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From: "law at redhat dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/94655] [10 Regression] Implicit assignment operator triggers stringop-overflow warning since r10-5451-gef29b12cfbb4979a
Date: Tue, 21 Apr 2020 20:10:24 +0000	[thread overview]
Message-ID: <bug-94655-4-mPc6G6BSxE@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-94655-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94655

Jeffrey A. Law <law at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|NEW                         |RESOLVED
                 CC|                            |law at redhat dot com

--- Comment #6 from Jeffrey A. Law <law at redhat dot com> ---
Fundamentally if we're relying on the type of the MEM_REF, then we're going to
run into problems.  It simply does not map back to what the user originally
wrote.  That's the key issue Richi and Jakub are raising.

pr94675 is another recently reported example.  In that case as well FRE creates
a MEM_REF from address arithmetic, but the type isn't useful and leads to a
false positive out of bounds array warning.  Forwprop can do this stuff as
well, and I suspect if we were to dig elsewhere we'd find more examples.

While I don't want to lose these warnings, they are proving problematical in
the MEM_REF cases and I'm wondering if we need a distinct knob to disable them
in the MEM_REF cases given the fundamental incompatibility between giving good
diagnostics and the actions of various optimization passes.


In the immediate term I'm going to mark this as a dup of 94675 (and any others
I encounter in my BZ wanderings).

*** This bug has been marked as a duplicate of bug 94675 ***

  parent reply	other threads:[~2020-04-21 20:10 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-18 23:35 [Bug c++/94655] New: Implicit assignment operator triggers stringop-overflow warning drahflow at gmx dot de
2020-04-20  7:10 ` [Bug tree-optimization/94655] [10 Regression] " rguenth at gcc dot gnu.org
2020-04-20  7:24 ` [Bug tree-optimization/94655] [10 Regression] Implicit assignment operator triggers stringop-overflow warning since r10-5451-gef29b12cfbb4979a marxin at gcc dot gnu.org
2020-04-20  8:52 ` jakub at gcc dot gnu.org
2020-04-20 15:35 ` msebor at gcc dot gnu.org
2020-04-20 15:42 ` jakub at gcc dot gnu.org
2020-04-20 16:57 ` msebor at gcc dot gnu.org
2020-04-21 20:10 ` law at redhat dot com [this message]
2020-04-21 21:27 ` msebor at gcc dot gnu.org
2020-04-30 16:14 ` [Bug tree-optimization/94655] [10/11 " msebor at gcc dot gnu.org
2020-05-07 11:56 ` jakub at gcc dot gnu.org
2020-07-21 14:55 ` msebor at gcc dot gnu.org
2020-07-21 20:08 ` msebor at gcc dot gnu.org
2020-07-21 20:46 ` pinskia at gcc dot gnu.org
2020-07-23  6:51 ` rguenth at gcc dot gnu.org
2021-01-14  8:38 ` rguenth at gcc dot gnu.org
2021-01-14 20:11 ` msebor at gcc dot gnu.org
2021-01-21 22:34 ` [Bug tree-optimization/94655] [10/11 Regression] -Wstringop-overflow on implicit string assignment with vectorized char store msebor at gcc dot gnu.org
2021-01-21 23:48 ` msebor at gcc dot gnu.org
2021-03-04  0:05 ` cvs-commit at gcc dot gnu.org
2021-04-08 12:02 ` [Bug tree-optimization/94655] [10 " rguenth at gcc dot gnu.org
2022-03-17 19:54 ` msebor at gcc dot gnu.org
2022-06-28 10:40 ` jakub at gcc dot gnu.org
2023-07-07  8:49 ` rguenth at gcc dot gnu.org

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