Developing the FPGA of ADALM-PLUTO

Hello Everyone,  

         I would like to use the FPGA of plutot for computing the FFT for my application, so I start by using the projet given on GitHub - analogdevicesinc/hdl with vivado.

        I found out that there are a lot of things that are already there. Can someone explain to me what this is, because I see things that normally exist in AD9363, like the FIR filter, the Decimator and Interpolator... and all this uses a lot of FPGA resources! Why are they there ? Are they indispensable ?

Thanks,

Regards.

Es,