Digital signal processor having instruction set with an x^Kfunction using reduced look-up table

摘要

A digital signal processor is provided having an instruction set with an xK function that uses a reduced look-up table. The disclosed digital signal processor evaluates an xK function for an input value, x, by computing Log(x) in hardware; multiplying the Log(x) value by K; and determining the xK function by applying an exponential function in hardware to a result of the multiplying step. One or more of the computation of Log(x) and the exponential function employ at least one look-up table having entries with a fewer number of bits than a number of bits in the input value, x.

主权项

1. A method performed by a vector-based digital signal processor for evaluating a non-linear xK function for an input vector, x, said method comprising:
obtaining one or more xK software instructions that implement said non-linear xK function; receiving said input vector comprising at least two scalar numbers and K; in response to a predefined software instruction keyword for said at least one of said obtained xK software instructions, invoking at least one hardware functional unit that implements said one or more xK software instructions to perform the following steps for each component of said input vector, wherein said vector-based processor processes said at least two scalar numbers of said input vector substantially simultaneously; computing Log(x) in hardware; multiplying said Log(x) value by K; and determining said xK function by applying an exponential function in hardware to a result of said multiplying step, wherein one or more of said computation of Log(x) and said exponential function employ at least one look-up table having entries with a fewer number of bits than a number of bits in the input vector, x, wherein said one or more xK software instructions that implement said non-linear xK function is part of an instruction set of said vector-based digital signal processor and wherein said non-linear xK function computes a Kth power of said input vector, x.