js/src/fdlibm/e_scalb.c

   1 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  *
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   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
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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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  39
  40 /* @(#)e_scalb.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  * __ieee754_scalb(x, fn) is provide for
  54  * passing various standard test suite. One
  55  * should use scalbn() instead.
  56  */
  57
  58 #include "fdlibm.h"
  59
  60 #ifdef _SCALB_INT
  61 #ifdef __STDC__
  62         double __ieee754_scalb(double x, int fn)
  63 #else
  64         double __ieee754_scalb(x,fn)
  65         double x; int fn;
  66 #endif
  67 #else
  68 #ifdef __STDC__
  69         double __ieee754_scalb(double x, double fn)
  70 #else
  71         double __ieee754_scalb(x,fn)
  72         double x, fn;
  73 #endif
  74 #endif
  75 {
  76 #ifdef _SCALB_INT
  77         return fd_scalbn(x,fn);
  78 #else
  79         if (fd_isnan(x)||fd_isnan(fn)) return x*fn;
  80         if (!fd_finite(fn)) {
  81             if(fn>0.0) return x*fn;
  82             else       return x/(-fn);
  83         }
  84         if (fd_rint(fn)!=fn) return (fn-fn)/(fn-fn);
  85         if ( fn > 65000.0) return fd_scalbn(x, 65000);
  86         if (-fn > 65000.0) return fd_scalbn(x,-65000);
  87         return fd_scalbn(x,(int)fn);
  88 #endif
  89 }