u-boot/fs/yaffs2/yaffs_qsort.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

140 lines
3.1 KiB
C

// SPDX-License-Identifier: BSD-3-Clause
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*/
#include "yportenv.h"
/* #include <linux/string.h> */
/*
* Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
*/
#define swapcode(TYPE, parmi, parmj, n) do { \
long i = (n) / sizeof(TYPE); \
register TYPE *pi = (TYPE *) (parmi); \
register TYPE *pj = (TYPE *) (parmj); \
do { \
register TYPE t = *pi; \
*pi++ = *pj; \
*pj++ = t; \
} while (--i > 0); \
} while (0)
#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
es % sizeof(long) ? 2 : es == sizeof(long) ? 0 : 1;
static inline void
swapfunc(char *a, char *b, int n, int swaptype)
{
if (swaptype <= 1)
swapcode(long, a, b, n);
else
swapcode(char, a, b, n);
}
#define yswap(a, b) do { \
if (swaptype == 0) { \
long t = *(long *)(a); \
*(long *)(a) = *(long *)(b); \
*(long *)(b) = t; \
} else \
swapfunc(a, b, es, swaptype); \
} while (0)
#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
static inline char *
med3(char *a, char *b, char *c, int (*cmp)(const void *, const void *))
{
return cmp(a, b) < 0 ?
(cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a))
: (cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c));
}
#ifndef min
#define min(a, b) (((a) < (b)) ? (a) : (b))
#endif
void
yaffs_qsort(void *aa, size_t n, size_t es,
int (*cmp)(const void *, const void *))
{
char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
int d, r, swaptype, swap_cnt;
register char *a = aa;
loop: SWAPINIT(a, es);
swap_cnt = 0;
if (n < 7) {
for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es)
for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
pl -= es)
yswap(pl, pl - es);
return;
}
pm = (char *)a + (n / 2) * es;
if (n > 7) {
pl = (char *)a;
pn = (char *)a + (n - 1) * es;
if (n > 40) {
d = (n / 8) * es;
pl = med3(pl, pl + d, pl + 2 * d, cmp);
pm = med3(pm - d, pm, pm + d, cmp);
pn = med3(pn - 2 * d, pn - d, pn, cmp);
}
pm = med3(pl, pm, pn, cmp);
}
yswap(a, pm);
pa = pb = (char *)a + es;
pc = pd = (char *)a + (n - 1) * es;
for (;;) {
while (pb <= pc && (r = cmp(pb, a)) <= 0) {
if (r == 0) {
swap_cnt = 1;
yswap(pa, pb);
pa += es;
}
pb += es;
}
while (pb <= pc && (r = cmp(pc, a)) >= 0) {
if (r == 0) {
swap_cnt = 1;
yswap(pc, pd);
pd -= es;
}
pc -= es;
}
if (pb > pc)
break;
yswap(pb, pc);
swap_cnt = 1;
pb += es;
pc -= es;
}
if (swap_cnt == 0) { /* Switch to insertion sort */
for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
pl -= es)
yswap(pl, pl - es);
return;
}
pn = (char *)a + n * es;
r = min(pa - (char *)a, pb - pa);
vecswap(a, pb - r, r);
r = min((long)(pd - pc), (long)(pn - pd - es));
vecswap(pb, pn - r, r);
r = pb - pa;
if (r > es)
yaffs_qsort(a, r / es, es, cmp);
r = pd - pc;
if (r > es) {
/* Iterate rather than recurse to save stack space */
a = pn - r;
n = r / es;
goto loop;
}
/* yaffs_qsort(pn - r, r / es, es, cmp);*/
}