Processor having reduced branch history table size through global branch history compression and method of branch prediction utilizing compressed global branch history

摘要

A processor and method of predicting a resolution of a speculative branch instruction are described. According to the present invention, a plurality of predicted resolutions of speculative branch instructions and at least one group of bits that indicates a plurality of previous resolutions of branch instructions are stored. A compressed branch history is generated that indicates a number of like previous resolutions within each group of bits. In response to a detection of a speculative branch instruction, a particular predicted resolution among the plurality of predicted resolutions is accessed utilizing the compressed branch history, such that the size of the storage utilized to store the predicted resolutions is reduced as compared to prior art systems.