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 defined(LIBC_SCCS) && !defined(lint) 31static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93"; 32#endif /* LIBC_SCCS and not lint */ 33#include <sys/cdefs.h> 34__FBSDID("$FreeBSD: src/lib/libc/stdlib/qsort.c,v 1.15 2008/01/14 09:21:34 das Exp $"); 35 36#include <stdlib.h> 37#include <string.h> 38 39#ifdef I_AM_QSORT_R 40typedef int cmp_t(void *, const void *, const void *); 41#else 42typedef int cmp_t(const void *, const void *); 43#endif 44#ifdef I_AM_QSORT_B 45static inline char *med3(char *, char *, char *, cmp_t ^, void *) __attribute__((always_inline)); 46#else 47static inline char *med3(char *, char *, char *, cmp_t *, void *) __attribute__((always_inline)); 48#endif 49static inline void swapfunc(char *, char *, int, int) __attribute__((always_inline)); 50 51#define min(a, b) (a) < (b) ? a : b 52 53/* 54 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". 55 */ 56#define swapcode(TYPE, parmi, parmj, n) { \ 57 long i = (n) / sizeof (TYPE); \ 58 TYPE *pi = (TYPE *) (parmi); \ 59 TYPE *pj = (TYPE *) (parmj); \ 60 do { \ 61 TYPE t = *pi; \ 62 *pi++ = *pj; \ 63 *pj++ = t; \ 64 } while (--i > 0); \ 65} 66 67#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \ 68 es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1; 69 70static inline void 71swapfunc(a, b, n, swaptype) 72 char *a, *b; 73 int n, swaptype; 74{ 75 if(swaptype <= 1) 76 swapcode(long, a, b, n) 77 else 78 swapcode(char, a, b, n) 79} 80 81#define swap(a, b) \ 82 if (swaptype == 0) { \ 83 long t = *(long *)(a); \ 84 *(long *)(a) = *(long *)(b); \ 85 *(long *)(b) = t; \ 86 } else \ 87 swapfunc(a, b, es, swaptype) 88 89#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype) 90 91#ifdef I_AM_QSORT_R 92#define CMP(t, x, y) (cmp((t), (x), (y))) 93#else 94#define CMP(t, x, y) (cmp((x), (y))) 95#endif 96 97static inline char * 98med3(char *a, char *b, char *c, 99#ifdef I_AM_QSORT_B 100cmp_t ^cmp, 101#else 102cmp_t *cmp, 103#endif 104void *thunk 105#ifndef I_AM_QSORT_R 106__unused 107#endif 108) 109{ 110 return CMP(thunk, a, b) < 0 ? 111 (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a )) 112 :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c )); 113} 114 115#ifdef __LP64__ 116#define DEPTH(x) (2 * (flsl((long)(x)) - 1)) 117#else /* !__LP64__ */ 118#define DEPTH(x) (2 * (fls((int)(x)) - 1)) 119#endif /* __LP64__ */ 120 121#ifdef I_AM_QSORT_R 122int __heapsort_r(void *, size_t, size_t, void *, int (*)(void *, const void *, const void *)); 123#endif 124 125static void 126_qsort(void *a, size_t n, size_t es, 127#ifdef I_AM_QSORT_R 128void *thunk, 129#else 130#define thunk NULL 131#endif 132#ifdef I_AM_QSORT_B 133cmp_t ^cmp, 134#else 135cmp_t *cmp, 136#endif 137int depth_limit) 138{ 139 char *pa, *pb, *pc, *pd, *pl, *pm, *pn; 140 size_t d, r; 141 int cmp_result; 142 int swaptype, swap_cnt; 143 144loop: 145 if (depth_limit-- <= 0) { 146#ifdef I_AM_QSORT_B 147 heapsort_b(a, n, es, cmp); 148#elif defined(I_AM_QSORT_R) 149 __heapsort_r(a, n, es, thunk, cmp); 150#else 151 heapsort(a, n, es, cmp); 152#endif 153 return; 154 } 155 SWAPINIT(a, es); 156 swap_cnt = 0; 157 if (n < 7) { 158 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 159 for (pl = pm; 160 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 161 pl -= es) 162 swap(pl, pl - es); 163 return; 164 } 165 pm = (char *)a + (n / 2) * es; 166 if (n > 7) { 167 pl = a; 168 pn = (char *)a + (n - 1) * es; 169 if (n > 40) { 170 d = (n / 8) * es; 171 pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk); 172 pm = med3(pm - d, pm, pm + d, cmp, thunk); 173 pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk); 174 } 175 pm = med3(pl, pm, pn, cmp, thunk); 176 } 177 swap(a, pm); 178 pa = pb = (char *)a + es; 179 180 pc = pd = (char *)a + (n - 1) * es; 181 for (;;) { 182 while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) { 183 if (cmp_result == 0) { 184 swap_cnt = 1; 185 swap(pa, pb); 186 pa += es; 187 } 188 pb += es; 189 } 190 while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) { 191 if (cmp_result == 0) { 192 swap_cnt = 1; 193 swap(pc, pd); 194 pd -= es; 195 } 196 pc -= es; 197 } 198 if (pb > pc) 199 break; 200 swap(pb, pc); 201 swap_cnt = 1; 202 pb += es; 203 pc -= es; 204 } 205 206 pn = (char *)a + n * es; 207 r = min(pa - (char *)a, pb - pa); 208 vecswap(a, pb - r, r); 209 r = min(pd - pc, pn - pd - es); 210 vecswap(pb, pn - r, r); 211 212 if (swap_cnt == 0) { /* Switch to insertion sort */ 213 r = 1 + n / 4; /* n >= 7, so r >= 2 */ 214 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es) 215 for (pl = pm; 216 pl > (char *)a && CMP(thunk, pl - es, pl) > 0; 217 pl -= es) { 218 swap(pl, pl - es); 219 if (++swap_cnt > r) goto nevermind; 220 } 221 return; 222 } 223 224nevermind: 225 if ((r = pb - pa) > es) 226#ifdef I_AM_QSORT_R 227 _qsort(a, r / es, es, thunk, cmp, depth_limit); 228#else 229 _qsort(a, r / es, es, cmp, depth_limit); 230#endif 231 if ((r = pd - pc) > es) { 232 /* Iterate rather than recurse to save stack space */ 233 a = pn - r; 234 n = r / es; 235 goto loop; 236 } 237/* qsort(pn - r, r / es, es, cmp);*/ 238} 239 240void 241#ifdef I_AM_QSORT_R 242qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp) 243#elif defined(I_AM_QSORT_B) 244qsort_b(void *a, size_t n, size_t es, cmp_t ^cmp) 245#else 246qsort(void *a, size_t n, size_t es, cmp_t *cmp) 247#endif 248{ 249 _qsort(a, n, es, 250#ifdef I_AM_QSORT_R 251 thunk, 252#endif 253 cmp, DEPTH(n)); 254} 255