GCC __builtin_expect的作用
https://blog.csdn.net/shuimuniao/article/details/8017971
https://blog.csdn.net/joker0910/article/details/6670436
__builtin_expect(!!(x), 1) 此处使用!!为的是转换成BOOL类型
https://blog.csdn.net/shuimuniao/article/details/8017971
https://blog.csdn.net/joker0910/article/details/6670436
__builtin_expect(!!(x), 1) 此处使用!!为的是转换成BOOL类型