ir_node **in;
ir_node *unknown, *new_phi;
- arity = get_irn_arity(node);
- in = alloca(arity * sizeof(in[0]));
+ arity = get_irn_arity(node);
+ in = ALLOCAN(ir_node*, arity);
unknown = new_Unknown(config.lowered_mode);
for(i = 0; i < arity; ++i) {
in[i] = unknown;