anchor.diff:  		{killed,St} ->
   		    case member(R, Ds) of
   			true -> {killed,St};
  +			false -> check_liveness_block(R, Is, St)
  +		    end;
  +		{exit_not_used,St} ->
  +		    case member(R, Ds) of
  +			true -> {exit_not_used,St};
   			false -> check_liveness_block(R, Is, St)
   		    end;
   		{not_used,St} ->
  
positive.code: 		false ->
  		    if
  			R =:= Dst -> {killed,St};
  			true -> check_liveness(R, Is, St)
  		    end
  	    end
      end;
  
negative.code: %%
  %%    killed - Reg is assigned or killed by an allocation instruction.
  %%    not_used - the value of Reg is not used, but Reg must not be garbage
  %%    exit_not_used - the value of Reg is not used, but must not be garbage
  %%                    because the stack will be scanned because an
  %%                    exit BIF will raise an exception
  %%    used - Reg is used
  
  check_liveness(R, [{block,Blk}|Is], St0) ->
  