diff options
| author | ad <ad@NetBSD.org> | 2008-11-16 15:01:26 +0000 |
|---|---|---|
| committer | ad <ad@NetBSD.org> | 2008-11-16 15:01:26 +0000 |
| commit | e5c4df967af4e2b8df20034c8746b864f761f362 (patch) | |
| tree | 6bd55c200d5913bd068182a4ffdd807c95a33778 /common/lib/libc/stdlib | |
| parent | e2a270368e6994a2c0e7c9ed75d698e1e84cf3b5 (diff) | |
Make qsort() available in libkern.
Diffstat (limited to 'common/lib/libc/stdlib')
| -rw-r--r-- | common/lib/libc/stdlib/qsort.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/common/lib/libc/stdlib/qsort.c b/common/lib/libc/stdlib/qsort.c new file mode 100644 index 00000000000..c45d9836fab --- /dev/null +++ b/common/lib/libc/stdlib/qsort.c @@ -0,0 +1,188 @@ +/* $NetBSD: qsort.c,v 1.1 2008/11/16 15:01:26 ad Exp $ */ + +/*- + * 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 <sys/cdefs.h> +#if defined(LIBC_SCCS) && !defined(lint) +#if 0 +static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93"; +#else +__RCSID("$NetBSD: qsort.c,v 1.1 2008/11/16 15:01:26 ad Exp $"); +#endif +#endif /* LIBC_SCCS and not lint */ + +#include <sys/types.h> + +#ifdef _LIBC +#include <assert.h> +#include <errno.h> +#include <stdlib.h> +#endif + +#ifdef _KERNEL +#include <lib/libkern/libkern.h> +#endif + +static inline char *med3 __P((char *, char *, char *, + int (*)(const void *, const void *))); +static inline void swapfunc __P((char *, char *, size_t, 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) { \ + size_t i = (n) / sizeof (TYPE); \ + TYPE *pi = (TYPE *)(void *)(parmi); \ + TYPE *pj = (TYPE *)(void *)(parmj); \ + do { \ + 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, size_t 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 *)(void *)(a); \ + *(long *)(void *)(a) = *(long *)(void *)(b); \ + *(long *)(void *)(b) = t; \ + } else \ + swapfunc(a, b, es, swaptype) + +#define vecswap(a, b, n) if ((n) > 0) swapfunc((a), (b), (size_t)(n), swaptype) + +static inline char * +med3(char *a, char *b, char *c, + int (*cmp) __P((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 *a, size_t n, size_t es, + int (*cmp) __P((const void *, const void *))) +{ + char *pa, *pb, *pc, *pd, *pl, *pm, *pn; + size_t d, r; + int swaptype, swap_cnt, cmp_result; + + _DIAGASSERT(a != NULL); + _DIAGASSERT(cmp != NULL); + +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 && (cmp_result = cmp(pb, a)) <= 0) { + if (cmp_result == 0) { + swap_cnt = 1; + swap(pa, pb); + pa += es; + } + pb += es; + } + while (pb <= pc && (cmp_result = cmp(pc, a)) >= 0) { + if (cmp_result == 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(pd - pc, 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);*/ +} |
