An Efficient Code Generation Technique for Tiled Iteration Spaces

Goumas, G; Athanasaki, M; Koziris, N

dc.contributor.author	Goumas, G	en
dc.contributor.author	Athanasaki, M	en
dc.contributor.author	Koziris, N	en
dc.date.accessioned	2014-03-01T01:18:38Z
dc.date.available	2014-03-01T01:18:38Z
dc.date.issued	2003	en
dc.identifier.issn	1045-9219	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15119
dc.subject	Code generation	en
dc.subject	Fourier-Motzkin elimination	en
dc.subject	Loop tiling	en
dc.subject	Nonunimodular transformations	en
dc.subject	Supernodes	en
dc.subject.classification	Computer Science, Theory & Methods	en
dc.subject.classification	Engineering, Electrical & Electronic	en
dc.subject.other	Codes (symbols)	en
dc.subject.other	Computational complexity	en
dc.subject.other	Digital storage	en
dc.subject.other	Iterative methods	en
dc.subject.other	Mathematical transformations	en
dc.subject.other	Matrix algebra	en
dc.subject.other	Parallel processing systems	en
dc.subject.other	Code generation	en
dc.subject.other	Multilevel tiling	en
dc.subject.other	Program compilers	en
dc.title	An Efficient Code Generation Technique for Tiled Iteration Spaces	en
heal.type	journalArticle	en
heal.identifier.primary	10.1109/TPDS.2003.1239870	en
heal.identifier.secondary	http://dx.doi.org/10.1109/TPDS.2003.1239870	en
heal.language	English	en
heal.publicationDate	2003	en
heal.abstract	This paper presents a novel approach for the problem of generating tiled code for nested for-loops, transformed by a tiling transformation. Tiling or supernode transformation has been widely used to improve locality in multilevel memory hierarchies, as well as to efficiently execute loops onto parallel architectures. However, automatic code generation for tiled loops can be a very complex compiler work, especially when nonrectangular, tile shapes and iteration space bounds are concerned. Our method considerably enhances previous work on rewriting tiled loops: by considering parallelepiped tiles and arbitrary iteration space shapes. In order to generate tiled code, we first enumerate all tiles containing points within the iteration space and, second, sweep all points within each tile. For the first subproblem, we refine upon previous results concerning the computation of new loop bounds of an iteration space that has been transformed by a nonunimodular transformation. For the second subproblem, we transform the initial parallelepiped tile into a rectangular one, in order to generate efficient code with the aid of a nonunimodular transformation matrix and its Hermite Normal Form (HNF). Experimental results show that the proposed method significantly accelerates the compilation process and generates much more efficient code.	en
heal.publisher	IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC	en
heal.journalName	IEEE Transactions on Parallel and Distributed Systems	en
dc.identifier.doi	10.1109/TPDS.2003.1239870	en
dc.identifier.isi	ISI:000185984300006	en
dc.identifier.volume	14	en
dc.identifier.issue	10	en
dc.identifier.spage	1021	en
dc.identifier.epage	1034	en