Use flist for disconnection specification and component specification.

14 files changed, 133 insertions, 93 deletions

diff --git a/src/vhdl/canon.adb b/src/vhdl/canon.adb
index ed920f89a..f4050f92e 100644
--- a/src/vhdl/canon.adb
+++ b/src/vhdl/canon.adb
@@ -2216,7 +2216,7 @@ package body Canon is
 
       Bind : Iir;
       Comp : Iir;
-      Instances : Iir_List;
+      Instances : Iir_Flist;
       Entity_Aspect : Iir;
       Block : Iir_Block_Configuration;
       Map_Chain : Iir;
@@ -2229,9 +2229,9 @@ package body Canon is
          Instances := Get_Instantiation_List (Cfg);
          --  Designator_all and designator_others must have been replaced
          --  by a list during canon.
-         pragma Assert (Instances not in Iir_Lists_All_Others);
+         pragma Assert (Instances not in Iir_Flists_All_Others);
          Bind := Get_Default_Binding_Indication
-           (Get_Named_Entity (Get_First_Element (Instances)));
+           (Get_Named_Entity (Get_Nth_Element (Instances, 0)));
          if Bind = Null_Iir then
             --  Component is not bound.
             return;
@@ -2429,7 +2429,7 @@ package body Canon is
       Res_Binding : Iir_Binding_Indication;
       Entity : Iir;
       Instance_List : Iir_List;
-      Conf_Instance_List : Iir_List;
+      Conf_Instance_List : Iir_Flist;
       Instance : Iir;
       Instance_Name : Iir;
       N_Nbr : Natural;
@@ -2479,10 +2479,9 @@ package body Canon is
       --   replace component_configuration of them
       --   remove them in the instance list of COMP_CONF
       Instance_List := Create_Iir_List;
-      Set_Instantiation_List (Res, Instance_List);
       Conf_Instance_List := Get_Instantiation_List (Comp_Conf);
       N_Nbr := 0;
-      for I in 0 .. Get_Nbr_Elements (Conf_Instance_List) - 1 loop
+      for I in Flist_First .. Flist_Last (Conf_Instance_List) loop
          Instance_Name := Get_Nth_Element (Conf_Instance_List, I);
          Instance := Get_Named_Entity (Instance_Name);
          if Get_Component_Configuration (Instance) = Conf_Spec then
@@ -2490,11 +2489,13 @@ package body Canon is
             Set_Component_Configuration (Instance, Res);
             Append_Element (Instance_List, Instance_Name);
          else
-            Replace_Nth_Element (Conf_Instance_List, N_Nbr, Instance_Name);
+            Set_Nth_Element (Conf_Instance_List, N_Nbr, Instance_Name);
             N_Nbr := N_Nbr + 1;
          end if;
       end loop;
-      Set_Nbr_Elements (Conf_Instance_List, N_Nbr);
+      Set_Instantiation_List (Comp_Conf,
+                              Truncate_Flist (Conf_Instance_List, N_Nbr));
+      Set_Instantiation_List (Res, List_To_Flist (Instance_List));
 
       --  Insert RES.
       Set_Chain (Res, Get_Chain (Comp_Conf));
@@ -2502,7 +2503,7 @@ package body Canon is
    end Canon_Incremental_Binding;
 
    procedure Canon_Component_Specification_All_Others
-     (Conf : Iir; Parent : Iir; Spec : Iir_List; List : Iir_List; Comp : Iir)
+     (Conf : Iir; Parent : Iir; Spec : Iir_Flist; List : Iir_List; Comp : Iir)
    is
       El : Iir;
       Comp_Conf : Iir;
@@ -2526,14 +2527,14 @@ package body Canon is
                --  The component is already configured.
                --  Handle incremental configuration.
                if Get_Kind (Comp_Conf) = Iir_Kind_Configuration_Specification
-                 and then Spec = Iir_List_All
+                 and then Spec = Iir_Flist_All
                then
                   --  FIXME: handle incremental configuration.
                   raise Internal_Error;
                end if;
                --  Several component configuration for an instance.
                --  Must have been caught by sem.
-               pragma Assert (Spec = Iir_List_Others);
+               pragma Assert (Spec = Iir_Flist_Others);
             end if;
          end if;
          El := Get_Chain (El);
@@ -2541,15 +2542,14 @@ package body Canon is
    end Canon_Component_Specification_All_Others;
 
