POSTER: Variable Sized Cache-Block Compaction

Data blocks compressed to different sizes can be stored together inside a single cache-block to increase space utilization. However, the lack of a common size offset makes it challenging to locate individual blocks without additional tag overhead. We propose Variable Sized Cache-Block Compaction (VSCC) that allows us to store variable sized compressed blocks together and locate them inside a cache-block by using their compression encodings-available inside the tag metadata. We introduce a novel read/write scheme and a new BDI compression encoding, which reduce the necessary operations by 50%. Experimental results reveal that VSCC outperforms state-of-The-Art techniques from the performance and energy point of view while keeping the storage overheads within acceptable limits.