INSTALL

Installing MPAS
====

For general information on how to install MPAS, see https://mpas-dev.github.io.
Additional notes on building MPAS on specific architectures are summarized here.


gfortran-clang: Compiling MPAS on MacOSX (10.11 El Capitan - 10.12 Sierra)
----------
MPAS should compile out of the box on MacOSX with the standard (OS) clang compiler
and the gfortran compiler. The gfortran compiler can be installed using homebrew
(http://brew.sh), or using pre-compiled binaries from the MacOSX HPC website
(http://hpc.soureforge.net), or it can be compiled by the user from the GNU sources.

Caveats:

(1) MPAS cannot be compiled with gfortran-clang if GEN_F90=true.

(2) The standard clang compiler does not support OpenMP. Users wanting to compile MPAS
with OpenMP support on MacOSX will have to install the LLVM clang compiler, which is
accomplished easiest with homebrew. Since this alternative clang compiler is not in
the standard search/library path, the user will have to modify the call to the clang
and clang++ executable and add the library path to the compiler flags. Example:

...
	"FC_PARALLEL = mpif90" \
	"CC_PARALLEL = mpicc -cc=clang" \
	"CXX_PARALLEL = mpicxx -cxx=clang++" \
	"FC_SERIAL = gfortran" \
	"CC_SERIAL = clang" \
	"CXX_SERIAL = clang++" \
	"FFLAGS_PROMOTION = -fdefault-real-8 -fdefault-double-8" \
	"FFLAGS_OPT = -O3 -m64 -ffree-line-length-none -fconvert=big-endian -ffree-form" \
	"CFLAGS_OPT = -O3 -m64" \
	"CXXFLAGS_OPT = -O3 -m64" \
	"LDFLAGS_OPT = -O3 -m64" \
	"FFLAGS_DEBUG = -g -m64 -ffree-line-length-none -fconvert=big-endian -ffree-form -fbounds-check -fbacktrace -ffpe-trap=invalid,zero,overflow" \
	"CFLAGS_DEBUG = -g -m64" \
	"CXXFLAGS_DEBUG = -O3 -m64" \
	"LDFLAGS_DEBUG = -g -m64" \
...

would become

...
	"FC_PARALLEL = mpif90" \
	"CC_PARALLEL = mpicc -cc=/usr/local/opt/llvm/bin/clang" \
	"CXX_PARALLEL = mpicxx -cxx=/usr/local/opt/llvm/bin/clang++" \
	"FC_SERIAL = gfortran" \
	"CC_SERIAL = /usr/local/opt/llvm/bin/clang" \
	"CXX_SERIAL = /usr/local/opt/llvm/bin/clang++" \
	"FFLAGS_PROMOTION = -fdefault-real-8 -fdefault-double-8" \
	"FFLAGS_OPT = -O3 -m64 -ffree-line-length-none -fconvert=big-endian -ffree-form -L/usr/local/opt/llvm/lib" \
	"CFLAGS_OPT = -O3 -m64 -L/usr/local/opt/llvm/lib" \
	"CXXFLAGS_OPT = -O3 -m64 -L/usr/local/opt/llvm/lib" \
	"LDFLAGS_OPT = -O3 -m64 -L/usr/local/opt/llvm/lib" \
	"FFLAGS_DEBUG = -g -m64 -L/usr/local/opt/llvm/lib -ffree-line-length-none -fconvert=big-endian -ffree-form -fbounds-check -fbacktrace -ffpe-trap=invalid,zero,overflow" \
	"CFLAGS_DEBUG = -g -m64 -L/usr/local/opt/llvm/lib" \
	"CXXFLAGS_DEBUG = -O3 -m64 -L/usr/local/opt/llvm/lib" \
	"LDFLAGS_DEBUG = -g -m64 -L/usr/local/opt/llvm/lib" \
...

assuming that the LLVM clang compiler is installed in /usr/local/opt/llvm.


bluegene: Compiling MPAS on IBM Bluegene using the xl compilers
----------
All MPAS cores except the ocean compile on IBM Bluegene using the xl compilers. The ocean
core currently does not work on IBM Bluegene. Known limitations: OPENMP must be disabled
(OPENMP=false) for compiling, since the xl compilers do not support nested OpenMP directives.