Single Appearance Schedule with Dynamic Loop Count for Minimum Data Buffer from Synchronous Dataflow Graphs ABSTRACT Hyunok Oh

In this paper, we propose a new single appearance schedule for synchronous dataflow programs to minimize data memory and code memory size at the same time. When the software code is automatically synthesized from the dataflow program graphs, a single appearance schedule promises only one appearance of each node definition in the generated code. While several heuristics have been developed to find a single appearance schedule, they all have to pay significant amount of data memory overhead compared with a buffer optimal schedule. The key idea of the proposed technique is to make a dynamic decision of loop count to make a schedule quasi-static. The proposed quasi-static static schedule produces a single appearance schedule code with minimum data memory requirement. We prove that the proposed scheduling technique is optimal for a chain-structured graph in terms of data memory requirement while maintaining the single appearance schedule. The only penalty for the proposed technique is slight performance overhead of computing loop counts dynamically. Experimental results show that the proposed algorithm reduces 20 % total memory with less than 1 % performance overhead compared with the previous single appearance schedule algorithms for CD2DAT and non uniform filter bank applications