base/math/w_scalb.c

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#if !defined(__ppc__)
/* @(#)w_scalb.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice 
 * is preserved.
 * ====================================================
 */

#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: w_scalb.c,v 1.6 1995/05/10 20:49:48 jtc Exp $";
#endif

/*
 * wrapper scalb(double x, double fn) is provide for
 * passing various standard test suite. One 
 * should use scalbn() instead.
 */

#include "math.h"
#include "mathP.h"

#include <linux/errno.h>

extern int libm_errno;

#ifdef __STDC__
#ifdef _SCALB_INT
    double scalb(double x, int fn)      /* wrapper scalb */
#else
    double scalb(double x, double fn)   /* wrapper scalb */
#endif
#else
    double scalb(x,fn)          /* wrapper scalb */
#ifdef _SCALB_INT
    double x; int fn;
#else
    double x,fn;
#endif
#endif
{
#ifdef _IEEE_LIBM
    return __ieee754_scalb(x,fn);
#else
    double z;
    z = __ieee754_scalb(x,fn);
    if(_LIB_VERSION == _IEEE_) return z;
    if(!(finite(z)||isnan(z))&&finite(x)) {
        return __kernel_standard(x,(double)fn,32); /* scalb overflow */
    }
    if(z==0.0&&z!=x) {
        return __kernel_standard(x,(double)fn,33); /* scalb underflow */
    } 
#ifndef _SCALB_INT
    if(!finite(fn)) libm_errno = ERANGE;
#endif
    return z;
#endif 
}
#endif /* !__ppc__ */

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