crypto/external/bsd/heimdal/dist/lib/roken/qsort.c

   1 /*      $NetBSD: qsort.c,v 1.1.1.2 2014/04/24 12:45:52 pettai Exp $     */
   2
   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  * 4. 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 0
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 static char sccsid[] = "@(#)qsort.c     8.1 (Berkeley) 6/4/93";
  35 #endif /* LIBC_SCCS and not lint */
  36 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD$");
  38 #endif
  39
  40 #include <config.h>
  41
  42 #ifdef NEED_QSORT
  43
  44 #include <krb5/roken.h>
  45
  46 #include <stdlib.h>
  47
  48 #ifdef I_AM_QSORT_R
  49 typedef int              cmp_t(void *, const void *, const void *);
  50 #else
  51 typedef int              cmp_t(const void *, const void *);
  52 #endif
  53 static inline char      *med3(char *, char *, char *, cmp_t *, void *);
  54 static inline void       swapfunc(char *, char *, int, int);
  55
  56 /*
  57  * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
  58  */
  59 #define swapcode(TYPE, parmi, parmj, n) {               \
  60         long i = (n) / sizeof (TYPE);                   \
  61         TYPE *pi = (TYPE *) (parmi);            \
  62         TYPE *pj = (TYPE *) (parmj);            \
  63         do {                                            \
  64                 TYPE    t = *pi;                \
  65                 *pi++ = *pj;                            \
  66                 *pj++ = t;                              \
  67         } while (--i > 0);                              \
  68 }
  69
  70 #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
  71         es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
  72
  73 static inline void
  74 swapfunc(a, b, n, swaptype)
  75         char *a, *b;
  76         int n, swaptype;
  77 {
  78         if(swaptype <= 1)
  79                 swapcode(long, a, b, n)
  80         else
  81                 swapcode(char, a, b, n)
  82 }
  83
  84 #define swap(a, b)                                      \
  85         if (swaptype == 0) {                            \
  86                 long t = *(long *)(a);                  \
  87                 *(long *)(a) = *(long *)(b);            \
  88                 *(long *)(b) = t;                       \
  89         } else                                          \
  90                 swapfunc(a, b, es, swaptype)
  91
  92 #define vecswap(a, b, n)        if ((n) > 0) swapfunc(a, b, n, swaptype)
  93
  94 #ifdef I_AM_QSORT_R
  95 #define CMP(t, x, y) (cmp((t), (x), (y)))
  96 #else
  97 #define CMP(t, x, y) (cmp((x), (y)))
  98 #endif
  99
 100 static inline char *
 101 med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk
 102 #ifndef I_AM_QSORT_R
 103 /* __unused */
 104 #endif
 105 )
 106 {
 107         return CMP(thunk, a, b) < 0 ?
 108                (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a ))
 109               :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));
 110 }
 111
 112 #ifdef I_AM_QSORT_R
 113 void
 114 rk_qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
 115 #else
 116 #define thunk NULL
 117 void
 118 rk_qsort(void *a, size_t n, size_t es, cmp_t *cmp)
 119 #endif
 120 {
 121         char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
 122         size_t d, r;
 123         int cmp_result;
 124         int swaptype, swap_cnt;
 125
 126 loop:   SWAPINIT(a, es);
 127         swap_cnt = 0;
 128         if (n < 7) {
 129                 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
 130                         for (pl = pm;
 131                              pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
 132                              pl -= es)
 133                                 swap(pl, pl - es);
 134                 return;
 135         }
 136         pm = (char *)a + (n / 2) * es;
 137         if (n > 7) {
 138                 pl = a;
 139                 pn = (char *)a + (n - 1) * es;
 140                 if (n > 40) {
 141                         d = (n / 8) * es;
 142                         pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);
 143                         pm = med3(pm - d, pm, pm + d, cmp, thunk);
 144                         pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk);
 145                 }
 146                 pm = med3(pl, pm, pn, cmp, thunk);
 147         }
 148         swap(a, pm);
 149         pa = pb = (char *)a + es;
 150
 151         pc = pd = (char *)a + (n - 1) * es;
 152         for (;;) {
 153                 while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) {
 154                         if (cmp_result == 0) {
 155                                 swap_cnt = 1;
 156                                 swap(pa, pb);
 157                                 pa += es;
 158                         }
 159                         pb += es;
 160                 }
 161                 while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) {
 162                         if (cmp_result == 0) {
 163                                 swap_cnt = 1;
 164                                 swap(pc, pd);
 165                                 pd -= es;
 166                         }
 167                         pc -= es;
 168                 }
 169                 if (pb > pc)
 170                         break;
 171                 swap(pb, pc);
 172                 swap_cnt = 1;
 173                 pb += es;
 174                 pc -= es;
 175         }
 176         if (swap_cnt == 0) {  /* Switch to insertion sort */
 177                 for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
 178                         for (pl = pm;
 179                              pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
 180                              pl -= es)
 181                                 swap(pl, pl - es);
 182                 return;
 183         }
 184
 185         pn = (char *)a + n * es;
 186         r = min(pa - (char *)a, pb - pa);
 187         vecswap(a, pb - r, r);
 188         r = min(pd - pc, pn - pd - es);
 189         vecswap(pb, pn - r, r);
 190         if ((r = pb - pa) > es)
 191 #ifdef I_AM_QSORT_R
 192                 rk_qsort_r(a, r / es, es, thunk, cmp);
 193 #else
 194                 rk_qsort(a, r / es, es, cmp);
 195 #endif
 196         if ((r = pd - pc) > es) {
 197                 /* Iterate rather than recurse to save stack space */
 198                 a = pn - r;
 199                 n = r / es;
 200                 goto loop;
 201         }
 202 /*              rk_qsort(pn - r, r / es, es, cmp);*/
 203 }
 204
 205 #endif /* NEED_QSORT */