    procedure Canon_Component_Specification_List
-     (Conf : Iir; Parent : Iir; Spec : Iir_List)
+     (Conf : Iir; Parent : Iir; Spec : Iir_Flist)
    is
       El : Iir;
       Comp_Conf : Iir;
    begin
       --  Already has a designator list.
-      for I in Natural loop
+      for I in Flist_First .. Flist_Last (Spec) loop
          El := Get_Nth_Element (Spec, I);
-         exit when El = Null_Iir;
          El := Get_Named_Entity (El);
          Comp_Conf := Get_Component_Configuration (El);
          if Comp_Conf /= Null_Iir and then Comp_Conf /= Conf then
@@ -2567,15 +2567,15 @@ package body Canon is
    --  PARENT is the parent for the chain of concurrent statements.
    procedure Canon_Component_Specification (Conf : Iir; Parent : Iir)
    is
-      Spec : constant Iir_List := Get_Instantiation_List (Conf);
+      Spec : constant Iir_Flist := Get_Instantiation_List (Conf);
       List : Iir_Designator_List;
    begin
-      if Spec in Iir_Lists_All_Others then
+      if Spec in Iir_Flists_All_Others then
          List := Create_Iir_List;
          Canon_Component_Specification_All_Others
            (Conf, Parent, Spec, List,
             Get_Named_Entity (Get_Component_Name (Conf)));
-         Set_Instantiation_List (Conf, List);
+         Set_Instantiation_List (Conf, List_To_Flist (List));
       else
          --  Has Already a designator list.
          Canon_Component_Specification_List (Conf, Parent, Spec);
@@ -2586,7 +2586,7 @@ package body Canon is
    procedure Canon_Disconnection_Specification
      (Dis : Iir_Disconnection_Specification; Decl_Parent : Iir)
    is
-      Signal_List : Iir_List;
+      Signal_List : Iir_Flist;
       Force : Boolean;
       El : Iir;
       N_List : Iir_Designator_List;
@@ -2598,9 +2598,9 @@ package body Canon is
 
       if Canon_Flag_Specification_Lists then
          Signal_List := Get_Signal_List (Dis);
-         if Signal_List = Iir_List_All then
+         if Signal_List = Iir_Flist_All then
             Force := True;
-         elsif Signal_List = Iir_List_Others then
+         elsif Signal_List = Iir_Flist_Others then
             Force := False;
          else
             --  User list: nothing to do.
@@ -2609,7 +2609,6 @@ package body Canon is
 
          Dis_Type := Get_Type (Get_Type_Mark (Dis));
          N_List := Create_Iir_List;
-         Set_Signal_List (Dis, N_List);
          Set_Is_Ref (Dis, True);
          El := Get_Declaration_Chain (Decl_Parent);
          while El /= Null_Iir loop
@@ -2628,6 +2627,7 @@ package body Canon is
             end if;
             El := Get_Chain (El);
          end loop;
+         Set_Signal_List (Dis, List_To_Flist (N_List));
       end if;
    end Canon_Disconnection_Specification;
 
