This directory contains the MLD2P4 set of preconditioners. developed by Salvatore Filippone Pasqua D'Ambra Daniela di Serafino Alfredo Buttari To compile: 0. Unpack the tar file in a directory of your choice (preferrably outside the main PSBLAS directory). 1. run configure --with-psblas= adding the options for SuperLU, SuperLU_Dist, UMFPACK as desired. 2. Tweak Make.inc if you are not satisfied. 3. make; 4. Go into the test subdirectory and build the examples of your choice. Notes: The single precision version is supported only by SuperLU; thus, even if you specify at configure to use UMFPACK or SuperLU_Dist, the corresponding preconditioner options will be available only from the double precision version.