1. Circuitry for computing an inverse tangent function of an input, said circuitry comprising: circuitry for determining a relationship of said input to ‘1’ to generate an intermediate value; circuitry for multiplying said intermediate value by upper bits of said intermediate value to form a first product, to add said first product to ‘1’ to form a first sum, and to invert said first sum to form a first intermediate result; circuitry for multiplying lower bits of said intermediate value by said first intermediate result to form a second intermediate result; look-up table circuitry for determining a third intermediate result from said upper bits of said intermediate value; circuitry for adding said second intermediate result and said third intermediate result to form a preliminary result; and circuitry for deriving a final result from said preliminary result based on said relationship of said input to ‘1’.