The IMPACT Research Group
Illinois Microarchitecture Project utilizing Advanced Compiler Technology
Sam S. Stone
224 Coordinated Science Laboratory
MC 228
1308 West Main Street
Urbana, IL 61801
Tel: (217) 244-0160
Fax: (217) 333-5579
Email: ssstone2 at crhc dot uiuc dot edu
Biography
B.S. Computer Engineering, Virginia Tech, December 2003
M.S., Electrical and Computer Engineering, University of Illinois, August 2007

After his freshman year at Virginia Tech, Sam was awarded the Harry Lynde Bradley Scholarship, a merit-based scholarship providing tuition and fees, room and board, and a stipend for the remainder of his undergraduate study. In 2005, Sam was awarded a three-year Graduate Research Fellowship by the National Science Foundation. He was also named the 2006-2007 Rambus Computer Engineering Fellow by the ECE Department at the University of Illinois.

For his M.S. thesis research, Sam investigated store-load forwarding in conventional superscalar processors. Leveraging the insight that store multi-versioning in the store queue incurs significant complexity but rarely increases performance, Sam proposed the forwarding cache, a low-energy, complexity-effective alternative to the store queue. The forwarding cache achieves the same performance as the store queue while dissipating 10X less energy. Sam's M.S. thesis research was advised by Dr. Matthew Frank.

As a member of the IMPACT research group, Sam plans to develop compiler analyses and tools for feedback-driven parallelization of data-parallel applications. Given source code that contains syntactic errors, modern compilers identify those errors with great specificity, typically displaying the file name and line number in which each error is found, along with a description of the error. This information allows the programmer to quickly understand and correct syntax errors. By contrast, given source code that exhibits little parallelism, the compiler behaves as a black box, providing little or no useful feedback to the programmer. Programmers are left to blindly restructure and re-execute their algorithms until the desired level of performance is observed. Sam proposes to develop compiler tools that will assist the programmer by providing useful information about the compiler's view of the parallelism in the program. He is currently studying the parallelism in medical imaging applications in an effort to understand what types of compiler-provided feedback would be useful to programmers of data-parallel applications.

Research Interests
  • Medical imaging applications
  • Feedback-driven parallelization of implicitly parallel programs
  • Energy-efficient store-load forwarding
Links
  • CV/Resume: Available upon request
Conference Publications
Accelerating Advanced MRI Reconstructions on GPUs [ PDF | PDF slides ]
Sam S. Stone, Justin P. Haldar, Stephanie C. Tsao, Wen-mei W. Hwu, Zhi-Pei Liang, and Bradley P. Sutton
(C) ACM, (2008). This is the author's version of the work. It is posted here by permission of the ACM for your personal use. Not for redistribution. The definitive version was published in Proceedings of the 5th International Conference on Computing Frontiers, May 5-7, 2008, http://doi.acm.org/10.1145/1366230.1366274
Program Optimization Space Pruning for a Multithreaded GPU
Shane Ryoo, Christopher I. Rodrigues, Sam S. Stone, Sara S. Baghsorkhi, Sain-Zee Ueng, John A. Stratton, and Wen-mei W. Hwu
In Proceedings of the 2008 International Symposium on Code Generation and Optimization, April 2008.
Optimization Principles and Application Performance Evaluation of a Multithreaded GPU Using CUDA
Shane Ryoo, Christopher I. Rodrigues, Sara S. Baghsorkhi, Sam S. Stone, David B. Kirk (NVIDIA), and Wen-mei W. Hwu
Proceedings of the 13th ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming, February 2008.
Implicit Parallel Programming Models for Thousand-Core Microprocessors
Wen-mei Hwu, Shane Ryoo, Sain-Zee Ueng, John H. Kelm, Isaac Gelado, Sam S. Stone, Robert E. Kidd, Sara S. Baghsorkhi, Aqeel A. Mahesri, Stephanie C. Tsao, Nacho Navarro, Steve S. Lumetta, Matthew I. Frank, and Sanjay J. Patel
Proceedings of the 44th Annual Design Automation Conference, June 2007.
Exploiting Postdominance for Speculative Parallelization
Mayank Agarwal, Kshitiz Malik, Kevin M. Woley, Sam S. Stone, and Matthew I. Frank
Proceedings of the 13th Annual International Symposium on High-Performance Computer Architecture (HPCA-13), February 2007.
Address-Indexed Memory Disambiguation and Store-Load Forwarding [ PDF ]
Sam S. Stone, Kevin M. Woley, and Matthew I. Frank
Proceedings of the 38th Annual International Symposium on Microarchitecture (MICRO-38), November 2005.
Crossover and Mutation in Genetic Algorithms Using Graph-Encoded Chromosomes
Sam Stone, Brian Pillmore, and Walling Cyre
Late-Breaking Papers of the Genetic and Evolutionary Computation Conference (GECCO), June 2004.
Refereed Workshop Publications
MCUDA: An Efficient Implementation of CUDA Kernels for Multi-Core CPUs
[PS | PDF]
John A. Stratton, Sam S. Stone and Wen-mei W. Hwu
To Appear in the 21st International Workshop on Languages and Compilers for Parallel Computing, LNCS.
How GPUs Can Improve the Quality of Magnetic Resonance Imaging
[ PDF | PDF slides ]
Sam S. Stone, Haoran Yi, Wen-mei W. Hwu, Justin P. Haldar, Bradley P. Sutton, and Zhi-Pei Liang
The First Workshop on General Purpose Processing on Graphics Processing Units (GPGPU), October 2007.
(c) ACM, (2008). This is the author's version of the work. It is posted here by permission of the ACM for your personal use. Not for redistribution. The definitive version was published under the title 'Accelerating Advanced MRI Reconstructions on GPUs' in Proceedings of the 5th International Conference on Computing Frontiers, May 5-7, 2008, http://doi.acm.org/10.1145/1366230.1366274
Program Optimization Study on a 128-Core GPU
[ PS | PDF | PDF slides ]
Shane Ryoo, Christopher I. Rodrigues, Sam S. Stone, Sara S. Baghsorkhi, Sain-Zee Ueng, and Wen-mei W. Hwu
The First Workshop on General Purpose Processing on Graphics Processing Units (GPGPU), October 2007.
Technical Reports and Theses
Multiversioning in the Store Queue is the Root of All Store-Forwarding Evil [ PDF ]
Sam S. Stone
University of Illinois at Urbana-Champaign, Department of Electrical and Computer Engineering, July 2007.
Synchronizing Store Sets: Balancing the Benefits and Risks of Inter-thread Speculation [ PDF ]
Sam S. Stone, Kevin M. Woley, Kshitiz Malik, Mayank Agarwal, Vikram Dhar, and Matthew I. Frank
University of Illinois at Urbana-Champaign Center for Reliable and High-Performance Computing Technical Report Number CRHC-06-14.
Confidence Based Out-of-Order Renaming for Speculatively Multithreaded Processors [ PDF ]
Kshitiz Malik, Kevin M. Woley, Sam S. Stone, Mayank Agarwal, Vikram Dhar, and Matthew I. Frank
University of Illinois at Urbana-Champaign Center for Reliable and High-Performance Computing Technical Report Number CRHC-ENG-06-2208.

Maintained by John Stratton (stratton at crhc dot uiuc dot edu)