FLUME — FNL (OpenACC) Backend

FLUME is part of the ADAM framework, released under the GNU Lesser General Public License v3.0 (LGPLv3). Copyright (C) Andrea Di Mascio, Federico Negro, Giacomo Rossi, Francesco Salvadore, Stefano Zaghi.

The FNL backend (flume-fnl) is the GPU implementation of FLUME on the FNL library (OpenACC directives, each with its OpenMP offload twin), extending the backend-independent infrastructure of common/. The fields live on the device; the host copies are refreshed for output, restart and the coarse-fine seam fluxes of the reflux register.

Status: development (milestone M1, compressible Euler). Every verification test passes on both backends; the per-stage host copies of the seam faces dominate the run time of AMR cases.

Source Files

File	Description
adam_flume_fnl.F90	Entry point (program)
adam_flume_fnl_object.F90	flume_fnl_object: device data, ghost update, residual, Runge-Kutta integration, reflux, output
adam_flume_fnl_kernels.F90	Device kernels: face fluxes and flux difference (with the immersed-boundary variant), boundary conditions, time-step and conservation reductions, auxiliary fields, seam skin packing and reflux application
adam_flume_fnl_library.F90	Barrel re-export of all FNL modules

Build modes

fobis build --mode flume-fnl-nvf --varset local_nvf          # NVIDIA, OpenACC (verified)
fobis build --mode flume-fnl-nvf-debug --varset local_nvf    # NVIDIA, OpenACC, runtime checks
fobis build --mode flume-fnl-omp-amd                          # AMD, OpenMP offload (not verified)