Tiling optimizations for stencil computations

This thesis studies the techniques of tiling optimizations for stencil programs. Traditionally, research on tiling optimizations mainly focuses on tessellating tiling, atomic tiles and regular tile shapes. This thesis studies several novel tiling techniques which are out of the scope of traditional research. In order to represent a general tiling scheme uniformly, a unified tiling representation framework is introduced. With the unified tiling representation, three tiling techniques are studied. The first tiling technique is Hierarchical Overlapped Tiling, based on the idea of reducing communication overhead by introducing redundant computations. Hierarchical Overlapped Tiling also applies the idea of hierarchical tiling to take advantage of hardware hierarchy, so that the additional overhead introduced by redundant computations can be minimized. The second tiling technique is called Conjugate-Trapezoid Tiling, which schedules the computations and communications within a tile in an interleaving way in order to overlap the computation time and communication latency. Conjugate-Trapezoid Tiling forms a pipeline of computations and communications, hence the communication latency can be hidden. Third, this thesis studies the tile shape selection problem for hierarchical tiling. It is concluded that optimal tile shape selection for hierarchical tiling is a multidimensional, nonlinear, bi-level programming problem. Experimental results show that the irregular tile shapes selected by solving the optimization problem have the potential to outperform intuitive tiling shapes.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Computer Science

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2013

Author dc:creator

• Zhou, Xing

Contributors dc:contributor

• Padua, David A.
• Garzaran, Maria J.
• Gropp, William D.
• Hwu, Wen-Mei W.
• Kuhn, Robert H.

• Optimization
• Tiling
• Stencil Computation

Statement dc:rights

• Copyright 2013 Xing Zhou

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/44340

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/44340