libjava/classpath/native/fdlibm/e_scalb.c

   1
   2 /* @(#)e_scalb.c 1.3 95/01/18 */
   3 /*
   4  * ====================================================
   5  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   6  *
   7  * Developed at SunSoft, a Sun Microsystems, Inc. business.
   8  * Permission to use, copy, modify, and distribute this
   9  * software is freely granted, provided that this notice
  10  * is preserved.
  11  * ====================================================
  12  */
  13
  14 /*
  15  * __ieee754_scalb(x, fn) is provide for
  16  * passing various standard test suite. One
  17  * should use scalbn() instead.
  18  */
  19
  20 #include "fdlibm.h"
  21
  22 #ifdef _SCALB_INT
  23 #ifdef __STDC__
  24         double __ieee754_scalb(double x, int fn)
  25 #else
  26         double __ieee754_scalb(x,fn)
  27         double x; int fn;
  28 #endif
  29 #else
  30 #ifdef __STDC__
  31         double __ieee754_scalb(double x, double fn)
  32 #else
  33         double __ieee754_scalb(x,fn)
  34         double x, fn;
  35 #endif
  36 #endif
  37 {
  38 #ifdef _SCALB_INT
  39         return scalbn(x,fn);
  40 #else
  41         if (isnan(x)||isnan(fn)) return x*fn;
  42         if (!finite(fn)) {
  43             if(fn>0.0) return x*fn;
  44             else       return x/(-fn);
  45         }
  46         if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
  47         if ( fn > 65000.0) return scalbn(x, 65000);
  48         if (-fn > 65000.0) return scalbn(x,-65000);
  49         return scalbn(x,(int)fn);
  50 #endif
  51 }