With the emergence of multicore processors and hardware accelerators, polyhedral compilation techniques have gained a lot of attention in both academia and industry, as a way to design effective loop nest optimization frameworks for high performance. This workshop provides a high-quality forum for researchers and practitioners working on analysis, transformations, and optimizations using the polyhedral model to exchange and debate ideas and visions. This is the second edition of IMPACT, and is being organized in conjunction with HiPEAC 2012 in Paris, France as a full-day workshop.

We welcome both theoretical and experimental papers on all aspects of polyhedral compilation and optimization. We strongly encourage submissions describing early results, works in progress, wild ideas, available tools, position papers, and experience reports, with an aim to stimulate discussions, collaborations, and advances in the field. Topics of interest include but are not limited to:

• Polyhedral Compilation Flow
• Automatic Parallelization and Optimization
• Static Analysis
• Theoretical Foundations of the Polyhedral Model
• Robustness and Scalability of Polyhedral Techniques
• Extensions to the Polyhedral Model
• Hybrid Static-cum-Runtime Parallelization Techniques
• Hardware Synthesis
• Program Verification
• Model Checking
• Tool Demonstration

Call for papers (PDF)

Submissions

Submissions should not exceed 8 pages (recommended 6 pages) formatted as per ACM proceedings format. Please use the following template when preparing your manuscript: http://www.acm.org/sigs/publications/proceedings-templates
Submissions should be in PDF format and printable on US letter or A4 sized paper. Please send your submission by the deadline to:
impact-chairs@lists.gforge.inria.fr
Proceedings will be published online on the conference website. Publication at IMPACT will not prevent later publication of extended papers.

Important Dates

Submission deadline	Nov 14 Nov. 21, 2011
Notification of decision	Dec 14 Dec. 21, 2011
Final version due	Dec 29, 2011
Workshop	Jan 23, 2012

Program

Keynote (10am)

Session chair: Vincent Loechner



• « Here, There Be Dragons: Beyond the Polyhedral Model »
  Keshav Pingali (University of Texas, Austin, USA)
  [abstract]
  



Short break (11:00 - 11:30am)


Session I: Theory and Techniques (11:30am)

Session Chair: Armin Größlinger



• Approximating the Transitive Closure of a Boolean-Affine Relation
  Paul Feautrier
  [paper] [slides]


• A Case for Strongly Polynomial Time Sub-Polyhedral Scheduling Using Two-Variable-Per-Inequality Polyhedra
  Ramakrishna Upadrasta, Albert Cohen
  [paper] [slides]


• Dealing with Arithmetic Overflows in the Polyhedral Model
  Bruno Cuervo Parrino, Julien Narboux, Eric Violard, Nicolas Magaud
  [paper] [slides]



Lunch break (1:00 - 2:30pm)


Session II: Optimization and Parallelization (2:30pm)

Session Chair: Uday Bondhugula



• Optimizing Remote Accesses for Offloaded Kernels: Application to High-Level Synthesis for FPGA
  Christophe Alias, Alain Darte, Alexandru Plesco
  [paper] [slides]


• Trading Off Memory For Parallelism Quality
  Nicolas Vasilache, Benoit Meister, Albert Hartono, Muthu Baskaran, David Wohlford, Richard Lethin
  [paper] [slides]


• Joint Scheduling and Layout Optimization to Enable Multi-Level Vectorization
  Nicolas Vasilache, Benoit Meister, Muthu Baskaran, Richard Lethin
  [paper] [slides of the previous presentation, second part]



Short break (4:00 - 4:30pm)


Session III: Tools and Libraries (4:30pm)

Session Chair: Cédric Bastoul



• ZPolyTrans: A library for computing and enumerating integer transformations of Z-Polyhedra [Tool demo]
  Rachid Seghir
  [paper] [slides] [demo (txt)] [direct link to ZPolyTrans]


• A Library to Manipulate Z-polyhedra in Image Representation [Tool demo]
  Guillaume Iooss, Sanjay Rajopadhye
  [paper] [slides] [AlphaZ | direct link to the lib]


• Polyhedral Extraction Tool [Tool demo]
  Sven Verdoolaege, Tobias Grosser
  [paper] [slides] [direct link to libpet]


• Par4All: From Convex Array Regions to Heterogeneous Computing [Tool demo]
  Mehdi Amini, Béatrice Creusillet, Stéphanie Even, Ronan Keryell, Onig Goubier, Serge Guelton, Janice Onanian McMahon, François Xavier Pasquier, Grégoire Péan, Pierre Villalon
  [paper] [slides] [direct link to Par4All]



End (6:00pm)

Location

The workshop is organized in conjunction with HiPEAC 2012, in one of the most attractive venues in Paris, the EuroSites George V.

Contact us

Please send any questions or comments to Uday Bondhugula and Vincent Loechner: impact-chairs@lists.gforge.inria.fr.