[Announcement] Upcoming PSyclone 3.1.0 upgrade in LFRic Core and Apps

[TeranIvy]

Guidance to the upcoming PSyclone 3.1.0 upgrade

PSyclone 3.1.0 was released on 25 February 2025, delivering new functionality for supporting LFRic science and performance optimisation.

The new PSyclone release is being incorpoated into the LFRic software stack on the legacy and new platforms as part of the LFRic Apps vn2.1 release. Please note, this should be the last PSyclone upgrade on legacy Spice and XC platforms.

Changes in PSyclone 3.1.0 relevant for LFRic developers and users

More detailed information about new and modified functionality in PSyclone 3.1.0 can be found here. The most important changes relevant to LFRic are outlined below.

• The psyad command allows --config command-line option to point to a user-specific PSyclone configuration file, see "Rules for DoF Kernels".

• User-defined DoF kernels can use field vectors, see "The psyad command".

• Enabled split element orders and anisotropic quadrature points, see "Supported Function Spaces"
  and "Quadrature".

• Support for the Vernier timing library (see "Profiling").

• Improvements to kernel-extraction and driver-generation (PSyKE) functionality (support or character and logical datatypes), see "PSy Kernel Extractor (PSyKE)".

There are some non-backward compatible changes in PSyclone API which impact PSyAD patches in the LFRic Apps only.
The LFRic Core is backward compatible with PSyclone 3.0.0.

Guidance for LFRic developers and users

Although the changes are non-backward compatible, they are focused on a limited portion of code in the LFRic Apps. Running the Rose test suites on Met Office platforms will continue to work as we are using specific versions of LFRic software environments. The command-line builds may be affected due to change of default environments.

Met Office developers

• No changes are required if you are running Rose test suite (uses versioned environments).

• If you are building code from the command line, please load the specific environment versions instead of "default" ones (see "LFRic software environments" below for specific Met Office platforms).

• It is advisable to wait for the LFRic Apps vn2.1 release to be finalised before creating new development branches.

External developers

• No changes are required unless you are building LFRic from the command line on MONSooN. In that case, please load the specific environment versions instead of "default" ones (see "LFRic software environments" below for specific Met Office platforms).

• It is advisable to wait for the LFRic Apps vn2.1 release to be finalised before creating new development branches and upgrading environments to PSyclone 3.1.0. See "Installation" in the PSyclone user guide for installation instructions.

What will change in LFRic

LFRic Core

• LFRic software environments use PSyclone 3.1.0 (see "LFRic software environments" below for specific Met Office platforms). The impacted source are Cylc files in the rose-stem/site/meto/common/ directory.

LFRic Apps

• Use of PSyclone 3.1.0 in software environments (see "LFRic software environments" below for specific Met Office platforms). The impacted source are
  Cylc files in the rose-stem/site/meto/common/ directory.

• The psyad command uses the PSyclone configuration file in the LFRic Core. The impacted source is science/adjoint/build/psyad.mk.

• Adjoint model patches are modified to reflect recent developments in PSyAD and LFRic API. This impacts the source in the science/adjoint/patches/algorithm/ directory.

LFRic software environments

PSyclone 3.1.0 is now integrated into the LFRic software environments on the new (Azure Spice, EXA/B/Z) and legacy (Spice, Crays XCE/F/S) Met Office platforms. However, the default versions are not yet changed.

Azure Spice

The Gnu 12.2.0 compiler environment that uses PSyclone 3.1.0 is lfric/vn2.1 (Core and all Apps).

Note, if the specific version of a compiler environment is not loaded (e.g. module load lfric), command-line builds may fail when the build system defaults are changed. If you wish to continue to use PSyclone 3.0.0 for command-line development and testing, please load lfric/vn2.0.

