[Bug c++/106652] [C++23] P1467 - Extended floating-point types and standard names

["jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106652

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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  Attachment #53508|0                           |1
        is obsolete|                            |

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 53555
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53555&action=edit
gcc13-pr106652-wip.patch

Some further progress.  Introduces a helper extended_float_type_p and uses it
and attempts to implement 2) from above and add some testcase coverage for it
(not complete, because right now there are just float{16,32,64,128} effective
targets and not effective targets for various float/double/long double type
properties (e.g. if they are ieee type), so for the cases where there should be
an error on the conversion I've kept only cases where I know for sure using the
above mentioned effective targets, not where it is sometimes the case and
sometimes it isn't.  From the above list, 1) needs decision what to do about
arithmetics in that type, 4) needs discussion on where to diagnose it, 5) needs
implementation.