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/* @(#)s_ldexp.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.
 * ====================================================
 */
 
/*
FUNCTION
       <<ldexp>>, <<ldexpf>>---load exponent
 
INDEX
	ldexp
INDEX
	ldexpf
 
ANSI_SYNOPSIS
       #include <math.h>
       double ldexp(double <[val]>, int <[exp]>);
       float ldexpf(float <[val]>, int <[exp]>);
 
TRAD_SYNOPSIS
       #include <math.h>
 
       double ldexp(<[val]>, <[exp]>)
              double <[val]>;
              int <[exp]>;
 
       float ldexpf(<[val]>, <[exp]>)
              float <[val]>;
              int <[exp]>;
 
 
DESCRIPTION
<<ldexp>> calculates the value 
@ifinfo
<[val]> times 2 to the power <[exp]>.
@end ifinfo
@tex
$val\times 2^{exp}$.
@end tex
<<ldexpf>> is identical, save that it takes and returns <<float>>
rather than <<double>> values.
 
RETURNS
<<ldexp>> returns the calculated value.
 
Underflow and overflow both set <<errno>> to <<ERANGE>>.
On underflow, <<ldexp>> and <<ldexpf>> return 0.0.
On overflow, <<ldexp>> returns plus or minus <<HUGE_VAL>>.
 
PORTABILITY
<<ldexp>> is ANSI, <<ldexpf>> is an extension.
 
*/   
 
#include "fdlibm.h"
#include <errno.h>
 
#ifndef _DOUBLE_IS_32BITS
 
#ifdef __STDC__
	double ldexp(double value, int exp)
#else
	double ldexp(value, exp)
	double value; int exp;
#endif
{
	if(!finite(value)||value==0.0) return value;
	value = scalbn(value,exp);
	if(!finite(value)||value==0.0) errno = ERANGE;
	return value;
}
 
#endif /* _DOUBLE_IS_32BITS */