关于 __int128

__int128 是 GCC 提供的扩展（extension），可以当作 128 位整数使用。

关于 __int128 和 __int128_t

Normally, _t suffix means a typedef, __ prefix means reserved for compiler and _ prefix means reserved for standard library; I would guess that __int128 is the final native type supported by the compiler, while __int128_t was a temporary hack that they moved away from.
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如何判断你所使用的 GCC 版本是否包含 __int128 扩展

You can test for the __SIZEOF_INT128__ macro --- which is (typically) 16 if defined.
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REFERENCE:
https://stackoverflow.com/q/21886985
https://stackoverflow.com/q/29638723/6052725

转载于:https://www.cnblogs.com/Patt/p/8031138.html