Upgrade to Intel LLVM compilers

[DavidHuber-NOAA]

The 'classic' Intel compilers (ifort, icc, and icpc) are now discontinued and the new LLVM compilers (ifx and icx) are the only option starting with version 2024. All supported machines with working versions of the LLVM compilers should be upgraded to the LLVM suite.

Per @junwang-noaa - try to use the 2024 version as the 2023 version has some bugs.

[GeorgeGayno-NOAA]

Using 1056ef5, the unit tests were successfully run on Hercules and Hera.

NOTE: Setting CMAKE_C_FLAGS_RELEASE "-O2" (in ./CMakeLists.txt) caused the fre-nctools/tst_create_xgrid unit test to 'seg fault'. For now, I will set CMAKE_C_FLAGS_RELEASE "-O1" for IntelLLVM

[GeorgeGayno-NOAA]

@AlexanderRichert-NOAA - I want to update the Github workflows to use IntelLLVM. I think I completed part of the update at c10e85a. However, the libraries are built using https://github.com/GeorgeGayno-NOAA/UFS_UTILS/blob/intelLLVM/ci/spack.yaml. Can you or someone on the libraries team assist me with updating spack.yaml?

[GeorgeGayno-NOAA]

Hash c10e85a was tested on Hercules. All regression tests were run:

• global_cycle, ice_blend, ocnice_prep and snow2mdl and weight_gen all passed.
• chgres_cube tests 6, 7, and 11 failed. All others passed.
• cpld_gridgen - all tests failed.

All failed tests had roundoff differences from their baselines.

[GeorgeGayno-NOAA]

All regression tests were run on WCOSS2 using 9511885. All tests passed as expected.

[GeorgeGayno-NOAA]

My preliminary tests show UFS_UTILS is working with the existing spack-stacks.

Will hold off on further work until it is determined whether new versions of spack-stack (that use IntelLLVM) will be implemented.

[GeorgeGayno-NOAA]

@AlexanderRichert-NOAA - I want to update the Github workflows to use IntelLLVM. I think I completed part of the update at c10e85a. However, the libraries are built using https://github.com/GeorgeGayno-NOAA/UFS_UTILS/blob/intelLLVM/ci/spack.yaml. Can you or someone on the libraries team assist me with updating spack.yaml?

I tried updates at 56bf5e1 and 98f840a, but the spack build fails during the compilation of sigio library routine sigio_module.f. I also see numerous warnings concerning compiler options. For example:

warning: unknown warning option '-Wc90-c99-compat'; did you mean '-Wc99-compat'? [-Wunknown-warning-option]

[AlexanderRichert-NOAA]

It should work once JCSDA/spack#480 is merged.

[AlexanderRichert-NOAA]

(Done)

[GeorgeGayno-NOAA]

(Done)

Thanks. Now I am running into the same issue with sfcio v1.4.1. My unit tests no longer use sfcio, so I am removing it from the workflow. But other users will need access to v1.4.2.

[AlexanderRichert-NOAA]

sfcio 1.4.2 is now available under JCSDA Spack.