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

//

//      s_frexp.c

//

//      Part of the standard mathematical function library

//

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

//####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

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

// for more details.

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

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// 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

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

//####ECOSGPLCOPYRIGHTEND####

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

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

//

// Author(s):   jlarmour

// Contributors:  jlarmour

// Date:        1998-02-13

// Purpose:     

// Description: 

// Usage:       

//

//####DESCRIPTIONEND####

//

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

// CONFIGURATION

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

// Include the Math library?

#ifdef CYGPKG_LIBM     

// Derived from code with the following copyright

/* @(#)s_frexp.c 1.4 95/01/18 */

/*

 * ====================================================

 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

 *

 * Developed at SunSoft, a Sun Microsystems, Inc. business.

 * Permission to use, copy, modify, and distribute this

 * software is freely granted, provided that this notice

 * is preserved.

 * ====================================================

 */

/*

 * for non-zero x

 *      x = frexp(arg,&exp);

 * return a double fp quantity x such that 0.5 <= |x| <1.0

 * and the corresponding binary exponent "exp". That is

 *      arg = x*2^exp.

 * If arg is inf, 0.0, or NaN, then frexp(arg,&exp) returns arg

 * with *exp=0.

 */

#include "mathincl/fdlibm.h"

static const double

two54 =  1.80143985094819840000e+16; /* 0x43500000, 0x00000000 */

        double frexp(double x, int *eptr)

{

        int  hx, ix, lx;

        hx = CYG_LIBM_HI(x);

        ix = 0x7fffffff&hx;

        lx = CYG_LIBM_LO(x);

        *eptr = 0;

        if(ix>=0x7ff00000||((ix|lx)==0)) return x;      /* 0,inf,nan */

        if (ix<0x00100000) {            /* subnormal */

            x *= two54;

            hx = CYG_LIBM_HI(x);

            ix = hx&0x7fffffff;

            *eptr = -54;

        }

        *eptr += (ix>>20)-1022;

        hx = (hx&0x800fffff)|0x3fe00000;

        CYG_LIBM_HI(x) = hx;

        return x;

}

#endif // ifdef CYGPKG_LIBM     

// EOF s_frexp.c