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From: "Joost.VandeVondele at mat dot ethz.ch" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libgomp/59194] tsan detects race for real variables in an OMP reduction clause
Date: Wed, 20 Nov 2013 17:26:00 -0000	[thread overview]
Message-ID: <bug-59194-4-n2a8YdoqfT@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-59194-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59194

--- Comment #5 from Joost VandeVondele <Joost.VandeVondele at mat dot ethz.ch> ---
(In reply to Jakub Jelinek from comment #4)
> I bet tsan complains because the load is
> not atomic, but does it really matter?  

I think there are (at least) two possible answers to this.

1) No, it doesn't matter, because we get the right result. This actually is
great, already and your and other gcc-ers effort is much appreciated.

2) But yes, it does. For users, having a tool to help verify/debug an OMP
program is very valuable. tsan is pretty close to doing being exactly that, and
the gomp+tsan combination would be really a plus for gcc, increasing in
importance as OMP (or related variants) becomes more and more common. Such
false positives reduce the value of the gomp+tsan tool significantly.
Therefore, if these issues could be fixed easily without significant downside,
I think this should be done. I'd happy to try patches, and do some tsan+omp
testing.


  parent reply	other threads:[~2013-11-20 17:26 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-11-19 17:51 [Bug libgomp/59194] New: " Joost.VandeVondele at mat dot ethz.ch
2013-11-19 18:25 ` [Bug libgomp/59194] " pinskia at gcc dot gnu.org
2013-11-19 18:46 ` Joost.VandeVondele at mat dot ethz.ch
2013-11-20 13:43 ` Joost.VandeVondele at mat dot ethz.ch
2013-11-20 13:51 ` jakub at gcc dot gnu.org
2013-11-20 17:26 ` Joost.VandeVondele at mat dot ethz.ch [this message]
2013-11-20 17:54 ` Joost.VandeVondele at mat dot ethz.ch
2013-11-20 17:59 ` jakub at gcc dot gnu.org
2013-11-20 18:12 ` Joost.VandeVondele at mat dot ethz.ch
2013-11-21 12:34 ` dvyukov at google dot com
2014-01-09 16:12 ` Joost.VandeVondele at mat dot ethz.ch
2014-01-13  7:57 ` jakub at gcc dot gnu.org
2014-01-13 10:54 ` Joost.VandeVondele at mat dot ethz.ch

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