@@ -2941,7 +2941,7 @@ package body Canon is
                   Comp_Conf : Iir;
                   Res : Iir_Component_Configuration;
                   Designator_List : Iir_List;
-                  Inst_List : Iir_List;
+                  Inst_List : Iir_Flist;
                   Inst : Iir;
                   Inst_Name : Iir;
                begin
@@ -2960,7 +2960,8 @@ package body Canon is
                         Designator_List := Create_Iir_List;
                         Append_Element
                           (Designator_List, Build_Simple_Name (El, El));
-                        Set_Instantiation_List (Res, Designator_List);
+                        Set_Instantiation_List
+                          (Res, List_To_Flist (Designator_List));
                         Append (Last_Item, Conf, Res);
                      end if;
                   elsif Get_Kind (Comp_Conf)
@@ -2978,7 +2979,7 @@ package body Canon is
                      --  statements parts (vhdl-87 generate issue).
                      Inst_List := Get_Instantiation_List (Comp_Conf);
                      Designator_List := Create_Iir_List;
-                     for I in 0 .. Get_Nbr_Elements (Inst_List) - 1 loop
+                     for I in Flist_First .. Flist_Last (Inst_List) loop
                         Inst_Name := Get_Nth_Element (Inst_List, I);
                         Inst := Get_Named_Entity (Inst_Name);
                         if Get_Component_Configuration (Inst) = Comp_Conf
@@ -2989,7 +2990,8 @@ package body Canon is
                                            Build_Reference_Name (Inst_Name));
                         end if;
                      end loop;
-                     Set_Instantiation_List (Res, Designator_List);
+                     Set_Instantiation_List
+                       (Res, List_To_Flist (Designator_List));
                      Set_Binding_Indication
                        (Res, Get_Binding_Indication (Comp_Conf));
                      Set_Is_Ref (Res, True);
diff --git a/src/vhdl/configuration.adb b/src/vhdl/configuration.adb
index 9e425731f..f02c17d25 100644
--- a/src/vhdl/configuration.adb
+++ b/src/vhdl/configuration.adb
@@ -425,7 +425,7 @@ package body Configuration is
       Inst_Inter_Chain : Iir;
       Err : Boolean;
       Inst : Iir;
-      Inst_List : Iir_List;
+      Inst_List : Iir_Flist;
       Formal : Iir;
       Assoc_1 : Iir;
       Inter_1 : Iir;
@@ -460,9 +460,8 @@ package body Configuration is
 
       --  Second pass: check for port connected to open in instantiation.
       Inst_List := Get_Instantiation_List (Conf);
-      for I in Natural loop
+      for I in Flist_First .. Flist_Last (Inst_List) loop
          Inst := Get_Nth_Element (Inst_List, I);
-         exit when Inst = Null_Iir;
          Inst := Get_Named_Entity (Inst);
          Err := False;
 
@@ -543,7 +542,7 @@ package body Configuration is
    begin
       if Bind = Null_Iir then
          if Is_Warning_Enabled (Warnid_Binding) then
-            Inst := Get_First_Element (Get_Instantiation_List (Conf));
+            Inst := Get_Nth_Element (Get_Instantiation_List (Conf), 0);
             Inst := Strip_Denoting_Name (Inst);
             Warning_Msg_Elab
               (Warnid_Binding, Conf,
diff --git a/src/vhdl/disp_vhdl.adb b/src/vhdl/disp_vhdl.adb
index 6ff630e04..e36e1e1fd 100644
--- a/src/vhdl/disp_vhdl.adb
+++ b/src/vhdl/disp_vhdl.adb
@@ -1525,18 +1525,17 @@ package body Disp_Vhdl is
       end if;
    end Disp_Subprogram_Body;
 
-   procedure Disp_Instantiation_List (Insts: Iir_List) is
+   procedure Disp_Instantiation_List (Insts: Iir_Flist) is
       El : Iir;
    begin
-      if Insts = Iir_List_All then
+      if Insts = Iir_Flist_All then
          Put ("all");
-      elsif Insts = Iir_List_Others then
+      elsif Insts = Iir_Flist_Others then
          Put ("others");
       else
-         for I in Natural loop
+         for I in Flist_First .. Flist_Last (Insts) loop
             El := Get_Nth_Element (Insts, I);
-            exit when El = Null_Iir;
-            if I /= Natural'First then
+            if I /= Flist_First then
                Put (", ");
             end if;
             Disp_Name (El);
diff --git a/src/vhdl/flists.adb b/src/vhdl/flists.adb
index 4aca3d6ad..4c8067542 100644
--- a/src/vhdl/flists.adb
+++ b/src/vhdl/flists.adb
@@ -133,9 +133,9 @@ package body Flists is
       Flist := Null_Flist;
    end Destroy_Flist;
 
-   function Flast (Flist : Flist_Type) return Natural is
+   function Flast (Flist : Flist_Type) return Integer is
    begin
-      return Natural (Flistt.Table (Flist).Len - 1);
+      return Integer (Flistt.Table (Flist).Len - 1);
    end Flast;
 
    function Length (Flist : Flist_Type) return Natural is
diff --git a/src/vhdl/flists.ads b/src/vhdl/flists.ads
index 43f5ceca0..6c05d7695 100644
--- a/src/vhdl/flists.ads
+++ b/src/vhdl/flists.ads
@@ -38,7 +38,7 @@ package Flists is
 
