sl@0: /* S_LDEXP.C
sl@0:  * 
sl@0:  * Portions Copyright (c) 1993-2005 Nokia Corporation and/or its subsidiary(-ies).
sl@0:  * All rights reserved.
sl@0:  */
sl@0: 
sl@0: 
sl@0: /* @(#)s_ldexp.c 5.1 93/09/24 */
sl@0: /*
sl@0:  * ====================================================
sl@0:  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
sl@0:  *
sl@0:  * Developed at SunPro, a Sun Microsystems, Inc. business.
sl@0:  * Permission to use, copy, modify, and distribute this
sl@0:  * software is freely granted, provided that this notice 
sl@0:  * is preserved.
sl@0:  * ====================================================
sl@0:  */
sl@0: 
sl@0: /*
sl@0: FUNCTION
sl@0:        <<ldexp>>, <<ldexpf>>---load exponent
sl@0: 
sl@0: INDEX
sl@0: 	ldexp
sl@0: INDEX
sl@0: 	ldexpf
sl@0: 
sl@0: ANSI_SYNOPSIS
sl@0:        #include <math.h>
sl@0:        double ldexp(double <[val]>, int <[exp]>);
sl@0:        float ldexpf(float <[val]>, int <[exp]>);
sl@0: 
sl@0: TRAD_SYNOPSIS
sl@0:        #include <math.h>
sl@0: 
sl@0:        double ldexp(<[val]>, <[exp]>)
sl@0:               double <[val]>;
sl@0:               int <[exp]>;
sl@0: 
sl@0:        float ldexpf(<[val]>, <[exp]>)
sl@0:               float <[val]>;
sl@0:               int <[exp]>;
sl@0: 
sl@0: 
sl@0: DESCRIPTION
sl@0: <<ldexp>> calculates the value 
sl@0: @ifinfo
sl@0: <[val]> times 2 to the power <[exp]>.
sl@0: @end ifinfo
sl@0: @tex
sl@0: $val\times 2^{exp}$.
sl@0: @end tex
sl@0: <<ldexpf>> is identical, save that it takes and returns <<float>>
sl@0: rather than <<double>> values.
sl@0: 
sl@0: RETURNS
sl@0: <<ldexp>> returns the calculated value.
sl@0: 
sl@0: Underflow and overflow both set <<errno>> to <<ERANGE>>.
sl@0: On underflow, <<ldexp>> and <<ldexpf>> return 0.0.
sl@0: On overflow, <<ldexp>> returns plus or minus <<HUGE_VAL>>.
sl@0: 
sl@0: PORTABILITY
sl@0: <<ldexp>> is ANSI, <<ldexpf>> is an extension.
sl@0:               
sl@0: */   
sl@0: 
sl@0: #include "FDLIBM.H"
sl@0: #include <errno.h>
sl@0: 
sl@0: /**
sl@0: Get floating-point value from mantissa and exponent.
sl@0: Calculates the floating point value corresponding to 
sl@0: the given mantissa and exponent
sl@0: @return   Floating-point value equal to value * 2exp.
sl@0: @param x Floating point value representing mantissa 
sl@0: @param exp Integer exponent
sl@0: */	
sl@0: EXPORT_C double ldexp(double value, int exp) __SOFTFP
sl@0: {
sl@0: 	if(!finite(value)||value==0.0) return value;
sl@0: 	value = scalbn(value,exp);
sl@0: 	if(!finite(value)||value==0.0) errno = ERANGE;
sl@0: 	return value;
sl@0: }