ROME: Maximizing GPU Efficiency for All-Pairs Shortest Path via Taming Fine-Grained Irregularities

All-Pairs Shortest Path (APSP), a fundamental problem in graph analytics, can be solved efficiently by reducing the computational workload through vertex reordering. However, it fails on GPUs due to fine-grained granularity, shape, and dependency irregularities, which cause severe hardware underutilization. We introduce ROME, a system that tames these irregularities by spatially restructuring computation into regularized workloads and temporally overlapping them with an asynchronous pipeline. ROME achieves 14.7-244.5× speedup over the state-of-the-art multicore CPU solution and 11.2-338.0× speedup over the state-of-the-art GPU solution. Notably, our results achieve mostly above 20% and up to 34.7% of peak min-plus OPs across all tested graphs.