How to build the libraries, tests, and examples, run the tests, and verify the results

In a nutshell

In the root directory:

  • make libs makes the RTE and RRTMGP libraries, the unit tests, and the examples
  • make tests runs the tests
  • make check uses Python to verify results against reference calculations
  • make invoked without a target in the top level attempts all three steps.

Evaluating the results of the tests requires Python and the packages described in environment*.yml.

Building and testing using the handbuilt Makefiles

Before using the Makefiles supplied with the RTE+RRTMGP repository, the environment variables FC and FCFLAGS, identifying the Fortran compiler and flags passed to it, need to be set.

To build any of the examples in examples/ or tests the locations of the C and Fortran netCDF libraries and the location of the netCDF Fortran module file (netcdf.mod) must be in the search path. Non-standard paths can also be added via macros FCINCLUDE and/or LDFLAGS.

Building and testing using (Gnu) autotools

Sergey Kosukhin and his colleagues at the Max Planck Institute for Meteorology maintain the autoconf branch which adds Gnu autotools building to main branch.

Supplying data

Running the tests and verifying the results requires the RRTMGP data. Clone the data repository or download the Zenodo archive. Set the environment variable RRTMGP_DATA to the root of this directory.

Example compiler flags

In these examples FC is the Fortran compilers using flags FCFLAGS

Gnu Fortran

(see also the continuous integration) FC: gfortran-10 or gfortran-11 or gfortran-12

Debugging flags

FCFLAGS: "-ffree-line-length-none -m64 -std=f2008 -march=native -fbounds-check -finit-real=nan -DRTE_USE_CBOOL"

Even stricter debugging flags

FCFLAGS: "-ffree-line-length-none -m64 -std=f2008 -march=native -fbounds-check -fbacktrace -finit-real=nan -DRTE_USE_CBOOL -pedantic -g -Wall"

Intel Fortran Classic

(see also the continuous integration) FC: ifort

Debugging flags

FCFLAGS: "-m64 -g -traceback -heap-arrays -assume realloc_lhs -extend-source 132 -check bounds,uninit,pointers,stack -stand f08"

Optimization flags:

FCFLAGS:"-m64 -O3 -g -traceback -heap-arrays -assume realloc_lhs -extend-source 132"

Intel Fortran

(LLVM, see also the continuous integration) FC: ifort

Debugging flags

FCFLAGS: "-debug -traceback -heap-arrays -assume realloc_lhs -extend-source 132 -stand f08"

Using OpenMP GPU offload

See this open issue

NVFortran

(see also the see also the continuous integration) FC: nvfortran

Debugging flags

FCFLAGS: "-g -Minfo -Mbounds -Mchkptr -Mstandard -Kieee -Mchkstk -Mallocatable=03 -Mpreprocess"

Optimization flags:

FCFLAGS: "-O3 -fast -Minfo -Mallocatable=03 -Mpreprocess"

HPE CCE for GPU using OpenMP-acc: crayftn – requires at least CCE 14.0.0

FC: crayftn

Debugging flags (these appear to be insufficient during the link stage)

FCFLAGS: "-hnoacc -homp -O0"