Back to index

lightning-sunbird  0.9+nobinonly
w_exp.c
Go to the documentation of this file.
00001 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
00002  *
00003  * ***** BEGIN LICENSE BLOCK *****
00004  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
00005  *
00006  * The contents of this file are subject to the Mozilla Public License Version
00007  * 1.1 (the "License"); you may not use this file except in compliance with
00008  * the License. You may obtain a copy of the License at
00009  * http://www.mozilla.org/MPL/
00010  *
00011  * Software distributed under the License is distributed on an "AS IS" basis,
00012  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
00013  * for the specific language governing rights and limitations under the
00014  * License.
00015  *
00016  * The Original Code is Mozilla Communicator client code, released
00017  * March 31, 1998.
00018  *
00019  * The Initial Developer of the Original Code is
00020  * Sun Microsystems, Inc.
00021  * Portions created by the Initial Developer are Copyright (C) 1998
00022  * the Initial Developer. All Rights Reserved.
00023  *
00024  * Contributor(s):
00025  *
00026  * Alternatively, the contents of this file may be used under the terms of
00027  * either of the GNU General Public License Version 2 or later (the "GPL"),
00028  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
00029  * in which case the provisions of the GPL or the LGPL are applicable instead
00030  * of those above. If you wish to allow use of your version of this file only
00031  * under the terms of either the GPL or the LGPL, and not to allow others to
00032  * use your version of this file under the terms of the MPL, indicate your
00033  * decision by deleting the provisions above and replace them with the notice
00034  * and other provisions required by the GPL or the LGPL. If you do not delete
00035  * the provisions above, a recipient may use your version of this file under
00036  * the terms of any one of the MPL, the GPL or the LGPL.
00037  *
00038  * ***** END LICENSE BLOCK ***** */
00039 
00040 /* @(#)w_exp.c 1.3 95/01/18 */
00041 /*
00042  * ====================================================
00043  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
00044  *
00045  * Developed at SunSoft, a Sun Microsystems, Inc. business.
00046  * Permission to use, copy, modify, and distribute this
00047  * software is freely granted, provided that this notice 
00048  * is preserved.
00049  * ====================================================
00050  */
00051 
00052 /* 
00053  * wrapper exp(x)
00054  */
00055 
00056 #include "fdlibm.h"
00057 
00058 #ifdef __STDC__
00059 static const double
00060 #else
00061 static double
00062 #endif
00063 o_threshold=  7.09782712893383973096e+02,  /* 0x40862E42, 0xFEFA39EF */
00064 u_threshold= -7.45133219101941108420e+02;  /* 0xc0874910, 0xD52D3051 */
00065 
00066 #ifdef __STDC__
00067        double fd_exp(double x)            /* wrapper exp */
00068 #else
00069        double fd_exp(x)                   /* wrapper exp */
00070        double x;
00071 #endif
00072 {
00073 #ifdef _IEEE_LIBM
00074        return __ieee754_exp(x);
00075 #else
00076        double z;
00077        z = __ieee754_exp(x);
00078        if(_LIB_VERSION == _IEEE_) return z;
00079        if(fd_finite(x)) {
00080         int err;
00081            if(x>o_threshold)
00082                return __kernel_standard(x,x,6,&err); /* exp overflow */
00083            else if(x<u_threshold)
00084                return __kernel_standard(x,x,7,&err); /* exp underflow */
00085        } 
00086        return z;
00087 #endif
00088 }