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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/53265] Warn when undefined behavior implies smaller iteration count
Date: Tue, 30 Apr 2013 06:07:00 -0000 [thread overview]
Message-ID: <bug-53265-4-lUviZpw2fS@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-53265-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53265
--- Comment #28 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-04-30 06:07:23 UTC ---
The warning is only printed if the loop has a single exit and known constant
iteration count without the undefined behavior analysis, and when the warning
is printed, we don't apply the aggressive analysis anyway.
It is hard to warn in all cases, but what exactly would be the cases anyway,
the amount of surprise on undefined behavior varies a lot.
The point of the warning was to warn about the easy cases, for the rest applies
what we write in bugs.html - if a suspicious program behaviour goes away with
-fno-aggressive-loop-optimizations, most likely it is a fault of the compiled
code, not the compiler.
next prev parent reply other threads:[~2013-04-30 6:07 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-07 14:09 [Bug tree-optimization/53265] New: " amonakov at gcc dot gnu.org
2012-05-07 14:21 ` [Bug tree-optimization/53265] " rguenth at gcc dot gnu.org
2013-01-29 17:23 ` jakub at gcc dot gnu.org
2013-01-31 12:13 ` jakub at gcc dot gnu.org
2013-03-11 10:15 ` rguenth at gcc dot gnu.org
2013-03-11 14:14 ` rguenth at gcc dot gnu.org
2013-03-11 14:16 ` rguenth at gcc dot gnu.org
2013-03-11 14:17 ` rguenth at gcc dot gnu.org
2013-03-11 15:49 ` jakub at gcc dot gnu.org
2013-03-11 15:59 ` rguenth at gcc dot gnu.org
2013-03-11 16:16 ` amonakov at gcc dot gnu.org
2013-03-11 16:42 ` manu at gcc dot gnu.org
2013-03-11 16:50 ` manu at gcc dot gnu.org
2013-03-11 17:11 ` jakub at gcc dot gnu.org
2013-03-12 11:25 ` jakub at gcc dot gnu.org
2013-03-12 11:26 ` jakub at gcc dot gnu.org
2013-03-12 11:30 ` jakub at gcc dot gnu.org
2013-03-12 11:48 ` jakub at gcc dot gnu.org
2013-03-12 12:37 ` jakub at gcc dot gnu.org
2013-03-12 12:41 ` jakub at gcc dot gnu.org
2013-03-12 14:15 ` jakub at gcc dot gnu.org
2013-03-12 20:10 ` jakub at gcc dot gnu.org
2013-03-12 21:48 ` jakub at gcc dot gnu.org
2013-03-13 10:36 ` jakub at gcc dot gnu.org
2013-03-13 11:01 ` rguenth at gcc dot gnu.org
2013-03-14 9:14 ` jakub at gcc dot gnu.org
2013-03-14 10:55 ` jakub at gcc dot gnu.org
2013-04-29 23:18 ` ppluzhnikov at google dot com
2013-04-30 6:07 ` jakub at gcc dot gnu.org [this message]
2013-04-30 6:46 ` jakub at gcc dot gnu.org
2014-02-16 13:14 ` jackie.rosen at hushmail dot com
2023-06-09 16:52 ` pinskia at gcc dot gnu.org
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