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From: "navin dot kumar at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/45221] missed optimization with multiple bases and casting
Date: Sat, 07 Aug 2010 15:26:00 -0000	[thread overview]
Message-ID: <20100807152546.26810.qmail@sourceware.org> (raw)
In-Reply-To: <bug-45221-17658@http.gcc.gnu.org/bugzilla/>



------- Comment #5 from navin dot kumar at gmail dot com  2010-08-07 15:25 -------
Hi Richard,

Your explanation doesn't explain why foo1 would emit poorer assembly than foo3.

Or for that matter why fooA would emit poorer assembly than fooB.

In the case of foo1, foo3, fooA, and fooB, dereferencing occurs first, before
casting.  Yet only foo3 and fooB generate optimal assembly (so gcc is clearly
"capable" of outputting the desired asm).  This is all at -O3, where
"-fdelete-null-pointer-checks" is already enabled.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45221


  parent reply	other threads:[~2010-08-07 15:26 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-07  1:28 [Bug c++/45221] New: missed optimization on casting pointers even under -O3 navin dot kumar at gmail dot com
2010-08-07  1:29 ` [Bug c++/45221] " navin dot kumar at gmail dot com
2010-08-07  1:33 ` [Bug c++/45221] missed optimization with multiple bases and up casting and dereferencing pinskia at gcc dot gnu dot org
2010-08-07  2:27 ` navin dot kumar at gmail dot com
2010-08-07 10:37 ` [Bug c++/45221] missed optimization with multiple bases and casting rguenth at gcc dot gnu dot org
2010-08-07 15:26 ` navin dot kumar at gmail dot com [this message]
2010-08-07 16:19 ` rguenth at gcc dot gnu dot org
2010-08-07 16:23 ` navin dot kumar at gmail dot com
2010-08-07 16:25 ` rguenth at gcc dot gnu dot org
2010-08-07 16:27 ` rguenth at gcc dot gnu dot org
2010-08-07 17:28 ` navin dot kumar at gmail dot com
     [not found] <bug-45221-4@http.gcc.gnu.org/bugzilla/>
2011-05-17 15:49 ` navin.kumar at gmail dot com
2023-05-06 18:14 ` pinskia at gcc dot gnu.org

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