simul: add support of e8.

9 files changed, 205 insertions, 170 deletions

diff --git a/src/vhdl/simulate/annotations.adb b/src/vhdl/simulate/annotations.adb
index b5dcef417..e11bfed2d 100644
--- a/src/vhdl/simulate/annotations.adb
+++ b/src/vhdl/simulate/annotations.adb
@@ -186,7 +186,7 @@ package body Annotations is
                                  Res : in out String;
                                  Off : in out Natural)
    is
-      Scalar_Map : constant array (Iir_Value_Scalars) of Character := "bEIF";
+      Scalar_Map : constant array (Iir_Value_Scalars) of Character := "beEIF";
    begin
       case Get_Kind (Def) is
          when Iir_Kinds_Scalar_Type_Definition =>
@@ -301,18 +301,25 @@ package body Annotations is
 
       case Get_Kind (Def) is
          when Iir_Kind_Enumeration_Type_Definition =>
-            if Def = Std_Package.Boolean_Type_Definition
-              or else Def = Std_Package.Bit_Type_Definition
-            then
-               Set_Info (Def,
-                         new Sim_Info_Type'(Kind => Kind_Scalar_Type,
-                                            Scalar_Mode => Iir_Value_B1));
-            else
-               Set_Info (Def,
-                         new Sim_Info_Type'(Kind => Kind_Scalar_Type,
-                                            Scalar_Mode => Iir_Value_E32));
-            end if;
-            Annotate_Range_Expression (Block_Info, Get_Range_Constraint (Def));
+            declare
+               Mode : Iir_Value_Kind;
+            begin
+               if Def = Std_Package.Boolean_Type_Definition
+                 or else Def = Std_Package.Bit_Type_Definition
+               then
+                  Mode := Iir_Value_B1;
+               elsif (Get_Nbr_Elements (Get_Enumeration_Literal_List (Def))
+                        <= 256)
+               then
+                  Mode := Iir_Value_E8;
+               else
+                  Mode := Iir_Value_E32;
+               end if;
+               Set_Info (Def, new Sim_Info_Type'(Kind => Kind_Scalar_Type,
+                                                 Scalar_Mode => Mode));
+               Annotate_Range_Expression
+                 (Block_Info, Get_Range_Constraint (Def));
+            end;
 
          when Iir_Kind_Integer_Subtype_Definition
            | Iir_Kind_Floating_Subtype_Definition
diff --git a/src/vhdl/simulate/debugger.adb b/src/vhdl/simulate/debugger.adb
index 54e1b42a1..bbb16e231 100644
--- a/src/vhdl/simulate/debugger.adb
+++ b/src/vhdl/simulate/debugger.adb
@@ -362,10 +362,7 @@ package body Debugger is
          return;
       end if;
       case Value.Kind is
-         when Iir_Value_I64
-           | Iir_Value_F64
-           | Iir_Value_E32
-           | Iir_Value_B1
+         when Iir_Value_Scalars
            | Iir_Value_Access =>
             Disp_Iir_Value (Value, A_Type);
          when Iir_Value_Array =>
diff --git a/src/vhdl/simulate/elaboration.adb b/src/vhdl/simulate/elaboration.adb
index b18dda1b8..571abf705 100644
--- a/src/vhdl/simulate/elaboration.adb
+++ b/src/vhdl/simulate/elaboration.adb
@@ -93,10 +93,7 @@ package body Elaboration is
                   Res.Val_Record.V (I) := Create_Signal (Lit.Val_Record.V (I));
                end loop;
 
-            when Iir_Value_I64
-              | Iir_Value_F64
-              | Iir_Value_B1
-              | Iir_Value_E32 =>
+            when Iir_Value_Scalars =>
                Res := Create_Signal_Value (null);
 
             when Iir_Value_Signal
@@ -515,17 +512,19 @@ package body Elaboration is
                   Bounds := Execute_Bounds (Block, Decl);
                   Res := Bounds.Left;
                when Init_Value_Any =>
-                  case Get_Info (Get_Base_Type (Decl)).Scalar_Mode is
+                  case Iir_Value_Scalars
+                    (Get_Info (Get_Base_Type (Decl)).Scalar_Mode)
+                     is
                      when Iir_Value_B1 =>
                         Res := Create_B1_Value (False);
+                     when Iir_Value_E8 =>
+                        Res := Create_E8_Value (0);
                      when Iir_Value_E32 =>
                         Res := Create_E32_Value (0);
                      when Iir_Value_I64 =>
                         Res := Create_I64_Value (0);
                      when Iir_Value_F64 =>
                         Res := Create_F64_Value (0.0);
-                     when others =>
-                        raise Internal_Error;
                   end case;
                when Init_Value_Signal =>
                   Res := Create_Signal_Value (null);
@@ -670,7 +669,7 @@ package body Elaboration is
       if Slot /= Instance.Elab_Objects + 1
         or else Instance.Objects (Slot) /= null
       then
-         Error_Msg_Elab ("bad elaboration order");
+         Error_Msg_Elab ("bad elaboration order", Decl);
          raise Internal_Error;
       end if;
       --  One slot is reserved for default value
@@ -2830,9 +2829,7 @@ package body Elaboration is
       end if;
 
