function addf( x, y ) {
	return addon( x, y );
}
Computes the sum of two single-precision floating-point numbers `x` and `y`.

@private
@param {number} x - first input value
@param {number} y - second input value
@returns {number} sum

@example
var v = addf( -1.0, 5.0 );
// returns 4.0

@example
var v = addf( 2.0, 5.0 );
// returns 7.0

@example
var v = addf( 0.0, 5.0 );
// returns 5.0

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

@example
var v = addf( NaN, NaN );
// returns NaN