Digital processor having instruction set with complex exponential non-linear function

摘要

A digital processor is provided having an instruction set with a complex exponential function. The digital processor evaluates a complex exponential function for an input value, x, by obtaining a complex exponential software instruction having the input value, x, as an input; and in response to the complex exponential software instruction: invoking at least one complex exponential functional unit that implements complex exponential software instructions to apply the complex exponential function to the input value, x; and generating an output corresponding to the complex exponential of the input value, x. A complex exponential function for an input value, x, can be evaluated by wrapping the input value to maintain a given range; computing a coarse approximation angle using a look-up table; scaling the coarse approximation angle to obtain an angle from 0 to θ; and computing a fine corrective value using a polynomial approximation.

主权项

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, andcomputing a fine corrective value using a polynomial approximation to generate an output corresponding to said complex exponential of said input value, x.