//===========================================================================
|
//===========================================================================
|
//
|
//
|
// e_remainder.c
|
// e_remainder.c
|
//
|
//
|
// Part of the standard mathematical function library
|
// Part of the standard mathematical function library
|
//
|
//
|
//===========================================================================
|
//===========================================================================
|
//####ECOSGPLCOPYRIGHTBEGIN####
|
//####ECOSGPLCOPYRIGHTBEGIN####
|
// -------------------------------------------
|
// -------------------------------------------
|
// This file is part of eCos, the Embedded Configurable Operating System.
|
// This file is part of eCos, the Embedded Configurable Operating System.
|
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
|
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
|
//
|
//
|
// eCos is free software; you can redistribute it and/or modify it under
|
// 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
|
// 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.
|
// 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
|
// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
|
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
// for more details.
|
// for more details.
|
//
|
//
|
// You should have received a copy of the GNU General Public License along
|
// You should have received a copy of the GNU General Public License along
|
// with eCos; if not, write to the Free Software Foundation, Inc.,
|
// with eCos; if not, write to the Free Software Foundation, Inc.,
|
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
|
// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
|
//
|
//
|
// As a special exception, if other files instantiate templates or use macros
|
// 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
|
// 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
|
// 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
|
// 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
|
// License. However the source code for this file must still be made available
|
// in accordance with section (3) of the GNU General Public License.
|
// 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 exception does not invalidate any other reasons why a work based on
|
// this file might be covered by the GNU General Public License.
|
// this file might be covered by the GNU General Public License.
|
//
|
//
|
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
|
// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
|
// at http://sources.redhat.com/ecos/ecos-license/
|
// at http://sources.redhat.com/ecos/ecos-license/
|
// -------------------------------------------
|
// -------------------------------------------
|
//####ECOSGPLCOPYRIGHTEND####
|
//####ECOSGPLCOPYRIGHTEND####
|
//===========================================================================
|
//===========================================================================
|
//#####DESCRIPTIONBEGIN####
|
//#####DESCRIPTIONBEGIN####
|
//
|
//
|
// Author(s): jlarmour
|
// Author(s): jlarmour
|
// Contributors: jlarmour
|
// Contributors: jlarmour
|
// Date: 1998-02-13
|
// Date: 1998-02-13
|
// Purpose:
|
// Purpose:
|
// Description:
|
// Description:
|
// Usage:
|
// Usage:
|
//
|
//
|
//####DESCRIPTIONEND####
|
//####DESCRIPTIONEND####
|
//
|
//
|
//===========================================================================
|
//===========================================================================
|
|
|
// CONFIGURATION
|
// CONFIGURATION
|
|
|
#include <pkgconf/libm.h> // Configuration header
|
#include <pkgconf/libm.h> // Configuration header
|
|
|
// Include the Math library?
|
// Include the Math library?
|
#ifdef CYGPKG_LIBM
|
#ifdef CYGPKG_LIBM
|
|
|
// Derived from code with the following copyright
|
// Derived from code with the following copyright
|
|
|
|
|
/* @(#)e_remainder.c 1.3 95/01/18 */
|
/* @(#)e_remainder.c 1.3 95/01/18 */
|
/*
|
/*
|
* ====================================================
|
* ====================================================
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
*
|
*
|
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
* Permission to use, copy, modify, and distribute this
|
* Permission to use, copy, modify, and distribute this
|
* software is freely granted, provided that this notice
|
* software is freely granted, provided that this notice
|
* is preserved.
|
* is preserved.
|
* ====================================================
|
* ====================================================
|
*/
|
*/
|
|
|
/* __ieee754_remainder(x,p)
|
/* __ieee754_remainder(x,p)
|
* Return :
|
* Return :
|
* returns x REM p = x - [x/p]*p as if in infinite
|
* returns x REM p = x - [x/p]*p as if in infinite
|
* precise arithmetic, where [x/p] is the (infinite bit)
|
* precise arithmetic, where [x/p] is the (infinite bit)
|
* integer nearest x/p (in half way case choose the even one).
