Abstract
ACINCF and ACINCB are two incremental update algorithms for global data flow analysis which are based on our linear equations models of Allen/Cocke interval analysis. We have studied their performance on a robust structured programming language L. Given a set of localized program changes in a program in L, we can identify a priori the nodes in its flow graph whose corresponding data flow equations may be affected by the changes. We can characterize these affected nodes by their corresponding program structures and their relation to the original change sites, and do so without actually performing the incremental update algorithm. Our results can be refined to characterize the reduced equations affected when the structured loop exit mechanisms are used singly or together, thereby relating the richness of programming language usage to the ease of incremental updating.