LXR uboot/fs/yaffs2/yaffs

   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 * 3. 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/* XXX U-BOOT XXX */
  31#include <common.h>
  32
  33#include "yportenv.h"
  34//#include <linux/string.h>
  35
  36/*
  37 * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
  38 */
  39#define swapcode(TYPE, parmi, parmj, n) {               \
  40        long i = (n) / sizeof (TYPE);                   \
  41        register TYPE *pi = (TYPE *) (parmi);           \
  42        register TYPE *pj = (TYPE *) (parmj);           \
  43        do {                                            \
  44                register TYPE   t = *pi;                \
  45                *pi++ = *pj;                            \
  46                *pj++ = t;                              \
  47        } while (--i > 0);                              \
  48}
  49
  50#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
  51        es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
  52
  53static __inline void
  54swapfunc(char *a, char *b, int n, int swaptype)
  55{
  56        if (swaptype <= 1)
  57                swapcode(long, a, b, n)
  58        else
  59                swapcode(char, a, b, n)
  60}
  61
  62#define swap(a, b)                                      \
  63        if (swaptype == 0) {                            \
  64                long t = *(long *)(a);                  \
  65                *(long *)(a) = *(long *)(b);            \
  66                *(long *)(b) = t;                       \
  67        } else                                          \
  68                swapfunc(a, b, es, swaptype)
  69
  70#define vecswap(a, b, n)        if ((n) > 0) swapfunc(a, b, n, swaptype)
  71
  72static __inline char *
  73med3(char *a, char *b, char *c, int (*cmp)(const void *, const void *))
  74{
  75        return cmp(a, b) < 0 ?
  76               (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
  77              :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
  78}
  79
  80#ifndef min
  81#define min(a,b) (((a) < (b)) ? (a) : (b))
  82#endif
  83
  84void
  85yaffs_qsort(void *aa, size_t n, size_t es,
  86        int (*cmp)(const void *, const void *))
  87{
  88        char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
  89        int d, r, swaptype, swap_cnt;
  90        register char *a = aa;
  91
  92loop:   SWAPINIT(a, es);
  93        swap_cnt = 0;
  94        if (n < 7) {
  95                for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es)
  96                        for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
  97                             pl -= es)
  98                                swap(pl, pl - es);
  99                return;
 100        }
 101        pm = (char *)a + (n / 2) * es;
 102        if (n > 7) {
 103                pl = (char *)a;
 104                pn = (char *)a + (n - 1) * es;
 105                if (n > 40) {
 106                        d = (n / 8) * es;
 107                        pl = med3(pl, pl + d, pl + 2 * d, cmp);
 108                        pm = med3(pm - d, pm, pm + d, cmp);
 109                        pn = med3(pn - 2 * d, pn - d, pn, cmp);
 110                }
 111                pm = med3(pl, pm, pn, cmp);
 112        }
 113        swap(a, pm);
 114        pa = pb = (char *)a + es;
 115
 116        pc = pd = (char *)a + (n - 1) * es;
 117        for (;;) {
 118                while (pb <= pc && (r = cmp(pb, a)) <= 0) {
 119                        if (r == 0) {
 120                                swap_cnt = 1;
 121                                swap(pa, pb);
 122                                pa += es;
 123                        }
 124                        pb += es;
 125                }
 126                while (pb <= pc && (r = cmp(pc, a)) >= 0) {
 127                        if (r == 0) {
 128                                swap_cnt = 1;
 129                                swap(pc, pd);
 130                                pd -= es;
 131                        }
 132                        pc -= es;
 133                }
 134                if (pb > pc)
 135                        break;
 136                swap(pb, pc);
 137                swap_cnt = 1;
 138                pb += es;
 139                pc -= es;
 140        }
 141        if (swap_cnt == 0) {  /* Switch to insertion sort */
 142                for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
 143                        for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0;
 144                             pl -= es)
 145                                swap(pl, pl - es);
 146                return;
 147        }
 148
 149        pn = (char *)a + n * es;
 150        r = min(pa - (char *)a, pb - pa);
 151        vecswap(a, pb - r, r);
 152        r = min((long)(pd - pc), (long)(pn - pd - es));
 153        vecswap(pb, pn - r, r);
 154        if ((r = pb - pa) > es)
 155                yaffs_qsort(a, r / es, es, cmp);
 156        if ((r = pd - pc) > es) {
 157                /* Iterate rather than recurse to save stack space */
 158                a = pn - r;
 159                n = r / es;
 160                goto loop;
 161        }
 162/*              yaffs_qsort(pn - r, r / es, es, cmp);*/
 163}
 164