sysdeps/libm-ieee754/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 #if defined(LIBM_SCCS) && !defined(lint)
  17 static char rcsid[] = "$NetBSD: e_scalbf.c,v 1.3 1995/05/10 20:46:12 jtc Exp $";
  18 #endif
  19
  20 #include "math.h"
  21 #include "math_private.h"
  22
  23 #ifdef _SCALB_INT
  24 #ifdef __STDC__
  25         float __ieee754_scalbf(float x, int fn)
  26 #else
  27         float __ieee754_scalbf(x,fn)
  28         float x; int fn;
  29 #endif
  30 #else
  31 #ifdef __STDC__
  32         float __ieee754_scalbf(float x, float fn)
  33 #else
  34         float __ieee754_scalbf(x,fn)
  35         float x, fn;
  36 #endif
  37 #endif
  38 {
  39 #ifdef _SCALB_INT
  40         return __scalbnf(x,fn);
  41 #else
  42         if (__isnanf(x)||__isnanf(fn)) return x*fn;
  43         if (!__finitef(fn)) {
  44             if(fn>(float)0.0) return x*fn;
  45             else       return x/(-fn);
  46         }
  47         if (__rintf(fn)!=fn) return (fn-fn)/(fn-fn);
  48         if ( fn > (float)65000.0) return __scalbnf(x, 65000);
  49         if (-fn > (float)65000.0) return __scalbnf(x,-65000);
  50         return __scalbnf(x,(int)fn);
  51 #endif
  52 }