synth: preliminary support of sequential assertions. For #1273

3 files changed, 99 insertions, 23 deletions

diff --git a/src/synth/netlists-disp_vhdl.adb b/src/synth/netlists-disp_vhdl.adb
index 6faf3337f..a4644d4f6 100644
--- a/src/synth/netlists-disp_vhdl.adb
+++ b/src/synth/netlists-disp_vhdl.adb
@@ -1248,7 +1248,7 @@ package body Netlists.Disp_Vhdl is
             Put_Line (";");
          when Id_Assert =>
             Disp_Template
-              ("  \l0: assert \i0 = '1' severity error;" & NL, Inst);
+              ("  \l0: postponed assert \i0 = '1' severity error;" & NL, Inst);
          when Id_Assume =>
             Disp_Template
               ("  \l0: assert \i0 = '1' severity warning; --  assume" & NL,
diff --git a/src/synth/synth-stmts.adb b/src/synth/synth-stmts.adb
index b24425943..2f354ee6d 100644
--- a/src/synth/synth-stmts.adb
+++ b/src/synth/synth-stmts.adb
@@ -621,22 +621,34 @@ package body Synth.Stmts is
    end Synth_Conditional_Signal_Assignment;
 
    --  Return the enable net from C.
-   function Get_En (C : Seq_Context) return Net is
+   function Get_En (C : Seq_Context; Loc : Source.Syn_Src) return Net
+   is
+      Ncond, Nen : Net;
    begin
       if C.Mode = Mode_Static then
+         --  Always enabled.
          return No_Net;
       end if;
+
+      Ncond := C.W_Cond;
+
       if Is_Static_Wire (C.W_En) then
-         --  Must be True!
-         return No_Net;
-      else
-         return Get_Current_Value (Get_Build (C.Inst), C.W_En);
+         --  Cannot be 0.
+         return Ncond;
       end if;
+
+      Nen := Get_Current_Value (Get_Build (C.Inst), C.W_En);
+      if Ncond = No_Net then
+         return Nen;
+      end if;
+      Nen := Build_Dyadic (Get_Build (C.Inst), Id_And, Nen, Ncond);
+      Set_Location (Nen, Loc);
+      return Nen;
    end Get_En;
 
    procedure Synth_Variable_Assignment (C : Seq_Context; Stmt : Node)
    is
-      En : constant Net := Get_En (C);
+      En : constant Net := Get_En (C, Stmt);
       Targ : Target_Info;
       Val : Valtyp;
    begin
@@ -654,7 +666,7 @@ package body Synth.Stmts is
      (C : Seq_Context; Stmt : Node)
    is
       Target : constant Node := Get_Target (Stmt);
-      En : constant Net := Get_En (C);
+      En : constant Net := Get_En (C, Stmt);
       Targ_Type : Type_Acc;
       Cond : Node;
       Ce : Node;
@@ -692,11 +704,15 @@ package body Synth.Stmts is
    is
       Cond : constant Node := Get_Condition (Stmt);
       Els : constant Node := Get_Else_Clause (Stmt);
+      Ctxt : constant Context_Acc := Get_Build (C.Inst);
       Cond_Val : Valtyp;
+      Cond_Net : Net;
+      Not_Cond_Net : Net;
       Phi_True : Phi_Type;
       Phi_False : Phi_Type;
+      Prev_Cond : Net;
    begin
-      Cond_Val := Synth_Expression (C.Inst, Cond, Get_En (C));
+      Cond_Val := Synth_Expression (C.Inst, Cond, Get_En (C, Stmt));
       if Cond_Val = No_Valtyp then
          Set_Error (C.Inst);
          return;
@@ -722,13 +738,37 @@ package body Synth.Stmts is
             end if;
          end if;
       else
+         Prev_Cond := C.W_Cond;
+         Cond_Net := Get_Net (Cond_Val);
+
+         --  Set W_Cond (for the 'then' part).
+         if Prev_Cond = No_Net then
+            C.W_Cond := Cond_Net;
+         else
+            C.W_Cond := Build_Dyadic (Ctxt, Id_And, Prev_Cond, Cond_Net);
+            Set_Location (C.W_Cond, Stmt);
+         end if;
+
+         --  The statements for the 'then' part.
          Push_Phi;
          Synth_Sequential_Statements
            (C, Get_Sequential_Statement_Chain (Stmt));
          Pop_Phi (Phi_True);
 
