Multi-dimensional systems containing nested loops are widely used to model scientific applications such as image processing, geophysical signal processing and fluid dynamics. However, branches within these loops may degrade the performance of pipelined architectures. This paper presents the theory, supporting hardware and experiments of a novel technique, based on multi-dimensional retiming, for reducing pipeline hazards caused by branches within nested loops. This technique, called Multi-Dimensional Branch Anticipation Scheduling, is able to achieve nearoptimal schedule length for nested loops containing branch instructions.
Ted Zhihong Yu, Edwin Hsing-Mean Sha, Nelson L. Pa