The Complexity of Copy Constant Detection in Parallel Programs [chapter]

Markus Müller-Olm
2001 Lecture Notes in Computer Science  
Despite of the well-known state-explosion problem, certain simple but important data-flow analysis problems known as gen/kill problems can be solved efficiently and completely for parallel programs with a shared state [7, 6, 2, 3, 13] . This paper shows that, in all probability, these surprising results cannot be generalized to significantly larger classes of data-flow analysis problems. More specifically, we study the complexity of detecting copy constants in parallel programs, a problem that
more » ... ay be seen as representing the next level of difficulty of data-flow problems beyond gen/kill problems. We show that already the intraprocedural problem for loop-free parallel programs is co-NP-complete and that the interprocedural problem is even PSPACE-hard. 1 Gen/kill problems are characterized by the fact that all transfer functions are of the form λx.(x ∧ a) ∨ b, where a, b are constants from the underlying lattice of data-flow facts.
doi:10.1007/3-540-44693-1_43 fatcat:35x4aaeuxjbincrud4iemih26m