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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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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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* 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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* 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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* The Original Code is Mozilla Communicator client code, released
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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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* 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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* ***** END LICENSE BLOCK ***** */
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/* @(#)e_cosh.c 1.3 95/01/18 */
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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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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* ====================================================
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* mathematically cosh(x) if defined to be (exp(x)+exp(-x))/2
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* 1. Replace x by |x| (cosh(x) = cosh(-x)).
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* 0 <= x <= ln2/2 : cosh(x) := 1 + -------------------
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* ln2/2 <= x <= 22 : cosh(x) := -------------------
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* 22 <= x <= lnovft : cosh(x) := exp(x)/2
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* lnovft <= x <= ln2ovft: cosh(x) := exp(x/2)/2 * exp(x/2)
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* ln2ovft < x : cosh(x) := huge*huge (overflow)
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* cosh(x) is |x| if x is +INF, -INF, or NaN.
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* only cosh(0)=1 is exact for finite x.
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static const double one = 1.0, half=0.5, really_big = 1.0e300;
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static double one = 1.0, half=0.5, really_big = 1.0e300;
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double __ieee754_cosh(double x)
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double __ieee754_cosh(x)
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/* High word of |x|. */
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/* x is INF or NaN */
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if(ix>=0x7ff00000) return x*x;
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/* |x| in [0,0.5*ln2], return 1+expm1(|x|)^2/(2*exp(|x|)) */
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t = fd_expm1(fd_fabs(x));
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if (ix<0x3c800000) return w; /* cosh(tiny) = 1 */
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return one+(t*t)/(w+w);
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/* |x| in [0.5*ln2,22], return (exp(|x|)+1/exp(|x|)/2; */
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if (ix < 0x40360000) {
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t = __ieee754_exp(fd_fabs(x));
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return half*t+half/t;
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/* |x| in [22, log(maxdouble)] return half*exp(|x|) */
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if (ix < 0x40862E42) return half*__ieee754_exp(fd_fabs(x));
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/* |x| in [log(maxdouble), overflowthresold] */
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lx = *( (((*(unsigned*)&one)>>29)) + (unsigned*)&x);
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(ix==0x408633ce)&&(lx<=(unsigned)0x8fb9f87d)) {
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w = __ieee754_exp(half*fd_fabs(x));
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/* |x| > overflowthresold, cosh(x) overflow */
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return really_big*really_big;
added
removed
src/dom/js/fdlibm/e_cosh.c
