Tracking long GHV in high performance out-of-order superscalar processors

摘要

Tracking global history vector in high performance out of order superscalar processors, in one aspect, may comprise providing a shift register storing global history vector that stores branch predictions and outcomes. A counter is maintained to determine a number of bits to shift the shift register to recover branch history. In another aspect, the global history vector may be implemented with a circular buffer structure. Youngest and oldest pointers to the circular buffer are maintained and used in recovery.