       --  Sanity check: memory area for expressions must be empty.
-      if not Is_Empty (Expr_Pool) then
-         raise Internal_Error;
-      end if;
+      pragma Assert (Is_Empty (Expr_Pool));
    end Elaborate_Design;
 
 end Elaboration;
diff --git a/src/vhdl/simulate/execution.adb b/src/vhdl/simulate/execution.adb
index cf9fecac5..3d6cfd3d3 100644
--- a/src/vhdl/simulate/execution.adb
+++ b/src/vhdl/simulate/execution.adb
@@ -222,13 +222,13 @@ package body Execution is
       Mode : constant Iir_Value_Kind :=
         Get_Info (Base_Type).Scalar_Mode;
    begin
-      case Mode is
+      case Iir_Value_Enums (Mode) is
+         when Iir_Value_E8 =>
+            return Create_E8_Value (Ghdl_E8 (Pos));
          when Iir_Value_E32 =>
             return Create_E32_Value (Ghdl_E32 (Pos));
          when Iir_Value_B1 =>
             return Create_B1_Value (Ghdl_B1'Val (Pos));
-         when others =>
-            raise Internal_Error;
       end case;
    end Create_Enum_Value;
 
@@ -243,7 +243,7 @@ package body Execution is
          Iir_To);
       for I in Str'Range loop
          Res.Val_Array.V (1 + Iir_Index32 (I - Str'First)) :=
-           Create_E32_Value (Character'Pos (Str (I)));
+           Create_E8_Value (Character'Pos (Str (I)));
       end loop;
       return Res;
    end String_To_Iir_Value;
@@ -279,13 +279,13 @@ package body Execution is
                  Get_Enumeration_Literal_List (Get_Base_Type (Expr_Type));
                Pos : Natural;
             begin
-               case Val.Kind is
+               case Iir_Value_Enums (Val.Kind) is
                   when Iir_Value_B1 =>
                      Pos := Ghdl_B1'Pos (Val.B1);
+                  when Iir_Value_E8 =>
+                     Pos := Ghdl_E8'Pos (Val.E8);
                   when Iir_Value_E32 =>
                      Pos := Ghdl_E32'Pos (Val.E32);
-                  when others =>
-                     raise Internal_Error;
                end case;
                return Name_Table.Image
                  (Get_Identifier (Get_Nth_Element (Lits, Pos)));
@@ -805,81 +805,25 @@ package body Execution is
             Eval_Right;
             Result := Boolean_To_Lit (not Is_Equal (Left, Right));
          when Iir_Predefined_Integer_Less
-           | Iir_Predefined_Physical_Less =>
+           | Iir_Predefined_Physical_Less
+           | Iir_Predefined_Enum_Less =>
             Eval_Right;
-            case Left.Kind is
-               when Iir_Value_I64 =>
-                  Result := Boolean_To_Lit (Left.I64 < Right.I64);
-               when others =>
-                  raise Internal_Error;
-            end case;
+            Result := Boolean_To_Lit (Compare_Value (Left, Right) < Equal);
          when Iir_Predefined_Integer_Greater
-           | Iir_Predefined_Physical_Greater =>
+           | Iir_Predefined_Physical_Greater
+           | Iir_Predefined_Enum_Greater =>
             Eval_Right;
-            case Left.Kind is
-               when Iir_Value_I64 =>
-                  Result := Boolean_To_Lit (Left.I64 > Right.I64);
-               when others =>
-                  raise Internal_Error;
-            end case;
+            Result := Boolean_To_Lit (Compare_Value (Left, Right) > Equal);
          when Iir_Predefined_Integer_Less_Equal
-           | Iir_Predefined_Physical_Less_Equal =>
+           | Iir_Predefined_Physical_Less_Equal
+           | Iir_Predefined_Enum_Less_Equal =>
             Eval_Right;
-            case Left.Kind is
-               when Iir_Value_I64 =>
-                  Result := Boolean_To_Lit (Left.I64 <= Right.I64);
-               when others =>
-                  raise Internal_Error;
-            end case;
+            Result := Boolean_To_Lit (Compare_Value (Left, Right) <= Equal);
          when Iir_Predefined_Integer_Greater_Equal
-           | Iir_Predefined_Physical_Greater_Equal =>
-            Eval_Right;
-            case Left.Kind is
-               when Iir_Value_I64 =>
-                  Result := Boolean_To_Lit (Left.I64 >= Right.I64);
-               when others =>
-                  raise Internal_Error;
-            end case;
-         when Iir_Predefined_Enum_Less =>
-            Eval_Right;
-            case Left.Kind is
-               when Iir_Value_B1 =>
-                  Result := Boolean_To_Lit (Left.B1 < Right.B1);
-               when Iir_Value_E32 =>
-                  Result := Boolean_To_Lit (Left.E32 < Right.E32);
-               when others =>
-                  raise Internal_Error;
-            end case;
-         when Iir_Predefined_Enum_Greater =>
-            Eval_Right;
-            case Left.Kind is
-               when Iir_Value_B1 =>
-                  Result := Boolean_To_Lit (Left.B1 > Right.B1);
-               when Iir_Value_E32 =>
-                  Result := Boolean_To_Lit (Left.E32 > Right.E32);
-               when others =>
-                  raise Internal_Error;
-            end case;
-         when Iir_Predefined_Enum_Less_Equal =>
-            Eval_Right;
-            case Left.Kind is
-               when Iir_Value_B1 =>
-                  Result := Boolean_To_Lit (Left.B1 <= Right.B1);
-               when Iir_Value_E32 =>
-                  Result := Boolean_To_Lit (Left.E32 <= Right.E32);
-               when others =>
-                  raise Internal_Error;
-            end case;
-         when Iir_Predefined_Enum_Greater_Equal =>
+           | Iir_Predefined_Physical_Greater_Equal
+           | Iir_Predefined_Enum_Greater_Equal =>
             Eval_Right;
-            case Left.Kind is
-               when Iir_Value_B1 =>
-                  Result := Boolean_To_Lit (Left.B1 >= Right.B1);
-               when Iir_Value_E32 =>
-                  Result := Boolean_To_Lit (Left.E32 >= Right.E32);
-               when others =>
-                  raise Internal_Error;
-            end case;
+            Result := Boolean_To_Lit (Compare_Value (Left, Right) >= Equal);
 
