+ if (is_Cmp(a) && is_Cmp(b)) {
+ ir_node *a_left = get_Cmp_left(a);
+ ir_node *a_right = get_Cmp_right(a);
+ ir_node *b_left = get_Cmp_left(b);
+ ir_node *b_right = get_Cmp_right(b);
+ ir_relation a_relation = get_Cmp_relation(a);
+ ir_relation b_relation = get_Cmp_relation(b);
+ /* we can combine the relations of two compares with the same
+ * operands */
+ if (a_left == b_left && b_left == b_right) {
+ dbg_info *dbgi = get_irn_dbg_info(n);
+ ir_node *block = get_nodes_block(n);
+ ir_relation new_relation = a_relation & b_relation;
+ return new_rd_Cmp(dbgi, block, a_left, a_right, new_relation);
+ }
+ /* Cmp(a==0) and Cmp(b==0) can be optimized to Cmp(a|b==0) */
+ if (is_Const(a_right) && is_Const_null(a_right)
+ && is_Const(b_right) && is_Const_null(b_right)
+ && a_relation == b_relation && a_relation == ir_relation_equal
+ && !mode_is_float(get_irn_mode(a_left))
+ && !mode_is_float(get_irn_mode(b_left))) {
+ dbg_info *dbgi = get_irn_dbg_info(n);
+ ir_node *block = get_nodes_block(n);
+ ir_mode *mode = get_irn_mode(a_left);
+ ir_node *n_b_left = get_irn_mode(b_left) != mode ?
+ new_rd_Conv(dbgi, block, b_left, mode) : b_left;
+ ir_node *or = new_rd_Or(dbgi, block, a_left, n_b_left, mode);
+ ir_graph *irg = get_irn_irg(n);
+ ir_node *zero = create_zero_const(irg, mode);
+ return new_rd_Cmp(dbgi, block, or, zero, ir_relation_equal);
+ }
+ }
+