The Community for Technology Leaders
2010 19th International Conference on Parallel Architectures and Compilation Techniques (PACT) (2010)
Vienna, Austria
Sept. 11, 2010 to Sept. 15, 2010
ISBN: 978-1-5090-5032-1
pp: 513-522
I-Jui Sung , Center for Reliable and High-Performance Computing, University of Illinois at Urbana-Champaign, USA
John A. Stratton , Center for Reliable and High-Performance Computing, University of Illinois at Urbana-Champaign, USA
Wen-Mei W. Hwu , Center for Reliable and High-Performance Computing, University of Illinois at Urbana-Champaign, USA
ABSTRACT
We present automatic data layout transformation as an effective compiler performance optimization for memory-bound structured grid applications. Structured grid applications include stencil codes and other code structures using a dense, regular grid as the primary data structure. Fluid dynamics and heat distribution, which both solve partial differential equations on a discretized representation of space, are representative of many important structured grid applications. Using the information available through variable-length array syntax, standardized in C99 and other modern languages, we have enabled automatic data layout transformations for structured grid codes with dynamically allocated arrays. We also present how a tool can guide these transformations to statically choose a good layout given a model of the memory system, using a modern GPU as an example. A transformed layout that distributes concurrent memory requests among parallel memory system components provides substantial speedup for structured grid applications by improving their achieved memory-level parallelism. Even with the overhead of more complex address calculations, we observe up to 560% performance increases over the language-defined layout, and a 7% performance gain in the worst case, in which the language-defined layout and access pattern is already well-vectorizable by the underlying hardware.
INDEX TERMS
Data layout transformation, GPU, Parallel programming
CITATION
I-Jui Sung, John A. Stratton, Wen-Mei W. Hwu, "Data layout transformation exploiting memory-level parallelism in structured grid many-core applications", 2010 19th International Conference on Parallel Architectures and Compilation Techniques (PACT), vol. 00, no. , pp. 513-522, 2010, doi:
159 ms
(Ver 3.3 (11022016))