Reducing I-cache energy of multimedia applications through low cost tag comparison elimination

Abstract

Tag comparison elimination (TCE) is an effective approach to reduce I-cache energy. Current research focuses on finding good trade-offs between hardware cost and percentage of comparisons that can be removed. For this purpose, two low cost innovations are proposed in this paper. We design a small dedicated TCE table whose size is flexible both horizontally (entry size) and vertically (number of entries). The design also minimizes interactions with the I-cache. For a 64-way 16K cache, the new design reduces the tag comparisons to 2.7% with a fraction only 20% of the hardware cost of the way memoization technique. The result is 50% better compared to a recent proposed low cost design of comparable hardware cost.