          Push_Phi;
+
          if Is_Valid (Els) then
+            --  Set W_Cond (for the 'else' part).
+            Not_Cond_Net := Build_Monadic (Ctxt, Id_Not, Cond_Net);
+            Set_Location (Not_Cond_Net, Stmt);
+            if Prev_Cond = No_Net then
+               C.W_Cond := Not_Cond_Net;
+            else
+               C.W_Cond := Build_Dyadic
+                 (Ctxt, Id_And, Prev_Cond, Not_Cond_Net);
+               Set_Location (C.W_Cond, Stmt);
+            end if;
+
             if Is_Null (Get_Condition (Els)) then
                --  Final else part.
                Synth_Sequential_Statements
@@ -738,10 +778,12 @@ package body Synth.Stmts is
                Synth_If_Statement (C, Els);
             end if;
          end if;
+
+         --  Restore value.
+         C.W_Cond := Prev_Cond;
          Pop_Phi (Phi_False);
 
-         Merge_Phis (Get_Build (C.Inst),
-                     Get_Net (Cond_Val), Phi_True, Phi_False, Stmt);
+         Merge_Phis (Ctxt, Cond_Net, Phi_True, Phi_False, Stmt);
       end if;
    end Synth_If_Statement;
 
@@ -954,7 +996,7 @@ package body Synth.Stmts is
                Choice_Data (Choice_Idx) :=
                  (Val => Convert_To_Uns64 (C.Inst,
                                            Get_Choice_Expression (Choice),
-                                           Get_En (C)),
+                                           Get_En (C, Stmt)),
                   Alt => Alt_Idx);
             when Iir_Kind_Choice_By_Others =>
                Others_Alt_Idx := Alt_Idx;
@@ -1166,7 +1208,8 @@ package body Synth.Stmts is
       Expr : constant Node := Get_Expression (Stmt);
       Sel : Valtyp;
    begin
-      Sel := Synth_Expression_With_Basetype (C.Inst, Expr, Get_En (C));
+      Sel := Synth_Expression_With_Basetype
+        (C.Inst, Expr, Get_En (C, Stmt));
       Strip_Const (Sel);
       if Is_Static (Sel.Val) then
          case Sel.Typ.Kind is
@@ -1739,6 +1782,7 @@ package body Synth.Stmts is
             W_En => No_Wire_Id,
             W_Ret => No_Wire_Id,
             W_Val => No_Wire_Id,
+            W_Cond => No_Net,
             Ret_Init => No_Net,
             Ret_Value => No_Valtyp,
             Ret_Typ => null,
@@ -1767,11 +1811,9 @@ package body Synth.Stmts is
 
       Set_Wire_Gate
         (C.W_En, Build_Control_Signal (Sub_Inst, 1, Imp));
-      if En = No_Net then
-         Phi_Assign_Static (C.W_En, Bit1);
-      else
-         Phi_Assign_Net (Ctxt, C.W_En, En, 0);
-      end if;
+      Phi_Assign_Static (C.W_En, Bit1);
+
+      C.W_Cond := En;
 
       Set_Wire_Gate
         (C.W_Ret, Build_Control_Signal (Sub_Inst, 1, Imp));
@@ -2207,7 +2249,7 @@ package body Synth.Stmts is
       Phi_False : Phi_Type;
    begin
       if Cond /= Null_Node then
-         Cond_Val := Synth_Expression (C.Inst, Cond, Get_En (C));
+         Cond_Val := Synth_Expression (C.Inst, Cond, Get_En (C, Stmt));
          Static_Cond := Is_Static_Val (Cond_Val.Val);
          if Static_Cond then
             if Get_Static_Discrete (Cond_Val) = 0 then
@@ -2503,7 +2545,7 @@ package body Synth.Stmts is
       if Expr /= Null_Node then
          --  Return in function.
          Val := Synth_Expression_With_Type
-           (C.Inst, Expr, C.Ret_Typ, Get_En (C));
+           (C.Inst, Expr, C.Ret_Typ, Get_En (C, Stmt));
          if Val = No_Valtyp then
             Set_Error (C.Inst);
             return;
@@ -2628,6 +2670,30 @@ package body Synth.Stmts is
       Synth_Static_Report (C, Stmt);
    end Synth_Static_Assertion_Statement;
 
