Parameterized Looped Schedules for Compact Representationof Execution Sequences

This paper is concerned with the compact representation of execution sequences in terms of efficient looping constructs. Here, by a looping construct, we mean a compact way of specifying a finite repetition of a set of execution primitives. Such compaction, which can be viewed as a form of hierarchical run-length encoding (RLE), has application in many DSP system synthesis contexts, including efficient control generation for Kahn processes on FPGAs, and software synthesis for static dataflow models of computation. In this paper, we significantly generalize previous models for loop-based code compaction of DSP programs to yield a configurable code compression methodology that exhibits a broad range of achievable trade-offs. Specifically, we formally develop and apply to DSP hardware and software implementation a parameterizable loop scheduling approach with compact format, dynamic reconfigurability, and low-overhead decompression. In our experiments, this new approach demonstrates up to 99% storage saving (versus RLE) and up to 46% frequency enhancement (versus another parameterized approach) in FPGA synthesis, and an average of 11% code size reduction in software synthesis compared to existing methods for code size reduction.