A Register Allocation Algorithm for Shared and Clustered Hybrid Register Files Organization

• Main Authors: Jer-Yu Hsu, 許哲宇
• Other Authors: Yeh-Ching Chung
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/62559906445607133409

碩士 === 國立清華大學 === 資訊工程學系 === 94 === In VLIW processor design, clustered architecture becomes a popular solution for better hardware efficiency. But the inter-cluster communication (ICC) will cause the execution cycles overhead. In this thesis, we propose a shared cluster register file (SCRF) architecture and a SCRF register allocation algorithm to reduce the ICC overhead. The SCRF architecture is a hybrid register file (RF) organization composed of shared RF (SRF) and clustered RFs (CRFs). By putting the frequently used variables that need ICCs on SRF, we can reduce the number of data communication of clusters and thus reduce the ICC overhead. The SCRF register allocation algorithm exploits this architecture feature to perform optimization on ICC reduction and spill codes balancing. The SCRF register allocation algorithm is a heuristic based on graph coloring. To evaluate the performance of the proposed architecture and the SCRF register allocation algorithm, the frequently used two-cluster architecture with and without the SRF scheme are simulated on Trimaran, a compiler framework. A set of multimedia programs from mediabench is used as the benchmarks. The simulation results show that the performance of the SCRF architecture is better than that of the clustered RF architecture for all test programs in all measured metrics. In the SCRF architecture with macro registers defined in the SRF, the execution cycles, the ICC overhead, the spill codes overhead, and the code density can get 11.6%, 55.6%, 52.7%, and 18.2% reduction in average, respectively.