1. A data processing system comprising: an execution device; and a floating point unit coupled to the execution device, the floating point unit comprising: a single adder having a first input and a second input and an output; a plurality of storage devices wherein each storage device in the plurality of storage devices has an input coupled to the output of the single adder so that each storage device is coupled to a same output of the single adder, each storage device in the plurality of storage devices having an output; and a selection circuit having an output and a plurality of inputs wherein each input in the plurality of inputs is coupled to a unique one output of one of the storage devices in the plurality of storage devices, wherein: (1) the single adder receives a first exponent value via the first input and a second exponent value via the second input in a first time period to produce a first result which is stored in a first storage device in the plurality of storage devices; and (2) the single adder receives a third exponent value via the first input and a fourth exponent value via the second input in a second time period which occurs after the first time period to produce a second exponent result which is stored in a second storage device in the plurality of storage devices, and wherein the selection circuitry selects one of either the first result or the second results from one of either the first storage device or the second storage device to provide as a correct exponent result via the output of the selection circuit.