[Bug c/106117] Use of option -fexcess-precision for operation-by-operation emulation for _Float16 arithmetics.

[rjmccall at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106117

John McCall <rjmccall at gmail dot com> changed:

           What    |Removed                     |Added
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                 CC|                            |rjmccall at gmail dot com

--- Comment #1 from John McCall <rjmccall at gmail dot com> ---
To clarify one point: Clang plans to use excess precision arithmetic as the
default for _Float16 when AVX512-FP16 isn't available, following the C
standard's rules, i.e. `-fexcess-precision=standard`.  We'd like to offer users
a way to disable this and force operation-by-operation translation, but as far
as we can tell, there isn't a way to request this in GCC today.  It feels like
`-fexcess-precision=none` (or some similar spelling) would be the most
appropriate way to do this, since of course this conflicts with other values of
`-fexcess-precision`.

Since GCC originated `-fexcess-precision`, we're trying to being neighborly and
ask whether you have a problem with this extension.