anchor.diff:      Fail = shortcut_bs_test(Fail1, Is, D),
       Sel = {select,select_val,Reg,{f,Fail},List},
       backward(Is, D, [Sel|Acc]);
  -backward([{jump,{f,To0}},{move,Src,Reg}=Move0|Is], D, Acc) ->
  -    {To,Move} = case Src of
  -		    {atom,Val0} ->
  -			To1 = shortcut_select_label(To0, Reg, Val0, D),
  -			{To2,Val} = shortcut_boolean_label(To1, Reg, Val0, D),
  -			{To2,{move,{atom,Val},Reg}};
  -		    _ ->
  -			{shortcut_label(To0, D),Move0}
  -		end,
  +backward([{jump,{f,To0}},{move,Src0,Reg}|Is], D, Acc) ->
  +    To1 = shortcut_select_label(To0, Reg, Src0, D),
  +    {To,Src} = shortcut_boolean_label(To1, Reg, Src0, D),
  +    Move = {move,Src,Reg},
       Jump = {jump,{f,To}},
       case beam_utils:is_killed_at(Reg, To, D) of
   	false -> backward([Move|Is], D, [Jump|Acc]);
  
positive.code: backward([{test,bs_start_match2,{f,To0},Live,[Src|_]=Info,Dst}|Is], D, Acc) ->
      To = shortcut_bs_start_match(To0, Src, D),
      I = {test,bs_start_match2,{f,To},Live,Info,Dst},
      backward(Is, D, [I|Acc]);
  backward([{test,is_eq_exact,{f,To0},[Reg,{atom,Val}]=Ops}|Is], D, Acc) ->
      To1 = shortcut_bs_test(To0, Is, D),
      To = shortcut_fail_label(To1, Reg, Val, D),
      I = combine_eqs(To, Ops, D, Acc),
      backward(Is, D, [I|Acc]);
  backward([{test,Op,{f,To0},Ops0}|Is], D, Acc) ->
      To1 = shortcut_bs_test(To0, Is, D),
  
negative.code: 	_ -> To0
      end.
  
  shortcut_select_label(To, Reg, Lit, D) ->
      shortcut_rel_op(To, is_ne_exact, [Reg,Lit], D).
  
  shortcut_boolean_label(To0, Reg, {atom,Bool0}=Lit, D) when is_boolean(Bool0) ->
      case beam_utils:code_at(To0, D) of
  	[{line,_},{bif,'not',_,[Reg],Reg},{jump,{f,To}}|_] ->
  	    Bool = {atom,not Bool0},
  	    {shortcut_select_label(To, Reg, Bool, D),Bool};
  	_ ->
  	    {To0,Lit}
      end;
  shortcut_boolean_label(To, _, Bool, _) -> {To,Bool}.
  
  replace_comp_op(To, Reg, Op, Ops, D) ->
      False = comp_op_find_shortcut(To, Reg, {atom,false}, D),
      True = comp_op_find_shortcut(To, Reg, {atom,true}, D),
      [bif_to_test(Op, Ops, False),{jump,{f,True}}].
  
  comp_op_find_shortcut(To0, Reg, Val, D) ->
  