+/** find entity used as base for an address calculation */
+static ir_entity *find_entity(ir_node *ptr)
+{
+ switch(get_irn_opcode(ptr)) {
+ case iro_SymConst:
+ return get_SymConst_entity(ptr);
+ case iro_Sel: {
+ ir_node *pred = get_Sel_ptr(ptr);
+ if (get_irg_frame(get_irn_irg(ptr)) == pred)
+ return get_Sel_entity(ptr);
+
+ return find_entity(pred);
+ }
+ case iro_Sub:
+ case iro_Add: {
+ ir_node *left = get_binop_left(ptr);
+ ir_node *right;
+ if (mode_is_reference(get_irn_mode(left)))
+ return find_entity(left);
+ right = get_binop_right(ptr);
+ if (mode_is_reference(get_irn_mode(right)))
+ return find_entity(right);
+ return NULL;
+ }
+ default:
+ return NULL;
+ }
+}
+