NEMO Examples

These examples may all be found in the examples/nemo directory.

Example 1: OpenMP parallelisation of tra_adv

Demonstrates the use of PSyclone to parallelise loops in a NEMO tracer-advection benchmark using OpenMP for CPUs and for GPUs.

Example 2: OpenMP parallelisation of traldf_iso

Demonstrates the use of PSyclone to parallelise loops in some NEMO tracer-diffusion code using OpenMP for CPUs and for GPUs.

Example 3: OpenACC parallelisation of tra_adv

Demonstrates the introduction of simple OpenACC parallelisation (using the data and kernels directives) for a NEMO tracer-advection benchmark.

Example 4: Transforming Fortran code to the SIR

Demonstrates that simple Fortran code can be transformed to the Stencil Intermediate Representation (SIR). The SIR is the front-end language to DAWN (MeteoSwiss-APN/dawn), a tool which generates optimised cuda, or gridtools code. Thus various simple Fortran examples and the computational part of the tracer-advection benchmark can be transformed to optimised cuda and/or gridtools code by using PSyclone and then DAWN.

Example 5: Kernel Data Extraction

This example shows the use of kernel data extraction in PSyclone for generic Fortran code. It instruments each kernel in the NEMO tracer-advection benchmark with the PSyData-based kernel extraction code. Detailed compilation instructions are in the README.md file, including how to switch from using the stand-alone extraction library to the NetCDF-based one (see Extraction Libraries for details).

Example 6: Read-only Verification

This example shows the use of read-only verification with PSyclone for generic Fortran code. It instruments each kernel in a small Fortran program with the PSyData-based read-only verification code. Detailed compilation instructions are in the README.md file.

Scripts

This contains examples of two different scripts that aid the use of PSyclone with the full NEMO model. The first, process_nemo.py is a simple wrapper script that allows a user to control which source files are transformed, which only have profiling instrumentation added and which are ignored altogether. The second, kernels_trans.py is a PSyclone transformation script which adds the largest possible OpenACC Kernels regions to the code being processed.

For more details see the examples/nemo/README.md file.

Note that these scripts are here to support the ongoing development of PSyclone to transform the NEMO source. They are not intended as ‘turn-key’ solutions but as a starting point.