This application calls a built FFTX library using an interface like that in WarpX.

To use and build this demo application you must have installed FFTX and spiral-software. Ensure your environment sets FFTX_HOME and SPIRAL_HOME to point to the locations of FFTX and Spiral.

Clone spiral-software to a location on your computer. E.g., do:

cd ~/work
git clone https://www.github.com/spiral-software/spiral-software

This location is known as SPIRAL HOME and you must set an environment variable SPIRAL_HOME to point to this location later.

You must also install two spiral packages, do the following:

cd ~/work/spiral-software/namespaces/packages
git clone https://www.github.com/spiral-software/spiral-package-fftx fftx
git clone https://www.github.com/spiral-software/spiral-package-simt simt

NOTE: The spiral packages must be installed under the directory $SPIRAL_HOME/namespaces/packages and must be placed in folders with the prefix spiral-package removed.

Follow the build instructions for spiral-software (see the README here ).

You should be using the develop branch of all of these repos:

pushd $SPIRAL_HOME
git checkout develop
pushd namespace/packages/fftx
git checkout develop
pushd ../simt
git checkout develop
popd
popd

Clone FFTX to a location on your computer. E.g., do:

cd ~/work
git clone https://www.github.com/spiral-software/fftx

Then FFTX_HOME should be set to ~/work/fftx . Use the develop branch:

pushd $FFTX_HOME
git checkout develop

In order to build the FFTX library, you first need to generate files with ./create_lib_code.sh . It is set up to work with CUDA, but you can have it work with HIP by simply changing references to "cuda" in that script to "hip".

cd $FFTX_HOME/examples/library
./create_lib_code.sh

Now follow the build instructions for FFTX (see the README here ).

Ensure you have valid settings for FFTX_HOME and SPIRAL_HOME.

This application also needs AMREX_SRC and AMREX_BUILD to be set to AMReX source directories. For example:

setenv AMREX_SRC $HOME/warpx_directory/WarpX/build/_deps/fetchedamrex-src/Src/Base
setenv AMREX_BUILD $HOME/warpx_directory/WarpX/build/_deps/fetchedamrex-build

Clone the demo application. E.g., do:

cd ~/work
git clone https://www.github.com/spiral-software/fftx-demo-warpx-app
cd fftx-demo-warpx-app
cmake -S . -B build
cmake --build build --target install

The demo application will be installed at ~/work/fftx-demo-warpx-app/build/bin/testwarpx .