/*- * 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. * 4. 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. */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93"; #endif /* LIBC_SCCS and not lint */ #include __FBSDID("$FreeBSD$"); #include #ifdef I_AM_QSORT_R typedef int cmp_t(void *, const void *, const 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 *, int, int); #define min(a, b) (a) < (b) ? a : b /* * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". */ #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, 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, void *thunk, cmp_t *cmp) #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 d, r; int swaptype, swap_cnt; 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(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 && (r = CMP(thunk, pb, a)) <= 0) { if (r == 0) { swap_cnt = 1; swap(pa, pb); pa += es; } pb += es; } while (pb <= pc && (r = CMP(thunk, pc, a)) >= 0) { if (r == 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; 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 ((r = pb - pa) > es) #ifdef I_AM_QSORT_R qsort_r(a, r / es, es, thunk, cmp); #else qsort(a, r / es, es, cmp); #endif if ((r = pd - pc) > es) { /* Iterate rather than recurse to save stack space */ a = pn - r; n = r / es; goto loop; } /* qsort(pn - r, r / es, es, cmp);*/ }