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/* @(#)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.
* ====================================================
*/
/*
* wrapper scalb(double x, double fn) is provide for
* passing various standard test suite. One
* should use scalbn() instead.
*/
#include "fdlibm.h"
#include <errno.h>
#ifndef _DOUBLE_IS_32BITS
#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;
#ifndef HUGE_VAL
#define HUGE_VAL inf
double inf = 0.0;
SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */
#endif
struct exception exc;
z = __ieee754_scalb(x,fn);
if(_LIB_VERSION == _IEEE_) return z;
if(!(finite(z)||isnan(z))&&finite(x)) {
/* scalb overflow; SVID also returns +-HUGE_VAL */
exc.type = OVERFLOW;
exc.name = "scalb";
exc.err = 0;
exc.arg1 = x;
exc.arg2 = fn;
exc.retval = x > 0.0 ? HUGE_VAL : -HUGE_VAL;
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
if (exc.err != 0)
errno = exc.err;
return exc.retval;
}
if(z==0.0&&z!=x) {
/* scalb underflow */
exc.type = UNDERFLOW;
exc.name = "scalb";
exc.err = 0;
exc.arg1 = x;
exc.arg2 = fn;
exc.retval = copysign(0.0,x);
if (_LIB_VERSION == _POSIX_)
errno = ERANGE;
else if (!matherr(&exc)) {
errno = ERANGE;
}
if (exc.err != 0)
errno = exc.err;
return exc.retval;
}
#ifndef _SCALB_INT
if(!finite(fn)) errno = ERANGE;
#endif
return z;
#endif
}
#endif /* defined(_DOUBLE_IS_32BITS) */
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