Research And Application Of Fast Program Flow Analysis Method

The most important parameter judging the system is the Worst-Case Execution Time (WCET). The purpose of WCET estimation is getting the right limit of the certain task, which should consider the software and hardware configuration comprehensively. For the dynamic measure method of WCET can not pledge the safety of the estimation, most researchers apply themselves to analysis WCET by static method. With the development of the scale and complication of program, it makes fast WCET estimation become much hard.In program flow analysis of WCET, this paper gives definition and its presentation based on the feature of the C programming language with algorithms for constructing control flow graph from abstract syntax tree, static single assignment form can be made from control flow graph, and then can get data dependency, control dependency and program dependency graph. System dependency graph can be extended from program dependency graph, and then the reachable graphic algorithm is used to compute the program slicing. We introduce a simple program slicing algorithm based-on data dependency, which is suitable for slicing all conditions. After program slicing, it uses abstract interpretation to automatically get the constraints of program flow, thereby avoiding the need for manual annotations.We introduce a method of fast and automatic program flow analysis based on static single assignment, program slicing, abstract interpretation in the program flow analysis of WCET. To compare with former methods, the one we mentioned will get the constraints of program flow fact faster and effectively, which is applicable to the WCET flow analysis of the program with complicated software configuration. Based on graph theory, compiler optimization and program slicing, this paper, which is a trial for doing research on WCET program flow analysis, have discussed an integral strategy for implementing a tool in WCET program flow analysis.