synth: add bit0/bit1 in instance.

4 files changed, 33 insertions, 14 deletions

diff --git a/src/synth/synth-context.adb b/src/synth/synth-context.adb
index b6c5916b5..730f5b6aa 100644
--- a/src/synth/synth-context.adb
+++ b/src/synth/synth-context.adb
@@ -112,6 +112,9 @@ package body Synth.Context is
                                       Cur_Module => M,
                                       Bit0 => No_Net,
                                       Bit1 => No_Net);
+      Builders.Set_Parent (Base.Builder, M);
+      Base.Bit0 := Build_Const_UB32 (Base.Builder, 0, 1);
+      Base.Bit1 := Build_Const_UB32 (Base.Builder, 1, 1);
       Inst.Base := Base;
    end Set_Instance_Module;
 
@@ -136,6 +139,16 @@ package body Synth.Context is
       return Inst.Base.Builder;
    end Get_Build;
 
+   function Get_Inst_Bit0 (Inst : Synth_Instance_Acc) return Net is
+   begin
+      return Inst.Base.Bit0;
+   end Get_Inst_Bit0;
+
+   function Get_Inst_Bit1 (Inst : Synth_Instance_Acc) return Net is
+   begin
+      return Inst.Base.Bit1;
+   end Get_Inst_Bit1;
+
    function Create_Value_Instance (Inst : Synth_Instance_Acc)
                                   return Value_Acc is
    begin
diff --git a/src/synth/synth-context.ads b/src/synth/synth-context.ads
index 296c89a78..708d42a73 100644
--- a/src/synth/synth-context.ads
+++ b/src/synth/synth-context.ads
@@ -61,6 +61,12 @@ package Synth.Context is
    function Get_Instance_Module (Inst : Synth_Instance_Acc) return Module;
    pragma Inline (Get_Instance_Module);
 
+   --  Each base instance creates bit0 and bit1, which are used for control
+   --  flow.
+   function Get_Inst_Bit0 (Inst : Synth_Instance_Acc) return Net;
+   function Get_Inst_Bit1 (Inst : Synth_Instance_Acc) return Net;
+   pragma Inline (Get_Inst_Bit0, Get_Inst_Bit1);
+
    procedure Create_Object
      (Syn_Inst : Synth_Instance_Acc; Decl : Iir; Val : Value_Acc);
 
diff --git a/src/synth/synth-insts.adb b/src/synth/synth-insts.adb
index 793717764..9996ccfbb 100644
--- a/src/synth/synth-insts.adb
+++ b/src/synth/synth-insts.adb
@@ -113,6 +113,7 @@ package body Synth.Insts is
       Arch : Node;
       Config : Node;
       Syn_Inst : Synth_Instance_Acc;
+      M : Module;
    end record;
 
    function Hash (Params : Inst_Params) return Hash_Value_Type
@@ -162,6 +163,7 @@ package body Synth.Insts is
       Nbr_Outputs : Port_Nbr;
       Num : Uns32;
       Cur_Module : Module;
+      Self_Inst : Instance;
    begin
       if Get_Kind (Params.Decl) = Iir_Kind_Component_Declaration then
          pragma Assert (Params.Arch = Null_Node);
@@ -221,7 +223,6 @@ package body Synth.Insts is
       Cur_Module := New_User_Module (Get_Top_Module (Root_Instance),
                                      New_Sname_User (Get_Identifier (Decl)),
                                      Id_User_None, Nbr_Inputs, Nbr_Outputs, 0);
-      Set_Instance_Module (Syn_Inst, Cur_Module);
 
       --  Add ports to module.
       declare
@@ -248,10 +249,14 @@ package body Synth.Insts is
          Set_Port_Desc (Cur_Module, Inports, Outports);
       end;
 
+      Self_Inst := Create_Self_Instance (Cur_Module);
+      pragma Unreferenced (Self_Inst);
+
       return Inst_Object'(Decl => Decl,
                           Arch => Arch,
                           Config => Params.Config,
-                          Syn_Inst => Syn_Inst);
+                          Syn_Inst => Syn_Inst,
+                          M => Cur_Module);
    end Build;
 
    package Insts_Interning is new Interning
@@ -371,7 +376,7 @@ package body Synth.Insts is
       --  TODO: free sub_inst.
 
       Inst := New_Instance (Get_Instance_Module (Syn_Inst),
-                            Get_Instance_Module (Inst_Obj.Syn_Inst),
+                            Inst_Obj.M,
                             New_Sname_User (Get_Identifier (Stmt)));
 
       Synth_Instantiate_Module
@@ -543,7 +548,7 @@ package body Synth.Insts is
       --  TODO: free sub_inst.
 
       Inst := New_Instance (Get_Instance_Module (Syn_Inst),
-                            Get_Instance_Module (Inst_Obj.Syn_Inst),
+                            Inst_Obj.M,
                             New_Sname_User (Get_Identifier (Stmt)));
 
       Synth_Instantiate_Module
@@ -764,7 +769,7 @@ package body Synth.Insts is
       Entity : constant Node := Inst.Decl;
       Arch : constant Node := Inst.Arch;
       Syn_Inst : constant Synth_Instance_Acc := Inst.Syn_Inst;
-      Self_Inst : Instance;
+      Self_Inst : constant Instance := Get_Self_Instance (Inst.M);
       Inter : Node;
       Nbr_Inputs : Port_Nbr;
       Nbr_Outputs : Port_Nbr;
@@ -774,9 +779,7 @@ package body Synth.Insts is
          return;
       end if;
 
-      Self_Inst := Create_Self_Instance (Get_Instance_Module (Syn_Inst));
-      Builders.Set_Parent (Get_Build (Syn_Inst),
-                           Get_Instance_Module (Syn_Inst));
+      Set_Instance_Module (Syn_Inst, Inst.M);
 
       --  Create wires for inputs and outputs.
       Inter := Get_Port_Chain (Entity);
diff --git a/src/synth/synth-stmts.adb b/src/synth/synth-stmts.adb
index ddef62a74..d577ff17d 100644
--- a/src/synth/synth-stmts.adb
+++ b/src/synth/synth-stmts.adb
@@ -1318,8 +1318,7 @@ package body Synth.Stmts is
       end if;
 
       --  The subprogram has returned.  Do not execute further statements.
-      Phi_Assign (Build_Context, C.W_Ret,
-                  Build_Const_UB32 (Build_Context, 1, 1), 0);
+      Phi_Assign (Build_Context, C.W_Ret, Get_Inst_Bit1 (C.Inst), 0);
       C.Nbr_Ret := C.Nbr_Ret + 1;
       C.T_En := False;
    end Synth_Return_Statement;
@@ -1521,13 +1520,11 @@ package body Synth.Stmts is
       Set_Wire_Gate (C.W_Ret, Build_Signal (Build_Context,
                                             New_Internal_Name (Build_Context),
                                             1));
-      Phi_Assign (Build_Context, C.W_Ret,
-                  Build_Const_UB32 (Build_Context, 0, 1), 0);
+      Phi_Assign (Build_Context, C.W_Ret, Get_Inst_Bit0 (Syn_Inst), 0);
 
       Decls.Synth_Declarations (C.Inst, Get_Declaration_Chain (Bod), True);
 
-      Synth_Sequential_Statements
-        (C, Get_Sequential_Statement_Chain (Bod));
+      Synth_Sequential_Statements (C, Get_Sequential_Statement_Chain (Bod));
 
       Pop_And_Merge_Phi (Build_Context, Bod);