Reducing Power with Dynamic Critical Path Information

John S. Seng, Eric S. Tune, Dean M. Tullsen


Recent research has shown that dynamic information regarding instruction criticality can be used to increase microprocessor performance. Critical path information can also be used in processors to achieve a better balance of power and performance. This paper uses the output of a dynamic critical path predictor to decrease the power consumption of key portions of the processor without incurring a corresponding decrease in performance. The optimizations include effective use of functional units with different power and latency characteristics and decreased issue logic power.