Dual-Issue Execution of Mixed Integer and Floating-Point Workloads on Energy-Efficient In-Order RISC-V Cores

2025/03/26 by Colagrande, Luca, Benini, Luca
#FOS: Computer and information sciences #Hardware Architecture (cs.AR)

paper · doi:10.48550/arxiv.2503.20590

Abstract

To meet the computational requirements of modern workloads under tight energy constraints, general-purpose accelerator architectures have to integrate an ever-increasing number of extremely area- and energy-efficient processing elements (PEs). In this context, single-issue in-order cores are commonplace, but lean dual-issue cores could boost PE IPC, especially for the common case of mixed integer and floating-point workloads. We develop the COPIFT methodology and RISC-V ISA extensions to enable low-cost and flexible dual-issue execution of mixed integer and floating-point instruction sequences. On such kernels, our methodology achieves speedups of 1.47x, reaching a peak 1.75 instructions per cycle, and 1.37x energy improvements on average, over optimized RV32G baselines.

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