Changes between Version 3 and Version 4 of ticket/0677_mpp_rep


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Timestamp:
2010-06-07T09:23:24+02:00 (10 years ago)
Author:
rblod
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  • ticket/0677_mpp_rep

    v3 v4  
    1111Implementation of both methods to get mpp reproducibility, one from ECMWF (key_mpp_rep1) and the other from DFO (key_mpp_rep2). The target is to choose one, thanks to my reviewer's advices, but athis time (7th of June), I made an intensive use of cpp keys to delimit clearly the both methods. 
    1212 
    13 Both are based on the Idea of self compensated summation, see the paper "Using Accurate Arithmetics to Improve Numerical Reproducibility and Stability in parallel applications, Yun He and Chris Ding, Journal of supercomputing, Vol 18, Number 3, pages 259-277, doi 10.1023/A1008153532043. 
     13Both are based on the Idea of self compensated summation, see the paper "Using Accurate Arithmetics to Improve Numerical Reproducibility and Stability in parallel applications, Yun He and Chris Ding, Journal of supercomputing, Vol 18, Number 3, pages 259-277, doi 10.1023/A1008153532043. 
    1414 
    1515We have: 
     
    2727These methods have been implemented in a new module lib_fortran.F90 with a few additions in lib_mpp.F90. In the sake of simplicity, I implemented a glob_sum function which is either a standard one( SUM + CALL mpp_sum), either one of the otw methods and the switch is done in lib_fortran. 
    2828 
    29 Nota: I also used this branch to implement a SIGN function which overwrite the standard fortran one (key_nosignedzero) to keep the f90 behaviour. 
     29I suppressed the nbit_cmp logical and added a lk_mpp_rep instead (still needed in limdyn for example). I had issues with both methods with agressive compilation options, and also with sea-ice (at least with ORCA2), so my ORCA2 tests are without sea-ice. 
     30 
     31Nota: I also used this branch to implement a SIGN function (in lib_fortran) which overwrite the standard fortran one (key_nosignedzero) to keep the f90 behaviour. 
    3032 
    3133=== Testing === 
    3234Testing could consider (where appropriate) other configurations in addition to NVTK]. 
    3335 
    34 ||NVTK Tested||!'''YES/NO!'''|| 
    35 ||Other model configurations||!'''YES/NO!'''|| 
     36||NVTK Tested||!'''YES!'''|| 
     37||Other model configurations||!'''YES!'''|| 
    3638||Processor configurations tested||[ Enter processor configs tested here ]|| 
    37 ||If adding new functionality please confirm that the [[BR]]New code doesn't change results when it is switched off [[BR]]and !''works!'' when switched on||!'''YES/NO/NA!'''|| 
     39||If adding new functionality please confirm that the [[BR]]New code doesn't change results when it is switched off [[BR]]and !''works!'' when switched on||!'''YES!'''|| 
    3840 
    3941(Answering UNSURE is likely to generate further questions from reviewers.) 
     
    4547 
    4648=== Bit Comparability === 
    47 ||Does this change preserve answers in your tested standard configurations (to the last bit) ?||!'''YES/NO !'''|| 
    48 ||Does this change bit compare across various processor configurations. (1xM, Nx1 and MxN are recommended)||!'''YES/NO!'''|| 
    49 ||Is this change expected to preserve answers in all possible model configurations?||!'''YES/NO!'''|| 
    50 ||Is this change expected to preserve all diagnostics? [[BR]]!,,!''Preserving answers in model runs does not necessarily imply preserved diagnostics. !''||!'''YES/NO!'''|| 
     49||Does this change preserve answers in your tested standard configurations (to the last bit) ?||!'''YES !'''|| 
     50||Does this change bit compare across various processor configurations. (1xM, Nx1 and MxN are recommended)||!'''YES!'''|| 
     51||Is this change expected to preserve answers in all possible model configurations?||!'''YES!'''|| 
     52||Is this change expected to preserve all diagnostics? [[BR]]!,,!''Preserving answers in model runs does not necessarily imply preserved diagnostics. !''||!'''YES!'''|| 
    5153 
    5254If you answered !'''NO!''' to any of the above, please provide further details: 
     
    6062---- 
    6163=== System Changes === 
    62 ||Does your change alter namelists?||!'''YES/NO !'''|| 
    63 ||Does your change require a change in compiler options?||!'''YES/NO !'''|| 
     64||Does your change alter namelists?||!'''YES !'''|| 
     65||Does your change require a change in compiler options?||!'''NO !'''|| 
    6466 
    6567If any of these apply, please document the changes required here.......