software/libbase: qsort
This commit is contained in:
Sebastien Bourdeauducq
parent
2dc346dfd6
commit
59f4490630
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@ -60,6 +60,8 @@ unsigned int rand(void);
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void srand(unsigned int seed);
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void abort(void);
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void qsort(void *base, size_t nmemb, size_t size, int(*compar)(const void *, const void *));
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/*
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* The following functions are not provided by this library.
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*/
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@ -1,7 +1,7 @@
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M2DIR=../..
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include $(M2DIR)/software/common.mak
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OBJECTS=setjmp.o libc.o errno.o crc16.o crc32.o console.o timer.o system.o board.o uart.o vsnprintf.o strtod.o
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OBJECTS=setjmp.o libc.o errno.o crc16.o crc32.o console.o timer.o system.o board.o uart.o vsnprintf.o strtod.o qsort.o
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all: libbase.a
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@ -0,0 +1,215 @@
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/****************************************************************************
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* lib/stdlib/lib_qsort.c
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*
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* Copyright (C) 2007, 2009, 2011 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Leveraged from:
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*
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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****************************************************************************/
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#include <stdlib.h>
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#define min(a, b) (a) < (b) ? a : b
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#define swapcode(TYPE, parmi, parmj, n) \
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{ \
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long i = (n) / sizeof (TYPE); \
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register TYPE *pi = (TYPE *) (parmi); \
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register TYPE *pj = (TYPE *) (parmj); \
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do { \
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register TYPE t = *pi; \
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*pi++ = *pj; \
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*pj++ = t; \
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} while (--i > 0); \
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}
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#define SWAPINIT(a, size) \
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swaptype = ((char *)a - (char *)0) % sizeof(long) || \
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size % sizeof(long) ? 2 : size == sizeof(long)? 0 : 1;
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#define swap(a, b) \
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if (swaptype == 0) \
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{ \
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long t = *(long *)(a); \
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*(long *)(a) = *(long *)(b); \
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*(long *)(b) = t; \
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} \
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else \
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{ \
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swapfunc(a, b, size, swaptype); \
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}
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#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
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static inline void swapfunc(char *a, char *b, int n, int swaptype);
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static inline char *med3(char *a, char *b, char *c,
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int (*compar)(const void *, const void *));
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static inline void swapfunc(char *a, char *b, int n, int swaptype)
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{
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if(swaptype <= 1)
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{
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swapcode(long, a, b, n)
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}
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else
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{
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swapcode(char, a, b, n)
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}
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}
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static inline char *med3(char *a, char *b, char *c,
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int (*compar)(const void *, const void *))
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{
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return compar(a, b) < 0 ?
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(compar(b, c) < 0 ? b : (compar(a, c) < 0 ? c : a ))
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:(compar(b, c) > 0 ? b : (compar(a, c) < 0 ? a : c ));
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}
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/****************************************************************************
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* Name: qsort
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*
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* Description:
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* Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
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*
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****************************************************************************/
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void qsort(void *base, size_t nmemb, size_t size,
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int(*compar)(const void *, const void *))
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{
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char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
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int d, r, swaptype, swap_cnt;
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loop:
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SWAPINIT(base, size);
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swap_cnt = 0;
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if (nmemb < 7)
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{
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for (pm = (char *) base + size; pm < (char *) base + nmemb * size; pm += size)
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{
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for (pl = pm; pl > (char *) base && compar(pl - size, pl) > 0; pl -= size)
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{
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swap(pl, pl - size);
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}
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}
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return;
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}
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pm = (char *) base + (nmemb / 2) * size;
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if (nmemb > 7)
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{
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pl = base;
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pn = (char *) base + (nmemb - 1) * size;
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if (nmemb > 40)
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{
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d = (nmemb / 8) * size;
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pl = med3(pl, pl + d, pl + 2 * d, compar);
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pm = med3(pm - d, pm, pm + d, compar);
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pn = med3(pn - 2 * d, pn - d, pn, compar);
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}
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pm = med3(pl, pm, pn, compar);
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}
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swap(base, pm);
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pa = pb = (char *) base + size;
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pc = pd = (char *) base + (nmemb - 1) * size;
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for (;;)
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{
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while (pb <= pc && (r = compar(pb, base)) <= 0)
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{
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if (r == 0)
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{
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swap_cnt = 1;
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swap(pa, pb);
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pa += size;
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}
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pb += size;
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}
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while (pb <= pc && (r = compar(pc, base)) >= 0)
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{
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if (r == 0)
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{
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swap_cnt = 1;
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swap(pc, pd);
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pd -= size;
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}
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pc -= size;
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}
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if (pb > pc)
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{
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break;
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}
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swap(pb, pc);
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swap_cnt = 1;
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pb += size;
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pc -= size;
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}
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if (swap_cnt == 0)
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{
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/* Switch to insertion sort */
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for (pm = (char *) base + size; pm < (char *) base + nmemb * size; pm += size)
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{
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for (pl = pm; pl > (char *) base && compar(pl - size, pl) > 0; pl -= size)
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{
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swap(pl, pl - size);
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}
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}
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return;
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}
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pn = (char *) base + nmemb * size;
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r = min(pa - (char *)base, pb - pa);
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vecswap(base, pb - r, r);
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r = min(pd - pc, pn - pd - size);
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vecswap(pb, pn - r, r);
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if ((r = pb - pa) > size)
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{
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qsort(base, r / size, size, compar);
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}
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if ((r = pd - pc) > size)
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{
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/* Iterate rather than recurse to save stack space */
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base = pn - r;
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nmemb = r / size;
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goto loop;
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}
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}
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