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) { \ 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 } 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 swap(a, b) \ 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 67 #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype) 68 69 static __inline char * 70 med3(char *a, char *b, char *c, int (*cmp)(const void *, const void *)) 71 { 72 return cmp(a, b) < 0 ? 73 (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a )) 74 :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c )); 75 } 76 77 #ifndef min 78 #define min(a,b) (((a) < (b)) ? (a) : (b)) 79 #endif 80 81 void 82 yaffs_qsort(void *aa, size_t n, size_t es, 83 int (*cmp)(const void *, const void *)) 84 { 85 char *pa, *pb, *pc, *pd, *pl, *pm, *pn; 86 int d, r, swaptype, swap_cnt; 87 register char *a = aa; 88 89 loop: SWAPINIT(a, es); 90 swap_cnt = 0; 91 if (n < 7) { 92 for (pm = (char *)a + es; pm < (char *) a + n * es; pm += es) 93 for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0; 94 pl -= es) 95 swap(pl, pl - es); 96 return; 97 } 98 pm = (char *)a + (n / 2) * es; 99 if (n > 7) { 100 pl = (char *)a; 101 pn = (char *)a + (n - 1) * es; 102 if (n > 40) { 103 d = (n / 8) * es; 104 pl = med3(pl, pl + d, pl + 2 * d, cmp); 105 pm = med3(pm - d, pm, pm + d, cmp); 106 pn = med3(pn - 2 * d, pn - d, pn, cmp); 107 } 108 pm = med3(pl, pm, pn, cmp); 109 } 110 swap(a, pm); 111 pa = pb = (char *)a + es; 112 113 pc = pd = (char *)a + (n - 1) * es; 114 for (;;) { 115 while (pb <= pc && (r = cmp(pb, a)) <= 0) { 116 if (r == 0) { 117 swap_cnt = 1; 118 swap(pa, pb); 119 pa += es; 120 } 121 pb += es; 122 } 123 while (pb <= pc && (r = cmp(pc, a)) >= 0) { 124 if (r == 0) { 125 swap_cnt = 1; 126 swap(pc, pd); 127 pd -= es; 128 } 129 pc -= es; 130 } 131 if (pb > pc) 132 break; 133 swap(pb, pc); 134 swap_cnt = 1; 135 pb += es; 136 pc -= es; 137 } 138 if (swap_cnt == 0) { /* Switch to insertion sort */ 139 for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es) 140 for (pl = pm; pl > (char *) a && cmp(pl - es, pl) > 0; 141 pl -= es) 142 swap(pl, pl - es); 143 return; 144 } 145 146 pn = (char *)a + n * es; 147 r = min(pa - (char *)a, pb - pa); 148 vecswap(a, pb - r, r); 149 r = min((long)(pd - pc), (long)(pn - pd - es)); 150 vecswap(pb, pn - r, r); 151 if ((r = pb - pa) > es) 152 yaffs_qsort(a, r / es, es, cmp); 153 if ((r = pd - pc) > es) { 154 /* Iterate rather than recurse to save stack space */ 155 a = pn - r; 156 n = r / es; 157 goto loop; 158 } 159 /* yaffs_qsort(pn - r, r / es, es, cmp);*/ 160 } 161