          when Iir_Predefined_Enum_Minimum
            | Iir_Predefined_Physical_Minimum =>
@@ -1639,7 +1583,7 @@ package body Execution is
       if Index.Kind /= Left_Pos.Kind or else Index.Kind /= Right_Pos.Kind then
          raise Internal_Error;
       end if;
-      case Index.Kind is
+      case Iir_Value_Discrete (Index.Kind) is
          when Iir_Value_B1 =>
             case Bounds.Dir is
                when Iir_To =>
@@ -1657,6 +1601,23 @@ package body Execution is
                      return Ghdl_B1'Pos (Left_Pos.B1) - Ghdl_B1'Pos (Index.B1);
                   end if;
             end case;
+         when Iir_Value_E8 =>
+            case Bounds.Dir is
+               when Iir_To =>
+                  if Index.E8 >= Left_Pos.E8 and then
+                    Index.E8 <= Right_Pos.E8
+                  then
+                     -- to
+                     return Iir_Index32 (Index.E8 - Left_Pos.E8);
+                  end if;
+               when Iir_Downto =>
+                  if Index.E8 <= Left_Pos.E8 and then
+                    Index.E8 >= Right_Pos.E8
+                  then
+                     -- downto
+                     return Iir_Index32 (Left_Pos.E8 - Index.E8);
+                  end if;
+            end case;
          when Iir_Value_E32 =>
             case Bounds.Dir is
                when Iir_To =>
@@ -1691,8 +1652,6 @@ package body Execution is
                      return Iir_Index32 (Left_Pos.I64 - Index.I64);
                   end if;
             end case;
-         when others =>
-            raise Internal_Error;
       end case;
       Error_Msg_Constraint (Expr);
       return 0;
@@ -1774,6 +1733,8 @@ package body Execution is
          case Element_Mode is
             when Iir_Value_B1 =>
                El := Create_B1_Value (Ghdl_B1'Val (Pos));
+            when Iir_Value_E8 =>
+               El := Create_E8_Value (Ghdl_E8'Val (Pos));
             when Iir_Value_E32 =>
                El := Create_E32_Value (Ghdl_E32'Val (Pos));
             when others =>
@@ -2431,12 +2392,17 @@ package body Execution is
    is
       Res : Iir_Value_Literal_Acc;
    begin
-      case Val.Kind is
+      case Iir_Value_Discrete (Val.Kind) is
          when Iir_Value_B1 =>
             if Val.B1 = False then
                Error_Msg_Constraint (Expr);
             end if;
             Res := Create_B1_Value (False);
+         when Iir_Value_E8 =>
+            if Val.E8 = 0 then
+               Error_Msg_Constraint (Expr);
+            end if;
+            Res := Create_E8_Value (Val.E8 - 1);
          when Iir_Value_E32 =>
             if Val.E32 = 0 then
                Error_Msg_Constraint (Expr);
@@ -2447,8 +2413,6 @@ package body Execution is
                Error_Msg_Constraint (Expr);
             end if;
             Res := Create_I64_Value (Val.I64 - 1);
-         when others =>
-            raise Internal_Error;
       end case;
       return Res;
    end Execute_Dec;
@@ -2460,7 +2424,7 @@ package body Execution is
    is
       Res : Iir_Value_Literal_Acc;
    begin
-      case Val.Kind is
+      case Iir_Value_Discrete (Val.Kind) is
          when Iir_Value_B1 =>
             if Val.B1 = True then
                Error_Msg_Constraint (Expr);
@@ -2471,13 +2435,16 @@ package body Execution is
                Error_Msg_Constraint (Expr);
             end if;
             Res := Create_E32_Value (Val.E32 + 1);
+         when Iir_Value_E8 =>
+            if Val.E8 = Ghdl_E8'Last then
+               Error_Msg_Constraint (Expr);
+            end if;
+            Res := Create_E8_Value (Val.E8 + 1);
          when Iir_Value_I64 =>
             if Val.I64 = Ghdl_I64'Last then
                Error_Msg_Constraint (Expr);
             end if;
             Res := Create_I64_Value (Val.I64 + 1);
-         when others =>
-            raise Internal_Error;
       end case;
       return Res;
    end Execute_Inc;
@@ -3018,6 +2985,8 @@ package body Execution is
                case Get_Info (Lit_Type).Scalar_Mode is
                   when Iir_Value_B1 =>
                      return Create_B1_Value (Ghdl_B1'Val (Lit));
