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#if defined(LIBC_SCCS) && !defined(lint) 33static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93"; 34#endif /* LIBC_SCCS and not lint */ 35// #include <sys/cdefs.h> 36 37#if defined(__GNUC__) 38#define __IDSTRING(name,string) __asm__(".ident\t\"" string "\"") 39#else 40/* 41 * The following definition might not work well if used in header files, 42 * but it should be better than nothing. If you want a "do nothing" 43 * version, then it should generate some harmless declaration, such as: 44 * #define __IDSTRING(name,string) struct __hack 45 */ 46#define __IDSTRING(name,string) static const char name[] __unused = string 47#endif 48 49/* 50 * Embed the rcs id of a source file in the resulting library. Note that in 51 * more recent ELF binutils, we use .ident allowing the ID to be stripped. 52 * Usage: 53 * __FBSDID("$FreeBSD$"); 54 */ 55#ifndef __FBSDID 56#if !defined(STRIP_FBSDID) 57#define __FBSDID(s) __IDSTRING(__CONCAT(__rcsid_,__LINE__),s) 58#else 59#define __FBSDID(s) struct __hack 60#endif 61#endif 62 63#if defined(__GNUC__) 64#define __GNUC_PREREQ__(ma, mi) \ 65 (__GNUC__ > (ma) || __GNUC__ == (ma) && __GNUC_MINOR__ >= (mi)) 66#else 67#define __GNUC_PREREQ__(ma, mi) 0 68#endif 69 70#if !__GNUC_PREREQ__(2, 5) 71#define __unused 72#endif 73#if __GNUC__ == 2 && __GNUC_MINOR__ >= 5 && __GNUC_MINOR__ < 7 74#define __unused 75/* XXX Find out what to do for __packed, __aligned and __section */ 76#endif 77#if __GNUC_PREREQ__(2, 7) 78#define __unused __attribute__((__unused__)) 79#endif 80 81#if __GNUC_PREREQ__(2, 96) 82#define __predict_false(exp) __builtin_expect((exp), 0) 83#else 84#define __predict_false(exp) (exp) 85#endif 86 87__FBSDID("$FreeBSD$"); 88 89#include <errno.h> 90#include <stdint.h> 91#include <stdlib.h> 92#include <string.h> 93// #include "libc_private.h" 94 95#if defined(I_AM_QSORT_R) 96typedef int cmp_t(void *, const void *, const void *); 97#elif defined(I_AM_QSORT_S) 98typedef int cmp_t(const void *, const void *, void *); 99#else 100typedef int cmp_t(const void *, const void *); 101#endif 102static inline char *med3(char *, char *, char *, cmp_t *, void *); 103 104#define MIN(a, b) ((a) < (b) ? a : b) 105 106/* 107 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". 108 */ 109 110static inline void 111swapfunc(char *a, char *b, size_t es) 112{ 113 char t; 114 115 do { 116 t = *a; 117 *a++ = *b; 118 *b++ = t; 119 } while (--es > 0); 120} 121 122#define vecswap(a, b, n) \ 123 if ((n) > 0) swapfunc(a, b, n) 124 125#if defined(I_AM_QSORT_R) 126#define CMP(t, x, y) (cmp((t), (x), (y))) 127#elif defined(I_AM_QSORT_S) 128#define CMP(t, x, y) (cmp((x), (y), (t))) 129#else 130#define CMP(t, x, y) (cmp((x), (y))) 131#endif 132 133static inline char * 134med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk 135#if !defined(I_AM_QSORT_R) && !defined(I_AM_QSORT_S) 136__unused 137#endif 138) 139{ 140 return CMP(thunk, a, b) < 0 ? 141 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a )) 142 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c )); 143} 144 145/* 146 * The actual qsort() implementation is static to avoid preemptible calls when 147 * recursing. Also give them different names for improved debugging. 