NAME

       iparam2stage - iparam2stage: sets parameters for 2-stage eig

SYNOPSIS

   Functions
       integer function iparam2stage (ispec, name, opts, ni, nbi, ibi, nxi)
           IPARAM2STAGE

Detailed Description

Function Documentation

   integer function iparam2stage (integer ispec, character*( * ) name, character*( * ) opts,
       integer ni, integer nbi, integer ibi, integer nxi)
       IPARAM2STAGE

       Purpose:

                 This program sets problem and machine dependent parameters
                 useful for xHETRD_2STAGE, xHETRD_HE2HB, xHETRD_HB2ST,
                 xGEBRD_2STAGE, xGEBRD_GE2GB, xGEBRD_GB2BD
                 and related subroutines for eigenvalue problems.
                 It is called whenever ILAENV is called with 17 <= ISPEC <= 21.
                 It is called whenever ILAENV2STAGE is called with 1 <= ISPEC <= 5
                 with a direct conversion ISPEC + 16.

       Parameters
           ISPEC

                     ISPEC is integer scalar
                         ISPEC specifies which tunable parameter IPARAM2STAGE should
                         return.

                         ISPEC=17: the optimal blocksize nb for the reduction to
                                   BAND

                         ISPEC=18: the optimal blocksize ib for the eigenvectors
                                   singular vectors update routine

                         ISPEC=19: The length of the array that store the Housholder
                                   representation for the second stage
                                   Band to Tridiagonal or Bidiagonal

                         ISPEC=20: The workspace needed for the routine in input.

                         ISPEC=21: For future release.

           NAME

                     NAME is character string
                          Name of the calling subroutine

           OPTS

                     OPTS is CHARACTER*(*)
                     The character options to the subroutine NAME, concatenated
                     into a single character string.  For example, UPLO = 'U',
                     TRANS = 'T', and DIAG = 'N' for a triangular routine would
                     be specified as OPTS = 'UTN'.

           NI

                     NI is INTEGER which is the size of the matrix

           NBI

                     NBI is INTEGER which is the used in the reduction,
                     (e.g., the size of the band), needed to compute workspace
                     and LHOUS2.

           IBI

                     IBI is INTEGER which represent the IB of the reduction,
                     needed to compute workspace and LHOUS2.

           NXI

                     NXI is INTEGER needed in the future release.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             Implemented by Azzam Haidar.

             All detail are available on technical report, SC11, SC13 papers.

             Azzam Haidar, Hatem Ltaief, and Jack Dongarra.
             Parallel reduction to condensed forms for symmetric eigenvalue problems
             using aggregated fine-grained and memory-aware kernels. In Proceedings
             of 2011 International Conference for High Performance Computing,
             Networking, Storage and Analysis (SC '11), New York, NY, USA,
             Article 8 , 11 pages.
             http://doi.acm.org/10.1145/2063384.2063394

             A. Haidar, J. Kurzak, P. Luszczek, 2013.
             An improved parallel singular value algorithm and its implementation
             for multicore hardware, In Proceedings of 2013 International Conference
             for High Performance Computing, Networking, Storage and Analysis (SC '13).
             Denver, Colorado, USA, 2013.
             Article 90, 12 pages.
             http://doi.acm.org/10.1145/2503210.2503292

             A. Haidar, R. Solca, S. Tomov, T. Schulthess and J. Dongarra.
             A novel hybrid CPU-GPU generalized eigensolver for electronic structure
             calculations based on fine-grained memory aware tasks.
             International Journal of High Performance Computing Applications.
             Volume 28 Issue 2, Pages 196-209, May 2014.
             http://hpc.sagepub.com/content/28/2/196

Author

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