An Optimization of Broadcast on Godson-T Many-Core System Architecture

Godson-T is a large scale many-core system architecture to be implemented by ultra-deep submicron MOS technology under development by the Group of Advanced Microsystem in the Key Laboratory of Computer System and Architecture of the Institute of Computer Technology, Chinese Academy of Sciences. The single port design of Godson-T on-chip memory saves the chips total area but limits the efficiency of data sharing. Broadcast is a basic parallel algorithm used to accelerate data sharing process, but implementing the traditional algorithm on Godson-T requires a large amount of synchronization and mutual exclusion expenses and therefore could not bring a good performance. Based on Godson-T system architecture, the authors optimize the important parallel algorithm Broadcast and enhance the efficiency of concurrent read. Three techniques are proposed for the optimization: eliminating bulk synchronization among threads, establishing mapping table between source addresses and destination addresses, and rearranging assembly instructions in Broadcast kernel. The first one reduces expenses of synchronizing a large amount of threads, the second one provides a quicker method for destination address search, and the last one fully makes use of the advantage of Godson-T architecture. The optimized Broadcast algorithm on Godson-T system architecture performs well; especially when core number is 32, the speedup of the algorithm can reach 5.8.