anchor.diff:      backward(Is, beam_utils:index_label(Lbl, Acc, D), [L|Acc]);
   backward([{select,select_val,Reg,{f,Fail0},List0}|Is], D, Acc) ->
       List1 = shortcut_select_list(List0, Reg, D, []),
  -    Fail1 = shortcut_label(Fail0, D),
  -    Fail = shortcut_bs_test(Fail1, Is, D),
  +    Fail = shortcut_label(Fail0, D),
       List = prune_redundant(List1, Fail),
       case List of
   	[] ->
  
positive.code:     %%        . . .		          ==>   ...
      %% Fail1: test Op {f,Fail2} Operands        Fail1: test Op {f,Fail2} Operands
      %%
      To = case beam_utils:code_at(To3, D) of
  	     [{test,Op,{f,To4},Ops}|_] ->
  		 case equal_ops(Ops0, Ops) of
  		     true -> To4;
  		     false -> To3
  		 end;
  	     _Code ->
  		 To3
  	 end,
      I = case Op of
  	    is_eq_exact -> combine_eqs(To, Ops0, D, Acc);
  
negative.code: 	    backward([I|Is], D, Acc)
      end;
  backward([{test,Op,{f,To0},Live,Ops0,Dst}|Is], D, Acc) ->
      To1 = shortcut_label(To0, D),
  
      %% Try to shortcut a repeated test:
      %%
      %%        test Op {f,Fail1} _ Ops _ 	test Op {f,Fail2} _ Ops _
      %%        . . .		          ==>   ...
      %% Fail1: test Op {f,Fail2} _ Ops _   Fail1: test Op {f,Fail2} _ Ops _
      %%
      To = case beam_utils:code_at(To1, D) of
  	     [{test,Op,{f,To2},_,Ops,_}|_] ->
  		 case equal_ops(Ops0, Ops) of
  		     true -> To2;
  		     false -> To1
  		 end;
  	     _Code ->
  		 To1
  	 end,
      I = {test,Op,{f,To},Live,Ops0,Dst},
      backward(Is, D, [I|Acc]);
  