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 #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 <fenv.h>
  21 #include <math.h>
  22 #include "math_private.h"
  23
  24 #ifdef _SCALB_INT
  25 #ifdef __STDC__
  26         float __ieee754_scalbf(float x, int fn)
  27 #else
  28         float __ieee754_scalbf(x,fn)
  29         float x; int fn;
  30 #endif
  31 #else
  32 #ifdef __STDC__
  33         float __ieee754_scalbf(float x, float fn)
  34 #else
  35         float __ieee754_scalbf(x,fn)
  36         float x, fn;
  37 #endif
  38 #endif
  39 {
  40 #ifdef _SCALB_INT
  41         return __scalbnf(x,fn);
  42 #else
  43         if (__isnanf(x)||__isnanf(fn)) return x*fn;
  44         if (!__finitef(fn)) {
  45             if(fn>(float)0.0) return x*fn;
  46             else if (x == 0)
  47               return x;
  48             else if (!__finitef (x))
  49               {
  50 # ifdef FE_INVALID
  51                 feraiseexcept (FE_INVALID);
  52 # endif
  53                 return __nanf ("");
  54               }
  55             else       return x/(-fn);
  56         }
  57         if (__rintf(fn)!=fn)
  58           {
  59 # ifdef FE_INVALID
  60             feraiseexcept (FE_INVALID);
  61 # endif
  62             return __nanf ("");
  63           }
  64         if ( fn > (float)65000.0) return __scalbnf(x, 65000);
  65         if (-fn > (float)65000.0) return __scalbnf(x,-65000);
  66         return __scalbnf(x,(int)fn);
  67 #endif
  68 }