+                  when Iir_Value_E8 =>
+                     return Create_E8_Value (Ghdl_E8'Val (Lit));
                   when Iir_Value_E32 =>
                      return Create_E32_Value (Ghdl_E32 (Lit));
                   when others =>
@@ -3149,16 +3118,15 @@ package body Execution is
                  Get_Info (Base_Type).Scalar_Mode;
             begin
                Res := Execute_Expression (Block, Get_Parameter (Expr));
-               case Mode is
+               case Iir_Value_Discrete (Mode) is
                   when Iir_Value_I64 =>
                      null;
+                  when Iir_Value_E8 =>
+                     Res := Create_E8_Value (Ghdl_E8 (Res.I64));
                   when Iir_Value_E32 =>
                      Res := Create_E32_Value (Ghdl_E32 (Res.I64));
                   when Iir_Value_B1 =>
                      Res := Create_B1_Value (Ghdl_B1'Val (Res.I64));
-                  when others =>
-                     Error_Kind ("execute_expression(val attribute)",
-                                 Prefix_Type);
                end case;
                Check_Constraints (Block, Res, Prefix_Type, Expr);
                return Res;
@@ -3173,18 +3141,18 @@ package body Execution is
                  Get_Info (Base_Type).Scalar_Mode;
             begin
                Res := Execute_Expression (Block, Get_Parameter (Expr));
-               case Mode is
+               case Iir_Value_Discrete (Mode) is
                   when Iir_Value_I64 =>
                      null;
                   when Iir_Value_B1 =>
                      N_Res := Create_I64_Value (Ghdl_B1'Pos (Res.B1));
                      Res := N_Res;
+                  when Iir_Value_E8 =>
+                     N_Res := Create_I64_Value (Ghdl_I64 (Res.E8));
+                     Res := N_Res;
                   when Iir_Value_E32 =>
                      N_Res := Create_I64_Value (Ghdl_I64 (Res.E32));
                      Res := N_Res;
-                  when others =>
-                     Error_Kind ("execute_expression(pos attribute)",
-                                 Base_Type);
                end case;
                Check_Constraints (Block, Res, Get_Type (Expr), Expr);
                return Res;
@@ -3924,11 +3892,15 @@ package body Execution is
                High := Bound.Left;
                Low := Bound.Right;
             end if;
-            case Get_Info (Base_Type).Scalar_Mode is
+            case Iir_Value_Scalars (Get_Info (Base_Type).Scalar_Mode) is
                when Iir_Value_I64 =>
                   if Value.I64 in Low.I64 .. High.I64 then
                      return;
                   end if;
+               when Iir_Value_E8 =>
+                  if Value.E8 in Low.E8 .. High.E8 then
+                     return;
+                  end if;
                when Iir_Value_E32 =>
                   if Value.E32 in Low.E32 .. High.E32 then
                      return;
@@ -3941,8 +3913,6 @@ package body Execution is
                   if Value.B1 in Low.B1 .. High.B1 then
                      return;
                   end if;
-               when others =>
-                  raise Internal_Error;
             end case;
          when Iir_Kind_Array_Subtype_Definition
            | Iir_Kind_Array_Type_Definition =>
@@ -4182,7 +4152,7 @@ package body Execution is
          begin
             for I in Report.Val_Array.V'Range loop
                Msg (Positive (I)) :=
-                 Character'Val (Report.Val_Array.V (I).E32);
+                 Character'Val (Report.Val_Array.V (I).E8);
             end loop;
             Execute_Failed_Assertion (Msg, Severity, Stmt);
          end;
@@ -4212,7 +4182,7 @@ package body Execution is
       Expr := Get_Severity_Expression (Stmt);
       if Expr /= Null_Iir then
          Severity_Lit := Execute_Expression (Instance, Expr);
-         Severity := Natural'Val (Severity_Lit.E32);
+         Severity := Natural'Val (Severity_Lit.E8);
       else
          Severity := Default_Severity;
       end if;
@@ -4270,16 +4240,15 @@ package body Execution is
             Max := Bounds.Left;
       end case;
 
