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- /*-
- * SPDX-License-Identifier: BSD-3-Clause
- *
- * Copyright (c) 1992, 1993
- * The Regents of the University of California. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
- #include <sys/param.h>
- #include <sys/libkern.h>
- #ifdef I_AM_QSORT_R
- typedef int cmp_t(const void *, const void *, void *);
- #else
- typedef int cmp_t(const void *, const void *);
- #endif
- static inline char *med3(char *, char *, char *, cmp_t *, void *);
- static inline void swapfunc(char *, char *, size_t, int, int);
- /*
- * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
- */
- #define swapcode(TYPE, parmi, parmj, n) { \
- size_t 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(TYPE, a, es) swaptype_ ## TYPE = \
- ((char *)a - (char *)0) % sizeof(TYPE) || \
- es % sizeof(TYPE) ? 2 : es == sizeof(TYPE) ? 0 : 1;
- static inline void
- swapfunc(char *a, char *b, size_t n, int swaptype_long, int swaptype_int)
- {
- if (swaptype_long <= 1)
- swapcode(long, a, b, n)
- else if (swaptype_int <= 1)
- swapcode(int, a, b, n)
- else
- swapcode(char, a, b, n)
- }
- #define swap(a, b) \
- if (swaptype_long == 0) { \
- long t = *(long *)(a); \
- *(long *)(a) = *(long *)(b); \
- *(long *)(b) = t; \
- } else if (swaptype_int == 0) { \
- int t = *(int *)(a); \
- *(int *)(a) = *(int *)(b); \
- *(int *)(b) = t; \
- } else \
- swapfunc(a, b, es, swaptype_long, swaptype_int)
- #define vecswap(a, b, n) \
- if ((n) > 0) swapfunc(a, b, n, swaptype_long, swaptype_int)
- #ifdef I_AM_QSORT_R
- #define CMP(t, x, y) (cmp((x), (y), (t)))
- #else
- #define CMP(t, x, y) (cmp((x), (y)))
- #endif
- static inline char *
- med3(char *a, char *b, char *c, cmp_t *cmp, 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 I_AM_QSORT_R
- void
- (qsort_r)(void *a, size_t n, size_t es, cmp_t *cmp, void *thunk)
- #else
- #define thunk NULL
- void
- qsort(void *a, size_t n, size_t es, cmp_t *cmp)
- #endif
- {
- char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
- size_t d1, d2;
- int cmp_result;
- int swaptype_long, swaptype_int, swap_cnt;
- loop: SWAPINIT(long, a, es);
- SWAPINIT(int, 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) {
- size_t 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;
- }
- 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(thunk, pl - es, pl) > 0;
- pl -= es)
- swap(pl, pl - es);
- return;
- }
- pn = (char *)a + n * es;
- d1 = MIN(pa - (char *)a, pb - pa);
- vecswap(a, pb - d1, d1);
- d1 = MIN(pd - pc, pn - pd - es);
- vecswap(pb, pn - d1, d1);
- d1 = pb - pa;
- d2 = pd - pc;
- if (d1 <= d2) {
- /* Recurse on left partition, then iterate on right partition */
- if (d1 > es) {
- #ifdef I_AM_QSORT_R
- qsort_r(a, d1 / es, es, cmp, thunk);
- #else
- qsort(a, d1 / es, es, cmp);
- #endif
- }
- if (d2 > es) {
- /* Iterate rather than recurse to save stack space */
- /* qsort(pn - d2, d2 / es, es, cmp); */
- a = pn - d2;
- n = d2 / es;
- goto loop;
- }
- } else {
- /* Recurse on right partition, then iterate on left partition */
- if (d2 > es) {
- #ifdef I_AM_QSORT_R
- qsort_r(pn - d2, d2 / es, es, cmp, thunk);
- #else
- qsort(pn - d2, d2 / es, es, cmp);
- #endif
- }
- if (d1 > es) {
- /* Iterate rather than recurse to save stack space */
- /* qsort(a, d1 / es, es, cmp); */
- n = d1 / es;
- goto loop;
- }
- }
- }
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