math/e_scalbl.c

   1 /* e_scalbl.c -- long double version of s_scalb.c.
   2  * Conversion to long double by Ulrich Drepper,
   3  * Cygnus Support, drepper@cygnus.com.
   4  */
   5
   6 /*
   7  * ====================================================
   8  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   9  *
  10  * Developed at SunPro, a Sun Microsystems, Inc. business.
  11  * Permission to use, copy, modify, and distribute this
  12  * software is freely granted, provided that this notice
  13  * is preserved.
  14  * ====================================================
  15  */
  16
  17 #if defined(LIBM_SCCS) && !defined(lint)
  18 static char rcsid[] = "$NetBSD: $";
  19 #endif
  20
  21 /*
  22  * __ieee754_scalbl(x, fn) is provide for
  23  * passing various standard test suite. One
  24  * should use scalbnl() instead.
  25  */
  26
  27 #include <fenv.h>
  28 #include <math.h>
  29 #include "math_private.h"
  30
  31 #ifdef _SCALB_INT
  32 #ifdef __STDC__
  33         long double __ieee754_scalbl(long double x, int fn)
  34 #else
  35         long double __ieee754_scalbl(x,fn)
  36         long double x; int fn;
  37 #endif
  38 #else
  39 #ifdef __STDC__
  40         long double __ieee754_scalbl(long double x, long double fn)
  41 #else
  42         long double __ieee754_scalbl(x,fn)
  43         long double x, fn;
  44 #endif
  45 #endif
  46 {
  47 #ifdef _SCALB_INT
  48         return __scalbnl(x,fn);
  49 #else
  50         if (__isnanl(x)||__isnanl(fn)) return x*fn;
  51         if (!__finitel(fn)) {
  52             if(fn>0.0) return x*fn;
  53             else if (x == 0)
  54               return x;
  55             else if (!__finitel (x))
  56               {
  57 # ifdef FE_INVALID
  58                 feraiseexcept (FE_INVALID);
  59 # endif
  60                 return __nanl ("");
  61               }
  62             else       return x/(-fn);
  63         }
  64         if (__rintl(fn)!=fn)
  65           {
  66 # ifdef FE_INVALID
  67             feraiseexcept (FE_INVALID);
  68 # endif
  69             return __nanl ("");
  70           }
  71         if ( fn > 65000.0) return __scalbnl(x, 65000);
  72         if (-fn > 65000.0) return __scalbnl(x,-65000);
  73         return __scalbnl(x,(int)fn);
  74 #endif
  75 }