-      case Val.Kind is
+      case Iir_Value_Discrete (Val.Kind) is
+         when Iir_Value_E8 =>
+            return Val.E8 >= Min.E8 and Val.E8 <= Max.E8;
          when Iir_Value_E32 =>
             return Val.E32 >= Min.E32 and Val.E32 <= Max.E32;
          when Iir_Value_B1 =>
             return Val.B1 >= Min.B1 and Val.B1 <= Max.B1;
          when Iir_Value_I64 =>
             return Val.I64 >= Min.I64 and Val.I64 <= Max.I64;
-         when others =>
-            raise Internal_Error;
-            return False;
       end case;
    end Is_In_Range;
 
@@ -4289,7 +4258,14 @@ package body Execution is
                                 Bounds : Iir_Value_Literal_Acc)
    is
    begin
-      case Val.Kind is
+      case Iir_Value_Discrete (Val.Kind) is
+         when Iir_Value_E8 =>
+            case Bounds.Dir is
+               when Iir_To =>
+                  Val.E8 := Val.E8 + 1;
+               when Iir_Downto =>
+                  Val.E8 := Val.E8 - 1;
+            end case;
          when Iir_Value_E32 =>
             case Bounds.Dir is
                when Iir_To =>
@@ -4311,8 +4287,6 @@ package body Execution is
                when Iir_Downto =>
                   Val.I64 := Val.I64 - 1;
             end case;
-         when others =>
-            raise Internal_Error;
       end case;
    end Update_Loop_Index;
 
diff --git a/src/vhdl/simulate/file_operation.adb b/src/vhdl/simulate/file_operation.adb
index 7addb3a26..d5d141c53 100644
--- a/src/vhdl/simulate/file_operation.adb
+++ b/src/vhdl/simulate/file_operation.adb
@@ -46,7 +46,7 @@ package body File_Operation is
       -- Convert the string to an Ada string.
       for I in External_Name.Val_Array.V'Range loop
          Name_Str (Name_Str'First + Ghdl_Index_Type (I - 1)) :=
-           Character'Val (External_Name.Val_Array.V (I).E32);
+           Character'Val (External_Name.Val_Array.V (I).E8);
       end loop;
 
       if Is_Text then
@@ -77,7 +77,7 @@ package body File_Operation is
    is
       pragma Unreferenced (Stmt);
       Is_Text : constant Boolean := Get_Text_File_Flag (Get_Type (File_Decl));
-      File_Mode : constant Ghdl_I32 := Ghdl_I32 (Mode.E32);
+      File_Mode : constant Ghdl_I32 := Ghdl_I32 (Mode.E8);
       Status : Ghdl_I32;
    begin
       File_Open (Status, File, Name, File_Mode, Is_Text, False);
@@ -95,11 +95,11 @@ package body File_Operation is
    is
       pragma Unreferenced (Stmt);
       Is_Text : constant Boolean := Get_Text_File_Flag (Get_Type (File_Decl));
-      File_Mode : constant Ghdl_I32 := Ghdl_I32 (Mode.E32);
+      File_Mode : constant Ghdl_I32 := Ghdl_I32 (Mode.E8);
       R_Status : Ghdl_I32;
    begin
       File_Open (R_Status, File, Name, File_Mode, Is_Text, True);
-      Status.E32 := Ghdl_E32 (R_Status);
+      Status.E8 := Ghdl_E8 (R_Status);
    end File_Open_Status;
 
    function Elaborate_File_Declaration
@@ -144,7 +144,7 @@ package body File_Operation is
       File_Name := Execute_Expression (Instance, External_Name);
       if Get_File_Open_Kind (Decl) /= Null_Iir then
          Mode := Execute_Expression (Instance, Get_File_Open_Kind (Decl));
-         File_Mode := Ghdl_I32 (Mode.E32);
+         File_Mode := Ghdl_I32 (Mode.E8);
       else
          case Get_Mode (Decl) is
             when Iir_In_Mode =>
@@ -190,6 +190,8 @@ package body File_Operation is
             Ghdl_Write_Scalar (File.File, Ghdl_Ptr (Value.B1'Address), 1);
          when Iir_Value_I64 =>
             Ghdl_Write_Scalar (File.File, Ghdl_Ptr (Value.I64'Address), 8);
+         when Iir_Value_E8 =>
+            Ghdl_Write_Scalar (File.File, Ghdl_Ptr (Value.E8'Address), 1);
          when Iir_Value_E32 =>
             Ghdl_Write_Scalar (File.File, Ghdl_Ptr (Value.E32'Address), 4);
          when Iir_Value_F64 =>
@@ -224,7 +226,7 @@ package body File_Operation is
       -- Convert the string to an Ada string.
       for I in Value.Val_Array.V'Range loop
          Val_Str (Val_Str'First + Ghdl_Index_Type (I - 1)) :=
-           Character'Val (Value.Val_Array.V (I).E32);
+           Character'Val (Value.Val_Array.V (I).E8);
       end loop;
 
