anchor.diff:  	  %% All arguments are untagged. Let's untag the destination.
   	  Dst = hipe_icode:phi_dst(I),
   	  NewDst = hipe_icode:mk_new_fvar(),
  -	  NewMap1 = gb_trees:enter(Dst, NewDst, NewMap),
  +	  NewMap1 = NewMap#{Dst => NewDst},
   	  NewI = subst_phi_uncond(I, NewDst, PhiMap),
   	  transform_instrs(Left, NewPhiMap, NewMap1, [NewI|Acc]);
   	_ ->
  
positive.code: update_maps(State, _From, [], _Map, Acc) ->
    {State, Acc}.
  
  transform_instrs([I|Left], PhiMap, Map, Acc) ->
    Defines = hipe_icode:defines(I),
    NewMap = delete_all(Defines, Map),
    NewPhiMap = delete_all(Defines, PhiMap),
    case I of
      #icode_phi{} ->
        Uses = hipe_icode:uses(I),
  
negative.code:       end
    end.
  
  -spec update_maps(#state{}, icode_lbl(), ordsets:ordset(icode_lbl()),
  		  var_map(), ordsets:ordset(icode_lbl()), var_map())
  		 -> fixpoint | {#state{}, [icode_lbl()]}.
  
  update_maps(State, Label, SuccSet, SuccMap, FailSet, FailMap) ->
    {NewState, Add1} = update_maps(State, Label, SuccSet, SuccMap, []),
    case update_maps(NewState, Label, FailSet, FailMap, Add1) of
      {_NewState1, []} -> fixpoint;
      {_NewState1, _Add} = Ret -> Ret
    end.
  
  -spec update_maps(#state{}, icode_lbl(), ordsets:ordset(icode_lbl()),
  		  var_map(), [icode_lbl()])
  		 -> {#state{}, [icode_lbl()]}.
  
  update_maps(State, From, [To|Left], Map, Acc) ->
    case state__map_update(State, From, To, Map) of
  