This paper evaluates the Triplet Based Architecture,TriBA-a new idea in chip multiprocessor architectures and a class of Direct Interconnection Network(DIN).TriBA consists of a 2D grid of small,programmable processing units,each physically connected to its three neighbors so that advantageous features of group locality can be fully and efficiently utilized.Any communication model can be well characterized by locality properties and,any topology has its intrinsic,structural,locality characteristics.We propose a new criterion in performance evaluation that is based on the concept of locality in an interconnection network,the "lower layer complete connect".Our proposed criterion depicts how completely a processing node is connected to all its neighbors.TriBA is compared with 2D Mesh and Binary Tree as static interconnection network.The comparison/evaluation is enumerated from three orthogonal view points,viz.,computational speed,physical layout and cost.Our analysis concludes that TriBA is computationally efficient interconnection strategy that exploits group locality in processing nodes.
在理论上,越来越复杂的分支预测算法和更大的存储结构会使分支预测精度不断提高,但当前复杂算法和庞大数据结构所引发的分支预测时延已无法满足流水线单周期运行要求.针对分支预测精度和时延的矛盾,设计提出提前分支预测结构(ahead branch prediction architecture,ABPA).ABPA为流水线前端取指部件提供简单的分支预测表,以实现快速分支预测;复杂的预测算法和较大的存储结构均被移至流水线后端实现,从而保证了分支预测精度.对于一直难以准确预测的多目标间接分支指令,设计提出基于分支历史和目标路径的间接分支预测算法(indirect branch prediction algorithm based on branch history and target path,BHTP algorithm).提前分支预测算法采用改进的高精度分支预测算法和BHTP算法的混合.嵌入提前分支预测算法的分支预测引擎实现流水线后端的分支推测和目标预测,以及流水线前端的分支预测表更新.实验结果表明:采用ABPA结构和BHTP算法的分支预测系统平均精度达到94.27%.设计不仅实现了快速、高精度分支预测,更为分支预测的深入研究提供了条件.
