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From: "law at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/96564] [11/12/13/14 Regression] New maybe use of
 uninitialized variable warning since r11-959
Date: Sun, 10 Mar 2024 22:49:07 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D96564

Jeffrey A. Law <law at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org

--- Comment #12 from Jeffrey A. Law <law at gcc dot gnu.org> ---
So I think we could solve this with a bit of help from the alias oracle.  We
have  the routine ptrs_compare_unequal, but points-to-null is going to get =
in
the way.

I think VRP and DOM have enough information to rule out NULL for both objec=
ts
in question.  So if we could query the points-to information, ignoring NULL
then we could likely solve this particular bug.

Essentially VRP or DOM would prove NULL isn't in the set of possible values=
 at
the comparison point.  Then we query the alias information ignoring NULL.=20
Voila we compute a static result for the comparison of the two pointers and=
 the
problematical block becomes unreachable and the bogus warning goes away.

Richi, any thoughts in viability of such an API?=