148 */ 149#if defined(I_AM_QSORT_R) 150#define local_qsort local_qsort_r 151#elif defined(I_AM_QSORT_S) 152#define local_qsort local_qsort_s 153#endif 154static void 155local_qsort(void *a, size_t n, size_t es, cmp_t *cmp, void *thunk) 156{ 157 char *pa, *pb, *pc, *pd, *pl, *pm, *pn; 158 size_t d1, d2; 159 int cmp_result; 160 int swap_cnt; 161 162 if (__predict_false(n == 0)) 163 return; 164loop: 165 swap_cnt = 0; 166 if (n < 7) { 167 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 168 for (pl = pm; 169 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 170 pl -= es) 171 swapfunc(pl, pl - es, es); 172 return; 173 } 174 pm = (char *)a + (n / 2) * es; 175 if (n > 7) { 176 pl = a; 177 pn = (char *)a + (n - 1) * es; 178 if (n > 40) { 179 size_t d = (n / 8) * es; 180 181 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk); 182 pm = med3(pm - d, pm, pm + d, cmp, thunk); 183 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk); 184 } 185 pm = med3(pl, pm, pn, cmp, thunk); 186 } 187 swapfunc(a, pm, es); 188 pa = pb = (char *)a + es; 189 190 pc = pd = (char *)a + (n - 1) * es; 191 for (;;) { 192 while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) { 193 if (cmp_result == 0) { 194 swap_cnt = 1; 195 swapfunc(pa, pb, es); 196 pa += es; 197 } 198 pb += es; 199 } 200 while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) { 201 if (cmp_result == 0) { 202 swap_cnt = 1; 203 swapfunc(pc, pd, es); 204 pd -= es; 205 } 206 pc -= es; 207 } 208 if (pb > pc) 209 break; 210 swapfunc(pb, pc, es); 211 swap_cnt = 1; 212 pb += es; 213 pc -= es; 214 } 215 if (swap_cnt == 0) { /* Switch to insertion sort */ 216 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 217 for (pl = pm; 218 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 219 pl -= es) 220 swapfunc(pl, pl - es, es); 221 return; 222 } 223 224 pn = (char *)a + n * es; 225 d1 = MIN(pa - (char *)a, pb - pa); 226 vecswap(a, pb - d1, d1); 227 d1 = MIN(pd - pc, pn - pd - es); 228 vecswap(pb, pn - d1, d1); 229 230 d1 = pb - pa; 231 d2 = pd - pc; 232 if (d1 <= d2) { 233 /* Recurse on left partition, then iterate on right partition */ 234 if (d1 > es) { 235 local_qsort(a, d1 / es, es, cmp, thunk); 236 } 237 if (d2 > es) { 238 /* Iterate rather than recurse to save stack space */ 239 /* qsort(pn - d2, d2 / es, es, cmp); */ 240 a = pn - d2; 241 n = d2 / es; 242 goto loop; 243 } 244 } else { 245 /* Recurse on right partition, then iterate on left partition */ 246 if (d2 > es) { 247 local_qsort(pn - d2, d2 / es, es, cmp, thunk); 248 } 249 if (d1 > es) { 250 /* Iterate rather than recurse to save stack space */ 251 /* qsort(a, d1 / es, es, cmp); */ 252 n = d1 / es; 253 goto loop; 254 } 255 } 256} 257 258#if defined(I_AM_QSORT_R) 259void 260qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp) 261{ 262 local_qsort_r(a, n, es, cmp, thunk); 263} 264#elif defined(I_AM_QSORT_S) 265errno_t 266qsort_s(void *a, rsize_t n, rsize_t es, cmp_t *cmp, void *thunk) 267{ 268 if (n > RSIZE_MAX) { 269 __throw_constraint_handler_s("qsort_s : n > RSIZE_MAX", EINVAL); 270 return (EINVAL); 271 } else if (es > RSIZE_MAX) { 272 __throw_constraint_handler_s("qsort_s : es > RSIZE_MAX", 273 EINVAL); 274 return (EINVAL); 275 } else if (n != 0) { 276 if (a == NULL) { 277 __throw_constraint_handler_s("qsort_s : a == NULL", 278 EINVAL); 279 return (EINVAL); 280 } else if (cmp == NULL) { 281 __throw_constraint_handler_s("qsort_s : cmp == NULL", 282 EINVAL); 283 return (EINVAL); 284 } 285 } 286 287 local_qsort_s(a, n, es, cmp, thunk); 288 return (0); 289} 290#else 291void 292qsort(void *a, size_t n, size_t es, cmp_t *cmp) 293{ 294 local_qsort(a, n, es, cmp, NULL); 295} 296#endif