https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93745
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |rguenth at gcc dot gnu.org
Target Milestone|--- |8.4
--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Object re-use unfortunately also applies to objects with declared types. Note
the GCC middle-end is _not_ a pure C middle-end and also not a C++42 middle-end
but a middle-end that needs to support a variety of language standards.
As to comment#1 the store simply isn't dead if p points to d and yes, if you
place a load of *p after d then we know that p doesn't point to d via TBAA.
So to optimize the original case we need to know that p doesn't point to d
which for the standalone testcase we can't.
It might be a "regression" but the earlier compiler was simply wrong so I'm
inclined to either SUSPEND this (a FE hint is missing) or close it as INVALID.
