[Bug c++/62306] [4.9/5 Regression?] Change in the comdat used for constructors

[rafael.espindola at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62306

--- Comment #10 from Rafael Avila de Espindola <rafael.espindola at gmail dot com> ---
(In reply to Jakub Jelinek from comment #9)
> (In reply to Jason Merrill from comment #8)
> > I think I'm sympathetic to Rafael's argument that we should stick with the
> > 4.7 behavior since that's what most deployed GCCs currently do.
> 
> 4.5+4.6+4.9 is more released compilers than 4.7/4.8 though, and 4.9 is
> already widely deployed too, IMHO it is worse to change this again
> mid-release.

Another option to start using a D6 COMDAT that is defined to always contain D1
and D2 and never contain D0.

This would mean a small bloat when mixing some .o files compiled with 5 and
some with previous releases, but would also mean better codegen and a clean
state for 5 and newer.