Method and apparatus for a single history register based branch predictor in a superscalar microprocessor

摘要

Methods and apparati predict whether conditional branch computer instructions should be taken or not taken. A history register is maintained to record the history of groups of instructions, updated only once for each group. The history register and an address of one of the bytes of one of the instructions in each group are appended or otherwise combined to create an address to a table of two-bit saturating counters. The value of one of the bits of the counter at the address created is used for predicting all the conditional branch instructions for each branch in the group.