1. A method performed by a digital processor for evaluating a complex exponential function for an input value, x, comprising: obtaining a single complex exponential software instruction having said input value, x, as an input operand; and in response to said single complex exponential software instruction, invoking at least one complex exponential functional unit that implements said single complex exponential software instruction, to apply said complex exponential function to said input value, x, by wrapping said input value to maintain a given range, computing a coarse approximation angle using a look-up table using a number of most significant bits (MSBs) of said input value, scaling said coarse approximation angle to obtain an angle from 0 to Θ, and computing a fine corrective value using a polynomial approximation to generate an output corresponding to said complex exponential of said input value, x.