michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: 
michael@0: /*-
michael@0:  * Copyright (c) 1992, 1993
michael@0:  *	The Regents of the University of California.  All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 1. Redistributions of source code must retain the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer.
michael@0:  * 2. Redistributions in binary form must reproduce the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer in the
michael@0:  *    documentation and/or other materials provided with the distribution.
michael@0:  * 3. Neither the name of the University nor the names of its contributors
michael@0:  *    may be used to endorse or promote products derived from this software
michael@0:  *    without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
michael@0:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
michael@0:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
michael@0:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
michael@0:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
michael@0:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
michael@0:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
michael@0:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
michael@0:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
michael@0:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
michael@0:  * SUCH DAMAGE.
michael@0:  */
michael@0: 
michael@0: /* We need this because Solaris' version of qsort is broken and
michael@0:  * causes array bounds reads.
michael@0:  */
michael@0: 
michael@0: #include <stdlib.h>
michael@0: #include "nsAlgorithm.h"
michael@0: #include "nsQuickSort.h"
michael@0: 
michael@0: extern "C" {
michael@0: 
michael@0: #if !defined(DEBUG) && (defined(__cplusplus) || defined(__gcc))
michael@0: # ifndef INLINE
michael@0: #  define INLINE inline
michael@0: # endif
michael@0: #else
michael@0: # define INLINE
michael@0: #endif
michael@0: 
michael@0: typedef int		 cmp_t(const void *, const void *, void *);
michael@0: static INLINE char	*med3(char *, char *, char *, cmp_t *, void *);
michael@0: static INLINE void	swapfunc(char *, char *, int, int);
michael@0: 
michael@0: /*
michael@0:  * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
michael@0:  */
michael@0: #define swapcode(TYPE, parmi, parmj, n) { 		\
michael@0: 	long i = (n) / sizeof (TYPE); 			\
michael@0: 	TYPE *pi = (TYPE *) (parmi); 			\
michael@0: 	TYPE *pj = (TYPE *) (parmj); 			\
michael@0: 	do { 						\
michael@0: 		TYPE	t = *pi;			\
michael@0: 		*pi++ = *pj;				\
michael@0: 		*pj++ = t;				\
michael@0:         } while (--i > 0);				\
michael@0: }
michael@0: 
michael@0: #define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
michael@0: 	es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
michael@0: 
michael@0: static INLINE void
michael@0: swapfunc(char *a, char *b, int n, int swaptype)
michael@0: {
michael@0: 	if(swaptype <= 1)
michael@0: 		swapcode(long, a, b, n)
michael@0: 	else
michael@0: 		swapcode(char, a, b, n)
michael@0: }
michael@0: 
michael@0: #define swap(a, b)					\
michael@0: 	if (swaptype == 0) {				\
michael@0: 		long t = *(long *)(a);			\
michael@0: 		*(long *)(a) = *(long *)(b);		\
michael@0: 		*(long *)(b) = t;			\
michael@0: 	} else						\
michael@0: 		swapfunc((char *)a, (char*)b, (int)es, swaptype)
michael@0: 
michael@0: #define vecswap(a, b, n) 	if ((n) > 0) swapfunc((char *)a, (char *)b, (int)n, swaptype)
michael@0: 
michael@0: static INLINE char *
michael@0: med3(char *a, char *b, char *c, cmp_t* cmp, void *data)
michael@0: {
michael@0: 	return cmp(a, b, data) < 0 ?
michael@0: 	       (cmp(b, c, data) < 0 ? b : (cmp(a, c, data) < 0 ? c : a ))
michael@0:               :(cmp(b, c, data) > 0 ? b : (cmp(a, c, data) < 0 ? a : c ));
michael@0: }
michael@0: 
michael@0: void NS_QuickSort (
michael@0: 	void *a,
michael@0: 	unsigned int n,
michael@0:     unsigned int es,
michael@0: 	cmp_t *cmp,
michael@0: 	void *data
michael@0:     )
michael@0: {
michael@0: 	char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
michael@0: 	int d, r, swaptype;
michael@0: 
michael@0: loop:	SWAPINIT(a, es);
michael@0: 	/* Use insertion sort when input is small */
michael@0: 	if (n < 7) {
michael@0: 		for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
michael@0: 			for (pl = pm; pl > (char *)a && cmp(pl - es, pl, data) > 0;
michael@0: 			     pl -= es)
michael@0: 				swap(pl, pl - es);
michael@0: 		return;
michael@0: 	}
michael@0: 	/* Choose pivot */
michael@0: 	pm = (char *)a + (n / 2) * es;
michael@0: 	if (n > 7) {
michael@0: 		pl = (char *)a;
michael@0: 		pn = (char *)a + (n - 1) * es;
michael@0: 		if (n > 40) {
michael@0: 			d = (n / 8) * es;
michael@0: 			pl = med3(pl, pl + d, pl + 2 * d, cmp, data);
michael@0: 			pm = med3(pm - d, pm, pm + d, cmp, data);
michael@0: 			pn = med3(pn - 2 * d, pn - d, pn, cmp, data);
michael@0: 		}
michael@0: 		pm = med3(pl, pm, pn, cmp, data);
michael@0: 	}
michael@0: 	swap(a, pm);
michael@0: 	pa = pb = (char *)a + es;
michael@0: 
michael@0: 	pc = pd = (char *)a + (n - 1) * es;
michael@0: 	/* loop invariants:
michael@0: 	 * [a, pa) = pivot
michael@0: 	 * [pa, pb) < pivot
michael@0: 	 * [pb, pc + es) unprocessed
michael@0: 	 * [pc + es, pd + es) > pivot
michael@0: 	 * [pd + es, pn) = pivot
michael@0: 	 */
michael@0: 	for (;;) {
michael@0: 		while (pb <= pc && (r = cmp(pb, a, data)) <= 0) {
michael@0: 			if (r == 0) {
michael@0: 				swap(pa, pb);
michael@0: 				pa += es;
michael@0: 			}
michael@0: 			pb += es;
michael@0: 		}
michael@0: 		while (pb <= pc && (r = cmp(pc, a, data)) >= 0) {
michael@0: 			if (r == 0) {
michael@0: 				swap(pc, pd);
michael@0: 				pd -= es;
michael@0: 			}
michael@0: 			pc -= es;
michael@0: 		}
michael@0: 		if (pb > pc)
michael@0: 			break;
michael@0: 		swap(pb, pc);
michael@0: 		pb += es;
michael@0: 		pc -= es;
michael@0: 	}
michael@0: 	/* Move pivot values */
michael@0: 	pn = (char *)a + n * es;
michael@0: 	r = XPCOM_MIN(pa - (char *)a, pb - pa);
michael@0: 	vecswap(a, pb - r, r);
michael@0: 	r = XPCOM_MIN<size_t>(pd - pc, pn - pd - es);
michael@0: 	vecswap(pb, pn - r, r);
michael@0: 	/* Recursively process partitioned items */
michael@0: 	if ((r = pb - pa) > (int)es)
michael@0:         NS_QuickSort(a, r / es, es, cmp, data);
michael@0: 	if ((r = pd - pc) > (int)es) {
michael@0: 		/* Iterate rather than recurse to save stack space */
michael@0: 		a = pn - r;
michael@0: 		n = r / es;
michael@0: 		goto loop;
michael@0: 	}
michael@0: /*		NS_QuickSort(pn - r, r / es, es, cmp, data);*/
michael@0: }
michael@0: 
michael@0: }
michael@0: 
michael@0: #undef INLINE
michael@0: #undef swapcode
michael@0: #undef SWAPINIT
michael@0: #undef swap
michael@0: #undef vecswap