Subversion Repositories openrisc

//===========================================================================

//

//      qsort.cxx

//

//      ANSI standard sorting function defined in section 7.10.5.2

//      of the standard

//

//===========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under

// the terms of the GNU General Public License as published by the Free

// Software Foundation; either version 2 or (at your option) any later version.

//

// eCos is distributed in the hope that it will be useful, but WITHOUT ANY

// WARRANTY; without even the implied warranty of MERCHANTABILITY or

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

// for more details.

//

// You should have received a copy of the GNU General Public License along

// with eCos; if not, write to the Free Software Foundation, Inc.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

// As a special exception, if other files instantiate templates or use macros

// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

// by itself cause the resulting work to be covered by the GNU General Public

// License. However the source code for this file must still be made available

// in accordance with section (3) of the GNU General Public License.

//

// This exception does not invalidate any other reasons why a work based on

// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//===========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):    jlarmour

// Contributors: 

// Date:         2000-04-30

// Purpose:     

// Description: 

// Usage:       

//

//####DESCRIPTIONEND####

//

//===========================================================================

//

// This code is based on original code with the following copyright:

//

/*-

 * 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.

 */

// CONFIGURATION

#include <pkgconf/libc_stdlib.h>   // Configuration header

// INCLUDES

#include <cyg/infra/cyg_type.h>    // Common type definitions and support

#include <cyg/infra/cyg_trac.h>    // Tracing support

#include <cyg/infra/cyg_ass.h>     // Assertion support

#include <stdlib.h>                // Header for all stdlib functions

                                   // (like this one)

// TRACING

# if defined(CYGDBG_USE_TRACING) && defined(CYGNUM_LIBC_QSORT_TRACE_LEVEL)

static int qsort_trace = CYGNUM_LIBC_QSORT_TRACE_LEVEL;

#  define TL1 (0 < qsort_trace)

# else

#  define TL1 (0)

# endif

// FUNCTION PROTOTYPES

static __inline__ char *med3(char *, char *, char *, __qsort_comparison_fn_t);

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

// MACRO FUNCTIONS

#define min(a, b)       ((a) < (b) ? (a) : (b))

//

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

//

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

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

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

        TYPE *pj = (TYPE *) (parmj);                    \

        do {                                            \

                TYPE   t = *pi;                         \

                *pi++ = *pj;                            \

                *pj++ = t;                              \

        } while (--i > 0);                              \

} while (0)

#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \

        es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;

#define swap(a, b)                                      \

        if (swaptype == 0) {                            \

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

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

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

        } else                                          \

                swapfunc(a, b, size, swaptype)

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

// FUNCTIONS

// Debug wrapper for comparison function

static __inline__ int

cmp_wrapper( __qsort_comparison_fn_t cmp, void *x, void *y )

{

    int retval;

    CYG_TRACE3( TL1, "Calling comparison function address %08x with args "

                "( %08x, %08x )", cmp, x, y );

    retval = cmp(x, y);

    CYG_TRACE1( TL1, "Comparison function returned %d", retval );

    return retval;

} // cmp_wrapper()

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);

} // swapfunc()

static __inline__ char *

med3( char *a, char *b, char *c, __qsort_comparison_fn_t cmp )

{

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

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

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

} // med3()

void

qsort( void *base, size_t nmemb, size_t size, __qsort_comparison_fn_t compar )

{

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

    int d, r, swaptype, swap_cnt;

    CYG_REPORT_FUNCNAME( "qsort" );

    CYG_REPORT_FUNCARG4( "base=%08x, nmemb=%d, size=%d, compar=%08x",

                         base, nmemb, size, compar );

    CYG_CHECK_DATA_PTR( base, "base is not a valid pointer!" );

    CYG_CHECK_FUNC_PTR( compar, "compar is not a valid function pointer!" );

loop:

    SWAPINIT(base, size);

    swap_cnt = 0;

    if (nmemb < 7) {

        for (pm = (char *) base + size;

             pm < (char *) base + nmemb * size;

             pm += size)

            for (pl = pm; pl > (char *) base && cmp_wrapper( compar, pl - size, pl) > 0;

                 pl -= size)

                swap(pl, pl - size);

        {

            CYG_REPORT_RETURN();

            return;

        } // for

    } // if

    pm = (char *) base + (nmemb / 2) * size;

    if (nmemb > 7) {

        pl = (char *) base;

        pn = (char *) base + (nmemb - 1) * size;

        if (nmemb > 40) {

            d = (nmemb / 8) * size;

            pl = med3(pl, pl + d, pl + 2 * d, compar);

            pm = med3(pm - d, pm, pm + d, compar);

            pn = med3(pn - 2 * d, pn - d, pn, compar);

        } // if

        pm = med3(pl, pm, pn, compar);

    } // if

    swap( (char *)base, pm );

    pa = pb = (char *) base + size;

    pc = pd = (char *) base + (nmemb - 1) * size;

    for (;;) {

        while (pb <= pc && (r = cmp_wrapper( compar, pb, base)) <= 0) {

            if (r == 0) {

                swap_cnt = 1;

                swap(pa, pb);

                pa += size;

            } // if

            pb += size;

        } // while

        while (pb <= pc && (r = cmp_wrapper( compar, pc, base)) >= 0) {

            if (r == 0) {

                swap_cnt = 1;

                swap(pc, pd);

                pd -= size;

            } // if

            pc -= size;

        } // while

        if (pb > pc)

            break;

        swap(pb, pc);

        swap_cnt = 1;

        pb += size;

        pc -= size;

    } // for

    if (swap_cnt == 0) {  // Switch to insertion sort

        for (pm = (char *) base + size;

             pm < (char *) base + nmemb * size;

             pm += size)

            for (pl = pm; pl > (char *) base && cmp_wrapper( compar, pl - size, pl) > 0;

                 pl -= size)

                swap(pl, pl - size);

        {

            CYG_REPORT_RETURN();

            return;

        } // for

    } //if

    pn = (char *) base + nmemb * size;

    r = min(pa - (char *)base, pb - pa);

    vecswap((char *)base, pb - r, r);

    r = min( (unsigned)(pd - pc), pn - pd - size );

    vecswap(pb, pn - r, r);

    if ((unsigned)(r = pb - pa) > size)

        qsort(base, r / size, size, compar);

    if ((unsigned)(r = pd - pc) > size) {

        // Iterate rather than recurse to save stack space

        base = pn - r;

        nmemb = r / size;

        goto loop;

    } // if

/*              qsort(pn - r, r / size, size, compar);*/

    CYG_REPORT_RETURN();

} // qsort()

// EOF qsort.cxx