update izumi port

[apcraig]

PR checklist

• Short (1 sentence) summary of your PR:
  update izumi port, add pgi and gnu

• Developer(s):
  apcraig, dabail10

• Suggest PR reviewers from list in the column to the right.

• Please copy the PR test results link or provide a summary of testing completed below.
  #2b36bee95f at https://github.com/CICE-Consortium/Test-Results/wiki/icepack_by_hash_forks

• How much do the PR code changes differ from the unmodified code?

  • bit for bit
  • different at roundoff level
  • more substantial

• Does this PR create or have dependencies on CICE or any other models?

  • Yes
  • No

• Does this PR add any new test cases?

  • Yes
  • No

• Is the documentation being updated? ("Documentation" includes information on the wiki or in the .rst files from doc/source/, which are used to create the online technical docs at https://readthedocs.org/projects/cice-consortium-cice/.)

  • Yes
  • No, does the documentation need to be updated at a later time?
    • Yes
    • No

• Please provide any additional information or relevant details below:

Update port to add gnu and pgi and fix a few minor issues.

[dabail10]

Looks good. It will be nice to have all of these compiler tests.

[dabail10]

Are we using OpenMP in icepack?

[apcraig]

There is no openmp in icepack at the present time. We do not invoke the openmp in any icepack testing. The scripts and most of the Macros files have openmp capability built in. I included the openmp option in the izumi macros as well, but they are not tested. We could remove it from all the Macros in icepack. I prefer to include it for potential future use, but am open on this point.

[dabail10]

I just saw the ICE_THREADED code in the Macros files. Maybe we could use it eventually? Given that we do the four points in Icepack, maybe this is a good candidate for threading.

[eclare108213]

The four grid points could be a good candidate for threading. The question is what we would be testing or why it's needed -- the threading presumably would only be testing the Icepack driver, since the column physics itself is independent of the grid. Maybe we ought to be more careful with the driver, but I feel like we have the parallelization aspects covered in CICE already and it's not needed for Icepack.

[eclare108213]

That said, if there are clever ways to utilize threading via some other type of decomposition, e.g. chunks of physics, that could be made useful for other purposes such as GPU architectures, let's hear them.

[dabail10]

I've always felt like we should be exploring threading over the categories or over the tracer index. However, I think these are good features to add down the line. For now I am fine with leaving threading out of Icepack.