compiler/stdc/math/e_scalbf.c

   1 /* e_scalbf.c -- float version of e_scalb.c.
   2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
   3  */
   4
   5 /*
   6  * ====================================================
   7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   8  *
   9  * Developed at SunPro, a Sun Microsystems, Inc. business.
  10  * Permission to use, copy, modify, and distribute this
  11  * software is freely granted, provided that this notice
  12  * is preserved.
  13  * ====================================================
  14  */
  15
  16 #ifndef lint
  17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/e_scalbf.c,v 1.12 2006/07/05 17:34:57 bde Exp $";
  18 #endif
  19
  20 #include "math.h"
  21 #include "math_private.h"
  22
  23 #ifdef _SCALB_INT
  24 float
  25 __ieee754_scalbf(float x, int fn)
  26 #else
  27 float
  28 __ieee754_scalbf(float x, float fn)
  29 #endif
  30 {
  31 #ifdef _SCALB_INT
  32         return scalbnf(x,fn);
  33 #else
  34         if ((__isnanf)(x)||(__isnanf)(fn)) return x*fn;
  35         if (!__isfinitef(fn)) {
  36             if(fn>(float)0.0) return x*fn;
  37             else       return x/(-fn);
  38         }
  39         if (rintf(fn)!=fn) return (fn-fn)/(fn-fn);
  40         if ( fn > (float)65000.0) return scalbnf(x, 65000);
  41         if (-fn > (float)65000.0) return scalbnf(x,-65000);
  42         return scalbnf(x,(int)fn);
  43 #endif
  44 }