       Ghdl_Text_Write (File.File, Val'Unrestricted_Access);
@@ -252,7 +254,7 @@ package body File_Operation is
    begin
       Len := Ghdl_Text_Read_Length (File.File, Val'Unrestricted_Access);
       for I in 1 .. Len loop
-         Value.Val_Array.V (Iir_Index32 (I)).E32 :=
+         Value.Val_Array.V (Iir_Index32 (I)).E8 :=
            Character'Pos (Val_Str (Ghdl_Index_Type (I)));
       end loop;
       Length.I64 := Ghdl_I64 (Len);
@@ -273,7 +275,7 @@ package body File_Operation is
       Ghdl_Untruncated_Text_Read
         (File.File, Val'Unrestricted_Access, Len'Unrestricted_Access);
       for I in 1 .. Len loop
-         Str.Val_Array.V (Iir_Index32 (I)).E32 :=
+         Str.Val_Array.V (Iir_Index32 (I)).E8 :=
            Character'Pos (Val_Str (Ghdl_Index_Type (I)));
       end loop;
       Length.I64 := Ghdl_I64 (Len);
@@ -288,6 +290,8 @@ package body File_Operation is
             Ghdl_Read_Scalar (File.File, Ghdl_Ptr (Value.B1'Address), 1);
          when Iir_Value_I64 =>
             Ghdl_Read_Scalar (File.File, Ghdl_Ptr (Value.I64'Address), 8);
+         when Iir_Value_E8 =>
+            Ghdl_Read_Scalar (File.File, Ghdl_Ptr (Value.E8'Address), 1);
          when Iir_Value_E32 =>
             Ghdl_Read_Scalar (File.File, Ghdl_Ptr (Value.E32'Address), 4);
          when Iir_Value_F64 =>
diff --git a/src/vhdl/simulate/grt_interface.adb b/src/vhdl/simulate/grt_interface.adb
index c4eab58c4..604d30d01 100644
--- a/src/vhdl/simulate/grt_interface.adb
+++ b/src/vhdl/simulate/grt_interface.adb
@@ -38,7 +38,7 @@ package body Grt_Interface is
    begin
       for I in Val.Val_Array.V'Range loop
          Str.Base (Ghdl_Index_Type (I - 1)) :=
-           Character'Val (Val.Val_Array.V (I).E32);
+           Character'Val (Val.Val_Array.V (I).E8);
       end loop;
    end Set_Std_String_From_Iir_Value;
 end Grt_Interface;
diff --git a/src/vhdl/simulate/iir_values.adb b/src/vhdl/simulate/iir_values.adb
index 3d308e7f6..7ebcc6816 100644
--- a/src/vhdl/simulate/iir_values.adb
+++ b/src/vhdl/simulate/iir_values.adb
@@ -33,6 +33,8 @@ package body Iir_Values is
       case Left.Kind is
          when Iir_Value_B1 =>
             return Left.B1 = Right.B1;
+         when Iir_Value_E8 =>
+            return Left.E8 = Right.E8;
          when Iir_Value_E32 =>
             return Left.E32 = Right.E32;
          when Iir_Value_I64 =>
@@ -105,6 +107,14 @@ package body Iir_Values is
             else
                return Greater;
             end if;
+         when Iir_Value_E8 =>
+            if Left.E8 < Right.E8 then
+               return Less;
+            elsif Left.E8 = Right.E8 then
+               return Equal;
+            else
+               return Greater;
+            end if;
          when Iir_Value_E32 =>
             if Left.E32 < Right.E32 then
                return Less;
@@ -211,6 +221,8 @@ package body Iir_Values is
             else
                raise Constraint_Error;
             end if;
+         when Iir_Value_E8 =>
+            Val.E8 := Val.E8 + 1;
          when Iir_Value_E32 =>
             Val.E32 := Val.E32 + 1;
          when Iir_Value_I64 =>
@@ -253,6 +265,8 @@ package body Iir_Values is
             end loop;
          when Iir_Value_B1 =>
             Dest.B1 := Src.B1;
+         when Iir_Value_E8 =>
+            Dest.E8 := Src.E8;
          when Iir_Value_E32 =>
             Dest.E32 := Src.E32;
          when Iir_Value_I64 =>
@@ -307,10 +321,7 @@ package body Iir_Values is
             if Src.Kind /= Dest.Kind then
                raise Internal_Error;
             end if;
-         when Iir_Value_B1
-           | Iir_Value_E32
-           | Iir_Value_I64
-           | Iir_Value_F64
+         when Iir_Value_Scalars
            | Iir_Value_Signal =>
             return;
          when Iir_Value_Range
@@ -393,6 +404,15 @@ package body Iir_Values is
         (Alloc (Current_Pool, (Kind => Iir_Value_B1, B1 => Val)));
    end Create_B1_Value;
 
