synth: handle alias (WIP, read only).

7 files changed, 86 insertions, 12 deletions

diff --git a/src/synth/synth-context.adb b/src/synth/synth-context.adb
index 48a0114b3..d7af882b5 100644
--- a/src/synth/synth-context.adb
+++ b/src/synth/synth-context.adb
@@ -436,6 +436,14 @@ package body Synth.Context is
                Build (Build_Context, C, Res);
                return Res;
             end;
+         when Value_Alias =>
+            declare
+               Res : Net;
+            begin
+               Res := Get_Current_Value (Build_Context, Val.A_Wid);
+               return Build_Extract (Build_Context, Res, Val.A_Off,
+                                     Get_Type_Width (Val.Typ));
+            end;
          when others =>
             raise Internal_Error;
       end case;
diff --git a/src/synth/synth-decls.adb b/src/synth/synth-decls.adb
index 2382558bd..d411ded68 100644
--- a/src/synth/synth-decls.adb
+++ b/src/synth/synth-decls.adb
@@ -22,14 +22,17 @@ with Types; use Types;
 with Mutils; use Mutils;
 with Netlists; use Netlists;
 with Netlists.Builders; use Netlists.Builders;
+
 with Vhdl.Errors; use Vhdl.Errors;
 with Vhdl.Utils; use Vhdl.Utils;
-with Vhdl.Ieee.Std_Logic_1164;
 with Vhdl.Std_Package;
+with Vhdl.Ieee.Std_Logic_1164;
+with Vhdl.Annotations; use Vhdl.Annotations;
+
 with Synth.Values; use Synth.Values;
 with Synth.Environment; use Synth.Environment;
 with Synth.Expr; use Synth.Expr;
-with Vhdl.Annotations; use Vhdl.Annotations;
+with Synth.Stmts;
 
 package body Synth.Decls is
    procedure Synth_Anonymous_Subtype_Indication
@@ -464,6 +467,18 @@ package body Synth.Decls is
                end if;
                Create_Var_Wire (Syn_Inst, Decl, Init);
             end;
+         when Iir_Kind_Object_Alias_Declaration =>
+            Synth_Declaration_Type (Syn_Inst, Decl);
+            declare
+               Wid : Wire_Id;
+               Off : Uns32;
+               Typ : Type_Acc;
+            begin
+               Stmts.Synth_Assignment_Prefix (Syn_Inst, Get_Name (Decl),
+                                              Wid, Off, Typ);
+               Create_Object (Syn_Inst, Decl,
+                              Create_Value_Alias (Wid, Off, Typ));
+            end;
          when Iir_Kind_Anonymous_Signal_Declaration =>
             Make_Object (Syn_Inst, Wire_Signal, Decl);
             Create_Var_Wire (Syn_Inst, Decl, null);
diff --git a/src/synth/synth-expr.adb b/src/synth/synth-expr.adb
index da6ea7190..d0abeec7b 100644
--- a/src/synth/synth-expr.adb
+++ b/src/synth/synth-expr.adb
@@ -1532,7 +1532,8 @@ package body Synth.Expr is
            | Iir_Kind_Anonymous_Signal_Declaration
            | Iir_Kind_Interface_Constant_Declaration
            | Iir_Kind_Constant_Declaration
-           | Iir_Kind_Iterator_Declaration =>
+           | Iir_Kind_Iterator_Declaration
+           | Iir_Kind_Object_Alias_Declaration =>
             return Get_Value (Syn_Inst, Name);
          when Iir_Kind_Enumeration_Literal =>
             return Create_Value_Discrete
diff --git a/src/synth/synth-stmts.adb b/src/synth/synth-stmts.adb
index a97a00558..a651f5e07 100644
--- a/src/synth/synth-stmts.adb
+++ b/src/synth/synth-stmts.adb
@@ -39,7 +39,6 @@ with Synth.Types; use Synth.Types;
 with Synth.Errors; use Synth.Errors;
 with Synth.Decls; use Synth.Decls;
 with Synth.Expr; use Synth.Expr;
-with Synth.Environment; use Synth.Environment;
 with Synth.Insts; use Synth.Insts;
 with Synth.Source;
 
