Fix PR#377 Enable Transmute script for bl imp and exp kernels - over i

[Benjamin Went (MetBenjaminWent)]

Create or enable a Transformation script for the boundary layer kernels which affect the domain to add OMP directives.
Introduced is a local.py script for kernels, which if the loop variable is an i or an l, then the OMP directive is added, instead of the top loop like the Transmute global script.
interfaces/physics_schemes_interface/source/kernel/bl_exp_kernel_mod.F90 - Local kernel script with Override
interfaces/physics_schemes_interface/source/kernel/bl_imp_kernel_mod.F90 - Local kernel script with Override
interfaces/physics_schemes_interface/source/kernel/bl_imp2_kernel_mod.F90 - Local kernel script with Override

Performance of all kernels improves as a result of the original changes in PR #377 , see #106. Combined with #416, the implicit umbrella of imp_kernel and imp2_kernel is much greater.

NOTE, these changes have not been explicitly tested, and may be marginally different than #377, though the same loops are still parallelised, but over a different index.

Sci/Tech Reviewer: Hacka Fett (Hacka Fett (@christophermaynard))](https://github.com/christophermaynard)
Code Reviewer: svadams (svadams (@svadams))](https://github.com/svadams)

Umbrella Issue: #106
Issue: #361

PR Summary

Sci/Tech Reviewer:
Code Reviewer:

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trac.log

Test Suite Results - lfric_apps - transmute_bl_exp_imp_kernels_2/run7

Suite Information

Item	Value
Suite Name	transmute_bl_exp_imp_kernels_2/run7
Suite User	benjamin.went
Workflow Start	2026-06-02T15:25:59
Groups Run	all

Dependency	Reference	Main Like
casim	MetOffice/casim@2026.03.2	True
jules	MetOffice/jules@3647a42	True
lfric_apps	MetBenjaminWent/lfric_apps@transmute_bl_exp_imp_kernels_2	False
lfric_core	MetOffice/lfric_core@bf23673	True
moci	MetOffice/moci@2026.03.2	True
SimSys_Scripts	MetOffice/SimSys_Scripts@3e2998b	True
socrates	MetOffice/socrates@2026.03.2	True
socrates-spectral	MetOffice/socrates-spectral@2026.03.2	True
ukca	MetOffice/ukca@1cdb9c2	True

Task Information

❌ failed tasks - 2

Task	State
run_lfric_atm_scm_gal9_gabls4-BiP2x2-50000x50000_ex1a_cce_fast-debug-32bit	failed
run_linear_integration_tests_azspice_gnu_64bit	failed

✅ succeeded tasks - 1570

Test Suite Results - lfric_apps - transmute_bl_exp_imp_kernels_2/run6

Suite Information

Item	Value
Suite Name	transmute_bl_exp_imp_kernels_2/run6
Suite User	benjamin.went
Workflow Start	2026-06-02T14:31:40
Groups Run	ex1a_omp_developer

Dependency	Reference	Main Like
casim	MetOffice/casim@2026.03.2	True
jules	MetOffice/jules@3647a42	True
lfric_apps	MetBenjaminWent/lfric_apps@transmute_bl_exp_imp_kernels_2	False
lfric_core	MetOffice/lfric_core@bf23673	True
moci	MetOffice/moci@2026.03.2	True
SimSys_Scripts	MetOffice/SimSys_Scripts@3e2998b	True
socrates	MetOffice/socrates@2026.03.2	True
socrates-spectral	MetOffice/socrates-spectral@2026.03.2	True
ukca	MetOffice/ukca@1cdb9c2	True

Task Information

✅ succeeded tasks - 51

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[Benjamin Went (MetBenjaminWent)]

As this is a continuation of PR #377 and issue #361, the performance data and existing approvals should still hold for this PR.

[Matthew Hambley (MatthewHambley)]

Code owner (build system) no change to build system itself, just extension of list in line with usage.

[Hacka Fett (christophermaynard)]

I have checked with the developer and developer tests have been run. I have the the CCE openMP tests and the OpenMP scaling looks good for these changes. The scripts are simpler and generate a consistent openMP parallelisation, with reasonable performance.

[Joerg Henrichs (hiker)]

I realise I am a bit late, and I am ok with this PR, given that it is consistent with the other existing transmute script.
As a
I do wonder though if it wouldn't be easier to understand if we had individual python files for each of the new files. In these files the trans function would just set the equivalent of SCRIPT_OPTIONS_DICT for this specific file only, and then call a common helper PSyclone function (which is the current local.py), which takes this SCRIPT_OPTIONS_DICT as argument? While that would be more files (atm 2 files, independent on how many source files it applies to; with the change we would have n+1 files, one for each of the n files plus one helper), but it feels easier to see how the flow works?

Consider that a philosophical pondering and just ignore, I am happy enough to get this merged in :)

[Benjamin Went (MetBenjaminWent)]

I realise I am a bit late, and I am ok with this PR, given that it is consistent with the other existing transmute script. As a I do wonder though if it wouldn't be easier to understand if we had individual python files for each of the new files. In these files the trans function would just set the equivalent of SCRIPT_OPTIONS_DICT for this specific file only, and then call a common helper PSyclone function (which is the current local.py), which takes this SCRIPT_OPTIONS_DICT as argument? While that would be more files (atm 2 files, independent on how many source files it applies to; with the change we would have n+1 files, one for each of the n files plus one helper), but it feels easier to see how the flow works?

Consider that a philosophical pondering and just ignore, I am happy enough to get this merged in :)

It's a good suggestion for the future of Transmute, we can look at that when we have more of an aligned strategy for now to do the scripts. We certainty could lift the core of this file into a callable function, which other scripts could use more readily. I'll link Joe who is looking into this for us.
In this PR, I was trying to go with a less is more approach in terms of numbers of files which is on trunk (See the Transmute global.py), and it works well enough accommodating that. I think your suggestion, whilst very good for clarity, would return us to a place where we have lots of individual scripts on trunk, which I was under the impression everyone felt we should move away from to aid maintenance.

[Benjamin Went (MetBenjaminWent)]

svadams (@svadams), this PR is ready for review.