Complexity of Bidirectional Data Flow Analysis

Abstract

The concept of an information flow path arising from the generalized theory of data flow analysis [21] is used to analyze the complexity of data flow analysis. The width (w) of a program flow graph with respect to a class of data flow problems is introduced as a measure of the complexity of round-robin iterative analysis. This provides the first known complexity result for round robin iterative analysis of bidirectional data flows commonly used in algorithms based on the suppression of partial redundancies [6, 7, 8, 9, 17, 18, 25]. We also show that width provides a better bound on the complexity of unidirectional data flows than the classical notion of depth.