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//===========================================================================
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//
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// s_frexp.c
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//
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// Part of the standard mathematical function library
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//
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//===========================================================================
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// ####ECOSGPLCOPYRIGHTBEGIN####
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// -------------------------------------------
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// This file is part of eCos, the Embedded Configurable Operating System.
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// Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
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//
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// eCos is free software; you can redistribute it and/or modify it under
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// the terms of the GNU General Public License as published by the Free
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// Software Foundation; either version 2 or (at your option) any later
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// version.
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//
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// eCos is distributed in the hope that it will be useful, but WITHOUT
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// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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// for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with eCos; if not, write to the Free Software Foundation, Inc.,
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// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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//
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// As a special exception, if other files instantiate templates or use
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// macros or inline functions from this file, or you compile this file
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// and link it with other works to produce a work based on this file,
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// this file does not by itself cause the resulting work to be covered by
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// the GNU General Public License. However the source code for this file
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// must still be made available in accordance with section (3) of the GNU
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// General Public License v2.
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//
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// This exception does not invalidate any other reasons why a work based
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// on this file might be covered by the GNU General Public License.
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// -------------------------------------------
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// ####ECOSGPLCOPYRIGHTEND####
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//===========================================================================
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//#####DESCRIPTIONBEGIN####
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//
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// Author(s): jlarmour
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// Contributors: jlarmour
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// Date: 1998-02-13
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// Purpose:
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// Description:
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// Usage:
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//
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//####DESCRIPTIONEND####
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//
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//===========================================================================
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// CONFIGURATION
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#include <pkgconf/libm.h> // Configuration header
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// Include the Math library?
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#ifdef CYGPKG_LIBM
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// Derived from code with the following copyright
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/* @(#)s_frexp.c 1.4 95/01/18 */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunSoft, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/*
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* for non-zero x
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* x = frexp(arg,&exp);
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* return a double fp quantity x such that 0.5 <= |x| <1.0
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* and the corresponding binary exponent "exp". That is
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* arg = x*2^exp.
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* If arg is inf, 0.0, or NaN, then frexp(arg,&exp) returns arg
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* with *exp=0.
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*/
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#include "mathincl/fdlibm.h"
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static const double
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two54 = 1.80143985094819840000e+16; /* 0x43500000, 0x00000000 */
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double frexp(double x, int *eptr)
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{
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int hx, ix, lx;
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hx = CYG_LIBM_HI(x);
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ix = 0x7fffffff&hx;
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lx = CYG_LIBM_LO(x);
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*eptr = 0;
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if(ix>=0x7ff00000||((ix|lx)==0)) return x; /* 0,inf,nan */
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if (ix<0x00100000) { /* subnormal */
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x *= two54;
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hx = CYG_LIBM_HI(x);
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ix = hx&0x7fffffff;
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*eptr = -54;
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}
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*eptr += (ix>>20)-1022;
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hx = (hx&0x800fffff)|0x3fe00000;
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CYG_LIBM_HI(x) = hx;
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return x;
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}
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#endif // ifdef CYGPKG_LIBM
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// EOF s_frexp.c
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