Instruction issue consumes a large amount of energy in out of order processors, largely in the wakeup logic. Proposed solutions to the problem require prediction or additional hardware complexity to reduce energy consumption and, in some cases, may have a negative impact on processor performance. This paper proposes a mechanism for instruction wakeup, which uses a multi-block instruction queue design. The blocks are turned off until the mechanism determines which blocks to access on wakeup using a simple successor tracking mechanism. The proposed approach is shown to require as
Marco A. Ramírez, Adrián Cristal, Al