lib/libm/src/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  * $NetBSD: e_scalbf.c,v 1.6 2002/05/26 22:01:52 wiz Exp $
  16  * $DragonFly: src/lib/libm/src/e_scalbf.c,v 1.1 2005/07/26 21:15:20 joerg Exp $
  17  */
  18
  19 #include <math.h>
  20 #include "math_private.h"
  21
  22 #ifdef _SCALB_INT
  23 float
  24 scalbf(float x, int fn)
  25 #else
  26 float
  27 scalbf(float x, float fn)
  28 #endif
  29 {
  30 #ifdef _SCALB_INT
  31         return scalbnf(x,fn);
  32 #else
  33         if (isnanf(x)||isnanf(fn)) return x*fn;
  34         if (!finitef(fn)) {
  35             if(fn>(float)0.0) return x*fn;
  36             else       return x/(-fn);
  37         }
  38         if (rintf(fn)!=fn) return (fn-fn)/(fn-fn);
  39         if ( fn > (float)65000.0) return scalbnf(x, 65000);
  40         if (-fn > (float)65000.0) return scalbnf(x,-65000);
  41         return scalbnf(x,(int)fn);
  42 #endif
  43 }