PYNQ: PYTHON PRODUCTIVITY

How to implement this mathematical equation on PYNQ Z1 using MyHDL module

How to implement the following mathematical equation on PYNQ Z1 using MyHDL module ?

   F(X)=(X)/(2.(H-sign(X-H).a))+(a)/(2.(a-sign(X-H).H) ) + 0,5           

Knowing that , X, a and H are real variables.

How to do the datapath design of the equation ?