%0 Generic
%D 2022
%T Analysis of the Communication and Computation Cost of FFT Libraries towards Exascale
%A Alan Ayala
%A Stanimire Tomov
%A Piotr Luszczek
%A Sebastien Cayrols
%A Gerald Ragghianti
%A Jack Dongarra
%B ICL Technical Report
%I Innovative Computing Laboratory
%8 2022-07
%G eng
%0 Generic
%D 2022
%T Communication Avoiding LU with Tournament Pivoting in SLATE
%A Rabab Alomairy
%A Mark Gates
%A Sebastien Cayrols
%A Dalal Sukkari
%A Kadir Akbudak
%A Asim YarKhan
%A Paul Bagwell
%A Jack Dongarra
%B SLATE Working Notes
%8 2022-01
%G eng
%0 Generic
%D 2022
%T FFT Benchmark Performance Experiments on Systems Targeting Exascale
%A Alan Ayala
%A Stanimire Tomov
%A Piotr Luszczek
%A Sebastien Cayrols
%A Gerald Ragghianti
%A Jack Dongarra
%B ICL Technical Report
%8 2022-03
%G eng
%0 Generic
%D 2022
%T Mixed precision and approximate 3D FFTs: Speed for accuracy trade-off with GPU-aware MPI and run-time data compression
%A Sebastien Cayrols
%A Jiali Li
%A George Bosilca
%A Stanimire Tomov
%A Alan Ayala
%A Jack Dongarra
%K All-to-all
%K Approximate FFTs
%K ECP
%K heFFTe
%K Lossy compression
%K mixed-precision algorithms
%K MPI
%B ICL Technical Report
%8 2022-05
%G eng
%0 Generic
%D 2022
%T PAQR: Pivoting Avoiding QR factorization
%A Wissam M. Sid-Lakhdar
%A Sebastien Cayrols
%A Daniel Bielich
%A Ahmad Abdelfattah
%A Piotr Luszczek
%A Mark Gates
%A Stanimire Tomov
%A Hans Johansen
%A David Williams-Young
%A Timothy A. Davis
%A Jack Dongarra
%X The solution of linear least-squares problems is at the heart of many scientific and engineering applications. While any method able to minimize the backward error of such problems is considered numerically stable, the theory states that the forward error depends on the condition number of the matrix in the system of equations. On the one hand, the QR factorization is an efficient method to solve such problems, but the solutions it produces may have large forward errors when the matrix is deficient. On the other hand, QR with column pivoting (QRCP) is able to produce smaller forward errors on deficient matrices, but its cost is prohibitive compared to QR. The aim of this paper is to propose PAQR, an alternative solution method with the same cost (or smaller) as QR and as accurate as QRCP in practical cases, for the solution of rank-deficient linear least-squares problems. After presenting the algorithm and its implementations on different architectures, we compare its accuracy and performance results on a variety of application problems.
%B ICL Technical Report
%8 2022-06
%G eng
%0 Generic
%D 2021
%T SLATE Performance Improvements: QR and Eigenvalues
%A Kadir Akbudak
%A Paul Bagwell
%A Sebastien Cayrols
%A Mark Gates
%A Dalal Sukkari
%A Asim YarKhan
%A Jack Dongarra
%B SLATE Working Notes
%8 2021-04
%G eng