function gcdf( a, b ) {
	return addon( a, b );
}
Computes the greatest common divisor (gcd) of two single-precision floating-point numbers.

@private
@param {number} a - first number
@param {number} b - second number
@returns {number} greatest common divisor

@example
var v = gcdf( 0.0, 0.0 );
// returns 0.0

@example
var v = gcdf( 48.0, 18.0 );
// returns 6.0