Puffin: an embedded domain-specific language for existing unstructured hydrodynamics codes

In this paper, we present Puffin, a domain-specific language embedded in C++98 for incremental adoption in existing unstructured hydrodynamics codes. Because HPC systems with heterogeneous architectures (traditional CPUs, GPUs, Xeon Phis, etc.) are becoming increasingly common, developers of existing HPC software projects need performance across multiple architectures. While Puffin is not yet complete and only supports CPU execution so far, our aim for Puffin is to provide performance portability to existing unstructured hydrodynamics simulation projects. Our preliminary results focus on two topics. First, we show what the costs of using Puffin are. Adopting Puffin has a initial cost of rewriting existing code into Puffin. Using Puffin has the ongoing costs of increased compilation times (2-3X slower) and runtime overhead (0-11% slower). Second, we show the current benefits of using Puffin and mention the potential future benefits. We show how Puffin can gradually be adopted into an existing project, by doing so with the existing test application, LULESH 2.0. We show a reduction in code length by porting code to Puffin.