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From: "ramana at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/42494] [4.4 Regression] Missed dead-code-elimination: GCC 4.2.1 generates better code than 4.4.0
Date: Tue, 29 Dec 2009 12:45:00 -0000 [thread overview]
Message-ID: <20091229124456.16480.qmail@sourceware.org> (raw)
In-Reply-To: <bug-42494-17572@http.gcc.gnu.org/bugzilla/>
------- Comment #3 from ramana at gcc dot gnu dot org 2009-12-29 12:44 -------
Steven,
(In reply to comment #2)
> The "if (outcnt == 1) func ();" bit is optimized for me with gcc-4.4.2 on
> x86_64 at -O1 and -O2, but not at -Os. I was a bit too hasty to call this alias
> related, it seems.
Yes it seems to go away at O1 and O2. I didn't see any comment from you earlier
so not sure what you are referring to here.
> The O2 and Os tree dumps start to diverge in the dom1 dump,
> where we have just one call to func after dom1 at -O2 and still two calls at
> -O2.
>
FWIW I saw this removed by dom2 in trunk at -Os. In any case I think the
component ought to be tree-optimization and changed.
Cheers
Ramana
--
ramana at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Component|c |tree-optimization
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42494
next prev parent reply other threads:[~2009-12-29 12:45 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-25 5:42 [Bug c/42494] New: Regression on " sliao at google dot com
2009-12-29 10:35 ` [Bug c/42494] [4.4 only] " ramana at gcc dot gnu dot org
2009-12-29 11:31 ` [Bug c/42494] [4.4 Regression] Missed " steven at gcc dot gnu dot org
2009-12-29 12:45 ` ramana at gcc dot gnu dot org [this message]
2009-12-30 23:21 ` [Bug tree-optimization/42494] [4.4 Regression] Missed dead-code-elimination rguenth at gcc dot gnu dot org
2009-12-30 23:34 ` rguenth at gcc dot gnu dot org
2009-12-31 15:36 ` rguenth at gcc dot gnu dot org
2010-01-07 9:19 ` sliao at google dot com
2010-01-07 9:49 ` steven at gcc dot gnu dot org
2010-01-07 21:30 ` steven at gcc dot gnu dot org
2010-01-07 21:36 ` steven at gcc dot gnu dot org
2010-01-07 22:08 ` steven at gcc dot gnu dot org
2010-01-07 22:08 ` steven at gcc dot gnu dot org
2010-01-21 13:19 ` jakub at gcc dot gnu dot org
2010-02-08 16:45 ` steven at gcc dot gnu dot org
2010-04-30 8:58 ` jakub at gcc dot gnu dot org
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