From what I recall, an elliptical wing gives optimum lift distribution with significant benefits with regard to lift dependent drag. Also the effective AoA is constant across the span.
A bit of a bugger to construct though. The efficiency of the Spitfire wing was all very fine, but it meant that the tapered wing Bf 109, though marginally less efficient, could be built far more quickly.
Swift? Not a very happy name for a military aeroplane in its earlier incarnation!