DLA-Future Fortran Interface

Fortran interface for DLA-Future, a task-based linear algebra library providing GPU-enabled distributed eigensolver.

Fortran API

The DLA-Future Fortran API provides the following functionality:

• DLA-Future and pika initialization/finalization: dlaf_initialize/dlaf_finalize
• Distributed grid creation/destruction: dlaf_create_grid_from_blacs/dlaf_free_grid
• Cholesky decomposition: dlaf_pXpotrf (X=s,d,c,z)
• Eigensolver for symmetric matrices: dlaf_pXsyevd (X=s,d)
• Eigensolver for hermitian matrices: dlaf_pXheevd (X=c,z)
• Generalised eigensolver for symmetric matrices: dlaf_pXsygvx (X=s,d)
• Generalised eigensolver for hermitian matrices: dlaf_pXhegvx (X=c,z)

ScaLAPACK Drop-In

The Fortran API (as well as the ScaLAPACK-like C API) is designed as drop-in replacement for ScaLAPACK.

If you have a ScaLAPACK call in your code

call pzheevd(&
    'V', 'L', n, &
    a, 1, 1, desca, &
    w, z, 1, 1, descz, &
    work, lwork, rwork, lrwork, iwork, liwork, info &
)

you can easily use DLA-Future as a drop-in replacement as follows (given a BLACS context ictxt):

call dlaf_initialize()
call dlaf_create_grid_from_blacs(ictxt)
! ...
call dlaf_pzheevd(&
    'L', n, &
    a, 1, 1, desca, &
    w, z, 1, 1, descz, &
    info &
)
! ...
call dlaf_free_grid(ictxt)
call dlaf_finalize()

Acknowledgements

The development of DLA-Future-Fortran is supported by the following organizations:

• CSCS: Swiss National Supercomputing Center
• ETH Zurich: Swiss Federal Institute of Technology Zurich
• PASC: Platform for Advanced Scientific Computing