11573Srgrimes/*- 21573Srgrimes * Copyright (c) 1992, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * Redistribution and use in source and binary forms, with or without 61573Srgrimes * modification, are permitted provided that the following conditions 71573Srgrimes * are met: 81573Srgrimes * 1. Redistributions of source code must retain the above copyright 91573Srgrimes * notice, this list of conditions and the following disclaimer. 101573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 111573Srgrimes * notice, this list of conditions and the following disclaimer in the 121573Srgrimes * documentation and/or other materials provided with the distribution. 13251672Semaste * 3. Neither the name of the University nor the names of its contributors 141573Srgrimes * may be used to endorse or promote products derived from this software 151573Srgrimes * without specific prior written permission. 161573Srgrimes * 171573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 181573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 191573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 201573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 211573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 221573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 231573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 241573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 251573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 261573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 271573Srgrimes * SUCH DAMAGE. 281573Srgrimes */ 291573Srgrimes 301573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 311573Srgrimesstatic char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93"; 321573Srgrimes#endif /* LIBC_SCCS and not lint */ 3392986Sobrien#include <sys/cdefs.h> 3492986Sobrien__FBSDID("$FreeBSD$"); 351573Srgrimes 361573Srgrimes#include <stdlib.h> 371573Srgrimes 38103165Swollman#ifdef I_AM_QSORT_R 39103165Swollmantypedef int cmp_t(void *, const void *, const void *); 40103165Swollman#else 4192905Sobrientypedef int cmp_t(const void *, const void *); 42103165Swollman#endif 43103165Swollmanstatic inline char *med3(char *, char *, char *, cmp_t *, void *); 4492905Sobrienstatic inline void swapfunc(char *, char *, int, int); 451573Srgrimes 461573Srgrimes#define min(a, b) (a) < (b) ? a : b 471573Srgrimes 481573Srgrimes/* 491573Srgrimes * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". 501573Srgrimes */ 511573Srgrimes#define swapcode(TYPE, parmi, parmj, n) { \ 521573Srgrimes long i = (n) / sizeof (TYPE); \ 5392889Sobrien TYPE *pi = (TYPE *) (parmi); \ 5492889Sobrien TYPE *pj = (TYPE *) (parmj); \ 551573Srgrimes do { \ 5692889Sobrien TYPE t = *pi; \ 571573Srgrimes *pi++ = *pj; \ 581573Srgrimes *pj++ = t; \ 591573Srgrimes } while (--i > 0); \ 601573Srgrimes} 611573Srgrimes 621573Srgrimes#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \ 631573Srgrimes es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1; 641573Srgrimes 651573Srgrimesstatic inline void 661573Srgrimesswapfunc(a, b, n, swaptype) 671573Srgrimes char *a, *b; 681573Srgrimes int n, swaptype; 691573Srgrimes{ 708870Srgrimes if(swaptype <= 1) 711573Srgrimes swapcode(long, a, b, n) 721573Srgrimes else 731573Srgrimes swapcode(char, a, b, n) 741573Srgrimes} 751573Srgrimes 761573Srgrimes#define swap(a, b) \ 771573Srgrimes if (swaptype == 0) { \ 781573Srgrimes long t = *(long *)(a); \ 791573Srgrimes *(long *)(a) = *(long *)(b); \ 801573Srgrimes *(long *)(b) = t; \ 811573Srgrimes } else \ 821573Srgrimes swapfunc(a, b, es, swaptype) 831573Srgrimes 841573Srgrimes#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype) 851573Srgrimes 86103165Swollman#ifdef I_AM_QSORT_R 87103165Swollman#define CMP(t, x, y) (cmp((t), (x), (y))) 88103165Swollman#else 89103165Swollman#define CMP(t, x, y) (cmp((x), (y))) 90103165Swollman#endif 91103165Swollman 921573Srgrimesstatic inline char * 93103165Swollmanmed3(char *a, char *b, char *c, cmp_t *cmp, void *thunk 94103165Swollman#ifndef I_AM_QSORT_R 95103165Swollman__unused 96103165Swollman#endif 97103165Swollman) 981573Srgrimes{ 99103165Swollman return CMP(thunk, a, b) < 0 ? 