lib/libm/src/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 #include <sys/cdefs.h>
  14 #if defined(LIBM_SCCS) && !defined(lint)
  15 __RCSID("$NetBSD: w_scalb.c,v 1.9 2002/05/26 22:02:02 wiz Exp $");
  16 #endif
  17
  18 /*
  19  * wrapper scalb(double x, double fn) is provide for
  20  * passing various standard test suite. One
  21  * should use scalbn() instead.
  22  */
  23
  24 #include "math.h"
  25 #include "math_private.h"
  26
  27 #include <errno.h>
  28
  29 #ifdef _SCALB_INT
  30 double
  31 scalb(double x, int fn)         /* wrapper scalb */
  32 #else
  33 double
  34 scalb(double x, double fn)      /* wrapper scalb */
  35 #endif
  36 {
  37 #ifdef _IEEE_LIBM
  38         return __ieee754_scalb(x,fn);
  39 #else
  40         double z;
  41         z = __ieee754_scalb(x,fn);
  42         if(_LIB_VERSION == _IEEE_) return z;
  43         if(!(finite(z)||isnan(z))&&finite(x)) {
  44             return __kernel_standard(x,(double)fn,32); /* scalb overflow */
  45         }
  46         if(z==0.0&&z!=x) {
  47             return __kernel_standard(x,(double)fn,33); /* scalb underflow */
  48         }
  49 #ifndef _SCALB_INT
  50         if(!finite(fn)) errno = ERANGE;
  51 #endif
  52         return z;
  53 #endif
  54 }