Decoupled iteration mapping: improving dependency-loop performance on SIMD processors

Abstract

Wide Single Instruction Multiple Data (SIMD) architectures are very important in the compute-intensive applications, but less efficient for applications with cross-iteration dependency loops which are difficult to parallelize and vectorize. This paper introduces Decoupled Iteration Mapping (DIM), a technique that dynamically maps a cross-iteration dependency loop onto the improved SIMD architecture which achieved multicore-like threadparallel performance.