+   function Create_E8_Value (Val : Ghdl_E8) return Iir_Value_Literal_Acc
+   is
+      subtype E8_Value is Iir_Value_Literal (Iir_Value_E8);
+      function Alloc is new Alloc_On_Pool_Addr (E8_Value);
+   begin
+      return To_Iir_Value_Literal_Acc
+        (Alloc (Current_Pool, (Kind => Iir_Value_E8, E8 => Val)));
+   end Create_E8_Value;
+
    function Create_E32_Value (Val : Ghdl_E32) return Iir_Value_Literal_Acc
    is
       subtype E32_Value is Iir_Value_Literal (Iir_Value_E32);
@@ -491,6 +511,12 @@ package body Iir_Values is
             else
                Len := 0;
             end if;
+         when Iir_Value_E8 =>
+            if High.E8 >= Low.E8 then
+               Len := Iir_Index32 (High.E8 - Low.E8 + 1);
+            else
+               Len := 0;
+            end if;
          when Iir_Value_I64 =>
             declare
                L : Ghdl_I64;
@@ -610,14 +636,16 @@ package body Iir_Values is
       Res: Iir_Value_Literal_Acc;
    begin
       case Src.Kind is
+         when Iir_Value_B1 =>
+            return Create_B1_Value (Src.B1);
          when Iir_Value_E32 =>
             return Create_E32_Value (Src.E32);
+         when Iir_Value_E8 =>
+            return Create_E8_Value (Src.E8);
          when Iir_Value_I64 =>
             return Create_I64_Value (Src.I64);
          when Iir_Value_F64 =>
             return Create_F64_Value (Src.F64);
-         when Iir_Value_B1 =>
-            return Create_B1_Value (Src.B1);
          when Iir_Value_Access =>
             return Create_Access_Value (Src.Val_Access);
          when Iir_Value_Array =>
@@ -762,6 +790,8 @@ package body Iir_Values is
    function Get_Enum_Pos (Val : Iir_Value_Literal_Acc) return Natural is
    begin
       case Val.Kind is
+         when Iir_Value_E8 =>
+            return Ghdl_E8'Pos (Val.E8);
          when Iir_Value_E32 =>
             return Ghdl_E32'Pos (Val.E32);
          when Iir_Value_B1 =>
@@ -790,6 +820,8 @@ package body Iir_Values is
       case Value.Kind is
          when Iir_Value_B1 =>
             Put_Line ("b1:" & Ghdl_B1'Image (Value.B1));
+         when Iir_Value_E8 =>
+            Put_Line ("E8:" & Ghdl_E8'Image (Value.E8));
          when Iir_Value_E32 =>
             Put_Line ("e32:" & Ghdl_E32'Image (Value.E32));
          when Iir_Value_I64 =>
@@ -1021,6 +1053,16 @@ package body Iir_Values is
       Put (")");
    end Disp_Iir_Value_Record;
 
+   procedure Disp_Iir_Value_Enum (Pos : Natural; A_Type : Iir)
+   is
+      Bt : constant Iir := Get_Base_Type (A_Type);
+      Id : Name_Id;
+   begin
+      Id := Get_Identifier
+        (Get_Nth_Element (Get_Enumeration_Literal_List (Bt), Pos));
+      Ada.Text_IO.Put (Name_Table.Image (Id));
+   end Disp_Iir_Value_Enum;
+
    procedure Disp_Iir_Value (Value: Iir_Value_Literal_Acc; A_Type: Iir) is
       use Ada.Text_IO;
    begin
@@ -1033,22 +1075,12 @@ package body Iir_Values is
             Put (Ghdl_I64'Image (Value.I64));
          when Iir_Value_F64 =>
             Put (Ghdl_F64'Image (Value.F64));
-         when Iir_Value_E32
-           | Iir_Value_B1 =>
-            declare
-               Bt : constant Iir := Get_Base_Type (A_Type);
-               Id : Name_Id;
-               Pos : Integer;
-            begin
-               if Value.Kind = Iir_Value_E32 then
-                  Pos := Ghdl_E32'Pos (Value.E32);
-               else
-                  Pos := Ghdl_B1'Pos (Value.B1);
-               end if;
-               Id := Get_Identifier
-                 (Get_Nth_Element (Get_Enumeration_Literal_List (Bt), Pos));
-               Put (Name_Table.Image (Id));
-            end;
+         when Iir_Value_E32 =>
+            Disp_Iir_Value_Enum (Ghdl_E32'Pos (Value.E32), A_Type);
+         when Iir_Value_E8 =>
+            Disp_Iir_Value_Enum (Ghdl_E8'Pos (Value.E8), A_Type);
+         when Iir_Value_B1 =>
+            Disp_Iir_Value_Enum (Ghdl_B1'Pos (Value.B1), A_Type);
          when Iir_Value_Access =>
             if Value.Val_Access = null then
                Put ("null");
diff --git a/src/vhdl/simulate/iir_values.ads b/src/vhdl/simulate/iir_values.ads
index aeb9b4f49..292e8424a 100644
--- a/src/vhdl/simulate/iir_values.ads
+++ b/src/vhdl/simulate/iir_values.ads
@@ -102,7 +102,7 @@ package Iir_Values is
    --  not done within the context of a process).
 
    type Iir_Value_Kind is
-     (Iir_Value_B1, Iir_Value_E32,
+     (Iir_Value_B1, Iir_Value_E8, Iir_Value_E32,
       Iir_Value_I64, Iir_Value_F64,
       Iir_Value_Access,
       Iir_Value_File,
@@ -124,6 +124,12 @@ package Iir_Values is
    subtype Iir_Value_Scalars is
      Iir_Value_Kind range Iir_Value_B1 .. Iir_Value_F64;
 
