Short vector code generation and adaptation for DSP algorithms

Most recent general purpose processors feature short vector SIMD instructions, like SSE on Pentium III/4. In this paper we automatically generate platform-adapted short vector code for DSP transform algorithms using SPIRAL. SPIRAL represents and generates fast algorithms as mathematical formulas, and translates them into code. Adaptation is achieved by searching in the space of algorithmic and coding alternatives for the fastest implementation on the given platform. We explain the mathematical foundation that relates formula constructs to vector code, and overview the vector code generator within SPIRAL. Experimental results show excellent speed-ups compared to ordinary C code for a variety of transforms and computing platforms. For the DFT on Pentium 4, our automatically generated code compares favorably with the handtuned Intel MKL vendor library.