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From: "ebotcazou at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/58041] Unaligned access to arrays in packed structure
Date: Fri, 02 Aug 2013 15:54:00 -0000 [thread overview]
Message-ID: <bug-58041-4-ozFhg6xPsq@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-58041-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58041
Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ebotcazou at gcc dot gnu.org
--- Comment #22 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> After thinking it over some more, I think you are right, Martin. We should
> go ahead with the optimization with the corrected alignment attached to the
> type. Please go ahead with your patch. I will run a round of regression
> testing on PowerPC (an architecture for which the generic test produces
> misaligned but legal memory references) as well.
>
> Sorry for going back and forth on this. I try to avoid wasting compile time
> on useless transformations, but in this case we will still see some benefit
> in some cases, and the code should be no worse than before when we don't.
We should be very wary of generating unaligned accesses during optimization for
targets that define SLOW_UNALIGNED_ACCESS. And note that most architectures
supported by GCC are STRICT_ALIGNMENT, not the other way around, so it's the
common case.
next prev parent reply other threads:[~2013-08-02 15:54 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-01 7:26 [Bug middle-end/58041] New: " bernd.edlinger at hotmail dot de
2013-08-01 7:31 ` [Bug middle-end/58041] " bernd.edlinger at hotmail dot de
2013-08-01 9:09 ` mikpe at it dot uu.se
2013-08-01 11:36 ` mikpe at it dot uu.se
2013-08-01 11:51 ` mikpe at it dot uu.se
2013-08-01 13:26 ` wschmidt at gcc dot gnu.org
2013-08-01 16:18 ` wschmidt at gcc dot gnu.org
2013-08-01 16:23 ` jamborm at gcc dot gnu.org
2013-08-01 16:48 ` jamborm at gcc dot gnu.org
2013-08-01 17:27 ` jamborm at gcc dot gnu.org
2013-08-01 17:49 ` wschmidt at gcc dot gnu.org
2013-08-01 17:54 ` wschmidt at gcc dot gnu.org
2013-08-01 18:17 ` bernd.edlinger at hotmail dot de
2013-08-01 18:29 ` wschmidt at gcc dot gnu.org
2013-08-01 18:32 ` wschmidt at gcc dot gnu.org
2013-08-01 19:09 ` bernd.edlinger at hotmail dot de
2013-08-01 19:20 ` wschmidt at gcc dot gnu.org
2013-08-01 19:36 ` mikpe at it dot uu.se
2013-08-01 23:06 ` jamborm at gcc dot gnu.org
2013-08-02 15:22 ` wschmidt at gcc dot gnu.org
2013-08-02 15:28 ` wschmidt at gcc dot gnu.org
2013-08-02 15:54 ` ebotcazou at gcc dot gnu.org [this message]
2013-08-02 16:06 ` wschmidt at gcc dot gnu.org
2013-08-02 16:58 ` jamborm at gcc dot gnu.org
2013-08-02 17:12 ` wschmidt at gcc dot gnu.org
2013-08-02 18:07 ` wschmidt at gcc dot gnu.org
2013-08-03 8:31 ` bernd.edlinger at hotmail dot de
2013-08-05 17:43 ` jamborm at gcc dot gnu.org
2013-08-06 11:59 ` jamborm at gcc dot gnu.org
2013-08-06 14:24 ` bernd.edlinger at hotmail dot de
2013-08-06 15:18 ` jamborm at gcc dot gnu.org
2013-08-06 15:19 ` jamborm at gcc dot gnu.org
2013-08-06 15:33 ` bernd.edlinger at hotmail dot de
2013-08-06 15:56 ` bernd.edlinger at hotmail dot de
2013-08-06 16:06 ` jamborm at gcc dot gnu.org
2013-08-06 16:12 ` bernd.edlinger at hotmail dot de
2013-08-06 16:36 ` bernd.edlinger at hotmail dot de
2013-08-06 16:59 ` jamborm at gcc dot gnu.org
2013-08-06 17:07 ` bernd.edlinger at hotmail dot de
2013-08-06 17:37 ` jamborm at gcc dot gnu.org
2013-08-06 18:19 ` wschmidt at gcc dot gnu.org
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