[committed] libstdc++: Make __int128 meet integer-class requirements [PR 96042]

Marc Glisse marc.glisse@inria.fr
Sat Aug 22 15:00:59 GMT 2020

On Sat, 22 Aug 2020, Jonathan Wakely via Gcc-patches wrote:

> On Sat, 22 Aug 2020 at 13:13, Jonathan Wakely <jwakely.gcc@gmail.com> wrote:
>> On Sat, 22 Aug 2020 at 10:52, Marc Glisse wrote:
>>> is there a particular reason to handle only __int128 this way, and not all
>>> the non-standard integer types? It looks like it would be a bit simpler to
>>> avoid a special case.
>> I have no objection to doing it for all of them, it just wasn't
>> necessary to solve the immediate problem that the library now uses
>> __int128 even when integral<__int128> is false. (Hmm, or is size_t  an
>> alias for __int20 on one arch, which would mean we do use it?)
> Oh I remember why I didn't do that now. I did actually want to do it
> that way initially.
> The macros like __GLIBCXX_TYPE_INT_N_0 are not defined in strict mode,
> so we have no generic way to name those types.

IIRC, those macros were introduced specifically to help libstdc++. If 
libstdc++ wants them defined in different circumstances, it should be fine 
to change the condition from "!flag_iso || int_n_data[i].bitsize == 
POINTER_SIZE" to whatever you need.

But now I understand why you did this, thanks.

Marc Glisse

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