    --  First and last index of FLIST.  Could be used to iterate.
    Ffirst : constant Natural := 0;
-   function Flast (Flist : Flist_Type) return Natural;
+   function Flast (Flist : Flist_Type) return Integer;
 
    --  Return the length of FLIST.
    function Length (Flist : Flist_Type) return Natural;
diff --git a/src/vhdl/iirs.adb b/src/vhdl/iirs.adb
index 2fb4f5d34..d3210dfaa 100644
--- a/src/vhdl/iirs.adb
+++ b/src/vhdl/iirs.adb
@@ -1275,20 +1275,20 @@ package body Iirs is
       Set_Field4 (Val, Attr);
    end Set_Attribute_Specification;
 
-   function Get_Signal_List (Target : Iir) return Iir_List is
+   function Get_Signal_List (Target : Iir) return Iir_Flist is
    begin
       pragma Assert (Target /= Null_Iir);
       pragma Assert (Has_Signal_List (Get_Kind (Target)),
                      "no field Signal_List");
-      return Iir_To_Iir_List (Get_Field3 (Target));
+      return Iir_To_Iir_Flist (Get_Field3 (Target));
    end Get_Signal_List;
 
-   procedure Set_Signal_List (Target : Iir; List : Iir_List) is
+   procedure Set_Signal_List (Target : Iir; List : Iir_Flist) is
    begin
       pragma Assert (Target /= Null_Iir);
       pragma Assert (Has_Signal_List (Get_Kind (Target)),
                      "no field Signal_List");
-      Set_Field3 (Target, Iir_List_To_Iir (List));
+      Set_Field3 (Target, Iir_Flist_To_Iir (List));
    end Set_Signal_List;
 
    function Get_Designated_Entity (Val : Iir_Attribute_Value) return Iir is
@@ -4283,20 +4283,20 @@ package body Iirs is
       Set_Field4 (Target, Name);
    end Set_Component_Name;
 
-   function Get_Instantiation_List (Target : Iir) return Iir_List is
+   function Get_Instantiation_List (Target : Iir) return Iir_Flist is
    begin
       pragma Assert (Target /= Null_Iir);
       pragma Assert (Has_Instantiation_List (Get_Kind (Target)),
                      "no field Instantiation_List");
-      return Iir_To_Iir_List (Get_Field1 (Target));
+      return Iir_To_Iir_Flist (Get_Field1 (Target));
    end Get_Instantiation_List;
 
-   procedure Set_Instantiation_List (Target : Iir; List : Iir_List) is
+   procedure Set_Instantiation_List (Target : Iir; List : Iir_Flist) is
    begin
       pragma Assert (Target /= Null_Iir);
       pragma Assert (Has_Instantiation_List (Get_Kind (Target)),
                      "no field Instantiation_List");
-      Set_Field1 (Target, Iir_List_To_Iir (List));
+      Set_Field1 (Target, Iir_Flist_To_Iir (List));
    end Set_Instantiation_List;
 
    function Get_Entity_Aspect (Target : Iir_Binding_Indication) return Iir is
diff --git a/src/vhdl/iirs.ads b/src/vhdl/iirs.ads
index 3ec70eaa8..de5348584 100644
--- a/src/vhdl/iirs.ads
+++ b/src/vhdl/iirs.ads
@@ -5406,6 +5406,9 @@ package Iirs is
    Iir_Flist_Others : constant Iir_Flist := Flists.Flist_Others;
    Iir_Flist_All    : constant Iir_Flist := Flists.Flist_All;
 
+   subtype Iir_Flists_All_Others is Iir_Flist
+     range Iir_Flist_Others .. Iir_Flist_All;
+
    Flist_First : constant Natural := Flists.Ffirst;
    function Flist_Last (Flist : Iir_Flist) return Natural
      renames Flists.Flast;
@@ -6001,8 +6004,8 @@ package Iirs is
    procedure Set_Attribute_Specification (Val : Iir; Attr : Iir);
 
