mpicxx  -fsycl halo_mpi.cc -o halo_mpi
mpicxx -O2 -std=c++11 io_mpi.cc -o io_mpi
# Frontier: (hipcc via mpicxx wrapper; ACC_HIP is the default in-file)
mpicxx -O2 -x hip gather_mpi.cc -o gather_mpi -L${ROCM_PATH}/lib -lamdhip64