C++ Logo


Advanced search

Re: [wg14/wg21 liaison] *_HAS_SUBNORM

From: Fred J. Tydeman <tydeman_at_[hidden]>
Date: Wed, 12 Jan 2022 08:50:23 -0800 (PST)
On Mon, 6 Dec 2021 21:40:30 +0100 Jens Maurer wrote:
>On 02/12/2021 17.18, Fred J. Tydeman via Liaison wrote:
>> Issue for C++ liason group.
>> The WG14 paper:
>> http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2797.htm
>> discusses several issues with the *_HAS_SUBNORM macros.
>The existing text tries to give semantics to the *_HAS_SUBNORM
>preprocessor macros.


>The "Proposal" removes any mention of these macros and just adds
>general text about subnormals.

Independent of what we do with the *_HAS_SUBNORM macros, we
should add the green text to remove undefined behaviour from C.

>That seems a step backwards; the values of the *_HAS_SUBNORM
>macros should continue to be related to subnormal behavior
>of the implementation.

Do you want to leave them as is? Or, try to expand them to cover the
implementations that flush either operands or results (but not both)?

>Put differently, are you suggesting to remove the *_HAS_SUBNORM
>macros from the C standard? If not, they appear to exist
>without any semantic definition given your proposal.

Yes, the suggestion was to remove.

Fred J. Tydeman        Tydeman Consulting
tydeman_at_[hidden]      Testing, numerics, programming
+1 (702) 608-6093      Vice-chair of PL22.11 (ANSI "C")
Sample C99+FPCE tests: http://www.tybor.com
Savers sleep well, investors eat well, spenders work forever.

Received on 2022-01-12 16:50:26