re PR tree-optimization/23157 (incorrect sharing of tree nodes regression)

	PR tree-optimization/23157
	* tree-scalar-evolution.c (scev_const_prop): Unshare trees
	before emitting them.

From-SVN: r102704

gcc/ChangeLog

+2005-08-03  Zdenek Dvorak  <dvorakz@suse.cz>
+
+	PR tree-optimization/23157
+	* tree-scalar-evolution.c (scev_const_prop): Unshare trees
+	before emitting them.
+
 2005-08-03  Volker Reichelt  <reichelt@igpm.rwth-aachen.de>
 
 	PR tree-optimization/19899

gcc/tree-scalar-evolution.c

@@ -2719,6 +2719,7 @@ scev_const_prop (void)
 	     in loop into account.  */
 	  if (force_expr_to_var_cost (def) >= target_spill_cost)
 	    continue;
+	  def = unshare_expr (def);
 
 	  if (is_gimple_val (def))
 	    stmts = NULL_TREE;