4 files changed, 49 insertions, 11 deletions
diff --git a/src/grt/grt-signals.adb b/src/grt/grt-signals.adb
index ea714ae20..9b669ee2f 100644
--- a/src/grt/grt-signals.adb
+++ b/src/grt/grt-signals.adb
@@ -252,6 +252,8 @@ package body Grt.Signals is
                               Nbr_Ports => 0,
                               Ports => null,
 
+                              Dump_Table_Idx => 0,
+
                               S => S);
 
       if Resolv /= null and then Resolv.Resolv_Ptr = System.Null_Address then
@@ -622,6 +624,8 @@ package body Grt.Signals is
                                      Nbr_Ports => 0,
                                      Ports => null,
 
+                                     Dump_Table_Idx => 0,
+
                                      S => (Mode_Sig => Mode_End));
 
 
@@ -3123,7 +3127,12 @@ package body Grt.Signals is
 
       Sig.Event := True;
       Sig.Last_Event := Current_Time;
-      Sig.Flags.RO_Event := True;
+      if not Sig.Flags.RO_Event then
+         Sig.Flags.RO_Event := True;
+         if Sig.Dump_Table_Idx /= 0 then
+            Changed_Sig_Table.Append(Sig);
+         end if;
+      end if;
 
       El := Sig.Event_List;
       while El /= null loop
diff --git a/src/grt/grt-signals.ads b/src/grt/grt-signals.ads
index 25af3e8b9..14d20dfb8 100644
--- a/src/grt/grt-signals.ads
+++ b/src/grt/grt-signals.ads
@@ -355,6 +355,8 @@ package Grt.Signals is
       Nbr_Ports : Ghdl_Index_Type;
       Ports : Signal_Arr_Ptr;
 
+      Dump_Table_Idx : Dump_Table_Index;
+
       --  Mode of the signal (in, out ...)
       --Mode_Signal : Mode_Signal_Type;
       S : Ghdl_Signal_Data;
@@ -367,6 +369,13 @@ package Grt.Signals is
       Table_Low_Bound => 0,
       Table_Initial => 128);
 
+   -- Signals with RO_Event set. Cleared in Grt.Wave.Wave_Cycle.
+   package Changed_Sig_Table is new Grt.Table
+     (Table_Component_Type => Ghdl_Signal_Ptr,
+      Table_Index_Type => Natural,
+      Table_Low_Bound => 1,
+      Table_Initial => 128);
+
    --  Read the value pointed by VALUE_PTR.  It cannot be simply deferred as
    --  pointer alignment may not be correct.
    function Read_Value (Value_Ptr : Ghdl_Value_Ptr; Mode : Mode_Type)
diff --git a/src/grt/grt-types.ads b/src/grt/grt-types.ads
index b4f4555e8..35b8f8e1e 100644
--- a/src/grt/grt-types.ads
+++ b/src/grt/grt-types.ads
@@ -180,6 +180,9 @@ package Grt.Types is
       First, Last : Sig_Table_Index;
    end record;
 
+   --  Signal index in Waves.Dump_Table.
+   type Dump_Table_Index is new Natural;
+
    --  Simple values, used for signals.
    type Mode_Type is
      (Mode_B1, Mode_E8, Mode_E32, Mode_I32, Mode_I64, Mode_F64);
diff --git a/src/grt/grt-waves.adb b/src/grt/grt-waves.adb
index a69aa119a..b3d575c3a 100644
--- a/src/grt/grt-waves.adb
+++ b/src/grt/grt-waves.adb
@@ -45,6 +45,7 @@ with Grt.Ghw; use Grt.Ghw;
 with Grt.Wave_Opt; use Grt.Wave_Opt;
 with Grt.Wave_Opt.File; use Grt.Wave_Opt.File;
 with Grt.Wave_Opt.Design; use Grt.Wave_Opt.Design;
+with Ada.Containers.Generic_Array_Sort;
 
 pragma Elaborate_All (Grt.Rtis_Utils);
 pragma Elaborate_All (Grt.Table);
@@ -853,6 +854,7 @@ package body Grt.Waves is
       --  If the signal number is 0, then assign a valid signal number.
       if Num = 0 then
          Nbr_Dumped_Signals := Nbr_Dumped_Signals + 1;
+         Sig.Dump_Table_Idx := Dump_Table_Index(Nbr_Dumped_Signals);
          Sig.Alink := To_Ghdl_Signal_Ptr
            (Integer_Address (Nbr_Dumped_Signals));
          Num := Nbr_Dumped_Signals;
@@ -1780,9 +1782,19 @@ package body Grt.Waves is
 
    procedure Wave_Cycle
    is
+      type Arr_Type is array (Dump_Table_Index range <>) of Ghdl_Signal_Ptr;
+
+      function Cmp (Left, Right : Ghdl_Signal_Ptr) return Boolean is
+      begin
+         return Left.Dump_Table_Idx < Right.Dump_Table_Idx;
+      end Cmp;
+
+      procedure Sort is new Ada.Containers.Generic_Array_Sort
+        (Dump_Table_Index, Ghdl_Signal_Ptr, Arr_Type, "<" => Cmp);
+
       Diff : Std_Time;
       Sig : Ghdl_Signal_Ptr;
-      Last : Natural;
+      Last : Dump_Table_Index;
    begin
       if not In_Cyc then
          Wave_Section ("CYC" & NUL);
@@ -1796,15 +1808,20 @@ package body Grt.Waves is
 
       --  Dump signals.
       Last := 0;
-      for I in Dump_Table.First .. Dump_Table.Last loop
-         Sig := Dump_Table.Table (I);
-         if Sig.Flags.RO_Event then
-            Wave_Put_ULEB128 (Ghdl_U32 (I - Last));
-            Last := I;
-            Write_Signal_Value (Sig);
-            Sig.Flags.RO_Event := False;
-         end if;
-      end loop;
+      if Changed_Sig_Table.First <= Changed_Sig_Table.Last then
+         Sort (Arr_Type (Changed_Sig_Table.Table
+                         (Changed_Sig_Table.First .. Changed_Sig_Table.Last)));
+         for I in Changed_Sig_Table.First .. Changed_Sig_Table.Last loop
+            Sig := Changed_Sig_Table.Table(I);
+            if Sig.Flags.RO_Event then
+               Wave_Put_ULEB128 (Ghdl_U32 (Sig.Dump_Table_Idx - Last));
+               Last := Sig.Dump_Table_Idx;
+               Write_Signal_Value (Sig);
+               Sig.Flags.RO_Event := False;
+            end if;
+         end loop;
+         Changed_Sig_Table.Set_Last (0);
+      end if;
       Wave_Put_Byte (0);
    end Wave_Cycle;