------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- This file is part of 'Finite Field Arithmetic', aka 'FFA'.               --
--                                                                          --
-- (C) 2017 Stanislav Datskovskiy ( www.loper-os.org )                      --
-- http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html     --
--                                                                          --
-- You do not have, nor can you ever acquire the right to use, copy or      --
-- distribute this software ; Should you use this software for any purpose, --
-- or copy and distribute it to anyone or in any manner, you are breaking   --
-- the laws of whatever soi-disant jurisdiction, and you promise to         --
-- continue doing so for the indefinite future. In any case, please         --
-- always : read and understand any software ; verify any PGP signatures    --
-- that you use - for any purpose.                                          --
--                                                                          --
-- See also http://trilema.com/2015/a-new-software-licensing-paradigm .     --
------------------------------------------------------------------------------
------------------------------------------------------------------------------

package body FZ_Lim is
   
   -- Determine if a proposed FFA Bitness is valid.
   function FZ_Valid_Bitness_P(B : in Positive) return Boolean is
      Result   : Boolean := False;
      T        : Natural := B;
      PopCount : Natural := 0;
   begin
      -- Supposing we meet the minimal bitness:
      if B >= FZ_Minimal_Bitness then
         while T > 0 loop
            if T mod 2 = 1 then
               PopCount := PopCount + 1;
            end if;
            T := T / 2;
         end loop;
         
         -- Is B a power of 2?
         if PopCount = 1 then
            Result := True;
         end if;
      end if;
      
      return Result;
   end FZ_Valid_Bitness_P;
   
end FZ_Lim;