FlexWalker: An Efficient Multi-Objective Design Space Exploration Framework for HLS Design

The HLS toolchain effectively reduces the design complexity of FPGA hardware accelerators. However, in scenarios involving the multi-objective optimization of large-scale HLS designs, determining the knob configurations of Pareto design points remains a challenging task for designers. Our work re-evaluates the key factors affecting the efficiency of multiobjective design space exploration in HLS design and proposes an efficient framework named FlexWalker. It utilizes the upper confidence bound algorithm to organize various heterogeneous regression models for predicting the quality of HLS designs with different knob configurations in the design space and introduces a probability sampling algorithm and an elastic Pareto frontier to counteract the negative impact of regression model errors. Experimental results show that our work can stably eliminate over 90% of non-Pareto frontier design points in the tested HLS design space, effectively enhancing the efficiency of multiobjective design space exploration.