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From: "msebor at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/98503] [11 regression] -Warray-bounds false positive with
 global variables at -O2 since r11-3306-g3f9a497d1b0dd9da
Date: Mon, 04 Jan 2021 17:41:03 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D98503

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |RESOLVED
         Resolution|---                         |INVALID

--- Comment #6 from Martin Sebor <msebor at gcc dot gnu.org> ---
In the test case in comment #0 the operand of the return statement in first=
()
dereferences the tmp pointer:

  return tmp->list.n;

The expression is equivalent to (*tmp).list.n where the dereference should =
be
more obvious.  The dereference is invalid if tmp points to an object of an
incompatible type.  This is a basic type-based aliasing requirement that GCC
relies on.

If the test case isn't representative of the problem you see in the code ba=
se
please submit one that does.=