Re: doc: Clarify list of platforms for year2038 support

[Adhemerval Zanella Netto]

On 11/04/23 02:33, Paul Eggert wrote:
> Oh, I forgot to send comments that partly explain my recent changes in this 
> area. Here they are, belatedly:
> 
> 
> On 2023-04-10 05:56, Bruno Haible wrote:
> 
>> +@item
>> +Linux/riscv32,
> 
> <https://reviews.llvm.org/D85095> says this platform used 64-bit time_t "from 
> the get go".

Yes, all newer 32 bits architectures added after y2038 work on glibc uses 64 
bit time_t 
as default (riscv32, ork1, arc).

> 
>> +Linux with musl libc on x86,
> 
> <https://musl.libc.org/releases.html> says that musl uses 64-bit time_t on 
> all architectures starting with 1.2.0.
> 
>> +@item
>> +Cygwin/x86,
> 
> Cygwin dropped 32-bit support last year (3.3.6 is the last version with x86), 
> so this could use a date. Come to think of it, other entries could use dates 
> too.
> 
>> +Whereas no failure will occur on the following 32-bit platforms or ABIs:
>> +@itemize
>> +@item
>> +Linux/x86 with glibc >= 2.34 on
>> +x86, arm, mips (32-bit or n32 ABI), powerpc, sparc, s390, hppa, m68k, sh, 
>> csky, microblaze, nios2,
> 
> I vaguely recall someone telling me that _TIME_BITS=64 makes a difference 
> only on x86 and arm. But perhaps that was just for one distro that doesn't do 
> those other ports.

It makes difference on all ABIs with has originally 32 bit time_t support:
i686, microblaze, arm, m68k, sh, csky, nios2, and hppa, powerpc32, sparc32,
s390, and mips o32.