Last-Touch Correlated Data Streaming

Recent research advocates address-correlating predictors to identify cache block addresses for prefetch. Unfortunately, address-correlating predictors require correlation data storage proportional in size to a program's active memory footprint. As a result, current proposals for this class of predictor are either limited in coverage due to constrained on-chip storage requirements or limited in prediction lookahead due to long off-chip correlation data lookup. In this paper, we propose Last-Touch Correlated Data Streaming (LT-cords), a practical address-correlating predictor. The key idea of LT-cords is to record correlation data off chip in the order they will be used and stream them into a practicallysized on-chip table shortly before they are needed, thereby obviating the need for scalable on-chip tables and enabling low-latency lookup. We use cycle-accurate simulation of an 8-way out-oforder superscalar processor to show that: (1) LT-cords with 214KB of on-chip storage can ach...

• Type: Conference
• Year: 2007
• Where: ISPASS
• Authors: Michael Ferdman, Babak Falsafi
• Keywords: Address-correlating Predictor, Correlation Data, ISPASS 2007, On-chip Storage, Software Engineering