1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32#include <sys/param.h> 33#include <sys/libkern.h> 34 35#ifdef I_AM_QSORT_R 36typedef int cmp_t(const void *, const void *, void *); 37#else 38typedef int cmp_t(const void *, const void *); 39#endif 40static inline char *med3(char *, char *, char *, cmp_t *, void *); 41static inline void swapfunc(char *, char *, size_t, int, int); 42 43/* 44 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". 45 */ 46#define swapcode(TYPE, parmi, parmj, n) { \ 47 size_t i = (n) / sizeof (TYPE); \ 48 TYPE *pi = (TYPE *) (parmi); \ 49 TYPE *pj = (TYPE *) (parmj); \ 50 do { \ 51 TYPE t = *pi; \ 52 *pi++ = *pj; \ 53 *pj++ = t; \ 54 } while (--i > 0); \ 55} 56 57#define SWAPINIT(TYPE, a, es) swaptype_ ## TYPE = \ 58 ((char *)a - (char *)0) % sizeof(TYPE) || \ 59 es % sizeof(TYPE) ? 2 : es == sizeof(TYPE) ? 0 : 1; 60 61static inline void 62swapfunc(char *a, char *b, size_t n, int swaptype_long, int swaptype_int) 63{ 64 if (swaptype_long <= 1) 65 swapcode(long, a, b, n) 66 else if (swaptype_int <= 1) 67 swapcode(int, a, b, n) 68 else 69 swapcode(char, a, b, n) 70} 71 72#define swap(a, b) \ 73 if (swaptype_long == 0) { \ 74 long t = *(long *)(a); \ 75 *(long *)(a) = *(long *)(b); \ 76 *(long *)(b) = t; \ 77 } else if (swaptype_int == 0) { \ 78 int t = *(int *)(a); \ 79 *(int *)(a) = *(int *)(b); \ 80 *(int *)(b) = t; \ 81 } else \ 82 swapfunc(a, b, es, swaptype_long, swaptype_int) 83 84#define vecswap(a, b, n) \ 85 if ((n) > 0) swapfunc(a, b, n, swaptype_long, swaptype_int) 86 87#ifdef I_AM_QSORT_R 88#define CMP(t, x, y) (cmp((x), (y), (t))) 89#else 90#define CMP(t, x, y) (cmp((x), (y))) 91#endif 92 93static inline char * 94med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk 95#ifndef I_AM_QSORT_R 96__unused 97#endif 98) 99{ 100 return CMP(thunk, a, b) < 0 ? 101 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a )) 102 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c )); 103} 104 105#ifdef I_AM_QSORT_R 106void 107(qsort_r)(void *a, size_t n, size_t es, cmp_t *cmp, void *thunk) 108#else 109#define thunk NULL 110void 111qsort(void *a, size_t n, size_t es, cmp_t *cmp) 112#endif 113{ 114 char *pa, *pb, *pc, *pd, *pl, *pm, *pn; 115 size_t d1, d2; 116 int cmp_result; 117 int swaptype_long, swaptype_int, swap_cnt; 118 119loop: SWAPINIT(long, a, es); 120 SWAPINIT(int, a, es); 121 swap_cnt = 0; 122 if (n < 7) { 123 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 124 for (pl = pm; 125 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 126 pl -= es) 127 swap(pl, pl - es); 128 return; 129 } 130 pm = (char *)a + (n / 2) * es; 131 if (n > 7) { 132 pl = a; 133 pn = (char *)a + (n - 1) * es; 134 if (n > 40) { 135 size_t d = (n / 8) * es; 136 137 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk); 138 pm = med3(pm - d, pm, pm + d, cmp, thunk); 139 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk); 140 } 141 pm = med3(pl, pm, pn, cmp, thunk); 142 } 143 swap(a, pm); 144 pa = pb = (char *)a + es; 145 146 pc = pd = (char *)a + (n - 1) * es; 147 for (;;) { 148 while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) { 149 if (cmp_result == 0) { 150 swap_cnt = 1; 151 swap(pa, pb); 152 pa += es; 153 } 154 pb += es; 155 } 156 while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) { 157 if (cmp_result == 0) { 158 swap_cnt = 1; 159 swap(pc, pd); 160 pd -= es; 161 } 162 pc -= es; 163 } 164 if (pb > pc) 165 break; 166 swap(pb, pc); 167 swap_cnt = 1; 168 pb += es; 169 pc -= es; 170 } 171 if (swap_cnt == 0) { /* Switch to insertion sort */ 172 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 173 for (pl = pm; 174 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 175 pl -= es) 176 swap(pl, pl - es); 177 return; 178 } 179 180 pn = (char *)a + n * es; 181 d1 = MIN(pa - (char *)a, pb - pa); 182 vecswap(a, pb - d1, d1); 183 d1 = MIN(pd - pc, pn - pd - es); 184 vecswap(pb, pn - d1, d1); 185 186 d1 = pb - pa; 187 d2 = pd - pc; 188 if (d1 <= d2) { 189 /* Recurse on left partition, then iterate on right partition */ 190 if (d1 > es) { 191#ifdef I_AM_QSORT_R 192 qsort_r(a, d1 / es, es, cmp, thunk); 193#else 194 qsort(a, d1 / es, es, cmp); 195#endif 196 } 197 if (d2 > es) { 198 /* Iterate rather than recurse to save stack space */ 199 /* qsort(pn - d2, d2 / es, es, cmp); */ 200 a = pn - d2; 201 n = d2 / es; 202 goto loop; 203 } 204 } else { 205 /* Recurse on right partition, then iterate on left partition */ 206 if (d2 > es) { 207#ifdef I_AM_QSORT_R 208 qsort_r(pn - d2, d2 / es, es, cmp, thunk); 209#else 210 qsort(pn - d2, d2 / es, es, cmp); 211#endif 212 } 213 if (d1 > es) { 214 /* Iterate rather than recurse to save stack space */ 215 /* qsort(a, d1 / es, es, cmp); */ 216 n = d1 / es; 217 goto loop; 218 } 219 } 220} 221