rather than recurse to save stack space */
140
/* yaffs_qsort(pn - r, r / es, es, cmp);*/