Performance-aware speculation control using wrong path usefulness prediction

Fetch gating mechanisms have been proposed to gate the processor pipeline to reduce the wasted energy consumption due to wrongpath (i.e. mis-speculated) instructions. These schemes assume that all wrong-path instructions are useless for processor performance and try to eliminate the execution of all wrong-path instructions. However, wrong-path memory references can be useful for performance by providing prefetching benefits for later correct-path operations. Therefore, eliminating wrong-path instructions without considering the usefulness of wrong-path execution can significantly reduce performance as well as increase overall energy consumption. This paper proposes a comprehensive, low-cost speculation control mechanism that takes into account the usefulness of wrong-path execution, while effectively reducing the energy consumption due to useless wrong-path instructions. One component of the mechanism is a simple, novel wrong-path usefulness predictor (WPUP) that can accurately predic...

• Type: Conference
• Year: 2008
• Where: HPCA
• Authors: Chang Joo Lee, Hyesoon Kim, Onur Mutlu, Yale N. Patt
• Keywords: Computer Architecture, Energy Consumption, Fetch Gating Mechanisms, Fetch Gating Scheme, HPCA 2008