Compiler-flags.md

Compiler flag Examples

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. Here are some examples used during development and testing.

To build any of the executables in examples/ or tests the locations of the C and Fortran netCDF libraries need to be set via environment variables NCHOME and NFHOME, and the variable RRTMGP_ROOT must be set to the root of the RTE+RRTMGP installation.

Gnu Fortran

(see also the continuous integration) FC: gfortran-10orgfortran-11orgfortran-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"