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From: Jonathan Wakely <jwakely.gcc@gmail.com>
Date: Thu, 11 Mar 2021 12:56:51 +0000
Message-ID: <CAH6eHdRwhyUzVPZdY1Qdc-5wJdmEtHxN5gh8zi49QXDXr7x8-w@mail.gmail.com>
Subject: Re: IEEE Interchange floating point and extended floating point for
 C++
To: Kito Cheng <kito.cheng@gmail.com>
Cc: GCC <gcc@gcc.gnu.org>, "Joseph S. Myers" <joseph@codesourcery.com>
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On Thu, 11 Mar 2021 at 09:43, Kito Cheng via Gcc <gcc@gcc.gnu.org> wrote:
>
> Hi:
>
> Would it be possible to support interchange floating point and/or
> extended floating point for C++, which is introduced by ISO/IEC TS
> 18661-3?
>
> I've read the note about C++ support from the initial commit log[1],
> so I know there is some concern about C++ support for that, is it
> possible to enable that for C++ like a language extension for C++?
>
> The main demand comes from the data type for half-precision, ISO/IEC
> TS 18661-3 is the only common spec which supports half-precision and
> both GCC and clang are supported.
>
> However it can't be used on C++ for GCC, so it's hard to use that as a
> workable solution for half-precision data types.
>
> Or maybe ISO/IEC JTC1 SC22 WG14 N2016[2] is a better way for
> half-precision data types?

See https://wg21.link/p1467 and https://wg21.link/p1467 for the
relevant C++ proposals.