+/*
+ * Check, if the value of a node cannot represent a NULL pointer.
+ *
+ * - Casts are skipped
+ * - If sel_based_null_check_elim is enabled, all
+ * Sel nodes can be skipped.
+ * - A SymConst(entity) is NEVER a NULL pointer
+ * - Confirms are evaluated
+ */
+int value_not_null(ir_node *n)
+{
+ ir_op *op;
+
+ n = skip_Cast(n);
+ op = get_irn_op(n);
+ assert(mode_is_reference(get_irn_mode(n)));
+ if (get_opt_sel_based_null_check_elim()) {
+ /* skip all Sel nodes and Cast's */
+ while (op == op_Sel) {
+ n = skip_Cast(get_Sel_ptr(n));
+ op = get_irn_op(n);
+ }
+ }
+ if (op == op_SymConst && get_SymConst_kind(n) == symconst_addr_ent)
+ return 1;
+ if (op == op_Confirm) {
+ if (get_Confirm_cmp(n) == pn_Cmp_Lg &&
+ classify_Const(get_Confirm_bound(n)) == CNST_NULL)
+ return 1;
+ }
+ return 0;
+}
+