Set-based (a.k.a. bit-vector-based) dataflow analysis is a fundamental building block for many static analysis tasks, and significant effort has been devoted to accelerating it. Existing acceleration approaches address the problem from a software perspective, leveraging various general-purpose computing platforms, such as single- and multi-core CPUs, GPUs, and distributed systems. In contrast, a hardware-centric approach—designing specialized hardware that directly accelerates dataflow analysis—remains unexplored.

Motivated by this gap and out of pure research curiosity, we conduct a preliminary exploration of designing specialized hardware for dataflow analysis using FPGAs, which are highly customizable and well suited for rapidly prototyping domain-specific hardware. As a first step toward hardware-accelerated dataflow analysis, we focus on the widely used intra-procedural dataflow analysis. However, we find that designing specialized hardware even for this setting is already challenging: a straightforward FPGA implementation of the classical worklist algorithm is infeasible, because its space complexity grows superlinearly with procedure size, quickly exhausting the FPGA's limited high-speed on-chip memory when analyzing large procedures.

To address this challenge, we introduce FpgaFlow, a specialized hardware design for dataflow analysis that (1) overcomes the spatial infeasibility challenge by leveraging the distributivity of set-based dataflow analysis to achieve linear spatial scalability, and (2) accelerates analysis through hardware-specific parallelism—pipelining with data forwarding and BRAM partitioning and replication.

We evaluate FpgaFlow on diverse and popular real-world Java projects (averaging 32.5k GitHub stars) using two representative dataflow analyses—live variables and reaching definitions—and compare it against their software implementations in a state-of-the-art Java static analyzer Tai-e. In terms of correctness, FpgaFlow produces exactly the same analysis results as Tai-e, amounting to 75 billion bits. In terms of acceleration, even on a modest Xilinx Zynq-7020 FPGA (55 MHz), FpgaFlow achieves an average speedup of 15.45x for live variables and 12.32x for reaching definitions compared with Tai-e running on a server-grade CPU (2.20 GHz to 3.00 GHz). We hope this work offers useful insights toward future FPGA-accelerated static analysis.