tree-ssa-dom.c (simplify_rhs_and_lookup_avail_expr): Do not perform…

tree-ssa-dom.c (simplify_rhs_and_lookup_avail_expr): Do not perform reassociation if the parent statement will not die as a result...

        * tree-ssa-dom.c (simplify_rhs_and_lookup_avail_expr): Do not
        perform reassociation if the parent statement will not die as
        a result of the optimization.

From-SVN: r106744

gcc/ChangeLog

+2005-11-04  Jeff Law  <law@redhat.com>
+
+	PR middle-end/23181
+	* tree-ssa-dom.c (simplify_rhs_and_lookup_avail_expr): Do not
+	perform reassociation if the parent statement will not die as
+	a result of the optimization.
+
 2005-11-10  Daniel Berlin  <dberlin@dberlin.org>
 
 	* tree-ssa-alias.c (compute_may_aliases): Remove call to 

gcc/tree-ssa-dom.c

@@ -1794,6 +1794,7 @@ simplify_rhs_and_lookup_avail_expr (tree stmt, int insert)
      assignment.  Add minus to this, as we handle it specially below.  */
   if ((associative_tree_code (rhs_code) || rhs_code == MINUS_EXPR)
       && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME
+      && num_imm_uses (TREE_OPERAND (rhs, 0)) == 1
       && is_gimple_min_invariant (TREE_OPERAND (rhs, 1)))
     {
       tree rhs_def_stmt = SSA_NAME_DEF_STMT (TREE_OPERAND (rhs, 0));