基于混合离散粒子群优化的Slew约束下X结构Steiner最小树算法  

Hybrid Discrete Particle Swarm Optimization Algorithm for X-Architecture Steiner Minimal Tree Construction with Slew Constraints

作　　者：刘耿耿[1,2] 黄逸飞 王鑫 郭文忠[1,2] 陈国龙 LIU Geng-Geng;HUANG Yi-Fei;WANG Xin;GUO Wen-Zhong;CHEN Guo-Long(College of Mathematics and Computer Sciences,Fuzhou University,Fuzhou 350116;Key Laboratory of Network Computing and Intelligent Information Processing,Fuzhou 350116;College of Intelligence and Computing,Tianjin University,Tianjin 300354;Tianjin Key Laboratory of Cognitive Computing and Application,Tianjin 300350)

机构地区：[1]福州大学计算机与大数据学院,福州350116 [2]福建省网络计算与智能信息处理重点实验室,福州350116 [3]天津大学智能与计算学部,天津300354 [4]天津市认知计算与应用重点实验室,天津300350

出　　处：《计算机学报》2021年第12期2542-2559,共18页Chinese Journal of Computers

基　　金：国家自然科学基金(61877010,11501114);国家重点基础研究发展计划(2011CB808000);计算机体系结构国家重点实验室开放课题(CARCIIB202014);福建省自然科学基金(2019J01243)资助。

摘　　要：Steiner最小树是超大规模集成电路中布线阶段的最佳模型,进一步考虑能够有效防止信号失真的电压转换速率(Slew)约束这一个更为贴近实际芯片设计模型和更具线长优化能力的X结构,首次提出基于混合离散粒子群优化的Slew约束下X结构Steiner最小树算法.首先,为了避免频繁的Slew约束计算,提出了高效的预处理策略,并且提出一种能够有效考虑Slew约束的针对性的惩罚机制.其次,为了能够有效求解该离散问题,基于遗传算子重新设计了粒子群优化算法的离散更新机制,并提出一种更适合遗传算子的引脚对编码方式.然后,为了进一步优化布线树的长度,提出一种有效的精炼策略.最终,提出一种混合修正策略以完全满足Slew约束.实验表明,所提算法可完全满足电压转换速率约束并取得同类工作中最佳的布线结果.Steiner minimal tree is the best model of routing stage in modern Very Large Scale Integration(VLSI) chips,and is often used for pre-routing,wirelength optimization,and congestion estimation.Therefore,it is of great significance to construct a high-performance Steiner minimal tree algorithm.However,with the emergence of obstacles such as IP blocks and the continuous improvement of circuit density,obstacles have become a factor that cannot be ignored in the Steiner minimal tree construction problem.Considering that obstacles usually only occupy the device layer and the lower metal layer in modern multi-layer routing,the routing on the top of obstacles is possible,which can make full use of routing resources and further optimize the wirelength.The construction of Steiner minimal tree is an NP-hard problem,and the particle swarm optimization algorithm has a good application prospect in solving NP-hard problems.Therefore,on the basis of the particle swarm optimization algorithm,and further considering the slew constraints model which can effectively prevent signal distortion and the X-architecture with better wirelength optimization,this paper is the first work to propose an X-architecture Steiner minimal tree algorithm with slew constraints based on hybrid discrete particle swarm optimization.Firstly,an efficient preprocessing strategy is proposed to reduce frequent slew calculation and judgment between routing and obstacles.In this preprocessing strategy,the information between all possible routing of any two pins and all obstacles is calculated in advance,and a suitable lookup table is generated for subsequent queries based on the information.Secondly,in order to effectively solve the discrete problem of Steiner minimal tree construction,an effective discrete update operation formula of particle swarm optimization algorithm is redesigned,which is based on the mutation operator and the crossover operator.At this stage,a pin-pair coding method which is more suitable for the discrete particle swarm optimization and a

关 键 词：粒子群优化 STEINER树 电压转换速率约束 X结构 超大规模集成电路 

分 类 号：TP18[自动化与计算机技术—控制理论与控制工程]