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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 | /* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <linux/kernel.h> #include <linux/string.h> /* * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". */ #define swapcode(TYPE, parmi, parmj, n) { \ long i = (n) / sizeof (TYPE); \ register TYPE *pi = (TYPE *) (parmi); \ register TYPE *pj = (TYPE *) (parmj); \ do { \ register TYPE t = *pi; \ *pi++ = *pj; \ *pj++ = t; \ } while (--i > 0); \ } #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \ es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1; static __inline void swapfunc(char *a, char *b, int n, int swaptype) { if (swaptype <= 1) swapcode(long, a, b, n) else swapcode(char, a, b, n) } #define swap(a, b) \ if (swaptype == 0) { \ long t = *(long *)(a); \ *(long *)(a) = *(long *)(b); \ *(long *)(b) = t; \ } else \ swapfunc(a, b, es, swaptype) #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype) static __inline char * med3(char *a, char *b, char *c, int (*cmp)(const void *, const void *)) { return cmp(a, b) < 0 ? (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a )) :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c )); } void qsort(void *aa, size_t n, size_t es, int (*cmp)(const void *, const void *)) { char *pa, *pb, *pc, *pd, *pl, *pm, *pn; int d, r, swaptype, swap_cnt; register char *a = aa; loop: SWAPINIT(a, es); swap_cnt = 0; if (n < 7) { for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es) for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0; pl -= es) swap(pl, pl - es); return; } pm = (char *)a + (n / 2) * es; if (n > 7) { pl = (char *)a; pn = (char *)a + (n - 1) * es; if (n > 40) { d = (n / 8) * es; pl = med3(pl, pl + d, pl + 2 * d, cmp); pm = med3(pm - d, pm, pm + d, cmp); pn = med3(pn - 2 * d, pn - d, pn, cmp); } pm = med3(pl, pm, pn, cmp); } swap(a, pm); pa = pb = (char *)a + es; pc = pd = (char *)a + (n - 1) * es; for (;;) { while (pb <= pc && (r = cmp(pb, a)) <= 0) { if (r == 0) { swap_cnt = 1; swap(pa, pb); pa += es; } pb += es; } while (pb <= pc && (r = cmp(pc, a)) >= 0) { if (r == 0) { swap_cnt = 1; swap(pc, pd); pd -= es; } pc -= es; } if (pb > pc) break; swap(pb, pc); swap_cnt = 1; pb += es; pc -= es; } if (swap_cnt == 0) { /* Switch to insertion sort */ for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es) for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0; pl -= es) swap(pl, pl - es); return; } pn = (char *)a + n * es; r = min(pa - (char *)a, pb - pa); vecswap(a, pb - r, r); r = min((long)(pd - pc), (long)(pn - pd - es)); vecswap(pb, pn - r, r); if ((r = pb - pa) > es) qsort(a, r / es, es, cmp); if ((r = pd - pc) > es) { /* Iterate rather than recurse to save stack space */ a = pn - r; n = r / es; goto loop; } /* qsort(pn - r, r / es, es, cmp);*/ } |