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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/111397] Spurious warning "'({anonymous})' is
 used uninitialized" when calling a __returns_twice__ function
 (-Wuninitialized -O2)
Date: Tue, 12 Sep 2023 21:15:51 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D111397

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Looks loop copy header change which allowed the warning not to happen.

The warning is about the argument of test_setjmpex. Because GCC does not
realize __builtin_frame_address cannot jump to the test_setjmpex ...

In the case of GCC 12-13, the copy of the loop header happens during
thread-full rather than earlier and inserts:
  _4(ab) =3D _11(D);

Which is what is warned about.
_11(D) does not get proped into the phi ...=