js/src/fdlibm/w_log.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  *
   3  * ***** BEGIN LICENSE BLOCK *****
   4  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   5  *
   6  * The contents of this file are subject to the Mozilla Public License Version
   7  * 1.1 (the "License"); you may not use this file except in compliance with
   8  * the License. You may obtain a copy of the License at
   9  * http://www.mozilla.org/MPL/
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  12  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  13  * for the specific language governing rights and limitations under the
  14  * License.
  15  *
  16  * The Original Code is Mozilla Communicator client code, released
  17  * March 31, 1998.
  18  *
  19  * The Initial Developer of the Original Code is
  20  * Sun Microsystems, Inc.
  21  * Portions created by the Initial Developer are Copyright (C) 1998
  22  * the Initial Developer. All Rights Reserved.
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  26  * Alternatively, the contents of this file may be used under the terms of
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  38  * ***** END LICENSE BLOCK ***** */
  39
  40 /* @(#)w_log.c 1.3 95/01/18 */
  41 /*
  42  * ====================================================
  43  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
  44  *
  45  * Developed at SunSoft, a Sun Microsystems, Inc. business.
  46  * Permission to use, copy, modify, and distribute this
  47  * software is freely granted, provided that this notice
  48  * is preserved.
  49  * ====================================================
  50  */
  51
  52 /*
  53  * wrapper log(x)
  54  */
  55
  56 #include "fdlibm.h"
  57
  58
  59 #ifdef __STDC__
  60         double fd_log(double x)         /* wrapper log */
  61 #else
  62         double fd_log(x)                        /* wrapper log */
  63         double x;
  64 #endif
  65 {
  66 #ifdef _IEEE_LIBM
  67         return __ieee754_log(x);
  68 #else
  69         double z;
  70     int err;
  71         z = __ieee754_log(x);
  72         if(_LIB_VERSION == _IEEE_ || fd_isnan(x) || x > 0.0) return z;
  73         if(x==0.0)
  74             return __kernel_standard(x,x,16,&err); /* log(0) */
  75         else
  76             return __kernel_standard(x,x,17,&err); /* log(x<0) */
  77 #endif
  78 }