AD Build

It is recommended to read the information at Build from Source first prior reading this section.

In order to use the discrete adjoint solver the compilation requires two additional libraries. CoDi provides the AD datatype and AdjointMPI provides the infrastructure for the MPI communication when the reverse mode of AD is used. Both libraries are added as submodules in externals/ in the git repository of SU2.

Configuration with AD support

The initialization and compilation of these libraries as well as the configuration of SU2 is handled by the python script preconfigure.py inside the main directory. This script accepts the same arguments as the usual configure script (except CXXFLAGS=...) but in addition it offers the option --enable-autodiff to enable AD (reverse mode) for the discrete adjoint solver.

Example

Assume that your configuration (see Simple Build, Parallel Build or Parallel and CGNS Build) is done using the command

./configure --enable-mpi --prefix=$SU2_INSTALLPATH --with-cgns-lib=$PATH_TO_CGNSLIB --with-cgns-include=$PATH_TO_CGNSINCLUDE CXXFLAGS="-O3 -Wall"

To enable the compilation of the binaries with AD support you'll need to change this command to

export CXXFLAGS="-O3 -Wall" && ./preconfigure.py --enable-autodiff --enable-mpi --prefix=$SU2_INSTALLPATH --with-cgns-lib=$PATH_TO_CGNSLIB --with-cgns-include=$PATH_TO_CGNSINCLUDE 

Note: If you have already called ./configure before in the source directory, a make distclean is required before calling ./preconfigure.py.

This script creates the folders SU2_BASE and SU2_AD and calls configure in each of the folders. SU2_BASE then contains the configuration to compile all of the base modules (SU2_CFD, SU2_DOT, SU2_SOL etc.) and SU2_AD contains the configuration to compile the modules SU2_CFD_AD and SU2_DOT_AD. Furthermore it creates a Makefile so that you can simply call make install in the main folder to compile and install everything into the specified directory or make install SU2_BASE or make install SU2_AD to compile and install them separately.