зеркало из https://github.com/mozilla/gecko-dev.git
121 строка
3.6 KiB
C
121 строка
3.6 KiB
C
/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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*
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* ***** BEGIN LICENSE BLOCK *****
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* Version: MPL 1.1/GPL 2.0/LGPL 2.1
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*
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* The contents of this file are subject to the Mozilla Public License Version
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* 1.1 (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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* http://www.mozilla.org/MPL/
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*
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* Software distributed under the License is distributed on an "AS IS" basis,
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* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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* for the specific language governing rights and limitations under the
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* License.
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*
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* The Original Code is Mozilla Communicator client code, released
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* March 31, 1998.
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*
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* The Initial Developer of the Original Code is
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* Sun Microsystems, Inc.
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* Portions created by the Initial Developer are Copyright (C) 1998
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* the Initial Developer. All Rights Reserved.
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*
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* Contributor(s):
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*
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* Alternatively, the contents of this file may be used under the terms of
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* either of the GNU General Public License Version 2 or later (the "GPL"),
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* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
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* in which case the provisions of the GPL or the LGPL are applicable instead
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* of those above. If you wish to allow use of your version of this file only
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* under the terms of either the GPL or the LGPL, and not to allow others to
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* use your version of this file under the terms of the MPL, indicate your
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* decision by deleting the provisions above and replace them with the notice
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* and other provisions required by the GPL or the LGPL. If you do not delete
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* the provisions above, a recipient may use your version of this file under
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* the terms of any one of the MPL, the GPL or the LGPL.
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*
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* ***** END LICENSE BLOCK ***** */
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/* @(#)e_remainder.c 1.3 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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/* __ieee754_remainder(x,p)
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* Return :
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* returns x REM p = x - [x/p]*p as if in infinite
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* precise arithmetic, where [x/p] is the (infinite bit)
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* integer nearest x/p (in half way case choose the even one).
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* Method :
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* Based on fmod() return x-[x/p]chopped*p exactlp.
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*/
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#include "fdlibm.h"
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#ifdef __STDC__
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static const double zero = 0.0;
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#else
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static double zero = 0.0;
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#endif
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#ifdef __STDC__
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double __ieee754_remainder(double x, double p)
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#else
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double __ieee754_remainder(x,p)
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double x,p;
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#endif
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{
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fd_twoints u;
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int hx,hp;
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unsigned sx,lx,lp;
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double p_half;
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u.d = x;
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hx = __HI(u); /* high word of x */
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lx = __LO(u); /* low word of x */
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u.d = p;
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hp = __HI(u); /* high word of p */
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lp = __LO(u); /* low word of p */
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sx = hx&0x80000000;
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hp &= 0x7fffffff;
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hx &= 0x7fffffff;
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/* purge off exception values */
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if((hp|lp)==0) return (x*p)/(x*p); /* p = 0 */
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if((hx>=0x7ff00000)|| /* x not finite */
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((hp>=0x7ff00000)&& /* p is NaN */
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(((hp-0x7ff00000)|lp)!=0)))
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return (x*p)/(x*p);
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if (hp<=0x7fdfffff) x = __ieee754_fmod(x,p+p); /* now x < 2p */
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if (((hx-hp)|(lx-lp))==0) return zero*x;
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x = fd_fabs(x);
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p = fd_fabs(p);
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if (hp<0x00200000) {
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if(x+x>p) {
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x-=p;
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if(x+x>=p) x -= p;
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}
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} else {
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p_half = 0.5*p;
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if(x>p_half) {
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x-=p;
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if(x>=p_half) x -= p;
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}
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}
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u.d = x;
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__HI(u) ^= sx;
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x = u.d;
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return x;
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}
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