LIME: a future-proof programming model for multi-cores

The Less Is More (LIME) programming model addresses known programmability, compositionality, predictability, and scalability problems related to parallel programming in embedded systems of new as well as legacy code in streaming applications. With LIME, the high-level functional aspects of algorithm design and implementation are decoupled from the low-level platform-specific mechanisms pertaining to communication and synchronization. The integration of both in the end-product is assisted by a tool-chain that has complete access to the computations and has compile-time knowledge of hardware-dependent performance aspects. Rather than proposing intrusive modifications of a sequential language, LIME postulates rules and restrictions on how to express algorithms using standard C and (de)compose them using a simple XML schema for connecting components in a graph. In the paper, we describe the design rationales behind LIME and discuss its features in detail. We outline the LIME tool-chain, show how it interacts with analysis tools, and describe how multi-core back-ends are constructed. We illustrate this by showing a LIME implementation on a real-life parallel embedded platform for Software-Defined Radio (SDR) and an implementation on a commodity GPU platform.