1 /*- 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #if 0 31 #if defined(LIBC_SCCS) && !defined(lint) 32 static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93"; 33 #endif /* LIBC_SCCS and not lint */ 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 #endif 37 38 #include <config.h> 39 40 #ifdef NEED_QSORT 41 42 #include "roken.h" 43 44 #include <stdlib.h> 45 46 #ifdef I_AM_QSORT_R 47 typedef int cmp_t(void *, const void *, const void *); 48 #else 49 typedef int cmp_t(const void *, const void *); 50 #endif 51 static inline char *med3(char *, char *, char *, cmp_t *, void *); 52 static inline void swapfunc(char *, char *, int, int); 53 54 /* 55 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". 56 */ 57 #define swapcode(TYPE, parmi, parmj, n) { \ 58 long i = (n) / sizeof (TYPE); \ 59 TYPE *pi = (TYPE *) (parmi); \ 60 TYPE *pj = (TYPE *) (parmj); \ 61 do { \ 62 TYPE t = *pi; \ 63 *pi++ = *pj; \ 64 *pj++ = t; \ 65 } while (--i > 0); \ 66 } 67 68 #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \ 69 es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1; 70 71 static inline void 72 swapfunc(a, b, n, swaptype) 73 char *a, *b; 74 int n, swaptype; 75 { 76 if(swaptype <= 1) 77 swapcode(long, a, b, n) 78 else 79 swapcode(char, a, b, n) 80 } 81 82 #define swap(a, b) \ 83 if (swaptype == 0) { \ 84 long t = *(long *)(a); \ 85 *(long *)(a) = *(long *)(b); \ 86 *(long *)(b) = t; \ 87 } else \ 88 swapfunc(a, b, es, swaptype) 89 90 #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype) 91 92 #ifdef I_AM_QSORT_R 93 #define CMP(t, x, y) (cmp((t), (x), (y))) 94 #else 95 #define CMP(t, x, y) (cmp((x), (y))) 96 #endif 97 98 static inline char * 99 med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk 100 #ifndef I_AM_QSORT_R 101 /* __unused */ 102 #endif 103 ) 104 { 105 return CMP(thunk, a, b) < 0 ? 106 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a )) 107 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c )); 108 } 109 110 #ifdef I_AM_QSORT_R 111 void 112 rk_qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp) 113 #else 114 #define thunk NULL 115 void 116 rk_qsort(void *a, size_t n, size_t es, cmp_t *cmp) 117 #endif 118 { 119 char *pa, *pb, *pc, *pd, *pl, *pm, *pn; 120 size_t d, r; 121 int cmp_result; 122 int swaptype, swap_cnt; 123 124 loop: SWAPINIT(a, es); 125 swap_cnt = 0; 126 if (n < 7) { 127 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 128 for (pl = pm; 129 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 130 pl -= es) 131 swap(pl, pl - es); 132 return; 133 } 134 pm = (char *)a + (n / 2) * es; 135 if (n > 7) { 136 pl = a; 137 pn = (char *)a + (n - 1) * es; 138 if (n > 40) { 139 d = (n / 8) * es; 140 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk); 141 pm = med3(pm - d, pm, pm + d, cmp, thunk); 142 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk); 143 } 144 pm = med3(pl, pm, pn, cmp, thunk); 145 } 146 swap(a, pm); 147 pa = pb = (char *)a + es; 148 149 pc = pd = (char *)a + (n - 1) * es; 150 for (;;) { 151 while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) { 152 if (cmp_result == 0) { 153 swap_cnt = 1; 154 swap(pa, pb); 155 pa += es; 156 } 157 pb += es; 158 } 159 while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) { 160 if (cmp_result == 0) { 161 swap_cnt = 1; 162 swap(pc, pd); 163 pd -= es; 164 } 165 pc -= es; 166 } 167 if (pb > pc) 168 break; 169 swap(pb, pc); 170 swap_cnt = 1; 171 pb += es; 172 pc -= es; 173 } 174 if (swap_cnt == 0) { /* Switch to insertion sort */ 175 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 176 for (pl = pm; 177 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 178 pl -= es) 179 swap(pl, pl - es); 180 return; 181 } 182 183 pn = (char *)a + n * es; 184 r = min(pa - (char *)a, pb - pa); 185 vecswap(a, pb - r, r); 186 r = min(pd - pc, pn - pd - es); 187 vecswap(pb, pn - r, r); 188 if ((r = pb - pa) > es) 189 #ifdef I_AM_QSORT_R 190 rk_qsort_r(a, r / es, es, thunk, cmp); 191 #else 192 rk_qsort(a, r / es, es, cmp); 193 #endif 194 if ((r = pd - pc) > es) { 195 /* Iterate rather than recurse to save stack space */ 196 a = pn - r; 197 n = r / es; 198 goto loop; 199 } 200 /* rk_qsort(pn - r, r / es, es, cmp);*/ 201 } 202 203 #endif /* NEED_QSORT */ 204