diff options
Diffstat (limited to 'main/mergesort.c')
| -rw-r--r-- | main/mergesort.c | 363 |
1 files changed, 0 insertions, 363 deletions
diff --git a/main/mergesort.c b/main/mergesort.c deleted file mode 100644 index 117f859e94..0000000000 --- a/main/mergesort.c +++ /dev/null @@ -1,363 +0,0 @@ -/*- - * Copyright (c) 1992, 1993 - * The Regents of the University of California. All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * Peter McIlroy. - * - * 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. - */ - -/* $Id$ */ - -#if defined(LIBC_SCCS) && !defined(lint) -static char sccsid[] = "@(#)merge.c 8.2 (Berkeley) 2/14/94"; -#endif /* LIBC_SCCS and not lint */ - -/* - * Hybrid exponential search/linear search merge sort with hybrid - * natural/pairwise first pass. Requires about .3% more comparisons - * for random data than LSMS with pairwise first pass alone. - * It works for objects as small as two bytes. - */ - -#define NATURAL -#define THRESHOLD 16 /* Best choice for natural merge cut-off. */ - -/* #define NATURAL to get hybrid natural merge. - * (The default is pairwise merging.) - */ - -#include <sys/types.h> - -#include <errno.h> -#include <stdlib.h> -#include <string.h> - -#include "php.h" - -#ifdef PHP_WIN32 -#include <winsock2.h> /* Includes definition for u_char */ -#endif - -#if defined(NETWARE) && !defined(NEW_LIBC) -/*#include <ws2nlm.h>*/ -#include <sys/socket.h> -#endif - -static void setup(u_char *list1, u_char *list2, size_t n, size_t size, int (*cmp)(const void *, const void * TSRMLS_DC) TSRMLS_DC); -static void insertionsort(u_char *a, size_t n, size_t size, int (*cmp)(const void *, const void * TSRMLS_DC) TSRMLS_DC); - -#define ISIZE sizeof(int) -#define PSIZE sizeof(u_char *) -#define ICOPY_LIST(src, dst, last) \ - do \ - *(int*)dst = *(int*)src, src += ISIZE, dst += ISIZE; \ - while(src < last) -#define ICOPY_ELT(src, dst, i) \ - do \ - *(int*) dst = *(int*) src, src += ISIZE, dst += ISIZE; \ - while (i -= ISIZE) - -#define CCOPY_LIST(src, dst, last) \ - do \ - *dst++ = *src++; \ - while (src < last) -#define CCOPY_ELT(src, dst, i) \ - do \ - *dst++ = *src++; \ - while (i -= 1) - -/* - * Find the next possible pointer head. (Trickery for forcing an array - * to do double duty as a linked list when objects do not align with word - * boundaries. - */ -/* Assumption: PSIZE is a power of 2. */ -#define EVAL(p) (u_char **) \ - ((u_char *)0 + \ - (((u_char *)p + PSIZE - 1 - (u_char *) 0) & ~(PSIZE - 1))) - -/* {{{ php_mergesort - * Arguments are as for qsort. - */ -int php_mergesort(void *base, size_t nmemb, size_t size, int (*cmp)(const void *, const void * TSRMLS_DC) TSRMLS_DC) -{ - register unsigned int i; - register int sense; - int big, iflag; - register u_char *f1, *f2, *t, *b, *tp2, *q, *l1, *l2; - u_char *list2, *list1, *p2, *p, *last, **p1; - - if (size < PSIZE / 2) { /* Pointers must fit into 2 * size. */ - errno = EINVAL; - return (-1); - } - - if (nmemb == 0) - return (0); - - /* - * XXX - * Stupid subtraction for the Cray. - */ - iflag = 0; - if (!(size % ISIZE) && !(((char *)base - (char *)0) % ISIZE)) - iflag = 1; - - if ((list2 = malloc(nmemb * size + PSIZE)) == NULL) - return (-1); - - list1 = base; - setup(list1, list2, nmemb, size, cmp TSRMLS_CC); - last = list2 + nmemb * size; - i = big = 0; - while (*EVAL(list2) != last) { - l2 = list1; - p1 = EVAL(list1); - for (tp2 = p2 = list2; p2 != last; p1 = EVAL(l2)) { - p2 = *EVAL(p2); - f1 = l2; - f2 = l1 = list1 + (p2 - list2); - if (p2 != last) - p2 = *EVAL(p2); - l2 = list1 + (p2 - list2); - while (f1 < l1 && f2 < l2) { - if ((*cmp)(f1, f2 TSRMLS_CC) <= 0) { - q = f2; - b = f1, t = l1; - sense = -1; - } else { - q = f1; - b = f2, t = l2; - sense = 0; - } - if (!big) { /* here i = 0 */ - while ((b += size) < t && cmp(q, b TSRMLS_CC) >sense) - if (++i == 6) { - big = 1; - goto EXPONENTIAL; - } - } else { -EXPONENTIAL: for (i = size; ; i <<= 1) - if ((p = (b + i)) >= t) { - if ((p = t - size) > b && - (*cmp)(q, p TSRMLS_CC) <= sense) - t = p; - else - b = p; - break; - } else if ((*cmp)(q, p