When I type
nonstandard extension used : '__int128' keyword not supported on this architecture
Additionally, never trust the syntax hilighter; it is user editable, and thus likely to either have bogus or 'future' types in it. (it is probably a reserved word however, due to the error, thus you should avoid naming any types
__int128, this follows the convention that anything prefixed with a double underscore should reserved for compiler use).
One would think the
__int128 might be available on x64/IPF machines via register spanning, like
__in64 is on 32bit targets, but right now the only 128 bit types stem from SIMD types (
__m128 and its various typed forms).