[Bug c++/125332] `flatten` attribute has no effect at -O0 optimization level

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125332

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |documentation
   Last reconfirmed|                            |2026-05-15
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
It doesn't make much sense at -O0 because important post-inlining scalar
optimizations are missing.  Confirmed.

"For a function marked with
this attribute, every call inside this function is inlined ..."

could say "is inlined when optimizing ..."