Efficiently derive parameter from generics vhdl

I have two generics on my entity:

clk_freq, io_delay: integer

From this, I want to calculate the number of cycles required for io_delay which is in ms. I also want to store this counter value in an unsigned variable so I'm not wasting loads of resources on an integer type. So I've implemented the following to do this:

constant COUNT_MAX_I: integer := integer(ceil(real(io_delay) * 0.001 * real(clk_freq)));
constant COUNTER_WIDTH: integer := integer(ceil(log2(real(COUNT_MAX_I))));
constant COUNT_HIGH: integer := unsigned(COUNTER_WIDTH - 1 downto 0) := to_unsigned(COUNT_MAX_I, COUNTER_WIDTH);

However, just looking at it that looks hugely inefficient. So my question is this:

Is there a more efficient way to do this and will the synthesis tools get rid of COUNT_MAX_I as it's only used in the calculation of other constants?

Generally speaking constant declarations themselves do not directly result in any synthesized logic. As such, there is nothing inefficient about the code as written.