NAME
	IEEEDPTanh -- compute the hyperbolic tangent of a floating point number

   SYNOPSIS
	  x   = IEEEDPTanh(  y  );
	d0/d1		   d0/d1

	double	x,y;

   FUNCTION
	Compute hyperbolic tangent of y in IEEE double precision

   INPUTS
	y - IEEE double precision floating point value

   RESULT
	x - IEEE double precision floating point value

   BUGS

   SEE ALSO
	IEEEDPSinh(), IEEEDPCosh()