IC 74374-getting incorrect simulation

[xorro]

VHDL code is my implementation of ic74ls374. When i did the simulation i get 'U' at the start. I am currently learning vhdl so the code i wrote might be messy. I would appreciate any help.
ic74374 datasheet--> http://ecee.colorado.edu/~mcclurel/dm74ls374.pdf

Waveform

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity ic74374 is
    port(
    oc:in std_logic;--OEx
    d1,d2,d3,d4,d5,d6,d7,d8:in std_logic;
    q1,q2,q3,q4,q5,q6,q7,q8:out std_logic;
    clk:in std_logic
    );
end ic74374;

architecture Behavioral of ic74374 is
   
begin
    proc: process (oc,clk) is
    variable temp_q1,temp_q2,temp_q3,temp_q4,temp_q5,temp_q6,temp_q7,temp_q8:std_logic;
    variable impedance:std_logic:='Z';
    variable cur_temp_q1,cur_temp_q2,cur_temp_q3,cur_temp_q4,cur_temp_q5,cur_temp_q6,cur_temp_q7,cur_temp_q8:std_logic;
    variable prev_temp_q1,prev_temp_q2,prev_temp_q3,prev_temp_q4,prev_temp_q5,prev_temp_q6,prev_temp_q7,prev_temp_q8:std_logic;
    begin
        q1<=temp_q1;
        q2<=temp_q2;
        q3<=temp_q3;
        q4<=temp_q4;
        q5<=temp_q5;
        q6<=temp_q6;
        q7<=temp_q7;
        q8<=temp_q8;

        if(oc='0')then--oc ->output control
           
            if(rising_edge(clk))then
                          
                if(prev_temp_q1='X')then
                    prev_temp_q1:=d1;
                    temp_q1:=prev_temp_q1;
                else
                    cur_temp_q1:=d1;--temp_d1;
                    temp_q1:=cur_temp_q1;
                    prev_temp_q1:=cur_temp_q1;
                end if;
                ---------------------------------
                if(prev_temp_q2='X')then
                    prev_temp_q2:=d2;
                    temp_q2:=prev_temp_q2;
                else
                    cur_temp_q2:=d2;
                    temp_q2:=d2;--temp_d2;
                    prev_temp_q2:=cur_temp_q2;
                end if;
                ---------------------------------   
                if(prev_temp_q3='X')then
                    prev_temp_q3:=d3;
                    temp_q3:=prev_temp_q3;
                else
                    cur_temp_q3:=d3;
                    temp_q3:=d3;--temp_d3;
                    prev_temp_q3:=cur_temp_q3;
                end if;
                ---------------------------------  
                if(prev_temp_q4='X')then
                    prev_temp_q4:=d4;
                    temp_q4:=prev_temp_q4;
                else
                    cur_temp_q4:=d4;
                    temp_q4:=d4;--temp_d4;
                    prev_temp_q4:=cur_temp_q4;
                end if;
                ----------------------------------
                if(prev_temp_q5='X')then
                    prev_temp_q5:=d5;
                    temp_q5:=prev_temp_q5;
                else   
                    cur_temp_q5:=d5;
                    temp_q5:=d5;--temp_d5;
                    prev_temp_q5:=cur_temp_q5;
                end if;
                ----------------------------------
                if(prev_temp_q6='X')then
                    prev_temp_q6:=d6;
                    temp_q6:=prev_temp_q6;
                else
                    cur_temp_q6:=d6;
                    temp_q6:=d6;--temp_d6;
                    prev_temp_q6:=cur_temp_q6;
                end if;
                ----------------------------------
                if(prev_temp_q7='X')then
                    prev_temp_q7:=d7;
                    temp_q7:=prev_temp_q7;
                else   
                   cur_temp_q7:=d7;
                   temp_q7:=d7;--temp_d7;
                   prev_temp_q7:=cur_temp_q7;
                end if;
                ----------------------------------
                if(prev_temp_q8='X')then
                    prev_temp_q8:=d8;
                    temp_q8:=prev_temp_q8;
                else
                    cur_temp_q8:=d8;
                    temp_q8:=d8;--temp_d8;
                    prev_temp_q8:=cur_temp_q8;
                end if;
            end if;
       
            if(clk'event and clk='0')then
                temp_q1:=prev_temp_q1;
                temp_q2:=prev_temp_q2;
                temp_q3:=prev_temp_q3;
                temp_q4:=prev_temp_q4;
                temp_q5:=prev_temp_q5;
                temp_q6:=prev_temp_q6;
                temp_q7:=prev_temp_q7;
                temp_q8:=prev_temp_q8;
            end if;
        elsif(oc='1')then
            temp_q1:=impedance;
            temp_q2:=impedance;
            temp_q3:=impedance;
            temp_q4:=impedance;
            temp_q5:=impedance;
            temp_q6:=impedance;
            temp_q7:=impedance;
            temp_q8:=impedance;
        end if;
   
    end process;

end Behavioral;

Testbench

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;

entity ic74374_tb is
--  Port ( );
end ic74374_tb;

architecture Behavioral of ic74374_tb is
    component ic74374 is
    port(
    oc:in std_logic;--OEx
    d1,d2,d3,d4,d5,d6,d7,d8:in std_logic;
    q1,q2,q3,q4,q5,q6,q7,q8:out std_logic;
    clk:in std_logic
    );
    end component;
   
    signal oc: std_logic;--OEx
    signal d1,d2,d3,d4,d5,d6,d7,d8: std_logic;
    signal q1,q2,q3,q4,q5,q6,q7,q8: std_logic;
    signal clk: std_logic:='1';
   
begin
    uut: ic74374 port map(
    oc=>oc,
    clk=>clk,
    d1=>d1,
    d2=>d2,
    d3=>d3,
    d4=>d4,
    d5=>d5,
    d6=>d6,
    d7=>d7,
    d8=>d8,
    q1=>q1,
    q2=>q2,
    q3=>q3,
    q4=>q4,
    q5=>q5,
    q6=>q6,
    q7=>q7,
    q8=>q8
    );
   
    clk<= not clk after 50ns;
   
    sim: process begin
        d1<='1';
        d2<='0';
        d3<='1';
        d4<='0';
        d5<='1';
        d6<='0';
        d7<='1';
        d8<='0';
        oc<='0';
        wait for 100ns;
        d1<='0';
        oc<='0';
        wait for 600ns;
        oc<='0';
        wait for 100ns;
        oc<='0';
        wait;
    end process;

end Behavioral;