The RISE of Programmability – From a High-Level Language to an Embedded Heterogeneous System

Heterogeneous computing has emerged as a key paradigm for improving performance and energy efficiency. While fully customized accelerators achieve the best results in the applications for which they are designed, in terms of performance and energy efficiency, programmable accelerators strike a balance between these gains and applicability to multiple application domains. However, such systems are inherently hard to program. They are often programmed using imperative languages through low-level programming interfaces, requiring deep knowledge of the underlying architectural details. For domain scientists who could make the most use of the processing power available in such systems, the lack of abstraction in the programming model renders the learning curves unnecessarily steep. In this paper, we address the problem of programmability for heterogeneous embedded systems with programmable accelerators by systematically extending the domain-specific programming language Rise and its compiler Shine for an exemplary edge computing heterogeneous platform (PULP). Ultimately, Rise enables the programmer to express a problem in terms of what is being computed, while Shine optimizes the expression and compiles it to the language native to the target platform. We evaluated our approach against the native programming model (C) of our test platform as well as against other prominent solutions targeting embedded heterogeneous hardware. Our results show performance comparable to competing approaches while offering a cleaner and more concise programming model.