Speculative load of look up table entries based upon coarse index calculation in parallel with fine index calculation

摘要

A computer implemented method accesses data in a look up table via an index divided into a coarse index and a fine index. The method calculates the coarse index and fetches plural look up table entries. While the fetch is in progress, the method calculates the fine index. The method determines and extracts the look up table entry corresponding to the combined coarse and fine indexes Fetching plural look up table entries includes executing a single word load instruction, a doubleword load instruction or a pair of sequential or simultaneous single word load instructions. Extracting the look up table entry may include a section select move instruction, an extract and zero-extend bit field instruction or a shift and mask operation.