100103165Swollman (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a )) 101103165Swollman :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c )); 1021573Srgrimes} 1031573Srgrimes 104103165Swollman#ifdef I_AM_QSORT_R 1051573Srgrimesvoid 106103165Swollmanqsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp) 107103165Swollman#else 108103165Swollman#define thunk NULL 109103165Swollmanvoid 110103165Swollmanqsort(void *a, size_t n, size_t es, cmp_t *cmp) 111103165Swollman#endif 1121573Srgrimes{ 1131573Srgrimes char *pa, *pb, *pc, *pd, *pl, *pm, *pn; 114175259Sdas size_t d, r; 115175317Sdas int cmp_result; 116175259Sdas int swaptype, swap_cnt; 1171573Srgrimes 1181573Srgrimesloop: SWAPINIT(a, es); 1191573Srgrimes swap_cnt = 0; 1201573Srgrimes if (n < 7) { 12117971Sbde for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 122103165Swollman for (pl = pm; 123103165Swollman pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 1241573Srgrimes pl -= es) 1251573Srgrimes swap(pl, pl - es); 1261573Srgrimes return; 1271573Srgrimes } 12817971Sbde pm = (char *)a + (n / 2) * es; 1291573Srgrimes if (n > 7) { 1301573Srgrimes pl = a; 13117971Sbde pn = (char *)a + (n - 1) * es; 1321573Srgrimes if (n > 40) { 1331573Srgrimes d = (n / 8) * es; 134103165Swollman pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk); 135103165Swollman pm = med3(pm - d, pm, pm + d, cmp, thunk); 136103165Swollman pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk); 1371573Srgrimes } 138103165Swollman pm = med3(pl, pm, pn, cmp, thunk); 1391573Srgrimes } 1401573Srgrimes swap(a, pm); 14117971Sbde pa = pb = (char *)a + es; 1421573Srgrimes 14317971Sbde pc = pd = (char *)a + (n - 1) * es; 1441573Srgrimes for (;;) { 145175317Sdas while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) { 146175317Sdas if (cmp_result == 0) { 1471573Srgrimes swap_cnt = 1; 1481573Srgrimes swap(pa, pb); 1491573Srgrimes pa += es; 1501573Srgrimes } 1511573Srgrimes pb += es; 1521573Srgrimes } 153175317Sdas while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) { 154175317Sdas if (cmp_result == 0) { 1551573Srgrimes swap_cnt = 1; 1561573Srgrimes swap(pc, pd); 1571573Srgrimes pd -= es; 1581573Srgrimes } 1591573Srgrimes pc -= es; 1601573Srgrimes } 1611573Srgrimes if (pb > pc) 1621573Srgrimes break; 1631573Srgrimes swap(pb, pc); 1641573Srgrimes swap_cnt = 1; 1651573Srgrimes pb += es; 1661573Srgrimes pc -= es; 1671573Srgrimes } 1681573Srgrimes if (swap_cnt == 0) { /* Switch to insertion sort */ 16917971Sbde for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 170103165Swollman for (pl = pm; 171103165Swollman pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 1721573Srgrimes pl -= es) 1731573Srgrimes swap(pl, pl - es); 1741573Srgrimes return; 1751573Srgrimes } 1761573Srgrimes 17717971Sbde pn = (char *)a + n * es; 1781573Srgrimes r = min(pa - (char *)a, pb - pa); 1791573Srgrimes vecswap(a, pb - r, r); 1801573Srgrimes r = min(pd - pc, pn - pd - es); 1811573Srgrimes vecswap(pb, pn - r, r); 1821573Srgrimes if ((r = pb - pa) > es) 183103165Swollman#ifdef I_AM_QSORT_R 184103165Swollman qsort_r(a, r / es, es, thunk, cmp); 185103165Swollman#else 1861573Srgrimes qsort(a, r / es, es, cmp); 187103165Swollman#endif 1888870Srgrimes if ((r = pd - pc) > es) { 1891573Srgrimes /* Iterate rather than recurse to save stack space */ 1901573Srgrimes a = pn - r; 1911573Srgrimes n = r / es; 1921573Srgrimes goto loop; 1931573Srgrimes } 1941573Srgrimes/* qsort(pn - r, r / es, es, cmp);*/ 1951573Srgrimes} 196