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48

Alfredo Buttari


I am currently a CNRS (Centre National de la Recherche Scientifique) researcher at the IRIT (Institut de Recherche en Informatique de Toulouse) laboratory in Toulouse (France) where I am a member of the APO (Algorithmes Parallèles et Optimisation). My interest are in High Performance Computing, parallel computing, computational linear algebra (numerical software in general). Here is my CV and a short bio:

  • since 2008: CNRS researcher @ IRIT
  • 2018: Habilitation à Diriger des Recherches (manuscript, presentation).
  • 2008: post-doc at INRIA Rhone-Alpes in Lyon (France) where I was a member of the Laboratoire de l'Informatique du Parallelisme (LIP).
  • 2006-2007: post-doc in the Innovative Computing Laboratory (ICL) lead by Prof. Jack Dongarra at the University of Tennessee Knoxville.
  • 2003-2006 Ph.D. at Dipartimento Informatica Sistemi e Produzione of University of Rome "Tor Vergata". (manuscript)

 


Journal articles23 documents

  • Patrick Amestoy, Alfredo Buttari, Jean-Yves l'Excellent, Theo Mary. Bridging the gap between flat and hierarchical low-rank matrix formats: the multilevel BLR format. SIAM Journal on Scientific Computing, Society for Industrial and Applied Mathematics, 2019, 41 (3), pp.A1414-A1442. ⟨10.1137/18M1182760⟩. ⟨hal-01774642v3⟩
  • Alfredo Buttari, Dominique Orban, Daniel Ruiz, David Titley-Peloquin. A Tridiagonalization Method for Symmetric Saddle-Point Systems. SIAM Journal on Scientific Computing, Society for Industrial and Applied Mathematics, 2019, 41 (5), pp.S409-S432. ⟨10.1137/18M1194900⟩. ⟨hal-02343661⟩
  • Patrick Amestoy, Alfredo Buttari, Jean-Yves l'Excellent, Théo Mary. Performance and Scalability of the Block Low-Rank Multifrontal Factorization on Multicore Architectures. ACM Transactions on Mathematical Software, Association for Computing Machinery, 2019, 45 (1), pp.1-23. ⟨10.1145/3242094⟩. ⟨hal-01955766v2⟩
  • Daniil Shantsev, Piyoosh Jaysaval, Sébastien de la Kethulle de Ryhove, Patrick R. Amestoy, Alfredo Buttari, et al.. Large-scale 3D EM modeling with a Block Low-Rank multifrontal direct solver. Geophysical Journal International, Oxford University Press (OUP), 2017, 209 (3), pp.1558-1571. ⟨10.1093/gji/ggx106⟩. ⟨hal-01672952⟩
  • Alfredo Buttari, Jack Dongarra, Julie Langou, Julien Langou, Piotr Luszczek, et al.. Mixed Precision Iterative Refinement Techniques for the Solution of Dense Linear Systems. International Journal of High Performance Computing Applications, SAGE Publications, 2016, 21 (4), pp.457-466. ⟨10.1177/1094342007084026⟩. ⟨hal-02421121⟩
  • Alfredo Buttari, Victor Eijkhout, Julien Langou, Salvatore Filippone. Performance Optimization and Modeling of Blocked Sparse Kernels. International Journal of High Performance Computing Applications, SAGE Publications, 2016, 21 (4), pp.467-484. ⟨10.1177/1094342007083801⟩. ⟨hal-02421133⟩
  • Emmanuel Agullo, Patrick Amestoy, Alfredo Buttari, Abdou Guermouche, Jean-Yves l'Excellent, et al.. Robust memory-aware mappings for parallel multifrontal factorizations. SIAM Journal on Scientific Computing, Society for Industrial and Applied Mathematics, 2016, 38 (3), pp.23. ⟨hal-01334113v2⟩
  • Patrick Amestoy, Alfredo Buttari, Jean-Yves l'Excellent, Théo Mary. On the Complexity of the Block Low-Rank Multifrontal Factorization. SIAM Journal on Scientific Computing, Society for Industrial and Applied Mathematics, 2016, 39 (4), pp.34. ⟨10.1137/16M1077192⟩. ⟨hal-01322230v3⟩
  • Emmanuel Agullo, Alfredo Buttari, Abdou Guermouche, Florent Lopez. Implementing multifrontal sparse solvers for multicore architectures with Sequential Task Flow runtime systems. ACM Transactions on Mathematical Software, Association for Computing Machinery, 2016, ⟨10.1145/2898348⟩. ⟨hal-01333645⟩
  • Patrick R. Amestoy, Romain Brossier, Alfredo Buttari, Jean-Yves l'Excellent, Théo Mary, et al.. Fast 3D frequency-domain full waveform inversion with a parallel Block Low-Rank multifrontal direct solver: application to OBC data from the North Sea. Geophysics, Society of Exploration Geophysicists, 2016, 81 (6), pp.R363-R383. ⟨10.1190/geo2016-0052.1⟩. ⟨hal-01349119⟩