TSRMLS_CC) <= sense) { - t = p; - if (i == size) - big = 0; - goto FASTCASE; - } else - b = p; - while (t > b+size) { - i = (((t - b) / size) >> 1) * size; - if ((*cmp)(q, p = b + i TSRMLS_CC) <= sense) - t = p; - else - b = p; - } - goto COPY; -FASTCASE: while (i > size) - if ((*cmp)(q, - p = b + (i >>= 1) TSRMLS_CC) <= sense) - t = p; - else - b = p; -COPY: b = t; - } - i = size; - if (q == f1) { - if (iflag) { - ICOPY_LIST(f2, tp2, b); - ICOPY_ELT(f1, tp2, i); - } else { - CCOPY_LIST(f2, tp2, b); - CCOPY_ELT(f1, tp2, i); - } - } else { - if (iflag) { - ICOPY_LIST(f1, tp2, b); - ICOPY_ELT(f2, tp2, i); - } else { - CCOPY_LIST(f1, tp2, b); - CCOPY_ELT(f2, tp2, i); - } - } - } - if (f2 < l2) { - if (iflag) - ICOPY_LIST(f2, tp2, l2); - else - CCOPY_LIST(f2, tp2, l2); - } else if (f1 < l1) { - if (iflag) - ICOPY_LIST(f1, tp2, l1); - else - CCOPY_LIST(f1, tp2, l1); - } - *p1 = l2; - } - tp2 = list1; /* swap list1, list2 */ - list1 = list2; - list2 = tp2; - last = list2 + nmemb*size; - } - if (base == list2) { - memmove(list2, list1, nmemb*size); - list2 = list1; - } - free(list2); - return (0); -} -/* }}} */ - -#define swap(a, b) { \ - s = b; \ - i = size; \ - do { \ - tmp = *a; *a++ = *s; *s++ = tmp; \ - } while (--i); \ - a -= size; \ - } -#define reverse(bot, top) { \ - s = top; \ - do { \ - i = size; \ - do { \ - tmp = *bot; *bot++ = *s; *s++ = tmp; \ - } while (--i); \ - s -= size2; \ - } while(bot < s); \ -} - -/* {{{ setup - * Optional hybrid natural/pairwise first pass. Eats up list1 in runs of - * increasing order, list2 in a corresponding linked list. Checks for runs - * when THRESHOLD/2 pairs compare with same sense. (Only used when NATURAL - * is defined. Otherwise simple pairwise merging is used.) - */ -static void setup(u_char *list1, u_char *list2, size_t n, size_t size, int (*cmp)(const void *, const void * TSRMLS_DC) TSRMLS_DC) -{ - int i, length, size2, tmp, sense; - u_char *f1, *f2, *s, *l2, *last, *p2; - - size2 = size*2; - if (n <= 5) { - insertionsort(list1, n, size, cmp TSRMLS_CC); - *EVAL(list2) = (u_char*) list2 + n*size; - return; - } - /* - * Avoid running pointers out of bounds; limit n to evens - * for simplicity. - */ - i = 4 + (n & 1); - insertionsort(list1 + (n - i) * size, i, size, cmp TSRMLS_CC); - last = list1 + size * (n - i); - *EVAL(list2 + (last - list1)) = list2 + n * size; - -#ifdef NATURAL - p2 = list2; - f1 = list1; - sense = (cmp(f1, f1 + size TSRMLS_CC) > 0); - for (; f1 < last; sense = !sense) { - length = 2; - /* Find pairs with same sense. */ - for (f2 = f1 + size2; f2 < last; f2 += size2) { - if ((cmp(f2, f2+ size TSRMLS_CC) > 0) != sense) - break; - length += 2; - } - if (length < THRESHOLD) { /* Pairwise merge */ - do { - p2 = *EVAL(p2) = f1 + size2 - list1 + list2; - if (sense > 0) - swap (f1, f1 + size); - } while ((f1 += size2) < f2); - } else { /* Natural merge */ - l2 = f2; - for (f2 = f1 + size2; f2 < l2; f2 += size2) { - if ((cmp(f2-size, f2 TSRMLS_CC) > 0) != sense) { - p2 = *EVAL(p2) = f2 - list1 + list2; - if (sense > 0) - reverse(f1, f2-size); - f1 = f2; - } - } - if (sense > 0) - reverse (f1, f2-size); - f1 = f2; - if (f2 < last || cmp(f2 - size, f2 TSRMLS_CC) > 0) - p2 = *EVAL(p2) = f2 - list1 + list2; - else - p2 = *EVAL(p2) = list2 + n*size; - } - } -#else /* pairwise merge only. */ - for (f1 = list1, p2 = list2; f1 < last; f1 += size2) { - p2 = *EVAL(p2) = p2 + size2; - if (cmp (f1, f1 + size TSRMLS_CC) > 0) - swap(f1, f1 + size); - } -#endif /* NATURAL */ -} -/* }}} */ - -/* {{{ insertionsort - * This is to avoid out-of-bounds addresses in sorting the - * last 4 elements. - */ -static void insertionsort(u_char *a, size_t n, size_t size, int (*cmp)(const void *, const void * TSRMLS_DC) TSRMLS_DC) -{ - u_char *ai, *s, *t, *u, tmp; - int i; - - for (ai = a+size; --n >= 1; ai += size) - for (t = ai; t > a; t -= size) { - u = t - size; - if (cmp(u, t TSRMLS_CC) <= 0) - break; - swap(u, t); - } -} -/* }}} */ - -/* - * Local variables: - * tab-width: 4 - * c-basic-offset: 4 - * End: - * vim600: fdm=marker - * vim: noet sw=4 ts=4 - */ |