Red blue traces: Trace cache redundancy

The objective of this paper is to improve the use of the hardware resources of the trace cache mechanism, reducing the implementation cost with no performance degradation, eliminating trace and basic block replication. Two previous works approach a cost reduction for the trace cache. The software trace cache is a code reordering scheme which builds as many traces at compile-time as possible. This increases the performance of the core fetch unit, providing traces from the instruction cache, and obtaining similar or better performance with less trace cache storage space. The block-based trace cache is a hardware alternative to the trace cache targeting an elimination of the basic block redundancy among the stored traces. The trace cache used together with the software trace cache are generating a high degree of redundancy between the traces stored in the trace cache and those present in the instruction cache. Also, the block-based trace cache introduces a high degree of fragmentation wit..