    --  Field: Field3 Of_Maybe_Ref (uc)
-   function Get_Signal_List (Target : Iir) return Iir_List;
-   procedure Set_Signal_List (Target : Iir; List : Iir_List);
+   function Get_Signal_List (Target : Iir) return Iir_Flist;
+   procedure Set_Signal_List (Target : Iir; List : Iir_Flist);
 
    --  Field: Field3 Forward_Ref
    function Get_Designated_Entity (Val : Iir_Attribute_Value) return Iir;
@@ -6952,8 +6955,8 @@ package Iirs is
    procedure Set_Component_Name (Target : Iir; Name : Iir);
 
    --  Field: Field1 (uc)
-   function Get_Instantiation_List (Target : Iir) return Iir_List;
-   procedure Set_Instantiation_List (Target : Iir; List : Iir_List);
+   function Get_Instantiation_List (Target : Iir) return Iir_Flist;
+   procedure Set_Instantiation_List (Target : Iir; List : Iir_Flist);
 
    --  Field: Field3
    function Get_Entity_Aspect (Target : Iir_Binding_Indication) return Iir;
diff --git a/src/vhdl/iirs_utils.adb b/src/vhdl/iirs_utils.adb
index d60bd12c0..d96be7600 100644
--- a/src/vhdl/iirs_utils.adb
+++ b/src/vhdl/iirs_utils.adb
@@ -74,6 +74,20 @@ package body Iirs_Utils is
       return Res;
    end List_To_Flist;
 
+   function Truncate_Flist (L : Iir_Flist; Len : Natural) return Iir_Flist
+   is
+      Res : Iir_Flist;
+      Temp_L : Iir_Flist;
+   begin
+      Res := Create_Iir_Flist (Len);
+      for I in 0 .. Len - 1 loop
+         Set_Nth_Element (Res, I, Get_Nth_Element (L, I));
+      end loop;
+      Temp_L := L;
+      Destroy_Iir_Flist (Temp_L);
+      return Res;
+   end Truncate_Flist;
+
    function Get_Operator_Name (Op : Iir) return Name_Id is
    begin
       case Get_Kind (Op) is
diff --git a/src/vhdl/iirs_utils.ads b/src/vhdl/iirs_utils.ads
index 25fb936fa..f741b4066 100644
--- a/src/vhdl/iirs_utils.ads
+++ b/src/vhdl/iirs_utils.ads
@@ -46,6 +46,9 @@ package Iirs_Utils is
    --  Convert a list L to an Flist, and free L.
    function List_To_Flist (L : Iir_List) return Iir_Flist;
 
+   --  Return a copy of the LEN first elements of L.  L is destroyed.
+   function Truncate_Flist (L : Iir_Flist; Len : Natural) return Iir_Flist;
+
    --  Convert an operator node to a name.
    function Get_Operator_Name (Op : Iir) return Name_Id;
 
