2LEV-D2P4: a package of high-performance preconditioners for scientific and engineering applications

We present a package of parallel preconditioners which implements one-level and two-level Domain Decomposition algorithms on the top of the PSBLAS library for sparse matrix computations. The package, named 2LEV-D2P4 (Two-LEVel Domain Decomposition Parallel Preconditioners Package based on PSBLAS), currently includes various versions of additive Schwarz preconditioners that are combined with a coarse-level correction to obtain two-level preconditioners. A pure algebraic formulation of the preconditioners is considered. 2LEV-D2P4 has been written in Fortran 95, exploiting features such as abstract data type creation, functional overloading and dynamic memory management, while providing a smooth path towards the integration in legacy application codes. The package, used with Krylov solvers implemented in PSBLAS, has been tested on large-scale linear systems arising from model problems and real applications, showing its effectiveness