Have a personal or library account? Click to login
Tiling arbitrarily nested loops by means of the transitive Cover
Open Access
|Dec 2016

Abstract

A novel approach to generation of tiled code for arbitrarily nested loops is presented. It is derived via a combination of the polyhedral and iteration space slicing frameworks. Instead of program transformations represented by a set of affine functions, one for each statement, it uses the transitive closure of a loop nest dependence graph to carry out corrections of original rectangular tiles so that all dependences of the original loop nest are preserved under the lexicographic order of target tiles. Parallel tiled code can be generated on the basis of valid serial tiled code by means of applying affine transformations or transitive closure using on input an inter-tile dependence graph whose vertices are represented by target tiles while edges connect dependent target tiles. We demonstrate how a relation describing such a graph can be formed. The main merit of the presented approach in comparison with the well-known ones is that it does not require full permutability of loops to generate both serial and parallel tiled codes; this increases the scope of loop nests to be tiled.

DOI: https://doi.org/10.1515/amcs-2016-0065 | Journal eISSN: 2083-8492 | Journal ISSN: 1641-876X
Language: English
Page range: 919 - 939
Submitted on: Nov 3, 2015
|
Accepted on: Aug 9, 2016
|
Published on: Dec 30, 2016
In partnership with: Paradigm Publishing Services
Publication frequency: 4 issues per year

© 2016 Włodzimierz Bielecki, Marek Pałkowski, published by University of Zielona Góra
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.