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      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 }
     55