Arithmetic operation log

[Altera_Forum]

Please, i need to calculate this function (X²)(Z=2) with vhdl language and Z it is real number. There are two maners: calculate it directly or applicate the log10 function. how can i resolve this problem. 

Thinks

[Altera_Forum]

I would say the best way is to use a NIOS. 

Did you find any log10 IP core ?

[Altera_Forum]

I use nios II, but he need many time to calculate the value. for exemple i find that it need's about 0.5 seconde to calculate 1000 result. But in my application, this time is greatest. For this reason i decide to change this function in vhdl to will be fast. 

For this reason i search how i implement my function in vhdl(component), to will be more fast that the software solution.

[Altera_Forum]

if Z is a real number (ie floating point) dont expect it to be any quicker in an FPGA. I dont quite understand the function thouhg. What is Z=2 meant to mean?