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From: "christian.prochaska@genode-labs.com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/104288] [11/12 Regression] EVRP null pointer check removal for strcmp (and maybe others) is not flow senative
Date: Sun, 09 Apr 2023 07:07:32 +0000 [thread overview]
Message-ID: <bug-104288-4-PyRev6v7Vq@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-104288-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104288
--- Comment #16 from Christian Prochaska <christian.prochaska@genode-labs.com> ---
(In reply to Andrew Pinski from comment #14)
>
> There was a deferencing of myself before:
> Nova::Utcb &utcb = *(Nova::Utcb *)myself->utcb();
I see. The 'Thread::utcb()' function handles the null pointer case internally
with a 'this == 0' check and a local '-fno-delete-null-pointer-checks'
attribute:
https://github.com/genodelabs/genode/blob/a84af9a9606450471b8038a35f9b55057efa0850/repos/base-nova/src/lib/base/stack.cc#L110
So, the elimination of the 'myself' null pointer check is basically a result of
undefined behavior with the 'Thread::utcb()' function?
next prev parent reply other threads:[~2023-04-09 7:07 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-30 10:09 [Bug c/104288] New: Null pointer check invalidly deleted nrk at disroot dot org
2022-01-30 10:26 ` [Bug middle-end/104288] [11/12 Regression] " pinskia at gcc dot gnu.org
2022-01-30 10:29 ` [Bug tree-optimization/104288] [11/12 Regression] EVRP null pointer check removal for strcmp (and maybe others) is not flow senative pinskia at gcc dot gnu.org
2022-01-30 11:03 ` jakub at gcc dot gnu.org
2022-01-31 8:21 ` rguenth at gcc dot gnu.org
2022-01-31 14:53 ` amacleod at redhat dot com
2022-01-31 15:34 ` jakub at gcc dot gnu.org
2022-01-31 22:39 ` amacleod at redhat dot com
2022-02-01 8:04 ` rguenther at suse dot de
2022-02-02 21:52 ` amacleod at redhat dot com
2022-02-08 15:03 ` cvs-commit at gcc dot gnu.org
2022-02-09 14:10 ` cvs-commit at gcc dot gnu.org
2022-02-09 14:11 ` amacleod at redhat dot com
2023-04-09 3:59 ` christian.prochaska@genode-labs.com
2023-04-09 4:12 ` pinskia at gcc dot gnu.org
2023-04-09 4:12 ` pinskia at gcc dot gnu.org
2023-04-09 7:07 ` christian.prochaska@genode-labs.com [this message]
2023-04-09 7:43 ` pinskia at gcc dot gnu.org
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