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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 on casting pointers even under -O3
Date: Sat, 07 Aug 2010 01:29:00 -0000	[thread overview]
Message-ID: <20100807012909.6414.qmail@sourceware.org> (raw)
In-Reply-To: <bug-45221-17658@http.gcc.gnu.org/bugzilla/>



------- Comment #1 from navin dot kumar at gmail dot com  2010-08-07 01:29 -------
The assembly generated for foo1 & foo2 (under -O3) are identical:
    leaq    -4(%rdi), %rdx
    xorl    %eax, %eax
    testq   %rdi, %rdi
    cmovne  %rdx, %rax
    movl    8(%rax), %eax
    ret

The assembly generated for foo3 is the most optimal:
    movl    4(%rdi), %eax
    ret


-- 


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


  reply	other threads:[~2010-08-07  1:29 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-07  1:28 [Bug c++/45221] New: " navin dot kumar at gmail dot com
2010-08-07  1:29 ` navin dot kumar at gmail dot com [this message]
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
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

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