@@ -121,14 +120,13 @@ package body Synth.Stmts is
 
    procedure Synth_Assignment_Prefix (Syn_Inst : Synth_Instance_Acc;
                                       Pfx : Node;
-                                      Loc : Node;
                                       Dest_Wid : out Wire_Id;
                                       Dest_Off : out Uns32;
                                       Dest_Type : out Type_Acc) is
    begin
       case Get_Kind (Pfx) is
          when Iir_Kind_Simple_Name =>
-            Synth_Assignment_Prefix (Syn_Inst, Get_Named_Entity (Pfx), Loc,
+            Synth_Assignment_Prefix (Syn_Inst, Get_Named_Entity (Pfx),
                                      Dest_Wid, Dest_Off, Dest_Type);
          when Iir_Kind_Interface_Signal_Declaration
            | Iir_Kind_Variable_Declaration
@@ -148,7 +146,7 @@ package body Synth.Stmts is
                Off : Uns32;
                W : Width;
             begin
-               Synth_Assignment_Prefix (Syn_Inst, Get_Prefix (Pfx), Loc,
+               Synth_Assignment_Prefix (Syn_Inst, Get_Prefix (Pfx),
                                         Dest_Wid, Dest_Off, Dest_Type);
                Synth_Indexed_Name
                  (Syn_Inst, Pfx, Dest_Type, Voff, Mul, Off, W);
@@ -171,12 +169,35 @@ package body Synth.Stmts is
                Idx : constant Iir_Index32 :=
                  Get_Element_Position (Get_Named_Entity (Pfx));
             begin
-               Synth_Assignment_Prefix (Syn_Inst, Get_Prefix (Pfx), Loc,
+               Synth_Assignment_Prefix (Syn_Inst, Get_Prefix (Pfx),
                                         Dest_Wid, Dest_Off, Dest_Type);
                Dest_Off := Dest_Off + Dest_Type.Rec.E (Idx + 1).Off;
                Dest_Type := Dest_Type.Rec.E (Idx + 1).Typ;
             end;
 
+         when Iir_Kind_Slice_Name =>
+            declare
+               Res_Bnd : Bound_Type;
+               Inp : Net;
+               Step : Uns32;
+               Sl_Off : Int32;
+               Wd : Uns32;
+            begin
+               Synth_Assignment_Prefix (Syn_Inst, Get_Prefix (Pfx),
+                                        Dest_Wid, Dest_Off, Dest_Type);
+               Synth_Slice_Suffix (Syn_Inst, Pfx, Dest_Type.Vbound,
+                                   Res_Bnd, Inp, Step, Sl_Off, Wd);
+
+               if Inp /= No_Net then
+                  Error_Msg_Synth
+                    (+Pfx, "dynamic index must be the last suffix");
+                  return;
+               end if;
+
+               Dest_Type := Create_Vector_Type (Res_Bnd, Dest_Type.Vec_El);
+               Dest_Off := Dest_Off + Uns32 (Sl_Off);
+            end;
+
          when others =>
             Error_Kind ("synth_assignment_prefix", Pfx);
       end case;
@@ -201,7 +222,7 @@ package body Synth.Stmts is
                Off : Uns32;
                Typ : Type_Acc;
             begin
-               Synth_Assignment_Prefix (Syn_Inst, Target, Loc, Wid, Off, Typ);
+               Synth_Assignment_Prefix (Syn_Inst, Target, Wid, Off, Typ);
                Synth_Assign (Wid, Typ, Val, Off, Loc);
             end;
          when Iir_Kind_Indexed_Name =>
@@ -218,7 +239,7 @@ package body Synth.Stmts is
                Targ_Net : Net;
                V : Net;
             begin
-               Synth_Assignment_Prefix (Syn_Inst, Get_Prefix (Target), Loc,
+               Synth_Assignment_Prefix (Syn_Inst, Get_Prefix (Target),
                                         Wid, Off, Typ);
                Synth_Indexed_Name (Syn_Inst, Target, Typ,
                                    Voff, Mul, Idx_Off, W);
@@ -254,7 +275,7 @@ package body Synth.Stmts is
                Res_Type : Type_Acc;
                V : Net;
             begin
-               Synth_Assignment_Prefix (Syn_Inst, Get_Prefix (Target), Loc,
+               Synth_Assignment_Prefix (Syn_Inst, Get_Prefix (Target),
                                         Wid, Off, Typ);
                Synth_Slice_Suffix (Syn_Inst, Target, Typ.Vbound,
                                    Res_Bnd, Inp, Step, Sl_Off, Wd);
diff --git a/src/synth/synth-stmts.ads b/src/synth/synth-stmts.ads
index cdd26e8eb..884ea299b 100644
--- a/src/synth/synth-stmts.ads
+++ b/src/synth/synth-stmts.ads
@@ -22,6 +22,7 @@ with Types; use Types;
 with Vhdl.Nodes; use Vhdl.Nodes;
 with Synth.Values; use Synth.Values;
 with Synth.Context; use Synth.Context;
+with Synth.Environment; use Synth.Environment;
 
