Interprocedural Control Flow Analysis of First-Order Programs with Tail-Call Optimization

Abstract

Knowledge of low-level control flow is essential for many compiler optimizations. In systems with tail-call optimization, the determination of interprocedural control flow is complicated by the fact that because of tail-call optimization, control flow at procedure returns is not readily evident from the call graph of the program. This article shows how interprocedural control-flow analysis of first-order programs can be carried out using well-known concepts from parsing theory. In particular, we show that context-insensitive (or zeroth-order) control-flow analysis corresponds to the notion of FOLLOW sets in context-free grammars, while context-sensitive (or first-order) control-flow analysis corresponds to the notion of LR(1) items. The control-flow information so obtained can be used to improve the precision of interprocedural dataflow analyses as well as to extend certain low-level code optimizations across procedure boundaries.