Rescue to the Curse of universality  

作　　者：Yongwei ZHAO Zidong DU Qi GUO Zhiwei XU Yunji CHEN 

机构地区：[1]State Key Lab of Processors,Institute of Computing Technology,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Beijing Academy of Artificial Intelligence,Beijing 100084,China

出　　处：《Science China(Information Sciences)》2023年第9期130-146,共17页中国科学（信息科学）（英文版）

基　　金：National Key Research and Development Program of China(Grant No.2018AAA0103300);National Natural Science Foundation of China(Grant Nos.61925208,62102398,U19B2019);Strategic Priority Research Program of Chinese Academy of Science(Grant No.XDB32050200);Beijing Academy of Artificial Intelligence(BAAI)and Beijing Nova Program of Science and Technology(Grant No.Z191100001119093);CAS Project for Young Scientists in Basic Research(Grant No.YSBR-029);Youth Innovation Promotion Association CAS and Xplore Prize。

摘　　要：From the very beginning of computers,universality has been the core focus in the building of computing machines,such as the universal Turing machine,von Neumann architecture,random-access machines,and universal circuits.Academia has taken universality as the primary principle ever since.However,the Curse of universality,implied from L.G.Valiant's Universal Circuit,states that computers based on logic circuits cannot be both universal and efficient,as the cost of universality isΩ(n log_2 n).Though the Curse has been hidden by the rapid advancement of semiconductor technologies,it has been wielding its effects noticeably in recent years.Due to the ending of Dennard scaling and Moore's law,general-purpose processors leave less room for improvement.Therefore,domain-specific architectures(DSAs),such as deep learning processors,have been exploding,leading to the new golden age of computer architectures.For DSAs,universality is traded off for optimal efficiency.However,we predict that universality will once again be a major concern for post-golden-age computers.In this paper,we discuss how much universality could an efficient computer keep.As a rescue to the Curse,we define and discuss quasi-universal architectures.Quasi-universal architectures can solve any computable problem and are efficient for a wide range of problems.The proposed Recursive-Encapsulated(RE_(NC))architecture achieves maximal universality while keeping optimal efficiency as found in specialized architectures.The discovery of RE_(NC)suggests that current golden-age architectures are not Pareto optimal.

关 键 词：UNIVERSALITY general-purpose architecture specialized architecture deep learning processor universal circuit 

分 类 号：TP30[自动化与计算机技术—计算机系统结构]