  • Patrick R. Amestoy, Cleve Ashcraft, Olivier Boiteau, Alfredo Buttari, Jean-Yves l'Excellent, et al.. Improving Multifrontal Methods by Means of Block Low-Rank Representations. SIAM Journal on Scientific Computing, Society for Industrial and Applied Mathematics, 2015, 37 (3), pp.A1451-A1474. ⟨10.1137/120903476⟩. ⟨hal-01237169⟩
  • Patrick Amestoy, Alfredo Buttari, Guillaume Joslin, Jean-Yves l'Excellent, Mohamed Sid-Lakhdar, et al.. Shared memory parallelism and low-rank approximation techniques applied to direct solvers in FEM simulation. IEEE Transactions on Magnetics, Institute of Electrical and Electronics Engineers, 2014, vol. 50 (n° 2), pp. 1-4. ⟨10.1109/TMAG.2013.2284024⟩. ⟨hal-01123557⟩
  • Laurent Bouchet, Patrick Amestoy, Alfredo Buttari, François-Henry Rouet, Maxime Chauvin. Simultaneous analysis of large INTEGRAL/SPI datasets: optimizing the computation of the solution and its variance using sparse matrix algorithms. Astronomy and Computing, Elsevier 2013, vol. 1, pp. 59-69. ⟨10.1016/j.ascom.2013.03.002⟩. ⟨hal-01125193⟩
  • Alfredo Buttari. Fine-Grained Multithreading for the Multifrontal QR Factorization of Sparse Matrices. SIAM Journal on Scientific Computing, Society for Industrial and Applied Mathematics, 2013, vol. 35 (n° 4), pp. 323-345. ⟨10.1137/110846427⟩. ⟨hal-01122471⟩
  • Laurent Bouchet, Patrick Amestoy, Alfredo Buttari, François-Henry Rouet, Maxime Chauvin. INTEGRAL/SPI data segmentation to retrieve sources intensity variations. Astronomy and Astrophysics - A&A, EDP Sciences, 2013, vol. 555 (n° A55), pp. 1-22. ⟨10.1051/0004-6361/201219605⟩. ⟨hal-01124774⟩
  • Salvatore Filippone, Alfredo Buttari. Object-Oriented Techniques for Sparse Matrix Computations in Fortran 2003. ACM Transactions on Mathematical Software, Association for Computing Machinery, 2012, 38 (4), pp.1-20. ⟨10.1145/2331130.2331131⟩. ⟨hal-02419121⟩
  • Alfredo Buttari, Julien Langou, Jakub Kurzak, Jack Dongarra. A class of parallel tiled linear algebra algorithms for multicore architectures. Parallel Computing, Elsevier, 2009, 35 (1), pp.38-53. ⟨10.1016/j.parco.2008.10.002⟩. ⟨hal-02420965⟩
  • Marc Baboulin, Alfredo Buttari, Jack Dongarra, Jakub Kurzak, Julie Langou, et al.. Accelerating scientific computations with mixed precision algorithms. Computer Physics Communications, Elsevier, 2009, 180 (12), pp.2526-2533. ⟨10.1016/j.cpc.2008.11.005⟩. ⟨hal-02420940⟩
  • Jakub Kurzak, Alfredo Buttari, Piotr Luszczek, Jack Dongarra. The PlayStation 3 for High-Performance Scientific Computing. Computing in Science & Engineering, IEEE, 2008, 10 (3), pp.84-87. ⟨10.1109/MCSE.2008.85⟩. ⟨hal-02421063⟩
  • Jakub Kurzak, Alfredo Buttari, Jack Dongarra. Solving Systems of Linear Equations on the CELL Processor Using Cholesky Factorization. IEEE Transactions on Parallel and Distributed Systems, Institute of Electrical and Electronics Engineers, 2008, 19 (9), pp.1175-1186. ⟨10.1109/TPDS.2007.70813⟩. ⟨hal-02421046⟩
  • Alfredo Buttari, Julien Langou, Jakub Kurzak, Jack Dongarra. Parallel tiled QR factorization for multicore architectures. Concurrency and Computation: Practice and Experience, Wiley, 2008, 20 (13), ⟨10.1002/cpe.v20:13⟩. ⟨hal-02421078⟩
  • Alfredo Buttari, Jack Dongarra, Jakub Kurzak, Piotr Luszczek, Stanimir Tomov. Using Mixed Precision for Sparse Matrix Computations to Enhance the Performance while Achieving 64-bit Accuracy. ACM Transactions on Mathematical Software, Association for Computing Machinery, 2008, 34 (4), pp.1-22. ⟨10.1145/1377596.1377597⟩. ⟨hal-02421028⟩
  • Alfredo Buttari, Pasqua D’ambra, Daniela Di Serafino, Salvatore Filippone. 2LEV-D2P4: a package of high-performance preconditioners for scientific and engineering applications. Applicable Algebra in Engineering, Communication and Computing, Springer Verlag, 2007, 18 (3), pp.223-239. ⟨10.1007/s00200-007-0035-z⟩. ⟨hal-02421066⟩

