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From: "rguenther at suse dot de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/50904] [4.7 regression] pessimization when -fno-protect-parens is enabled by -Ofast
Date: Thu, 01 Dec 2011 08:51:00 -0000 [thread overview]
Message-ID: <bug-50904-4-QfS37Rev5y@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-50904-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50904
--- Comment #18 from rguenther at suse dot de <rguenther at suse dot de> 2011-12-01 08:51:07 UTC ---
On Sat, 12 Nov 2011, ebotcazou at gcc dot gnu.org wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50904
>
> Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:
>
> What |Removed |Added
> ----------------------------------------------------------------------------
> Status|ASSIGNED |NEW
> CC| |rguenth at gcc dot gnu.org
> Component|rtl-optimization |tree-optimization
> AssignedTo|ebotcazou at gcc dot |unassigned at gcc dot
> |gnu.org |gnu.org
>
> --- Comment #15 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-11-12 16:45:13 UTC ---
> > I don't see why RTL invariant motion should move the one variant but not
> > the other. Of course this also shows that we should, after loop unrolling
> > on the tree level, also perform loop invariant motion again ...
>
> AFAICS we already do that (lim3 is run after cunroll). The problem is that
> lim3 considers that the loads cannot be hoisted because they are "dependent".
> And it looks like a ccp pass is missing after cunroll as there is a lot of
> cruft...
lim3 was added as a "hack", now yes, cunroll needs ccp after it (but it's
there in the form of DOM and VRP). It's a pass ordering issue that we
cannot ever solve.
> Recategorizing, at least temporarily, for further investigation. If nothing
> can be done at the Tree level, we could consider applying the RTL patch.
Please - it seems like a missed optimization there, too.
Richard.
next prev parent reply other threads:[~2011-12-01 8:51 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-28 17:19 [Bug rtl-optimization/50904] New: Induct benchmark of polyhedron slows down " venkataramanan.kumar.gnu at gmail dot com
2011-10-28 19:14 ` [Bug rtl-optimization/50904] " dominiq at lps dot ens.fr
2011-10-30 9:41 ` rguenth at gcc dot gnu.org
2011-10-30 9:41 ` rguenth at gcc dot gnu.org
2011-10-30 11:25 ` dominiq at lps dot ens.fr
2011-10-30 11:35 ` dominiq at lps dot ens.fr
2011-11-01 13:53 ` ebotcazou at gcc dot gnu.org
2011-11-02 5:51 ` venkataramanan.kumar.gnu at gmail dot com
2011-11-04 21:55 ` ebotcazou at gcc dot gnu.org
2011-11-05 11:54 ` [Bug rtl-optimization/50904] [4.7 regression] pessimization " rguenth at gcc dot gnu.org
2011-11-07 0:33 ` ebotcazou at gcc dot gnu.org
2011-11-08 0:43 ` ebotcazou at gcc dot gnu.org
2011-11-09 9:03 ` ebotcazou at gcc dot gnu.org
2011-11-09 10:40 ` venkataramanan.kumar.gnu at gmail dot com
2011-11-11 23:04 ` venkataramanan.kumar.gnu at gmail dot com
2011-11-12 17:22 ` [Bug tree-optimization/50904] " ebotcazou at gcc dot gnu.org
2011-11-19 7:18 ` venkataramanan.kumar.gnu at gmail dot com
2011-11-19 9:09 ` ebotcazou at gcc dot gnu.org
2011-12-01 8:51 ` rguenther at suse dot de [this message]
2011-12-01 19:53 ` [Bug rtl-optimization/50904] " ebotcazou at gcc dot gnu.org
2011-12-02 9:49 ` rguenther at suse dot de
2011-12-02 10:56 ` ebotcazou at gcc dot gnu.org
2011-12-02 11:51 ` rguenth at gcc dot gnu.org
2011-12-02 14:04 ` burnus at gcc dot gnu.org
2011-12-02 14:32 ` rguenther at suse dot de
2011-12-02 14:41 ` burnus at gcc dot gnu.org
2011-12-02 15:04 ` rguenther at suse dot de
2011-12-02 16:03 ` burnus at gcc dot gnu.org
2011-12-02 16:13 ` howarth at nitro dot med.uc.edu
2011-12-02 16:15 ` rguenther at suse dot de
2011-12-02 16:30 ` burnus at gcc dot gnu.org
2011-12-02 16:33 ` rguenther at suse dot de
2011-12-02 16:38 ` dominiq at lps dot ens.fr
2011-12-02 16:47 ` dominiq at lps dot ens.fr
2011-12-02 17:07 ` burnus at gcc dot gnu.org
2011-12-02 21:21 ` ebotcazou at gcc dot gnu.org
2011-12-03 14:55 ` dominiq at lps dot ens.fr
2011-12-05 8:19 ` rguenther at suse dot de
2011-12-05 8:27 ` rguenther at suse dot de
2011-12-05 9:21 ` ebotcazou at gcc dot gnu.org
2011-12-05 9:57 ` rguenther at suse dot de
2011-12-05 10:13 ` dominiq at lps dot ens.fr
2011-12-05 10:21 ` rguenth at gcc dot gnu.org
2011-12-05 10:28 ` [Bug tree-optimization/50904] " ebotcazou at gcc dot gnu.org
2011-12-05 11:13 ` rguenth at gcc dot gnu.org
2011-12-05 14:38 ` rguenth at gcc dot gnu.org
2011-12-05 14:40 ` rguenth at gcc dot gnu.org
2011-12-05 17:30 ` ebotcazou at gcc dot gnu.org
2011-12-05 17:59 ` dominiq at lps dot ens.fr
2011-12-06 10:00 ` venkataramanan.kumar.gnu at gmail dot com
2011-12-07 13:21 ` venkataramanan.kumar.gnu at gmail dot com
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