public void visit_putfield(final Instruction inst) {
		final MemberRef field = (MemberRef) inst.operand();
		final Type type = field.nameAndType().type();
		final Expr value = stack.pop(type);
		final Expr obj = stack.pop(Type.OBJECT);
		Expr ucCheck = obj;

		if (Tree.USE_PERSISTENT) {
			ucCheck = new UCExpr(obj, UCExpr.POINTER, obj.type());
		}

		final Expr check = new ZeroCheckExpr(ucCheck, obj.type());
		final FieldExpr target = new FieldExpr(check, field, type);
		addStore(target, value);
	}