Fast automatic software implementations of FIR filters

SPIRAL is a generator for platform-adapted libraries of DSP transform algorithms. SPIRAL represents and automatically generates fast algorithms as mathematical formulas and translates them into programs. Adaptation is achieved by searching in the space of algorithmic and coding alternatives for the fastest implementation. We extend SPIRAL to generate platform-adapted implementations of FIR filters. First, we present various filter algorithms and introduce the mathematical constructs needed to include them into SPIRAL´s architecture. Then we use SPIRAL to find fast filter implementations. The results show runtime improvements to a standard loop implementation of up to 70% using different blocking techniques. Further, we show that the usefulness of frequency-domain methods is not determined by the number of operations.