Installing FFTW

Procedure

1. Use PuTTY to log in to the server as the root user.
2. Download the FFTW installation package.

   wget https://fftw.org/pub/fftw/fftw-3.3.8.tar.gz

3. Decompress the FFTW installation package.

   tar -zxvf fftw-3.3.8.tar.gz

4. Go to the FFTW installation package directory.

   cd fftw-3.3.8

5. Install FFTW.

   export CC=clang CXX=clang++ FC=flang
   ./bootstrap.sh
   ./configure --prefix=/path/to/FFTW --enable-single --enable-float --enable-neon --enable-shared --enable-threads --enable-openmp --enable-mpi CFLAGS="-O3 -fomit-frame-pointer -fstrict-aliasing"
   make -j && make install
   make clean
   ./configure --prefix=/path/to/FFTW --enable-long-double --enable-shared --enable-threads --enable-openmp --enable-mpi CFLAGS="-O3 -fomit-frame-pointer -fstrict-aliasing"
   make -j && make install
   make clean
   ./configure --prefix=/path/to/FFTW --enable-shared --enable-threads --enable-openmp --enable-mpi CFLAGS="-O3 -fomit-frame-pointer -fstrict-aliasing"
   make -j && make install

6. Set the environment variables.

   export PATH=/path/to/FFTW/bin:$PATH
   export LD_LIBRARY_PATH=/path/to/FFTW/lib:$LD_LIBRARY_PATH