From OpenACC to OpenMP 4: Toward Automatic Translation

For the past few years, OpenACC has been the primary directive-based API for programming accelerator devices like GPUs. OpenMP 4.0 is now a competitor in this space, with support from different vendors. In this paper, we describe an algorithm to convert (a subset of) OpenACC to OpenMP 4; we implemented this algorithm in a prototype tool and evaluated it by translating the EPCC Level 1 OpenACC benchmarks. We discuss some of the challenges in the conversion process and propose what parts of the process should be automated, what should be done manually by the programmer, and what future research and development is necessary in this area.