with Report;
with Ada.Real_Time;
with Text_IO;

procedure Sieve is

   use Report;
   use Ada.Real_Time;
   use Text_IO;

   package IO is new Integer_IO (Integer);
   use IO;

   Start_Time, Stop_Time : Time;

   --

   Size : constant := 8190;

   k, Prime, Count : Natural;

   type ftype is array (0 .. Size) of Boolean;
   Flags : Ftype;

begin
 
   Test ("sieve", "The Sieve benchmark");

   Start_Time := Clock;

   for Iter in 1 .. 10 loop
      Count := 0;

      for i in 0 .. Size loop
         Flags (i) := True;
      end loop;

      for i in 0 .. Size loop
         if Flags (i) then
            Prime := i + i + 3;
            k := i + Prime;
            while k <= Size loop
               Flags (k) := False;
               k := k + Prime;
            end loop;
            Count := Count + 1;
         end if;
      end loop;
   end loop;

   Stop_Time := Clock;

   if Count /= 1899 then
      Failed ("Count has wrong value");
   end if;

   Put ("Time taken = ");
   Put (Integer (1000.0 * To_Duration (Time_Span'(Stop_Time - Start_Time))), 0);
   Put (" mSec");
   New_Line;

   Result;
end Sieve;