Conference papers16 documents

  • Emmanuel Agullo, Alfredo Buttari, Abdou Guermouche, Arnaud Legrand, Ian Masliah, et al.. Simulation of a Sparse Direct Solver on Heterogeneous Systems using Starpu and Simgrid. CSE 2019 - SIAM Conference on Computational Science and Engineering, Feb 2019, Spokane, United States. ⟨hal-02073725⟩
  • Gabriel Hautreux, Alfredo Buttari, Arnaud Beck, Victor Cameo, Dimitri Lecas, et al.. Pre-exascale Architectures: OpenPOWER Performance and Usability Assessment for French Scientific Community. ISC High Performance 2017: High Performance Computing, Jun 2017, Frankfurt, Germany. pp.309-324, ⟨10.1007/978-3-319-67630-2_23⟩. ⟨hal-02129651⟩
  • Emmanuel Agullo, George Bosilca, Alfredo Buttari, Abdou Guermouche, Florent Lopez. Exploiting a Parametrized Task Graph model for the parallelization of a sparse direct multifrontal solver. Euro-Par 2016: Parallel Processing Workshops, Aug 2016, Grenoble, France. ⟨10.1007/978-3-319-58943-5_14⟩. ⟨hal-01337748⟩
  • Patrick R. Amestoy, Romain Brossier, Alfredo Buttari, Jean-Yves l'Excellent, Théo Mary, et al.. Efficient 3D frequency-domain full-waveform inversion of ocean-bottom cable data with sparse block low-rank direct solver: a real data case study from the North Sea. SEG Annual meeting, Oct 2015, New Orleans, United States. pp.1303-1308, ⟨10.1190/segam2015-5713962.1⟩. ⟨hal-01239896⟩
  • Patrick R. Amestoy, Romain Brossier, Alfredo Buttari, Jean-Yves l'Excellent, Théo Mary, et al.. 3D frequency-domain seismic modeling with a Parallel BLR multifrontal direct solver. SEG Annual meeting, Oct 2015, New Orleans, United States. pp.3606-3611. ⟨hal-01237869⟩
  • Emmanuel Agullo, Alfredo Buttari, Abdou Guermouche, Florent Lopez. Task-based multifrontal QR solver for GPU-accelerated multicore architectures. IEEE International Conference on High Performance Computing (HiPC 2015), Dec 2015, Bangalore, India. ⟨hal-01270145⟩
  • Luka Stanisic, Emmanuel Agullo, Alfredo Buttari, Abdou Guermouche, Arnaud Legrand, et al.. Fast and Accurate Simulation of Multithreaded Sparse Linear Algebra Solvers. The 21st IEEE International Conference on Parallel and Distributed Systems, Dec 2015, Melbourne, Australia. ⟨hal-01180272v2⟩
  • Emmanuel Agullo, Alfredo Buttari, Abdou Guermouche, Florent Lopez. Multifrontal QR Factorization for Multicore Architectures over Runtime Systems. 19th International Conference Euro-Par (EuroPar 2013), Aug 2013, Aachen, Germany. pp. 521-532. ⟨hal-01220611⟩
