https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110283
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Antonio Sanchez from comment #3) > @Andrew Pinsky can you elaborate on what's potentially wrong in the Eigen > code? > > The template argument will ignore the `may_alias` attribute, but the > `typedef`s do not, so `Packet4f` and `unpacket_traits<Packet4f>::half` are > still marked as `may_alias` and do allow aliasing without strict-aliasing > warnings. As I said potentially wrong because of the template arguments ignorning the attributes and I didn't look further into the code to see if Eigen used that template argument in anyway except for matching. But that is a different issue overall. Anyways the warning here is complex due to how complex the code Eigen causes to be inlined and someone will have to figure out why the warning is happening if it is a true bug or just warning about dead code or something GCC could not figure out is not out of bounds.
