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Diffstat (limited to 'firmware/libc/qsort.c')
| -rw-r--r-- | firmware/libc/qsort.c | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/firmware/libc/qsort.c b/firmware/libc/qsort.c new file mode 100644 index 0000000000..8c4d1ad511 --- /dev/null +++ b/firmware/libc/qsort.c @@ -0,0 +1,222 @@ +/* +FUNCTION +<<qsort>>---sort an array + +INDEX + qsort + +ANSI_SYNOPSIS + #include <stdlib.h> + void qsort(void *<[base]>, size_t <[nmemb]>, size_t <[size]>, + int (*<[compar]>)(const void *, const void *) ); + +TRAD_SYNOPSIS + #include <stdlib.h> + qsort(<[base]>, <[nmemb]>, <[size]>, <[compar]> ) + char *<[base]>; + size_t <[nmemb]>; + size_t <[size]>; + int (*<[compar]>)(); + +DESCRIPTION +<<qsort>> sorts an array (beginning at <[base]>) of <[nmemb]> objects. +<[size]> describes the size of each element of the array. + +You must supply a pointer to a comparison function, using the argument +shown as <[compar]>. (This permits sorting objects of unknown +properties.) Define the comparison function to accept two arguments, +each a pointer to an element of the array starting at <[base]>. The +result of <<(*<[compar]>)>> must be negative if the first argument is +less than the second, zero if the two arguments match, and positive if +the first argument is greater than the second (where ``less than'' and +``greater than'' refer to whatever arbitrary ordering is appropriate). + +The array is sorted in place; that is, when <<qsort>> returns, the +array elements beginning at <[base]> have been reordered. + +RETURNS +<<qsort>> does not return a result. + +PORTABILITY +<<qsort>> is required by ANSI (without specifying the sorting algorithm). +*/ + +/*- + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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 <_ansi.h> +#include <stdlib.h> + +#ifndef __GNUC__ +#define inline +#endif + +static inline char *med3 _PARAMS((char *, char *, char *, int (*cmp)(const _PTR,const _PTR))); +static inline void swapfunc _PARAMS((char *, char *, int, int)); + +#define min(a, b) (a) < (b) ? a : b + +/* + * 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 +_DEFUN(swapfunc, (a, b, n, swaptype), + char *a _AND + char *b _AND + int n _AND + 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 * +_DEFUN(med3, (a, b, c, cmp), + char *a _AND + char *b _AND + char *c _AND + int (*cmp)(const _PTR,const _PTR)) +{ + 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 +_DEFUN(qsort, (a, n, es, cmp), + void *a _AND + size_t n _AND + size_t es _AND + int (*cmp)(const _PTR,const _PTR)) +{ + char *pa, *pb, *pc, *pd, *pl, *pm, *pn; + int d, r, swaptype, swap_cnt; + +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 = 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((unsigned int)(pd - pc), pn - pd - es); + vecswap(pb, pn - r, r); + if ((unsigned int)(r = pb - pa) > es) + qsort(a, r / es, es, cmp); + if ((unsigned int)(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);*/ +} |