%0 Journal Article
%A Carazo, Pablo
%A Apollini, Ruben
%A Castro Rodríguez, Fernando
%A Chaver Martínez, Daniel Ángel
%A Piñuel Moreno, Luis
%A Tirado Fernández, José Francisco
%T Reducing cache hierarchy energy consumption by predicting forwarding and disabling associative sets
%D 2012
%@ 0218-1266
%U https://hdl.handle.net/20.500.14352/44467
%X The first level data cache in modern processors has become a major consumer of energy due to its increasing size and high frequency access rate. In order to reduce this high energy consumption, we propose in this paper a straightforward filtering technique based on a highly accurate forwarding predictor. Specifically, a simple structure predicts whether a load instruction will obtain its corresponding data via forwarding from the load-store structure - thus avoiding the data cache access - or if it will be provided by the data cache. This mechanism manages to reduce the data cache energy consumption by an average of 21.5% with a negligible performance penalty of less than 0.1%. Furthermore, in this paper we focus on the cache static energy consumption too by disabling a portion of sets of the L2 associative cache. Overall, when merging both proposals, the combined L1 and L2 total energy consumption is reduced by an average of 29.2% with a performance penalty of just 0.25%.
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