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From: "rguenth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/37868] code that breaks TBAA is misoptimized even with -fno-strict-aliasing
Date: Sat, 18 Oct 2008 18:58:00 -0000 [thread overview]
Message-ID: <20081018185718.23504.qmail@sourceware.org> (raw)
In-Reply-To: <bug-37868-15165@http.gcc.gnu.org/bugzilla/>
------- Comment #2 from rguenth at gcc dot gnu dot org 2008-10-18 18:57 -------
I don't see why it _should_ work with -fno-strict-aliasing. It may. Note that
this testcase also violates pointer arithmetic rules - you have a pointer that
doesn't point to a valid object.
On the 4.3 branch we still optimize it because we use SFTs for the individual
elements and offset disambiguation selects only one. On the trunk PTA seems
to prune the symbol.
--
rguenth at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu dot
| |org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37868
next prev parent reply other threads:[~2008-10-18 18:58 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-18 18:17 [Bug tree-optimization/37868] New: code that doesn't " edwintorok at gmail dot com
2008-10-18 18:30 ` [Bug tree-optimization/37868] code that " sabre at nondot dot org
2008-10-18 18:58 ` rguenth at gcc dot gnu dot org [this message]
2008-10-18 22:36 ` rguenth at gcc dot gnu dot org
2008-10-18 22:44 ` rguenth at gcc dot gnu dot org
2008-10-22 11:48 ` [Bug tree-optimization/37868] [4.3 Regression] " rguenth at gcc dot gnu dot org
2008-10-22 13:50 ` rguenth at gcc dot gnu dot org
2008-11-03 11:29 ` jakub at gcc dot gnu dot org
2008-11-07 12:51 ` rguenth at gcc dot gnu dot org
2008-11-20 12:14 ` rguenth at gcc dot gnu dot org
2008-11-20 12:15 ` rguenth at gcc dot gnu dot org
2008-11-20 12:28 ` rguenth at gcc dot gnu dot org
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