1 /* 2 * qsort taken from FreeBSD, slightly modified to match glibc's 3 * argument ordering 4 */ 5 6 /* FIXME: should use mergesort instead */ 7 8 /*- 9 * Copyright (c) 1992, 1993 10 * The Regents of the University of California. All rights reserved. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #if defined(LIBC_SCCS) && !defined(lint) 38 static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93"; 39 #endif /* LIBC_SCCS and not lint */ 40 #include <sys/cdefs.h> 41 42 /* $FreeBSD: src/lib/libc/stdlib/qsort.c,v 1.13.2.1.8.1 2010/12/21 17:10:29 kensmith Exp $ */ 43 44 #include <stdlib.h> 45 46 typedef int cmp_t(const void *, const void *, void *); 47 static inline char *med3(char *, char *, char *, cmp_t *, void *); 48 static inline void swapfunc(char *, char *, int, int); 49 50 #define min(a, b) (a) < (b) ? a : b 51 52 /* 53 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". 54 */ 55 #define swapcode(TYPE, parmi, parmj, n) { \ 56 long i = (n) / sizeof (TYPE); \ 57 TYPE *pi = (TYPE *) (parmi); \ 58 TYPE *pj = (TYPE *) (parmj); \ 59 do { \ 60 TYPE t = *pi; \ 61 *pi++ = *pj; \ 62 *pj++ = t; \ 63 } while (--i > 0); \ 64 } 65 66 #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \ 67 es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1; 68 69 static inline void 70 swapfunc(a, b, n, swaptype) 71 char *a, *b; 72 int n, swaptype; 73 { 74 if(swaptype <= 1) 75 swapcode(long, a, b, n) 76 else 77 swapcode(char, a, b, n) 78 } 79 80 #define swap(a, b) \ 81 if (swaptype == 0) { \ 82 long t = *(long *)(a); \ 83 *(long *)(a) = *(long *)(b); \ 84 *(long *)(b) = t; \ 85 } else \ 86 swapfunc(a, b, es, swaptype) 87 88 #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype) 89 90 #define CMP(t, x, y) (cmp((x), (y), (t))) 91 92 static inline char * 93 med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk) 94 { 95 return CMP(thunk, a, b) < 0 ? 96 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a )) 97 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c )); 98 } 99 100 void 101 solv_sort(void *a, size_t n, size_t es, cmp_t *cmp, void *thunk) 102 { 103 char *pa, *pb, *pc, *pd, *pl, *pm, *pn; 104 size_t d, r; 105 int cmp_result; 106 int swaptype, swap_cnt; 107 108 loop: SWAPINIT(a, es); 109 swap_cnt = 0; 110 if (n < 7) { 111 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 112 for (pl = pm; 113 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 114 pl -= es) 115 swap(pl, pl - es); 116 return; 117 } 118 pm = (char *)a + (n / 2) * es; 119 if (n > 7) { 120 pl = a; 121 pn = (char *)a + (n - 1) * es; 122 if (n > 40) { 123 d = (n / 8) * es; 124 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk); 125 pm = med3(pm - d, pm, pm + d, cmp, thunk); 126 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk); 127 } 128 pm = med3(pl, pm, pn, cmp, thunk); 129 } 130 swap(a, pm); 131 pa = pb = (char *)a + es; 132 133 pc = pd = (char *)a + (n - 1) * es; 134 for (;;) { 135 while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) { 136 if (cmp_result == 0) { 137 swap_cnt = 1; 138 swap(pa, pb); 139 pa += es; 140 } 141 pb += es; 142 } 143 while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) { 144 if (cmp_result == 0) { 145 swap_cnt = 1; 146 swap(pc, pd); 147 pd -= es; 148 } 149 pc -= es; 150 } 151 if (pb > pc) 152 break; 153 swap(pb, pc); 154 swap_cnt = 1; 155 pb += es; 156 pc -= es; 157 } 158 if (swap_cnt == 0) { /* Switch to insertion sort */ 159 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 160 for (pl = pm; 161 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 162 pl -= es) 163 swap(pl, pl - es); 164 return; 165 } 166 167 pn = (char *)a + n * es; 168 r = min(pa - (char *)a, pb - pa); 169 vecswap(a, pb - r, r); 170 r = min(pd - pc, pn - pd - es); 171 vecswap(pb, pn - r, r); 172 if ((r = pb - pa) > es) 173 solv_sort(a, r / es, es, cmp, thunk); 174 if ((r = pd - pc) > es) { 175 /* Iterate rather than recurse to save stack space */ 176 a = pn - r; 177 n = r / es; 178 goto loop; 179 } 180 /* qsort(pn - r, r / es, es, cmp);*/ 181 } 182