diff --git a/src/vhdl/nodes_meta.adb b/src/vhdl/nodes_meta.adb
index 12e08c5e0..995d7bb88 100644
--- a/src/vhdl/nodes_meta.adb
+++ b/src/vhdl/nodes_meta.adb
@@ -62,7 +62,7 @@ package body Nodes_Meta is
       Field_Attribute_Designator => Type_Iir,
       Field_Attribute_Specification_Chain => Type_Iir,
       Field_Attribute_Specification => Type_Iir,
-      Field_Signal_List => Type_Iir_List,
+      Field_Signal_List => Type_Iir_Flist,
       Field_Designated_Entity => Type_Iir,
       Field_Formal => Type_Iir,
       Field_Actual => Type_Iir,
@@ -248,7 +248,7 @@ package body Nodes_Meta is
       Field_Parent => Type_Iir,
       Field_Loop_Label => Type_Iir,
       Field_Component_Name => Type_Iir,
-      Field_Instantiation_List => Type_Iir_List,
+      Field_Instantiation_List => Type_Iir_Flist,
       Field_Entity_Aspect => Type_Iir,
       Field_Default_Entity_Aspect => Type_Iir,
       Field_Binding_Indication => Type_Iir,
@@ -5911,6 +5911,8 @@ package body Nodes_Meta is
       case F is
          when Field_Simple_Aggregate_List =>
             return Get_Simple_Aggregate_List (N);
+         when Field_Signal_List =>
+            return Get_Signal_List (N);
          when Field_Enumeration_Literal_List =>
             return Get_Enumeration_Literal_List (N);
          when Field_Group_Constituent_List =>
@@ -5925,6 +5927,8 @@ package body Nodes_Meta is
             return Get_Elements_Declaration_List (N);
          when Field_Index_List =>
             return Get_Index_List (N);
+         when Field_Instantiation_List =>
+            return Get_Instantiation_List (N);
          when Field_Type_Marks_List =>
             return Get_Type_Marks_List (N);
          when others =>
@@ -5939,6 +5943,8 @@ package body Nodes_Meta is
       case F is
          when Field_Simple_Aggregate_List =>
             Set_Simple_Aggregate_List (N, V);
+         when Field_Signal_List =>
+            Set_Signal_List (N, V);
          when Field_Enumeration_Literal_List =>
             Set_Enumeration_Literal_List (N, V);
          when Field_Group_Constituent_List =>
@@ -5953,6 +5959,8 @@ package body Nodes_Meta is
             Set_Elements_Declaration_List (N, V);
          when Field_Index_List =>
             Set_Index_List (N, V);
+         when Field_Instantiation_List =>
+            Set_Instantiation_List (N, V);
          when Field_Type_Marks_List =>
             Set_Type_Marks_List (N, V);
          when others =>
@@ -6089,16 +6097,12 @@ package body Nodes_Meta is
             return Get_Analysis_Checks_List (N);
          when Field_Entity_Name_List =>
             return Get_Entity_Name_List (N);
-         when Field_Signal_List =>
-            return Get_Signal_List (N);
          when Field_Sensitivity_List =>
             return Get_Sensitivity_List (N);
          when Field_Callees_List =>
             return Get_Callees_List (N);
          when Field_Guard_Sensitivity_List =>
             return Get_Guard_Sensitivity_List (N);
-         when Field_Instantiation_List =>
-            return Get_Instantiation_List (N);
          when Field_Overload_List =>
             return Get_Overload_List (N);
          when Field_PSL_Clock_Sensitivity =>
@@ -6121,16 +6125,12 @@ package body Nodes_Meta is
             Set_Analysis_Checks_List (N, V);
          when Field_Entity_Name_List =>
             Set_Entity_Name_List (N, V);
-         when Field_Signal_List =>
-            Set_Signal_List (N, V);
          when Field_Sensitivity_List =>
             Set_Sensitivity_List (N, V);
          when Field_Callees_List =>
             Set_Callees_List (N, V);
          when Field_Guard_Sensitivity_List =>
             Set_Guard_Sensitivity_List (N, V);
-         when Field_Instantiation_List =>
-            Set_Instantiation_List (N, V);
          when Field_Overload_List =>
             Set_Overload_List (N, V);
          when Field_PSL_Clock_Sensitivity =>
diff --git a/src/vhdl/parse.adb b/src/vhdl/parse.adb
index 7653083c3..58be80bea 100644
--- a/src/vhdl/parse.adb
+++ b/src/vhdl/parse.adb
@@ -3914,26 +3914,35 @@ package body Parse is
    --  signal_list ::= signal_name { , signal_name }
    --                | OTHERS
    --                | ALL
-   function Parse_Signal_List return Iir_List
+   function Parse_Signal_List return Iir_Flist
    is
       Res : Iir_List;
    begin
       case Current_Token is
          when Tok_Others =>
+            --  Skip 'others'.
             Scan;
-            return Iir_List_Others;
+
+            return Iir_Flist_Others;
+
          when Tok_All =>
+            --  Skip 'all'.
             Scan;
-            return Iir_List_All;
+
+            return Iir_Flist_All;
+
          when others =>
             Res := Create_Iir_List;
             loop
                Append_Element (Res, Parse_Name);
                exit when Current_Token = Tok_Colon;
+
+               --  Skip ','
                Expect (Tok_Comma);
                Scan;
             end loop;
-            return Res;
+
+            return List_To_Flist (Res);
       end case;
    end Parse_Signal_List;
 