 package Synth.Stmts is
    procedure Synth_Subprogram_Association (Subprg_Inst : Synth_Instance_Acc;
@@ -29,6 +30,12 @@ package Synth.Stmts is
                                            Inter_Chain : Node;
                                            Assoc_Chain : Node);
 
+   procedure Synth_Assignment_Prefix (Syn_Inst : Synth_Instance_Acc;
+                                      Pfx : Node;
+                                      Dest_Wid : out Wire_Id;
+                                      Dest_Off : out Uns32;
+                                      Dest_Type : out Type_Acc);
+
    procedure Synth_Assignment (Syn_Inst : Synth_Instance_Acc;
                                Target : Node;
                                Val : Value_Acc;
diff --git a/src/synth/synth-values.adb b/src/synth/synth-values.adb
index ded8e6a1b..6265a64dd 100644
--- a/src/synth/synth-values.adb
+++ b/src/synth/synth-values.adb
@@ -401,6 +401,19 @@ package body Synth.Values is
                                   (Kind => Value_Subtype, Typ => Typ)));
    end Create_Value_Subtype;
 
+   function Create_Value_Alias (Wid : Wire_Id; Off : Uns32; Typ : Type_Acc)
+                               return Value_Acc
+   is
+      subtype Value_Type_Alias is Value_Type (Value_Alias);
+      function Alloc is new Areapools.Alloc_On_Pool_Addr (Value_Type_Alias);
+   begin
+      return To_Value_Acc (Alloc (Current_Pool,
+                                  (Kind => Value_Alias,
+                                   A_Wid => Wid,
+                                   A_Off => Off,
+                                   Typ => Typ)));
+   end Create_Value_Alias;
+
    function Copy (Src: in Value_Acc) return Value_Acc
    is
       Res: Value_Acc;
diff --git a/src/synth/synth-values.ads b/src/synth/synth-values.ads
index e7d5acc20..a0db0f5fb 100644
--- a/src/synth/synth-values.ads
+++ b/src/synth/synth-values.ads
@@ -147,7 +147,10 @@ package Synth.Values is
       --  A package.
       Value_Instance,
 
-      --  A subtype.
+      --  An alias
+      Value_Alias,
+
+      --  A subtype.  Contains only a type.
       Value_Subtype
      );
 
@@ -191,6 +194,9 @@ package Synth.Values is
             Rec : Value_Array_Acc;
          when Value_Instance =>
             Instance : Instance_Id;
+         when Value_Alias =>
+            A_Wid : Wire_Id;
+            A_Off : Uns32;
       end case;
    end record;
 
@@ -262,6 +268,9 @@ package Synth.Values is
 
    function Create_Value_Instance (Inst : Instance_Id) return Value_Acc;
 
+   function Create_Value_Alias (Wid : Wire_Id; Off : Uns32; Typ : Type_Acc)
+                               return Value_Acc;
+
    function Unshare (Src : Value_Acc; Pool : Areapool_Acc)
                     return Value_Acc;