History based branch prediction accessed via a history based earlier instruction address

摘要

An improved history table is disclosed in which at least some of the entries are stored and accessed based upon the address of an instruction which historically preceeds the branch instruction itself. The access address may be used to determine the location of the entry in the table and/or may be stored in whole or in part in the entry itself. Furthermore, the improved history table may be of any known type including but not limited to branch history table types and decode history table types. The entries in the improved history table preferably are stored and accessed by the address of the preceeding taken branch target and preferably contain a number indicative of the number of instructions between the access address and the address of the branch instruction or its target.