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      1 /* @(#)e_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: e_scalb.c,v 1.10 2010/04/23 19:17:07 drochner Exp $");
     16 #endif
     17 
     18 /*
     19  * __ieee754_scalb(x, fn) is provide for
     20  * passing various standard test suite. One
     21  * should use scalbn() instead.
     22  */
     23 
     24 #include "namespace.h"
     25 #include "math.h"
     26 #include "math_private.h"
     27 
     28 #ifdef _SCALB_INT
     29 double
     30 __ieee754_scalb(double x, int fn)
     31 #else
     32 double
     33 __ieee754_scalb(double x, double fn)
     34 #endif
     35 {
     36 #ifdef _SCALB_INT
     37 	return scalbn(x,fn);
     38 #else
     39 	if (isnan(x)||isnan(fn)) return x*fn;
     40 	if (!finite(fn)) {
     41 	    if(fn>0.0) return x*fn;
     42 	    else       return x/(-fn);
     43 	}
     44 	if (rint(fn)!=fn) return (fn-fn)/(fn-fn);
     45 	if ( fn > 65000.0) return scalbn(x, 65000);
     46 	if (-fn > 65000.0) return scalbn(x,-65000);
     47 	return scalbn(x,(int)fn);
     48 #endif
     49 }
     50