Incorporation of openmp memory consistency into conventional dataflow analysis

Abstract

Current OpenMP compilers are often limited in their analysis and optimization of OpenMP programs by the challenge of incorporating OpenMP memory consistency semantics into conventional data flow algorithms. An important reason for this is that data flow analysis within current compilers traverse the program's control-flow graph (CFG) and the CFG does not accurately model the memory consistency specifications of OpenMP. In this paper, we present techniques to incorporate memory consistency semantics into conventional dataflow analysis by transforming the program's CFG into an OpenMP Producer-Consumer Flow Graph (PCFG), where a path exists from writes to reads of shared data if and only if a dependence is implied by the OpenMP memory consistency model. We present algorithms for these transformations, prove the correctness of these algorithms and discuss a case where this transformation is used. © 2008 Springer-Verlag Berlin Heidelberg.