toolchain/gcc/newlib/libm/mathfp/e_scalb.c

   1
   2 /* @(#)e_scalb.c 5.1 93/09/24 */
   3 /*
   4  * ====================================================
   5  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   6  *
   7  * Developed at SunPro, 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 #ifndef _DOUBLE_IS_32BITS
  23
  24 #ifdef _SCALB_INT
  25 #ifdef __STDC__
  26         double scalb(double x, int fn)
  27 #else
  28         double scalb(x,fn)
  29         double x; int fn;
  30 #endif
  31 #else
  32 #ifdef __STDC__
  33         double scalb(double x, double fn)
  34 #else
  35         double scalb(x,fn)
  36         double x, fn;
  37 #endif
  38 #endif
  39 {
  40 #ifdef _SCALB_INT
  41         return scalbn(x,fn);
  42 #else
  43         if (isnan(x)||isnan(fn)) return x*fn;
  44         if (!finite(fn)) {
  45             if(fn>0.0) return x*fn;
  46             else       return x/(-fn);
  47         }
  48         if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
  49         if ( fn > 65000.0) return scalbn(x, 65000);
  50         if (-fn > 65000.0) return scalbn(x,-65000);
  51         return scalbn(x,(int)fn);
  52 #endif
  53 }
  54
  55 #endif /* defined(_DOUBLE_IS_32BITS) */