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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/106922] [12 Regression] Bogus uninitialized
 warning on boost::optional<<std::vector<std::string>>>, missed FRE
Date: Wed, 21 Sep 2022 12:52:28 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106922

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #53597|0                           |1
        is obsolete|                            |

--- Comment #14 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 53599
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=3D53599&action=3Dedit
candidate patch 2

OK, so I think I know what's going wrong eventually.  The following impleme=
nts
the trick differently.  We might eventually be able to use dominance of the
virtual operands to check for the cross-iteration case as further improveme=
nt.=