Cray EXA/B/Z

Please note that porting of LFRic Core and Apps to the new Cray EXA/B is in progress, and not all Apps are working on the new platforms. Compiler environments that use PSyclone 3.1.0 are:

• Gnu 12.1.0 LFRic environment: lfric-gnu/12.2.0/1.0,
• Cray 15.0.0 LFRic environment: lfric-cray/15.0.0/1.0.

Similar to Azure Spice, command-line builds may fail if the specific version of a compiler environment is not loaded when the build system defaults are changed. If you wish to continue to use PSyclone 3.0.0 for command-line development and testing, please use:

• Gnu 12.1.0 LFRic environment: lfric-gnu/12.2.0/0.5,
• Cray 15.0.0 LFRic environment: lfric-cray/15.0.0/0.5.

Spice/Desktop (legacy)

Compiler environments that use PSyclone 3.1.0 are:

• Intel 19.0.1 LFRic environment: environment/lfric/ifort/19.0_64/10 (Core and all Apps),
• Gnu 11.2.0 LFRic environment: environment/lfric/gcc/11.2.0/11 (Core and all Apps except for LFRic Inputs),
• Gnu 6.1.0 LFRic environment: environment/lfric/gcc/6.1.0/11 (LFRic Inputs App).

Again, if the specific version of a compiler environment is not loaded (e.g. module load environment/lfric/ifort), command-line builds may fail when the build system defaults are changed. If you wish to continue to use PSyclone 3.0.0 for command-line development and testing, please load:

• Intel 19.0.1 LFRic environment: environment/lfric/ifort/19.0_64/9 (Core and all Apps, PSyclone 3.0.0),
• Gnu 11.2.0 LFRic environment: environment/lfric/gcc/11.2.0/9 (Core and all Apps except for LFRic Inputs, PSyclone 3.0.0),
• Gnu 6.1.0 LFRic environment: environment/lfric/gcc/6.1.0/10 (LFRic Inputs App, PSyclone 3.0.0).

Cray XCE/F (legacy)

Compiler environments that use PSyclone 3.1.0 are:

• Intel 17.0.1 LFRic environment: meto-environment/lfric/intel/17.0.0.098/11 (Core and all Apps except for LFRic Coupled),
• Cray 8.7.0 LFRic environment: meto-environment/lfric/cce/8.7.0/8 (Core and all Apps except for LFRic Coupled),
• Intel 17.0.1 MOCI environment: GC5-PrgEnv/intel/17.0.0.098/2024-12-ifort/5551 (LFRic Coupled App).

Cray XCS/MONSooN (legacy)

Compiler environments that use PSyclone 3.1.0 are:

• Intel 17.0.1 LFRic environment: meto-environment/lfric/intel/17.0.0.098/11 (Core and all Apps except for LFRic Coupled),
• Cray 8.7.0 LFRic environment: meto-environment/lfric/cray/8.7.0/9 (Core and all Apps except for LFRic Coupled),
• Intel 17.0.1 MOCI environment: GC5-PrgEnv/intel/17.0.0.098/2024-12-ifort/5552 (LFRic Coupled App).

Again, if the specific version of a compiler environment is not loaded (e.g. module load meto-environment/lfric/intel), command-line builds may fail when the build system defaults are changed. If you wish to continue to use PSyclone 3.0.0 for command-line development and testing, please load:

• Intel 17.0.1 LFRic environment: meto-environment/lfric/intel/17.0.0.098/10 (Core and all Apps except for LFRic Coupled, PSyclone 3.0.0),
• Cray 8.7.0 LFRic environment: meto-environment/lfric/cray/8.7.0/8 (Core and all Apps except for LFRic Coupled, PSyclone 3.0.0),
• Intel 17.0.1 MOCI environment: GC5-PrgEnv/intel/17.0.0.098/2024-12-ifort/5425 (LFRic Coupled App, PSyclone 3.0.0).

Iva, on behalf of Sim IT - with thanks to the STFC PSyclone developers and Sim IT SSEs (releases are a lot of work!) 😃