https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107919
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Blocks| |24639
Last reconfirmed| |2022-11-30
Status|UNCONFIRMED |NEW
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed on trunk. Hmm,
After normalization [USE]:
MEM[(struct _Tuple_impl *)this_5(D)] = __tmp_653;
is conditional on:
((_109 == 0))
After normalization [DEF]:
__tmp_653 = PHI <__tmp_652(44), __tmp_652(98), __tmp_365(91)>
is conditional on:
((_145 != 0B) AND (_531 == 2) AND (_109 == 0))
OR ((NOT (_145 != 0B)) AND (_531 == 2) AND (_109 == 0))
OR ((NOT (_531 == 2)) AND (_109 == 0))
the former conservatively describes the domain the use happens on while
the latter conservatively describes the domain the definition is
initialized.
We try to compute whether the initialized domain is a superset of the
use domain and compute that to be false.
I think that's misleading in the way that we fail to take into account
a conservative predicate that the definition is reached at all here,
that is, we prune the predicate that the domain of the use at the
definition.
There's the missing simplification
A && B || !A && B
to B in the DEF domain predicate and reducing it to a single
(_531 == 2) && (_109 == 0). That wouldn't help on its own, we still
have the domain constraint _531 == 2 that's not on the USE domain predicate.
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=24639
[Bug 24639] [meta-bug] bug to track all Wuninitialized issues
