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