|
* integer nearest x/p (in half way case choose the even one).
|
* Method :
|
* Method :
|
* Based on fmod() return x-[x/p]chopped*p exactlp.
|
* Based on fmod() return x-[x/p]chopped*p exactlp.
|
*/
|
*/
|
|
|
#include "mathincl/fdlibm.h"
|
#include "mathincl/fdlibm.h"
|
|
|
static const double zero = 0.0;
|
static const double zero = 0.0;
|
|
|
|
|
double __ieee754_remainder(double x, double p)
|
double __ieee754_remainder(double x, double p)
|
{
|
{
|
int hx,hp;
|
int hx,hp;
|
unsigned sx,lx,lp;
|
unsigned sx,lx,lp;
|
double p_half;
|
double p_half;
|
|
|
hx = CYG_LIBM_HI(x); /* high word of x */
|
hx = CYG_LIBM_HI(x); /* high word of x */
|
lx = CYG_LIBM_LO(x); /* low word of x */
|
lx = CYG_LIBM_LO(x); /* low word of x */
|
hp = CYG_LIBM_HI(p); /* high word of p */
|
hp = CYG_LIBM_HI(p); /* high word of p */
|
lp = CYG_LIBM_LO(p); /* low word of p */
|
lp = CYG_LIBM_LO(p); /* low word of p */
|
sx = hx&0x80000000;
|
sx = hx&0x80000000;
|
hp &= 0x7fffffff;
|
hp &= 0x7fffffff;
|
hx &= 0x7fffffff;
|
hx &= 0x7fffffff;
|
|
|
/* purge off exception values */
|
/* purge off exception values */
|
if((hp|lp)==0) return (x*p)/(x*p); /* p = 0 */
|
if((hp|lp)==0) return (x*p)/(x*p); /* p = 0 */
|
if((hx>=0x7ff00000)|| /* x not finite */
|
if((hx>=0x7ff00000)|| /* x not finite */
|
((hp>=0x7ff00000)&& /* p is NaN */
|
((hp>=0x7ff00000)&& /* p is NaN */
|
(((hp-0x7ff00000)|lp)!=0)))
|
(((hp-0x7ff00000)|lp)!=0)))
|
return (x*p)/(x*p);
|
return (x*p)/(x*p);
|
|
|
|
|
if (hp<=0x7fdfffff) x = __ieee754_fmod(x,p+p); /* now x < 2p */
|
if (hp<=0x7fdfffff) x = __ieee754_fmod(x,p+p); /* now x < 2p */
|
if (((hx-hp)|(lx-lp))==0) return zero*x;
|
if (((hx-hp)|(lx-lp))==0) return zero*x;
|
x = fabs(x);
|
x = fabs(x);
|
p = fabs(p);
|
p = fabs(p);
|
if (hp<0x00200000) {
|
if (hp<0x00200000) {
|
if(x+x>p) {
|
if(x+x>p) {
|
x-=p;
|
x-=p;
|
if(x+x>=p) x -= p;
|
if(x+x>=p) x -= p;
|
}
|
}
|
} else {
|
} else {
|
p_half = 0.5*p;
|
p_half = 0.5*p;
|
if(x>p_half) {
|
if(x>p_half) {
|
x-=p;
|
x-=p;
|
if(x>=p_half) x -= p;
|
if(x>=p_half) x -= p;
|
}
|
}
|
}
|
}
|
CYG_LIBM_HI(x) ^= sx;
|
CYG_LIBM_HI(x) ^= sx;
|
return x;
|
return x;
|
}
|
}
|
|
|
#endif // ifdef CYGPKG_LIBM
|
#endif // ifdef CYGPKG_LIBM
|
|
|
// EOF e_remainder.c
|
// EOF e_remainder.c
|
|
|