Re: [RFC] man7/system_data_types.7: Document [unsigned] __int128

[Szabolcs Nagy <szabolcs.nagy@arm.com>]

The 10/01/2020 12:14, Alejandro Colomar via Gcc wrote:
> Here is the rendered intmax_t:
> 
> intmax_t
>       Include: <stdint.h>.  Alternatively, <inttypes.h>.
> 
>       A  signed  integer type capable of representing any value of any
>       signed integer type supported by the implementation.   According
>       to  the C language standard, it shall be capable of storing val-
>       ues in the range [INTMAX_MIN, INTMAX_MAX].
> 
>       The macro INTMAX_C() expands its argument to an integer constant
>       of type intmax_t.
> 
>       The  length  modifier  for  intmax_t  for  the printf(3) and the
>       scanf(3) families of functions is j; resulting commonly  in  %jd
>       or %ji for printing intmax_t values.
> 
>       Bugs:  intmax_t  is not large enough to represent values of type
>       __int128 in implementations where __int128 is defined  and  long
>       long is less than 128 bits wide.

or __int128 is not an integer type.

integer types are either standard or extended.
and __int128 is neither because it can be
larger than intmax_t and stdint.h does not
provide the necessary macros for it.

> 
>       Conforming to: C99 and later; POSIX.1-2001 and later.
> 
>       See also the uintmax_t type in this page.