6.2 Linking and Initializing MPI FFTW

Programs using the MPI FFTW routines should be linked with -lfftw3_mpi -lfftw3 -lm on Unix in double precision, -lfftw3f_mpi -lfftw3f -lm in single precision, and so on (see section Precision). You will also need to link with whatever library is responsible for MPI on your system; in most MPI implementations, there is a special compiler alias named mpicc to compile and link MPI code.

Before calling any FFTW routines except possibly fftw_init_threads (see section Combining MPI and Threads), but after calling MPI_Init, you should call the function:

void fftw_mpi_init(void);

If, at the end of your program, you want to get rid of all memory and other resources allocated internally by FFTW, for both the serial and MPI routines, you can call:

void fftw_mpi_cleanup(void);

which is much like the fftw_cleanup() function except that it also gets rid of FFTW’s MPI-related data. You must not execute any previously created plans after calling this function.