/* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include "yportenv.h" /* #include */ /* * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function". */ #define swapcode(TYPE, parmi, parmj, n) do { \ 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); \ } while (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 yswap(a, b) do { \ if (swaptype == 0) { \ long t = *(long *)(a); \ *(long *)(a) = *(long *)(b); \ *(long *)(b) = t; \ } else \ swapfunc(a, b, es, swaptype); \ } while (0) #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)); } #ifndef min #define min(a, b) (((a) < (b)) ? (a) : (b)) #endif void yaffs_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) yswap(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); } yswap(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; yswap(pa, pb); pa += es; } pb += es; } while (pb <= pc && (r = cmp(pc, a)) >= 0) { if (r == 0) { swap_cnt = 1; yswap(pc, pd); pd -= es; } pc -= es; } if (pb > pc) break; yswap(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) yswap(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); r = pb - pa; if (r > es) yaffs_qsort(a, r / es, es, cmp); r = pd - pc; if (r > es) { /* Iterate rather than recurse to save stack space */ a = pn - r; n = r / es; goto loop; } /* yaffs_qsort(pn - r, r / es, es, cmp);*/ }