Linear analysis and optimization of stream programs

As more complex DSP algorithms are realized in practice, an increasing need for high-level stream abstractions that can be compiled without sacrificing efficiency. Toward this end, we present a set of aggressive optimizations that target linear sections of a stream program. Our input language is StreamIt, which represents programs as a hierarchical graph of autonomous filters. A filter is linear if each of its outputs can be represented as an affine combination of its inputs. Linearity is common in DSP components; examples include FIR filters, expanders, compressors, FFTs and DCTs. We demonstrate that several algorithmic transformations, traditionally hand-tuned by DSP experts, can be completely automated by the compiler. First, we present a linear extraction analysis that automatically detects linear filters from the C-like code in their work function. Then, we give a procedure for combining adjacent linear filters into a single filter, as well as for translating a linear fil...

• Type: Conference
• Year: 2003
• Where: PLDI
• Authors: Andrew A. Lamb, William Thies, Saman P. Amarasinghe
• Keywords: Linear, Linear filter, PLDI 2003, Programming Languages