Copy Propagation subsumes Constant Propagation

Abstract

Constant propagation and copy propagation are code transformations that may avoid some load operations and can enable other optimizations. In literature, constant and copy propagations are considered two independent transformations requiring two different data flow analyses. Here we give a generic definition for copy propagation which enables us to view constant propagation as a particular case of copy propagation and formulate a novel data flow analysis that unifies these two transformations.