+   procedure Synth_Dynamic_Assertion_Statement (C : Seq_Context; Stmt : Node)
+   is
+      Ctxt : constant Context_Acc := Get_Build (C.Inst);
+      En : constant Net := Get_En (C, Stmt);
+      Loc : constant Location_Type := Get_Location (Stmt);
+      Cond : Valtyp;
+      N : Net;
+      Inst : Instance;
+   begin
+      Cond := Synth_Expression
+        (C.Inst, Get_Assertion_Condition (Stmt), No_Net);
+      if Cond = No_Valtyp then
+         Set_Error (C.Inst);
+         return;
+      end if;
+      N := Get_Net (Cond);
+      if En /= No_Net then
+         --  Build: En -> Cond
+         N := Build2_Imp (Ctxt, En, N, Loc);
+      end if;
+      Inst := Build_Assert (Ctxt, Synth_Label (Stmt), N);
+      Set_Location (Inst, Loc);
+   end Synth_Dynamic_Assertion_Statement;
+
    procedure Synth_Sequential_Statements
      (C : in out Seq_Context; Stmts : Node)
    is
@@ -2667,9 +2733,11 @@ package body Synth.Stmts is
             when Iir_Kind_If_Statement =>
                Synth_If_Statement (C, Stmt);
             when Iir_Kind_Simple_Signal_Assignment_Statement =>
-               Synth_Simple_Signal_Assignment (C.Inst, Stmt, Get_En (C));
+               Synth_Simple_Signal_Assignment
+                 (C.Inst, Stmt, Get_En (C, Stmt));
             when Iir_Kind_Conditional_Signal_Assignment_Statement =>
-               Synth_Conditional_Signal_Assignment (C.Inst, Stmt, Get_En (C));
+               Synth_Conditional_Signal_Assignment
+                 (C.Inst, Stmt, Get_En (C, Stmt));
             when Iir_Kind_Variable_Assignment_Statement =>
                Synth_Variable_Assignment (C, Stmt);
             when Iir_Kind_Conditional_Variable_Assignment_Statement =>
@@ -2694,7 +2762,7 @@ package body Synth.Stmts is
             when Iir_Kind_Return_Statement =>
                Synth_Return_Statement (C, Stmt);
             when Iir_Kind_Procedure_Call_Statement =>
-               Synth_Procedure_Call (C.Inst, Stmt, Get_En (C));
+               Synth_Procedure_Call (C.Inst, Stmt, Get_En (C, Stmt));
             when Iir_Kind_Report_Statement =>
                if not Is_Dyn then
                   Synth_Static_Report_Statement (C, Stmt);
@@ -2702,6 +2770,8 @@ package body Synth.Stmts is
             when Iir_Kind_Assertion_Statement =>
                if not Is_Dyn then
                   Synth_Static_Assertion_Statement (C, Stmt);
+               else
+                  Synth_Dynamic_Assertion_Statement (C, Stmt);
                end if;
             when Iir_Kind_Exit_Statement
               | Iir_Kind_Next_Statement =>
@@ -2796,6 +2866,7 @@ package body Synth.Stmts is
             W_En => Alloc_Wire (Wire_Variable, Proc),
             W_Ret => No_Wire_Id,
             W_Val => No_Wire_Id,
+            W_Cond => No_Net,
             Ret_Init => No_Net,
             Ret_Value => No_Valtyp,
             Ret_Typ => null,
diff --git a/src/synth/synth-stmts.ads b/src/synth/synth-stmts.ads
index 330cf156e..3d5c12081 100644
--- a/src/synth/synth-stmts.ads
+++ b/src/synth/synth-stmts.ads
@@ -161,6 +161,11 @@ private
             --  Return value.
             W_Val : Wire_Id;
 
+            --  Condition.
+            --  If No_Net, then it is like True.
+            --  Set when the execution path is enabled.
+            W_Cond : Net;
+
             Ret_Init : Net;
 
          when Mode_Static =>