+   subtype Iir_Value_Discrete is
+     Iir_Value_Kind range Iir_Value_B1 .. Iir_Value_I64;
+
+   subtype Iir_Value_Enums is
+     Iir_Value_Kind range Iir_Value_B1 .. Iir_Value_E32;
+
    --  Abstrace numeric types.
    subtype Iir_Value_Numerics is
      Iir_Value_Kind range Iir_Value_I64 .. Iir_Value_F64;
@@ -155,6 +161,8 @@ package Iir_Values is
       case Kind is
          when Iir_Value_B1 =>
             B1 : Ghdl_B1;
+         when Iir_Value_E8 =>
+            E8 : Ghdl_E8;
          when Iir_Value_E32 =>
             E32 : Ghdl_E32;
          when Iir_Value_I64 =>
@@ -211,7 +219,7 @@ package Iir_Values is
                                      return Iir_Value_Literal_Acc;
 
    function Create_B1_Value (Val : Ghdl_B1) return Iir_Value_Literal_Acc;
-
+   function Create_E8_Value (Val : Ghdl_E8) return Iir_Value_Literal_Acc;
    function Create_E32_Value (Val : Ghdl_E32) return Iir_Value_Literal_Acc;
 
    -- Return an iir_value_literal_acc (iir_value_int64).
diff --git a/src/vhdl/simulate/simulation.adb b/src/vhdl/simulate/simulation.adb
index 7238bf9cf..2d2b1007b 100644
--- a/src/vhdl/simulate/simulation.adb
+++ b/src/vhdl/simulate/simulation.adb
@@ -39,6 +39,8 @@ package body Simulation is
       case Mode is
          when Mode_B1 =>
             return Create_B1_Value (Val.B1);
+         when Mode_E8 =>
+            return Create_E8_Value (Val.E8);
          when Mode_E32 =>
             return Create_E32_Value (Val.E32);
          when Mode_I64 =>
@@ -53,17 +55,17 @@ package body Simulation is
    procedure Iir_Value_To_Value (Src : Iir_Value_Literal_Acc;
                                  Dst : out Value_Union) is
    begin
-      case Src.Kind is
+      case Iir_Value_Scalars (Src.Kind) is
          when Iir_Value_B1 =>
             Dst.B1 := Src.B1;
+         when Iir_Value_E8 =>
+            Dst.E8 := Src.E8;
          when Iir_Value_E32 =>
             Dst.E32 := Src.E32;
          when Iir_Value_I64 =>
             Dst.I64 := Src.I64;
          when Iir_Value_F64 =>
             Dst.F64 := Src.F64;
-         when others =>
-            raise Internal_Error;  -- FIXME
       end case;
    end Iir_Value_To_Value;
 
@@ -414,6 +416,9 @@ package body Simulation is
             when Iir_Value_B1 =>
                Ghdl_Signal_Start_Assign_B1
                  (Target.Sig, Transactions.Reject, El.Value.B1, El.After);
+            when Iir_Value_E8 =>
+               Ghdl_Signal_Start_Assign_E8
+                 (Target.Sig, Transactions.Reject, El.Value.E8, El.After);
             when Iir_Value_E32 =>
                Ghdl_Signal_Start_Assign_E32
                  (Target.Sig, Transactions.Reject, El.Value.E32, El.After);
@@ -434,6 +439,9 @@ package body Simulation is
                when Iir_Value_B1 =>
                   Ghdl_Signal_Next_Assign_B1
                     (Target.Sig, El.Value.B1, El.After);
+               when Iir_Value_E8 =>
+                  Ghdl_Signal_Next_Assign_E8
+                    (Target.Sig, El.Value.E8, El.After);
                when Iir_Value_E32 =>
                   Ghdl_Signal_Next_Assign_E32
                     (Target.Sig, El.Value.E32, El.After);
@@ -1191,6 +1199,11 @@ package body Simulation is
                   return Create_Signal_Value
                     (Grt.Signals.Ghdl_Create_Signal_B1
                        (Val, null, System.Null_Address));
+               when Mode_E8 =>
+                  Val.E8 := 0;
+                  return Create_Signal_Value
+                    (Grt.Signals.Ghdl_Create_Signal_E8
+                       (Val, null, System.Null_Address));
                when Mode_E32 =>
                   Val.E32 := 0;
                   return Create_Signal_Value
@@ -1201,8 +1214,7 @@ package body Simulation is
                   return Create_Signal_Value
                     (Grt.Signals.Ghdl_Create_Signal_F64
                        (Val, null, System.Null_Address));
-               when Mode_E8
-                 | Mode_I32 =>
+               when Mode_I32 =>
                   raise Internal_Error;
             end case;
          when Iir_Value_Array =>
@@ -1536,6 +1548,10 @@ package body Simulation is
                Sig.Sig := Grt.Signals.Ghdl_Create_Signal_B1
                  (To_Ghdl_Value_Ptr (Val.B1'Address),
                   null, System.Null_Address);
+            when Iir_Value_E8 =>
+               Sig.Sig := Grt.Signals.Ghdl_Create_Signal_E8
+                 (To_Ghdl_Value_Ptr (Val.E8'Address),
+                  null, System.Null_Address);
             when Iir_Value_E32 =>
                Sig.Sig := Grt.Signals.Ghdl_Create_Signal_E32
                  (To_Ghdl_Value_Ptr (Val.E32'Address),