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
  16 #include <sys/cdefs.h>
  17 #if defined(LIBM_SCCS) && !defined(lint)
  18 __RCSID("$NetBSD: e_scalbf.c,v 1.5 1999/07/02 15:37:41 simonb Exp $");
  19 #endif
  20
  21 #include "math.h"
  22 #include "math_private.h"
  23
  24 #ifdef _SCALB_INT
  25 float
  26 __ieee754_scalbf(float x, int fn)
  27 #else
  28 float
  29 __ieee754_scalbf(float x, float fn)
  30 #endif
  31 {
  32 #ifdef _SCALB_INT
  33         return scalbnf(x,fn);
  34 #else
  35         if (isnanf(x)||isnanf(fn)) return x*fn;
  36         if (!finitef(fn)) {
  37             if(fn>(float)0.0) return x*fn;
  38             else       return x/(-fn);
  39         }
  40         if (rintf(fn)!=fn) return (fn-fn)/(fn-fn);
  41         if ( fn > (float)65000.0) return scalbnf(x, 65000);
  42         if (-fn > (float)65000.0) return scalbnf(x,-65000);
  43         return scalbnf(x,(int)fn);
  44 #endif
  45 }