https://blog.wongcw.com/2019/01/20/%e9%97%9c%e6%96%bc64-%e4%bd%8dphp-%e4%bd%bf%e7%94%a8php_int_size-%e8%bc%b8%e5%87%ba%e5%be%97%e5%88%b04-%e7%9a%84%e5%95%8f%e9%a1%8c/