Extending Explicit Management of SMMHS to OpenMP for Heterogeneous Architectures

In heterogeneous architectures with software-managed memory hierarchies system (SMMHS), software is deployed in charge of data placement of device memories and data movement between main memory and device ones. Considering the simplicity, portability, and performance characteristics of OpenMP, we argue that it is the most appropriate model for high level heterogeneous system programming. In this chapter, we address the problem of managing data storage and data transfer within SMMHS by proposing a potential extension to OpenMP. Meanwhile, we develop a method to compute the array region by applying the polyhedral model. Finally, we implement the automatic generation of the extended OpenMP clauses based on Open64, providing support for the migration of sequential programs to heterogeneous platforms. The experimental results show that OpenMP programs automatically generated with extended clauses get significant performance improvements on heterogeneous architectures. The extended OpenMP clauses could improve data placement of device memories and data movement between main memory and device ones evidently.