GLOBAL DATA FLOW ANALYSIS
Min Zhang · Chinese Journal of Computers · 1979
For global data flow analysis various algorithms have been developed. It is well-known that all these algorithms are to obtain the minimal solution of Boolean equations. The main trouble comes from the presence of diagonal terms in the equations. In this paper it is proved that the diagonal terms have actually no influence on the minimal solution, i.e. if we alter or even omit the diagonal terms, the minimal solution remains unchanged. Thus two transformations on Boolean equations can be introduced and a new algorithm can be devised which, unlike the algorithms mentioned above, imposes no restrictions on the flow graph of the problem.Moreover, through these transformations we can gain a better insight into the algorithms of Cocke-Allen and Kennedy.