Re: sub-optimal code for packed boolean arrays -- bug or inherent limitation

[Stefan Lucks <lucks@th.informatik.uni-mannheim.de>]

As Clear, internally using XOR, is optimised well, have you tried to 
rewrite Flip using XOR for bit-flipping, e.g., as follows:

     procedure Flip(B : in out Bitboard_T; I : in Index_T) is
        One: constant Bitborard := (others => True);
     begin
         B(i) := B(i) xor One;
     end;

(Even though the optimiser appararently could be improved here -- I would 
not consider this a bug, it is more like a missing feature -- this might 
perhaps solve your current problem without having to use inline-assembly.)


-- 
Stefan Lucks      (moved to Bauhaus-University Weimar, Germany)
 		       <Stefan.Lucks at medien.uni-weimar.de>
------  I  love  the  taste  of  Cryptanalysis  in  the  morning!  ------