Genetic Algorithm for Integrated SoftwarePipelining

• Main Author: Cai, Zesi
• Format: Others
• Language: English
• Published: Linköpings universitet, Institutionen för datavetenskap 2012
• Subjects: Code generation; compilers; instruction scheduling; modulo scheduling; genetic programming.; Computer Sciences; Datavetenskap (datalogi)
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-76088

The purpose of the thesis was to study the feasibility of using geneticalgorithm (GA) to do the integrated software pipelining (ISP). Different from phasedcode generation, ISP is a technique which integrates instruction selection, instructionscheduling, and register allocation together when doing code generation. ISP is able toprovide a lager solution space than phased way does, which means that ISP haspotential to generate more optimized code than phased code generation. However,integrated compiling costs more than phased compiling. GA is stochastic beam searchalgorithm which can accelerate the solution searching and find an optimized result.An experiment was designed for verifying feasibility of implementing GA for ISP(GASP). The implemented algorithm analyzed data dependency graphs of loop bodies,created genes for the graphs and evolved, generated schedules, calculated andevaluated fitness, and obtained optimized codes. The fitness calculation wasimplemented by calculating the maximum value between the smallest possibleresource initiation interval and the smallest possible recurrence initiation interval. Theexperiment was conducted by generating codes from data dependency graphsprovided in FFMPEG and comparing the performance between GASP and integerlinear programming (ILP). The results showed that out of eleven cases that ILP hadgenerated code, GASP performed close to ILP in seven cases. In all twelve cases thatILP did not have result, GASP did generate optimized code. To conclude, the studyindicated that GA was feasible of being implemented for ISP. The generated codesfrom GASP performed similar with the codes from ILP. And for the dependencygraphs that ILP could not solve in a limited time, GASP could also generate optimizedresults.