@@ -8435,30 +8444,43 @@ package body Parse is
    --  instantiation_list ::= INSTANTIATION_label { , INSTANTIATION_label }
    --                       | OTHERS
    --                       | ALL
-   function Parse_Instantiation_List return Iir_List
+   --
+   --  FIXME: merge with parse_signal_list ?
+   function Parse_Instantiation_List return Iir_Flist
    is
       Res : Iir_List;
    begin
       case Current_Token is
          when Tok_All =>
+            --  Skip 'all'.
             Scan;
-            return Iir_List_All;
+
+            return Iir_Flist_All;
+
          when Tok_Others =>
+            --  Skip 'others'.
             Scan;
-            return Iir_List_Others;
+
+            return Iir_Flist_Others;
+
          when Tok_Identifier =>
             Res := Create_Iir_List;
             loop
                Append_Element (Res, Current_Text);
+               --  Skip identifier.
                Scan;
+
                exit when Current_Token /= Tok_Comma;
+
+               --  Skip ','.
                Expect (Tok_Comma);
                Scan;
             end loop;
-            return Res;
+            return List_To_Flist (Res);
+
          when others =>
             Error_Msg_Parse ("instantiation list expected");
-            return Null_Iir_List;
+            return Null_Iir_Flist;
       end case;
    end Parse_Instantiation_List;
 
@@ -8469,7 +8491,7 @@ package body Parse is
    --  component_specification ::= instantiation_list : COMPONENT_name
    procedure Parse_Component_Specification (Res : Iir)
    is
-      List : Iir_List;
+      List : Iir_Flist;
    begin
       List := Parse_Instantiation_List;
       Set_Instantiation_List (Res, List);
@@ -8564,7 +8586,7 @@ package body Parse is
    --          [ block_configuration ]
    --      END FOR ;
    function Parse_Component_Configuration (Loc : Location_Type;
-                                           Inst_List : Iir_List)
+                                           Inst_List : Iir_Flist)
      return Iir_Component_Configuration
    is
       Res : Iir_Component_Configuration;
@@ -8679,6 +8701,7 @@ package body Parse is
    is
       Loc : Location_Type;
       List : Iir_List;
+      Flist : Iir_Flist;
       El : Iir;
    begin
       Loc := Get_Token_Location;
@@ -8690,19 +8713,19 @@ package body Parse is
       case Current_Token is
          when Tok_All =>
             Scan;
-            return Parse_Component_Configuration (Loc, Iir_List_All);
+            return Parse_Component_Configuration (Loc, Iir_Flist_All);
          when Tok_Others =>
             Scan;
-            return Parse_Component_Configuration (Loc, Iir_List_Others);
+            return Parse_Component_Configuration (Loc, Iir_Flist_Others);
          when Tok_Identifier =>
             El := Current_Text;
             Scan;
             case Current_Token is
                when Tok_Colon =>
                   --  The identifier was a label from an instantiation list.
-                  List := Create_Iir_List;
-                  Append_Element (List, El);
-                  return Parse_Component_Configuration (Loc, List);
+                  Flist := Create_Iir_Flist (1);
+                  Set_Nth_Element (Flist, 0, El);
+                  return Parse_Component_Configuration (Loc, Flist);
                when Tok_Comma =>
                   --  The identifier was a label from an instantiation list.
                   List := Create_Iir_List;
@@ -8713,7 +8736,8 @@ package body Parse is
                      Scan;
                      exit when Current_Token /= Tok_Comma;
                   end loop;
-                  return Parse_Component_Configuration (Loc, List);
+                  Flist := List_To_Flist (List);
+                  return Parse_Component_Configuration (Loc, Flist);
                when Tok_Left_Paren =>
                   El := Parse_Name_Suffix (El);
                   return Parse_Block_Configuration_Suffix (Loc, El);
diff --git a/src/vhdl/sem_specs.adb b/src/vhdl/sem_specs.adb
index 0909315e1..a8a921c7b 100644
--- a/src/vhdl/sem_specs.adb
+++ b/src/vhdl/sem_specs.adb
@@ -959,7 +959,7 @@ package body Sem_Specs is
       Type_Mark : Iir;
       Atype : Iir;
       Time_Expr : Iir;
-      List : Iir_List;
+      List : Iir_Flist;
       El : Iir;
       Sig : Iir;
       Prefix : Iir;
@@ -984,17 +984,16 @@ package body Sem_Specs is
       end if;
 
