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 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

 /*-

  * 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.

  */

 /* We need this because Solaris' version of qsort is broken and

  * causes array bounds reads.

  */

 #include <stdlib.h>

 #include "nsAlgorithm.h"

 #include "nsQuickSort.h"

 extern "C" {

 #if !defined(DEBUG) && (defined(__cplusplus) || defined(__gcc))

 # ifndef INLINE

 #  define INLINE inline

 # endif

 #else

 # define INLINE

 #endif

 typedef int		 cmp_t(const void *, const void *, void *);

 static INLINE char	*med3(char *, char *, char *, cmp_t *, void *);

 static INLINE void	swapfunc(char *, char *, int, int);

 /*

  * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".

  */

 #define swapcode(TYPE, parmi, parmj, n) { 		\

 	long i = (n) / sizeof (TYPE); 			\

 	TYPE *pi = (TYPE *) (parmi); 			\

 	TYPE *pj = (TYPE *) (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, int 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 *)(a);			\

 		*(long *)(a) = *(long *)(b);		\

 		*(long *)(b) = t;			\

 	} else						\

 		swapfunc((char *)a, (char*)b, (int)es, swaptype)

 #define vecswap(a, b, n) 	if ((n) > 0) swapfunc((char *)a, (char *)b, (int)n, swaptype)

 static INLINE char *

 med3(char *a, char *b, char *c, cmp_t* cmp, void *data)

 {

 	return cmp(a, b, data) < 0 ?

 	       (cmp(b, c, data) < 0 ? b : (cmp(a, c, data) < 0 ? c : a ))

               :(cmp(b, c, data) > 0 ? b : (cmp(a, c, data) < 0 ? a : c ));

 }

 void NS_QuickSort (

 	void *a,

 	unsigned int n,

     unsigned int es,

 	cmp_t *cmp,

 	void *data

     )

 {

 	char *pa, *pb, *pc, *pd, *pl, *pm, *pn;

 	int d, r, swaptype;

 loop:	SWAPINIT(a, es);

 	/* Use insertion sort when input is small */

 	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, data) > 0;

 			     pl -= es)

 				swap(pl, pl - es);

 		return;

 	}

 	/* Choose pivot */

 	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, data);

 			pm = med3(pm - d, pm, pm + d, cmp, data);

 			pn = med3(pn - 2 * d, pn - d, pn, cmp, data);

 		}

 		pm = med3(pl, pm, pn, cmp, data);

 	}

 	swap(a, pm);

 	pa = pb = (char *)a + es;

 	pc = pd = (char *)a + (n - 1) * es;

 	/* loop invariants:

 	 * [a, pa) = pivot

 	 * [pa, pb) < pivot

 	 * [pb, pc + es) unprocessed

 	 * [pc + es, pd + es) > pivot

 	 * [pd + es, pn) = pivot

 	 */

 	for (;;) {

 		while (pb <= pc && (r = cmp(pb, a, data)) <= 0) {

 			if (r == 0) {

 				swap(pa, pb);

 				pa += es;

 			}

 			pb += es;

 		}

 		while (pb <= pc && (r = cmp(pc, a, data)) >= 0) {

 			if (r == 0) {

 				swap(pc, pd);

 				pd -= es;

 			}

 			pc -= es;

 		}

 		if (pb > pc)

 			break;

 		swap(pb, pc);

 		pb += es;

 		pc -= es;

 	}

 	/* Move pivot values */

 	pn = (char *)a + n * es;

 	r = XPCOM_MIN(pa - (char *)a, pb - pa);

 	vecswap(a, pb - r, r);

 	r = XPCOM_MIN<size_t>(pd - pc, pn - pd - es);

 	vecswap(pb, pn - r, r);

 	/* Recursively process partitioned items */

 	if ((r = pb - pa) > (int)es)

         NS_QuickSort(a, r / es, es, cmp, data);

 	if ((r = pd - pc) > (int)es) {

 		/* Iterate rather than recurse to save stack space */

 		a = pn - r;

 		n = r / es;

 		goto loop;

 	}

 /*		NS_QuickSort(pn - r, r / es, es, cmp, data);*/

 }

 }

 #undef INLINE

 #undef swapcode

 #undef SWAPINIT

 #undef swap

 #undef vecswap