From cde0d7d08450e2ee313d3ca5ab0ab8ca2cdce99a Mon Sep 17 00:00:00 2001
From: Jonas Maebe <jonas@freepascal.org>
Date: Sat, 8 Apr 2000 16:22:11 +0000
Subject: [PATCH]   * fixed concat_string optimization and enabled it when    
 -dnewoptimizations is used

---
 compiler/tcld.pas | 20 ++++++++++++++------
 compiler/tree.pas | 30 +++++++++++++++++++++++++++++-
 2 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/compiler/tcld.pas b/compiler/tcld.pas
index 6378bae802..8a49894a70 100644
--- a/compiler/tcld.pas
+++ b/compiler/tcld.pas
@@ -201,10 +201,10 @@ implementation
 *****************************************************************************}
 
     procedure firstassignment(var p : ptree);
-{$ifdef dummyi386}
+{$ifdef newoptimizations}
       var
         hp : ptree;
-{$endif}
+{$endif newoptimizations}
       begin
          { must be made unique }
          set_unique(p^.left);
@@ -273,8 +273,11 @@ implementation
             { the problem is for
               s:=s+s+s;
               this is broken here !! }
-            { while hp^.treetype=addn do hp:=hp^.left;
-            if equal_trees(p^.left,hp) then
+{$ifdef newoptimizations}
+            hp := p^.right;
+            while hp^.treetype=addn do hp:=hp^.left;
+            if equal_trees(p^.left,hp) and
+               not multiple_uses(p^.left,p^.right) then
               begin
                 p^.concat_string:=true;
                 hp:=p^.right;
@@ -283,7 +286,8 @@ implementation
                     hp^.use_strconcat:=true;
                     hp:=hp^.left;
                   end;
-              end; }
+              end;
+{$endif newoptimizations}
           end
          else
           begin
@@ -486,7 +490,11 @@ implementation
 end.
 {
   $Log$
-  Revision 1.61  2000-02-24 18:41:39  peter
+  Revision 1.62  2000-04-08 16:22:11  jonas
+    * fixed concat_string optimization and enabled it when
+      -dnewoptimizations is used
+
+  Revision 1.61  2000/02/24 18:41:39  peter
     * removed warnings/notes
 
   Revision 1.60  2000/02/17 14:53:43  florian
diff --git a/compiler/tree.pas b/compiler/tree.pas
index 15a2fb2ecf..1505e21634 100644
--- a/compiler/tree.pas
+++ b/compiler/tree.pas
@@ -307,6 +307,10 @@ unit tree;
     function getcopy(p : ptree) : ptree;
 
     function equal_trees(t1,t2 : ptree) : boolean;
+{$ifdef newoptimizations}
+    { checks if t1 is loaded more than once in t2 and its sub-trees }
+    function multiple_uses(t1,t2: ptree): boolean;
+{$endif newoptimizations}
 
     procedure swaptree(p:Ptree);
     procedure disposetree(p : ptree);
@@ -1731,6 +1735,26 @@ unit tree;
           equal_trees:=false;
      end;
 
+{$ifdef newoptimizations}
+    function multiple_uses(t1,t2: ptree): boolean;
+    var nr: longint;
+
+      procedure check_tree(t: ptree);
+      begin
+        inc(nr,ord(equal_trees(t1,t)));
+        if (nr < 2) and assigned(t^.left) then
+          check_tree(t^.left);
+        if (nr < 2) and assigned(t^.right) then
+          check_tree(t^.right);
+      end;
+
+    begin
+       nr := 0;
+       check_tree(t2);
+       multiple_uses := nr > 1;
+    end;
+{$endif newoptimizations}
+
     procedure set_unique(p : ptree);
 
       begin
@@ -2066,7 +2090,11 @@ unit tree;
 end.
 {
   $Log$
-  Revision 1.116  2000-03-01 15:36:12  florian
+  Revision 1.117  2000-04-08 16:22:11  jonas
+    * fixed concat_string optimization and enabled it when
+      -dnewoptimizations is used
+
+  Revision 1.116  2000/03/01 15:36:12  florian
     * some new stuff for the new cg
 
   Revision 1.115  2000/03/01 11:43:55  daniel