  • Clement Weisbecker, Patrick Amestoy, Olivier Boiteau, Romain Brossier, Alfredo Buttari, et al.. 3D frequency-domain seismic modeling with a Block Low-Rank algebraic multifrontal direct solver. SEG Technical Program Expanded Abstracts, SEG annual meeting, Houston, TX, USA, 2013, Houston, Texas, United States. ⟨10.1190/segam2013-0603.1⟩. ⟨hal-00924638⟩
  • Patrick Amestoy, Olivier Boiteau, Alfredo Buttari, Guillaume Joslin, Jean-Yves l'Excellent, et al.. Shared memory parallelism and low-rank approximation techniques applied to direct solvers in FEM simulation (regular paper). IEEE International Conference on the Computation of Electromagnetic Fields (COMPUMAG), 2013, Budapest, Hungary. ⟨hal-00924660⟩
  • Emmanuel Agullo, Patrick R. Amestoy, Alfredo Buttari, Abdou Guermouche, Guillaume Joslin, et al.. Recent advances in sparse direct solvers. SMiRT 2013 - 22nd International Conference on Structural Mechanics in Reactor Technology, Aug 2013, San Francisco, United States. pp.1-10. ⟨hal-01060301⟩
  • Patrick Amestoy, Cleve Ashcraft, Olivier Boiteau, Alfredo Buttari, Jean-Yves l'Excellent, et al.. Improving Multifrontal methods by means of Low-Rank Approximations techniques. SIAM Conference on Applied Linear Algebra, Jun 2012, Valencia, Spain. ⟨hal-00789684⟩
  • Patrick Amestoy, Alfredo Buttari, Abdou Guermouche, Jean-Yves l'Excellent, Mohamed W. Sid-Lakhdar. Exploiting Multithreaded Tree Parallelism for Multicore Systems in a Parallel Multifrontal Solver. SIAM Conference on Parallel Processing for Scientific Computing (SIAM PP12), Feb 2012, Savannah, GA, United States. ⟨hal-00789698⟩
  • François-Henry Rouet, Emmanuel Agullo, Patrick R. Amestoy, Alfredo Buttari, Abdou Guermouche, et al.. Robust Memory-Aware Mappings for Parallel Multifrontal Factorizations. SIAM Conference on Parallel Processing for Scientific Computing (SIAM PP 2012), Feb 2012, Savannah, Georgia, United States. ⟨hal-00726644⟩
  • Clement Weisbecker, Patrick Amestoy, Cleve Ashcraft, Olivier Boiteau, Alfredo Buttari, et al.. Grouping variables in Frontal Matrices to improve Low-Rank Approximations in a Multifrontal Solver. International Conference On Preconditioning Techniques For Scientific And Industrial Applications, Preconditioning 2011, May 2011, Bordeaux, France. ⟨inria-00581561⟩
  • Pasqua d'Ambra, Alfredo Buttari, Daniela Di Serafino, Salvatore Filippone, Simone Gentile, et al.. A Novel Aggregation Method based on Graph Matching for Algebraic MultiGrid Preconditioning of Sparse Linear Systems. International Conference On Preconditioning Techniques For Scientific And Industrial Applications, Preconditioning 2011, May 2011, Bordeaux, France. ⟨inria-00580434⟩

