How to use float in vhdl

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.ALL;
use IEEE.std_logic_signed.all;

-- Uncomment the following library declaration if using
-- arithmetic functions with Signed or Unsigned values
--use IEEE.NUMERIC_STD.ALL;

-- Uncomment the following library declaration if instantiating
-- any Xilinx leaf cells in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity lms2 is
    Port (wr9,wi9,xr,xi,u : in STD_LOGIC_VECTOR (12 downto 0);
           --u : in integer;
         
           yr,yi,er,ei,wr8,wi8,zzz,sum1 : out STD_LOGIC_VECTOR (12 downto 0));
end lms2;

architecture Behavioral of lms2 is


--variable r,s : real range 0.0 to 15.0;

begin

process(wr9,wi9,u,xr,xi)--process also runs without the parameters,but it gives problems during simulation
--process(u,xr,xi)
variable wr : std_logic_vector(12 downto 0);
variable wi : std_logic_vector(12 downto 0);

--variable wr : std_logic_vector(4 downto 0) :="00010";
--variable wi : std_logic_vector(4 downto 0) :="00011";
--variable wr : std_logic_vector(4 downto 0) :=wr9;
--variable wi : std_logic_vector(4 downto 0) :=wi9;
variable yr1 : integer;
variable yi1 : integer;
variable er1 : integer;
variable ei1 : integer;
variable wr1 : integer;
variable wi1 : integer;
variable uu  : integer;
variable zz  : integer;
variable sum : integer:= 0;
begin



--process(xr,xi,u)
--bi <= to_integer(unsigned(k)) ;
--bj <= to_integer(unsigned(l)) ;
--bk <= bi*bj;

uu := to_integer(unsigned(u)) ;
wr := wr9;
wi := wi9;

for z in 0 to 1 loop

yr1 := to_integer(unsigned(wr))*to_integer(unsigned(xr))- to_integer(unsigned(wi))*to_integer(unsigned(xi));
yi1 := to_integer(unsigned(wr))*to_integer(unsigned(xi))+to_integer(unsigned(wi))*to_integer(unsigned(xr));

er1 := to_integer(unsigned(wr))*to_integer(unsigned(xr))-to_integer(unsigned(wi))*to_integer(unsigned(xi))-to_integer(unsigned(xr));
ei1 := to_integer(unsigned(wr))*to_integer(unsigned(xi))+to_integer(unsigned(wi))*to_integer(unsigned(xr))-to_integer(unsigned(xi));

wr1 :=uu*(to_integer(unsigned(xr))*to_integer(unsigned(wr))*to_integer(unsigned(xr))-to_integer(unsigned(xr))*to_integer(unsigned(wi))*to_integer(unsigned(xi))-to_integer(unsigned(xr))*to_integer(unsigned(xr))-to_integer(unsigned(xi))*to_integer(unsigned(wr))*to_integer(unsigned(xi))-to_integer(unsigned(xi))*to_integer(unsigned(wi))*to_integer(unsigned(xr))+to_integer(unsigned(xi))*to_integer(unsigned(xi))+to_integer(unsigned(wr)));
wi1 :=uu*(to_integer(unsigned(xr))*to_integer(unsigned(wr))*to_integer(unsigned(xi))+to_integer(unsigned(xr))*to_integer(unsigned(wi))*to_integer(unsigned(xr))-to_integer(unsigned(xr))*to_integer(unsigned(xi))+to_integer(unsigned(xi))*to_integer(unsigned(wr))*to_integer(unsigned(xr))-to_integer(unsigned(xi))*to_integer(unsigned(wi))*to_integer(unsigned(xi))-to_integer(unsigned(xi))*to_integer(unsigned(xr))+to_integer(unsigned(wi)));


--o <= std_logic_vector(to_unsigned(i,5));
wr := std_logic_vector(to_unsigned(wr1,13));
wi := std_logic_vector(to_unsigned(wi1,13));

zz :=z;
sum := sum+2;



yr <= std_logic_vector(to_unsigned(yr1,13));
yi <= std_logic_vector(to_unsigned(yi1,13));

er <= std_logic_vector(to_unsigned(er1,13));
ei <= std_logic_vector(to_unsigned(ei1,13));

wr8 <= wr;
wi8 <= wi;

zzz <= std_logic_vector(to_unsigned(zz,13));
sum1 <= std_logic_vector(to_unsigned(sum,13));

end loop;

end process;


end Behavioral;