#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93";
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/stdlib/qsort.c,v 1.15 2008/01/14 09:21:34 das Exp $");
#include <stdlib.h>
#include <string.h>
#ifdef I_AM_QSORT_R
typedef int cmp_t(void *, const void *, const void *);
#else
typedef int cmp_t(const void *, const void *);
#endif
#ifdef I_AM_QSORT_B
static inline char *med3(char *, char *, char *, cmp_t ^, void *) __attribute__((always_inline));
#else
static inline char *med3(char *, char *, char *, cmp_t *, void *) __attribute__((always_inline));
#endif
static inline void swapfunc(char *, char *, int, int) __attribute__((always_inline));
#define min(a, b) (a) < (b) ? a : b
#define swapcode(TYPE, parmi, parmj, n) { \
long i = (n) / sizeof (TYPE); \
TYPE *pi = (TYPE *) (parmi); \
TYPE *pj = (TYPE *) (parmj); \
do { \
TYPE t = *pi; \
*pi++ = *pj; \
*pj++ = t; \
} while (--i > 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(a, b, n, swaptype)
char *a, *b;
int n, swaptype;
{
if(swaptype <= 1)
swapcode(long, a, b, n)
else
swapcode(char, a, b, n)
}
#define swap(a, b) \
if (swaptype == 0) { \
long t = *(long *)(a); \
*(long *)(a) = *(long *)(b); \
*(long *)(b) = t; \
} else \
swapfunc(a, b, es, swaptype)
#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
#ifdef I_AM_QSORT_R
#define CMP(t, x, y) (cmp((t), (x), (y)))
#else
#define CMP(t, x, y) (cmp((x), (y)))
#endif
static inline char *
med3(char *a, char *b, char *c,
#ifdef I_AM_QSORT_B
cmp_t ^cmp,
#else
cmp_t *cmp,
#endif
void *thunk
#ifndef I_AM_QSORT_R
__unused
#endif
)
{
return CMP(thunk, a, b) < 0 ?
(CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a ))
:(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));
}
#ifdef __LP64__
#define DEPTH(x) (2 * (flsl((long)(x)) - 1))
#else
#define DEPTH(x) (2 * (fls((int)(x)) - 1))
#endif
#ifdef I_AM_QSORT_R
int __heapsort_r(void *, size_t, size_t, void *, int (*)(void *, const void *, const void *));
#endif
static void
_qsort(void *a, size_t n, size_t es,
#ifdef I_AM_QSORT_R
void *thunk,
#else
#define thunk NULL
#endif
#ifdef I_AM_QSORT_B
cmp_t ^cmp,
#else
cmp_t *cmp,
#endif
int depth_limit)
{
char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
size_t d, r;
int cmp_result;
int swaptype, swap_cnt;
loop:
if (depth_limit-- <= 0) {
#ifdef I_AM_QSORT_B
heapsort_b(a, n, es, cmp);
#elif defined(I_AM_QSORT_R)
__heapsort_r(a, n, es, thunk, cmp);
#else
heapsort(a, n, es, cmp);
#endif
return;
}
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(thunk, pl - es, pl) > 0;
pl -= es)
swap(pl, pl - es);
return;
}
pm = (char *)a + (n / 2) * es;
if (n > 7) {
pl = a;
pn = (char *)a + (n - 1) * es;
if (n > 40) {
d = (n / 8) * es;
pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);
pm = med3(pm - d, pm, pm + d, cmp, thunk);
pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk);
}
pm = med3(pl, pm, pn, cmp, thunk);
}
swap(a, pm);
pa = pb = (char *)a + es;
pc = pd = (char *)a + (n - 1) * es;
for (;;) {
while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) {
if (cmp_result == 0) {
swap_cnt = 1;
swap(pa, pb);
pa += es;
}
pb += es;
}
while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) {
if (cmp_result == 0) {
swap_cnt = 1;
swap(pc, pd);
pd -= es;
}
pc -= es;
}
if (pb > pc)
break;
swap(pb, pc);
swap_cnt = 1;
pb += es;
pc -= es;
}
pn = (char *)a + n * es;
r = min(pa - (char *)a, pb - pa);
vecswap(a, pb - r, r);
r = min(pd - pc, pn - pd - es);
vecswap(pb, pn - r, r);
if (swap_cnt == 0) {
r = 1 + n / 4;
for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
for (pl = pm;
pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
pl -= es) {
swap(pl, pl - es);
if (++swap_cnt > r) goto nevermind;
}
return;
}
nevermind:
if ((r = pb - pa) > es)
#ifdef I_AM_QSORT_R
_qsort(a, r / es, es, thunk, cmp, depth_limit);
#else
_qsort(a, r / es, es, cmp, depth_limit);
#endif
if ((r = pd - pc) > es) {
a = pn - r;
n = r / es;
goto loop;
}
}
void
#ifdef I_AM_QSORT_R
qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
#elif defined(I_AM_QSORT_B)
qsort_b(void *a, size_t n, size_t es, cmp_t ^cmp)
#else
qsort(void *a, size_t n, size_t es, cmp_t *cmp)
#endif
{
_qsort(a, n, es,
#ifdef I_AM_QSORT_R
thunk,
#endif
cmp, DEPTH(n));
}