Loop parallelization algorithms: From parallelism extraction to code generation

Abstract

In this paper, we survey loop parallelization algorithms, analyzing the dependence representations they use, the loop transformations they generate, the code generation schemes they require, and their ability to incorporate various optimizing criteria such as maximal parallelism detection, permutable loop detection, minimization of synchronizations, easiness of code generation, etc. We complete the discussion by presenting new results related to code generation and loop fusion for a particular class of multidimensional schedules called shifted linear schedules. We demonstrate that algorithms based on such schedules lead to simple codes.