Mapping high-level programming languages to OpenCL 2.0: A compiler writer's perspective

While OpenCL was originally designed as an application programming interface (API) for human developers, it can also serve as an implementation platform for higher-level object-oriented programming languages such as C++. Targeting OpenCL rather than vendor-specific platforms allows high-level language compiler developers to focus on language implementation issues rather than the vendor-specific intricacies across different types of devices in a heterogeneous computing system. In this chapter, we show that OpenCL 2.0 provides a strong foundation for implementing C++ Accelerated Massive Parallelism (AMP), a parallel extension to C++. We show a mapping of C++ AMP constructs to OpenCL. We also demonstrate that the OpenCL kernels generated from C++ AMP parallel_for_all and related constructs with automatically generated data transfer API calls can achieve a performance level that is comparable to that of hand-coded OpenCL kernels. We expect that compiler developers who need to target other high-level languages to heterogeneous computing systems will benefit from the techniques and experience presented in this chapter.