The online documentation contains the attached passage as part of the "C-Extensions” chapter. There are no actual machines which have an " integer mode wide enough to hold 128 bits” as the document puts it. This would be a harmless confusion if it didn’t go on to say “… long long integer less than 128 bits wide” (???!!!) Whereas in reality "long long int” is 64 bits everywhere i have seen. KS ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 6.8 128-bit integers As an extension the integer scalar type __int128 is supported for targets which have an integer mode wide enough to hold 128 bits. Simply write __int128 for a signed 128-bit integer, or unsigned __int128 for an unsigned 128-bit integer. There is no support in GCC for expressing an integer constant of type __int128 for targets with long long integer less than 128 bits wide.
