[Cfp-interest 3342] Re: [isocpp-wg14/wg21-liaison] SG22 telco : P3477R0 and P2746R0

[Hans Boehm]

Please use https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p2746r6.pdf
or wg21.link/p2746 .

I'm happy to attend the CFP meeting, if desired.

Hans


On Thu, Jan 2, 2025 at 9:25 AM Jim Thomas <jaswthomas at sbcglobal.net> wrote:
>
> CFP will discuss
>
> https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2746r0.pdf
>
> as a C++ liaison item at its January 8th meeting.
>
> - Jim Thomas
>
> Begin forwarded message:
>
> From: Hans Boehm <boehm at acm.org>
> Subject: Re: [isocpp-wg14/wg21-liaison] SG22 telco : P3477R0 and P2746R0
> Date: December 23, 2024 at 4:37:35 PM PST
> To: Nina Dinka Ranns <dinka.ranns at googlemail.com>
> Cc: "boehm at acm.org" <boehm at acm.org>, Jim Thomas <jaswthomas at sbcglobal.net>, RAJAN BHAKTA <rbhakta at us.ibm.com>
>
> I'm fine with discussing either paper. I expect much less controversy
> around p3475, which made it through 2 different WG21 committees, with
> a total of 20 minutes of committee time. I would hope that a WG14
> version would get a similar reception. I'm not aware of any C compiler
> that implements memory_order_consume as intended either. It basically
> removes a never-implemented feature.
>
> Note that p2746 is not new to Jim or the CFP group, though the actual
> library proposal has evolved a bit.
>
> P2746 diverges from the WG14/C23 way of handling rounding modes. The
> reasons for that are discussed in the paper. Basically:
>
> 1) Everyone involved in the discussion so far seemed convinced that
> WG21 is very unlikely to accept the #pragma FENV_ROUND specification
> in C23. So compatibility does not appear feasible.
> 2) IMO, there are significant technical arguments in favor of a
> library-based, as opposed to scope-based approach. SG6 appears to
> agree. My impression from WG14/CFP was that they would rather defer to
> the more scope-based approach traditionally used by IEEE, mostly since
> they view their charter more as connecting two standards than I think
> SG6 does. Another major factor was presumably bad timing on my part,
> in that the C23 work on #pragma FENV_ROUND had essentially been
> completed by the time I presented P2746.
> 3) I'm concerned about what seems to me to be a disproportionately
> large implementation effort to fully support FENV_ROUND in an area
> that has relatively little client code that directly relies on it, and
> has previously suffered from lack of implementer enthusiasm. That may
> be improving; I'm not sure.
>
> There was at some point vague discussion of a possible alternative
> C23-like proposal to WG21/SG6, but that has not materialized. I'm not
> sure what it would look like.
>
> Hans
>
> On Mon, Dec 23, 2024 at 6:44 AM Nina Dinka Ranns
> <dinka.ranns at googlemail.com> wrote:
>
>
> Hi Hans,
>
> I suggest we discuss https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p3475r0.pdf on the 7th of January instead.
> Thoughts ?
>
> Thank you,
> Nina
>
> On Mon, 23 Dec 2024 at 14:38, Nina Dinka Ranns <dinka.ranns at googlemail.com> wrote:
>
>
> Hi Rajan,
>
> from my perspective, we can postpone for after the January 8th. SG22 can process other business instead.
>
>
> Best,
> Nina
>
>
> On Mon, 23 Dec 2024 at 14:31, RAJAN BHAKTA <rbhakta at us.ibm.com> wrote:
>
>
> Hi Nina,
>
>
>
> If Jim and Hans agree, can we delay P2746R0 until WG14’s CFP study group meets to discuss this (on the 8th)?
>
>
>
> Jim: Can we add this to the CFP agenda on January 8th as part of the C++ liaison section?
>
> Hans: Can this wait one month?
>
>
>
> Regards,
>
> Rajan Bhakta
>
>
>
>
>
> From: Liaison <liaison-bounces at lists.isocpp.org> on behalf of Nina Dinka Ranns via Liaison <liaison at lists.isocpp.org>
> Date: Monday, December 23, 2024 at 3:21 AM
> To: WG14/WG21 liaison mailing list <liaison at lists.isocpp.org>, Hans Boehm <boehm at acm.org>, Robert Seacord <rcseacord at gmail.com>, Davis Herring <herring at lanl.gov>, JeanHeyd Meneide <wg14 at soasis.org>
> Cc: Nina Dinka Ranns <dinka.ranns at googlemail.com>
> Subject: [EXTERNAL] [isocpp-wg14/wg21-liaison] SG22 telco : P3477R0 and P2746R0
>
> Hi, Nina Dinka Ranns is inviting you to a scheduled Zoom meeting. Topic: SG22 Telco : P3477R0 and P2746R0 This is a meeting to discuss P3477R0 There are exactly 8 bits in a byte (JF Bastien) P2746R0 Deprecate and Replace Fenv Rounding Modes
>
> Hi, Nina Dinka Ranns is inviting you to a scheduled Zoom meeting. Topic: SG22 Telco : P3477R0 and P2746R0
>
>
>
> This is a meeting to discuss
>
> P3477R0 There are exactly 8 bits in a byte (JF Bastien)
>
> P2746R0 Deprecate and Replace Fenv Rounding Modes (Hans Boehm)
>
>
>
> Time: Jan 7, 2025 07:00 PM Amsterdam, Berlin, Rome, Stockholm, Vienna (19:00 UTC)
>
>
>
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