* Added Tmoveins.id to be used for sorting and searching in Tmovelist, to

  produce the consistent order of elements.
  This fixes occasional differences in the register allocation caused by
  the address space randomization. When ASLR is in effect, the previous
  approach to sort elements by their memory addresses can't guarantee the
  consistent elements order for each compilation of the same source code.

compiler/rgobj.pas

@@ -66,18 +66,6 @@ unit rgobj;
         property bitmap[x,y:tsuperregister]:boolean read getbitmap write setbitmap;default;
       end;
 
-      Tmovelistheader=record
-        count,
-        maxcount,
-        sorted_until : cardinal;
-      end;
-
-      Tmovelist=record
-        header : Tmovelistheader;
-        data : array[tsuperregister] of Tlinkedlistitem;
-      end;
-      Pmovelist=^Tmovelist;
-
       {In the register allocator we keep track of move instructions.
        These instructions are moved between five linked lists. There
        is also a linked list per register to keep track about the moves
@@ -90,7 +78,20 @@ unit rgobj;
       Tmoveins=class(Tlinkedlistitem)
         moveset:Tmoveset;
         x,y:Tsuperregister;
+        id:tsuperregister;
+      end;
+
+      Tmovelistheader=record
+        count,
+        maxcount,
+        sorted_until : cardinal;
+      end;
+
+      Tmovelist=record
+        header : Tmovelistheader;
+        data : array[tsuperregister] of Tmoveins;
       end;
+      Pmovelist=^Tmovelist;
 
       Treginfoflag=(
         ri_coalesced,       { the register is coalesced with other register }
@@ -255,8 +256,8 @@ unit rgobj;
         backwards_was_first : tbitset;
         has_usedmarks: boolean;
         has_directalloc: boolean;
-
         spillinfo : array of tspillinfo;
+        moveins_id_counter: longint;
 
         { Disposes of the reginfo array.}
         procedure dispose_reginfo;
@@ -275,7 +276,7 @@ unit rgobj;
         function  spill_registers(list:TAsmList;headertai:tai):boolean;virtual;
         function  getnewreg(subreg:tsubregister):tsuperregister;
         procedure add_edges_used(u:Tsuperregister);
-        procedure add_to_movelist(u:Tsuperregister;data:Tlinkedlistitem);
+        procedure add_to_movelist(u:Tsuperregister;ins:Tmoveins);
         function move_related(n:Tsuperregister):boolean;
         procedure make_work_list;
         procedure sort_simplify_worklist;
@@ -330,11 +331,8 @@ unit rgobj;
 
     procedure sort_movelist(ml:Pmovelist);
 
-    {Ok, sorting pointers is silly, but it does the job to make Trgobj.combine
-     faster.}
-
     var h,i,p:longword;
-        t:Tlinkedlistitem;
+        t:Tmoveins;
 
     begin
       with ml^ do
@@ -351,7 +349,7 @@ unit rgobj;
                   i:=h;
                   t:=data[i];
                   repeat
-                    if ptruint(data[i-p])<=ptruint(t) then
+                    if data[i-p].id<=t.id then
                       break;
                     data[i]:=data[i-p];
                     dec(i,p);
@@ -456,6 +454,7 @@ unit rgobj;
          { Get reginfo for CPU registers }
          maxreginfo:=first_imaginary;
          maxreginfoinc:=16;
+         moveins_id_counter:=0;
          worklist_moves:=Tlinkedlist.create;
          move_garbage:=TLinkedList.Create;
          reginfo:=allocmem(first_imaginary*sizeof(treginfo));
@@ -795,7 +794,7 @@ unit rgobj;
     end;
 {$endif EXTDEBUG}
 
-    procedure trgobj.add_to_movelist(u:Tsuperregister;data:Tlinkedlistitem);
+    procedure trgobj.add_to_movelist(u:Tsuperregister;ins:Tmoveins);
     begin
 {$ifdef EXTDEBUG}
         if (u>=maxreginfo) then
@@ -820,7 +819,7 @@ unit rgobj;
                   reallocmem(movelist,ptruint(@movelist^.data)-ptruint(movelist)+movelist^.header.maxcount*sizeof(pointer));
                 end;
             end;
-          movelist^.data[movelist^.header.count]:=data;
+          movelist^.data[movelist^.header.count]:=ins;
           inc(movelist^.header.count);
         end;
     end;
@@ -953,7 +952,11 @@ unit rgobj;
       { How should we handle m68k move %d0,%a0? }
       if (getregtype(sreg)<>getregtype(dreg)) then
         exit;
+      if moveins_id_counter=high(moveins_id_counter) then
+        internalerror(2021112701);
+      inc(moveins_id_counter);
       i:=Tmoveins.create;
+      i.id:=moveins_id_counter;
       i.moveset:=ms_worklist_moves;
       worklist_moves.insert(i);
       ssupreg:=getsupreg(sreg);
@@ -1333,7 +1336,7 @@ unit rgobj;
     var adj : Psuperregisterworklist;
         i,n,p,q:cardinal;
         t : tsuperregister;
-        searched:Tlinkedlistitem;
+        searched:Tmoveins;
         found : boolean;
 
     begin
@@ -1379,7 +1382,7 @@ unit rgobj;
                   if q<>0 then
                     repeat
                       i:=(p+q) shr 1;
-                      if ptruint(searched)>ptruint(reginfo[u].movelist^.data[i]) then
+                      if searched.id>reginfo[u].movelist^.data[i].id then
                         p:=i+1
                       else
                         q:=i;
@@ -1390,7 +1393,7 @@ unit rgobj;
                         {Linear search the unsorted part of the list.}
                         found:=false;
                         for i:=header.sorted_until+1 to header.count-1 do
-                          if searched=data[i] then
+                          if searched.id=data[i].id then
                             begin
                               found:=true;
                               break;