The location cache should be small so that its access latency can be covered by the L1 cache access or the TLB translation. Table 1 lists the access delays of the location cache for various cache sizes. The L1 cache is a 16KB 4-way set-associative cache, with a cache line size of
64bytes, implemented with a 0.13µm technology. The results were produced using the
CACTI3.2 simulator. We chose the access delay of a 16KB direct-mapped cache as the baseline, which is the best-case delay when a way-prediction mechanism is implemented in the L1 cache. We normalized the baseline delay to
1. It is observed that a location cache with up-to 1024 entries has shorter access latency than the L1 cache. Though the organization of the location cache is similar to that of a direct-mapped cache,
there is a small change in the indexing rule. The block offset is 7 bit as the cache line size for the simulated L2 cache is 128 bytes. Thus the width of the tag is smaller for the location cache, compared with a regular cache.