       List := Get_Signal_List (Dis);
-      if List = Iir_List_All or List = Iir_List_Others then
+      if List in Iir_Flists_All_Others then
          --  FIXME: checks todo
          null;
       else
-         for I in Natural loop
+         for I in Flist_First .. Flist_Last (List) loop
             El := Get_Nth_Element (List, I);
-            exit when El = Null_Iir;
 
             Sem_Name (El);
             El := Finish_Sem_Name (El);
-            Replace_Nth_Element (List, I, El);
+            Set_Nth_Element (List, I, El);
 
             Sig := Get_Named_Entity (El);
             Sig := Name_To_Object (Sig);
@@ -1321,7 +1320,7 @@ package body Sem_Specs is
          return Res;
       end Apply_Component_Specification;
 
-      List : Iir_List;
+      List : Iir_Flist;
       El : Iir;
       Inter : Sem_Scopes.Name_Interpretation_Type;
       Comp : Iir;
@@ -1339,7 +1338,7 @@ package body Sem_Specs is
       end if;
 
       List := Get_Instantiation_List (Spec);
-      if List = Iir_List_All then
+      if List = Iir_Flist_All then
          --  LRM93 5.2
          --  * If the reserved word ALL is supplied, then the configuration
          --    specification applies to all instances of the specified
@@ -1354,7 +1353,7 @@ package body Sem_Specs is
             Warning_Msg_Sem (Warnid_Specs, +Spec,
                              "component specification applies to no instance");
          end if;
-      elsif List = Iir_List_Others then
+      elsif List = Iir_Flist_Others then
          --  LRM93 5.2
          --  * If the reserved word OTHERS is supplied, then the
          --    configuration specification applies to instances of the
@@ -1386,9 +1385,8 @@ package body Sem_Specs is
          --    instantiation statement whose corresponding instantiated unit
          --    does not name a component.
          -- FIXME: error message are *really* cryptic.
-         for I in Natural loop
+         for I in Flist_First .. Flist_Last (List) loop
             El := Get_Nth_Element (List, I);
-            exit when El = Null_Iir;
             Inter := Sem_Scopes.Get_Interpretation (Get_Identifier (El));
             if not Valid_Interpretation (Inter) then
                Error_Msg_Sem
diff --git a/src/vhdl/translate/trans-chap1.adb b/src/vhdl/translate/trans-chap1.adb
index 08b22098c..a8b61c4d4 100644
--- a/src/vhdl/translate/trans-chap1.adb
+++ b/src/vhdl/translate/trans-chap1.adb
@@ -568,13 +568,12 @@ package body Trans.Chap1 is
 
       --  Call the subprogram for the instantiation list.
       declare
-         List : Iir_List;
+         List : Iir_Flist;
          El   : Iir;
       begin
          List := Get_Instantiation_List (Cfg);
-         for I in Natural loop
+         for I in Flist_First .. Flist_Last (List) loop
             El := Get_Nth_Element (List, I);
-            exit when El = Null_Iir;
             El := Get_Named_Entity (El);
             case Get_Kind (El) is
                when Iir_Kind_Component_Instantiation_Statement =>
diff --git a/src/vhdl/translate/trans-chap5.adb b/src/vhdl/translate/trans-chap5.adb
index ac054f394..e989b8075 100644
--- a/src/vhdl/translate/trans-chap5.adb
+++ b/src/vhdl/translate/trans-chap5.adb
@@ -160,15 +160,14 @@ package body Trans.Chap5 is
      (Spec : Iir_Disconnection_Specification)
    is
       Val  : O_Dnode;
-      List : constant Iir_List := Get_Signal_List (Spec);
+      List : constant Iir_Flist := Get_Signal_List (Spec);
       El   : Iir;
    begin
       Val := Create_Temp_Init
         (Std_Time_Otype,
          Chap7.Translate_Expression (Get_Expression (Spec)));
-      for I in Natural loop
+      for I in Flist_First .. Flist_Last (List) loop
          El := Get_Nth_Element (List, I);
-         exit when El = Null_Iir;
          Gen_Elab_Disconnect (Chap6.Translate_Name (El, Mode_Signal),
                               Get_Type (El), Val);
       end loop;