diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d65dd24b0b6..e5e19ccd493 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -5,6 +5,9 @@
 	(unchecked_make_edge, remove_edge, redirect_edge_succ,
 	redirect_edge_pred): Use the new functions.
 
+	* tree-ssa-dom.c (tree_ssa_dominator_optimize): Call
+	free_dominance_info only when needed.
+
 2005-03-02  David Edelsohn  <edelsohn@gnu.org>
 
 	PR target/20276
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
index 5216c3b6313..242de47b610 100644
--- a/gcc/tree-ssa-dom.c
+++ b/gcc/tree-ssa-dom.c
@@ -444,7 +444,8 @@ tree_ssa_dominator_optimize (void)
 	  bitmap_zero (need_eh_cleanup);
 	}
 
-      free_dominance_info (CDI_DOMINATORS);
+      if (cfg_altered)
+	free_dominance_info (CDI_DOMINATORS);
       cfg_altered |= cleanup_tree_cfg ();
       calculate_dominance_info (CDI_DOMINATORS);