https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87634
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Status|UNCONFIRMED |NEW
Last reconfirmed| |2018-10-18
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
If that is possible then we cannot optimize the dynamic_cast<>. Certainly
GCC thinks that bar() clobbers what *a points to but it could possibly
thread the case when the dynamic cast fails (but that's too complex for
the threader to figure out as profitable).
