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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