Book sections3 documents

  • Patrick Amestoy, Alfredo Buttari, Abdou Guermouche, Jean-Yves l'Excellent, Bora Uçar. The minimum degree ordering with dynamical constraints. M. Beckers and J. Lotz and V. Mosenkis and U. Naumann. Abstracts of the 5th SIAM Workshop on Combinatorial Scientific Computing, SIAM, pp.36-38, 2011, Technical Report. ⟨hal-00945083⟩
  • Patrick Amestoy, Alfredo Buttari, Iain S. Duff, Abdou Guermouche, Jean-Yves l'Excellent, et al.. The Multifrontal Method. David Padua. Encyclopedia of Parallel Computing, Springer, pp.1209-1216, 2011. ⟨hal-00787015⟩
  • Patrick Amestoy, Alfredo Buttari, Iain S. Duff, Abdou Guermouche, Jean-Yves l'Excellent, et al.. MUMPS. David Padua. Encyclopedia of Parallel Computing, Springer, pp.1232-1238, 2011, ⟨10.1007/978-0-387-09766-4_204⟩. ⟨hal-00787042⟩

Preprints, Working Papers, ...1 document

  • Alfredo Buttari, Markus Huber, Philippe Leleux, Théo Mary, Ulrich Ruede, et al.. Block Low Rank Single Precision Coarse Grid Solvers for Extreme Scale Multigrid Methods. 2020. ⟨hal-02528532⟩

Reports4 documents

  • Alfredo Buttari, Søren Hauberg, Costy Kodsi. Parallel QR factorization of block-tridiagonal matrices. [Research Report] IRIT - Institut de recherche en informatique de Toulouse. 2019. ⟨hal-02370953⟩
  • Emmanuel Agullo, Alfredo Buttari, Mikko Byckling, Abdou Guermouche, Ian Masliah. Achieving high-performance with a sparse direct solver on Intel KNL. [Research Report] RR-9035, Inria Bordeaux Sud-Ouest; CNRS-IRIT; Intel corporation; Université Bordeaux. 2017, pp.15. ⟨hal-01473475⟩
  • Emmanuel Agullo, Alfredo Buttari, Abdou Guermouche, Florent Lopez. Task-based multifrontal QR solver for GPU-accelerated multicore architectures. [Research Report] IRI/RT--2015--02--FR-r1, IRIT, Toulouse. 2015. ⟨hal-01166312v2⟩
  • Patrick Amestoy, Cleve Ashcraft, Olivier Boiteau, Alfredo Buttari, Jean-Yves l'Excellent, et al.. Improving multifrontal methods by means of block low-rank representations. [Research Report] RR-8199, INRIA. 2013. ⟨hal-00776859⟩

Habilitation à diriger des recherches1 document

  • Alfredo Buttari. Scalability of parallel sparse direct solvers: methods, memory and performance. Distributed, Parallel, and Cluster Computing [cs.DC]. Toulouse INP, 2018. ⟨tel-01913033⟩