sysdeps/libm-ieee754/w_scalb.c

   1 /* @(#)w_scalb.c 5.1 93/09/24 */
   2 /*
   3  * ====================================================
   4  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   5  *
   6  * Developed at SunPro, a Sun Microsystems, Inc. business.
   7  * Permission to use, copy, modify, and distribute this
   8  * software is freely granted, provided that this notice
   9  * is preserved.
  10  * ====================================================
  11  */
  12
  13 #if defined(LIBM_SCCS) && !defined(lint)
  14 static char rcsid[] = "$NetBSD: w_scalb.c,v 1.6 1995/05/10 20:49:48 jtc Exp $";
  15 #endif
  16
  17 /*
  18  * wrapper scalb(double x, double fn) is provide for
  19  * passing various standard test suite. One
  20  * should use scalbn() instead.
  21  */
  22
  23 #include "math.h"
  24 #include "math_private.h"
  25
  26 #include <errno.h>
  27
  28 #ifdef __STDC__
  29 #ifdef _SCALB_INT
  30         double __scalb(double x, int fn)                /* wrapper scalb */
  31 #else
  32         double __scalb(double x, double fn)     /* wrapper scalb */
  33 #endif
  34 #else
  35         double __scalb(x,fn)                    /* wrapper scalb */
  36 #ifdef _SCALB_INT
  37         double x; int fn;
  38 #else
  39         double x,fn;
  40 #endif
  41 #endif
  42 {
  43 #ifdef _IEEE_LIBM
  44         return __ieee754_scalb(x,fn);
  45 #else
  46         double z;
  47         z = __ieee754_scalb(x,fn);
  48         if(_LIB_VERSION == _IEEE_) return z;
  49         if(!(__finite(z)||__isnan(z))&&__finite(x)) {
  50             return __kernel_standard(x,(double)fn,32); /* scalb overflow */
  51         }
  52         if(z==0.0&&z!=x) {
  53             return __kernel_standard(x,(double)fn,33); /* scalb underflow */
  54         }
  55 #ifndef _SCALB_INT
  56         if(!__finite(fn)) __set_errno (ERANGE);
  57 #endif
  58         return z;
  59 #endif
  60 }
  61 weak_alias (__scalb, scalb)