UDIR: Towards a Unified Compiler Framework for Reconfigurable Dataflow Architectures

Specialized hardware accelerators have gained traction as a means to improve energy efficiency over inefficient von Neumann cores. However, as specialized hardware is limited to a few applications, there is increasing interest in programmable, non-von Neumann architectures to improve efficiency on a wider range of programs. Reconfigurable dataflow architectures (RDAs) are a promising design, but the design space is fragmented and, in particular, existing compiler and software stacks are ad hoc and hard to use. Without a robust, mature software ecosystem, RDAs lose much of their advantage over specialized hardware. This letter proposes a unifying dataflow intermediate representation (UDIR) for RDA compilers. Popular von Neumann compiler representations are inadequate for dataflow architectures because they do not represent the dataflow control paradigm, which is the target of many common compiler analyses and optimizations. UDIR introduces contexts to break regions of instruction reuse in programs. Contexts generalize prior dataflow control paradigms, representing where in the program tokens must be synchronized. We evaluate UDIR on four prior dataflow architectures, providing simple rewrite rules to lower UDIR to their respective machine-specific representations, and demonstrate a case study of using UDIR to optimize memory ordering.