1. 29 Mar, 2016 1 commit
  2. 18 Mar, 2016 2 commits
    • Andreas Marek's avatar
    • Andreas Marek's avatar
      Allow ELPA to be build with single and double precision symbols in one · 647aa5a8
      Andreas Marek authored
      library
      
      It the configure option "--enable-single-precision" is specified,
      ELPA will also be build for single precision usage. The double precision
      and single precision will be available at the same time with names
      "solve_evp_real_1stage_double" or "solve_evp_real_1stage_single" and
      so on...
      
      This change immplied some major refactoring of the ELPA code:
      1.) functions/procedures had to be renamed with suffix "_double"
      
      2.) If necessary the same functions have to be available with suffix
      "_single"
      
      3.) Variable kind definitions have to be consistent with the
      intented use
      
      To avoid uneccessary code duplication this is done (most of the time)
      with preprocessor string substitution.
      
      The documentation has been updated.
      
      NOT SUPPORTED are at the moment:
      
      - single precision usage of ELPA2 with kernels, others than "generic"
        and "generic_simple"
      
      - single precision usage of GPU
      647aa5a8
  3. 04 Mar, 2016 2 commits
  4. 29 Feb, 2016 1 commit
  5. 26 Feb, 2016 7 commits
  6. 24 Feb, 2016 4 commits
    • Andreas Marek's avatar
      Merge migration notice for FHI Repo · 9af253bc
      Andreas Marek authored
      9af253bc
    • Andreas Marek's avatar
      Add migration notice · 31a03aa2
      Andreas Marek authored
      31a03aa2
    • Andreas Marek's avatar
      Template for print messages of test programs · 296e4f48
      Andreas Marek authored
      The test programs include the same template now, the
      printed messages are thus unified
      296e4f48
    • Andreas Marek's avatar
      Optional build of ELPA without MPI · 49f119aa
      Andreas Marek authored
      The configure flag "--enable-shared-memory-only" triggers a build
      of ELPA without MPI support:
      
      - all MPI calls are skipped (or overloaded)
      - all calls to scalapack functions are replaced by the corresponding
        lapack calls
      - all calls to blacs are skipped
      
      Using ELPA without MPI gives the same results as using ELPA with 1 MPI
      task!
      
      This version is not yet optimized for performance, here and there some
      unecessary copies are done.
      
      Ths version is intended for users, who do not have MPI in their
      application but still would like to use ELPA on one compute node
      49f119aa
  7. 18 Feb, 2016 2 commits
  8. 17 Feb, 2016 4 commits
  9. 15 Feb, 2016 1 commit
  10. 12 Feb, 2016 1 commit
    • Andreas Marek's avatar
      Single precision support for ELPA2 · 56043bdc
      Andreas Marek authored
      ELPA2 can now be build (as ELPA1) for single precision calculations.
      The ELPA2 kernles which are implemented in assembler, C, or C++ have NOT
      yet been ported.
      
      Thus at the moment only the GENERIC and GENERIC_SIMPLE kernels support
      single precision calculations
      56043bdc
  11. 11 Feb, 2016 1 commit
    • Andreas Marek's avatar
      Enable single-precision calculations for ELPA1 · de6a4fde
      Andreas Marek authored
      With the configure option "--enable-single-precision" ELPA1 is build
      with single-precision (half-words) only.
      
      The best precision in single-precision (float or complex) is
      2^-23 ~ 1.2e-7. The accuracy of the error residual of ELPA1 in
      single-precision mode is of the order 1e-4 to 1e-5. The orthogonality of
      the EV's is fullfilled up to about ~1e-6.
      
      Thus the precision of ELPA1 in single-precision mode is roughly 100 -
      1000 times less than the best achievable precison. This is consistent
      with the double-precision mode, where also a factor of 100 - 1000 less
      precision than the theoretical best one is found.
      
      The float EVs are identical to the double EVs to at least 1e-2, the
      precision of the EVs is thus about 1e-7/1e-2 = 1e5 times lower than the
      best theoretical precision. If the same holds for the double precision
      calculations, this implies that the double precision results can also
      be only trusted on the level 1e-11 (5 orders of magnitude larger
      than the best theoretical precision)
      
      The best speed-up compared to the double precision calculation is
      a factor of two. This is by far not achieved yet, since the singl
      precision version is not at all optimized at the moment
      de6a4fde
  12. 05 Feb, 2016 1 commit
  13. 04 Feb, 2016 2 commits
  14. 03 Feb, 2016 4 commits
  15. 02 Feb, 2016 7 commits