Method and apparatus for additive range reduction

摘要

A method and apparatus for additive range reduction are disclosed. A constant may be pre-stored in a look-up table (LUT), and at least one section of the constant may be retrieved from the LUT for generating a product of an input argument and the constant such that a precision of the product may be controlled in any granularity. For a trigonometric function, 2/π is stored in the LUT, and at least one section of 2/π may be retrieved from the LUT. The argument is multiplied with the retrieved sections of 2/π. The retrieved sections are determined to correctly generate the two least significant bits (LSBs) of an integer portion and a scalable number of most significant bits of the multiplication result. An output of the trigonometric function is generated for the argument with a fractional portion of the multiplication result based on two LSBs of the integer portion of the multiplication result.

主权项

1. A method implemented in a processor for generating an output of a function, the method comprising:
a processor receiving an argument of a function; the processor retrieving a section of a constant from a look-up table (LUT) in a memory, wherein the section of the constant is retrieved such that a product of the argument and the section of the constant generates at least two least significant bits (LSBs) of an integer portion of the product and a scalable number of most significant bits (MSBs) of the product; and the processor generating an output of the function based on multiplication of the argument and the retrieved section of the constant.