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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/50182] Performance degradation from gcc 4.1 (x86_64)
Date: Fri, 02 Mar 2012 08:29:00 -0000	[thread overview]
Message-ID: <bug-50182-4-veM6YfpF3q@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-50182-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50182

--- Comment #32 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-03-02 08:28:34 UTC ---
For me, 4.1 is equally fast to 4.6 on my CPU and on the reduced testcase I've
attached (not clear if it models what the original benchmark did right or not),
and on the trunk regressed with
http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=176072
Before that the inner loop looked like:
.L12:
        addl    $10, %edx
        addb    0(%rbp,%rcx), %dl
        addq    $1, %rcx
        cmpl    %ecx, %ebx
        jg      .L12
and now it looks like:
.L12:
        movzbl  0(%rbp,%rdx), %r8d
        addq    $1, %rdx
        cmpl    %edx, %ebx
        leal    10(%rcx,%r8), %ecx
        jg      .L12


  parent reply	other threads:[~2012-03-02  8:29 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-24 21:27 [Bug c++/50182] New: " oleg.smolsky at gmail dot com
2011-08-24 22:30 ` [Bug target/50182] " oleg.smolsky at gmail dot com
2011-08-25  0:14 ` xinliangli at gmail dot com
2011-08-25  0:52 ` xinliangli at gmail dot com
2011-08-25  9:00 ` jakub at gcc dot gnu.org
2011-08-25 15:21 ` oleg.smolsky at gmail dot com
2011-08-25 15:29 ` oleg.smolsky at gmail dot com
2011-08-25 16:18 ` hjl.tools at gmail dot com
2011-08-25 16:26 ` xinliangli at gmail dot com
2011-08-25 16:49 ` oleg.smolsky at gmail dot com
2011-08-25 22:48 ` oleg.smolsky at gmail dot com
2011-08-26  7:12 ` oleg.smolsky at gmail dot com
2011-08-30 20:37 ` matt at use dot net
2011-09-15 16:57 ` oleg at smolsky dot net
2011-09-15 17:39 ` xinliangli at gmail dot com
2011-10-21 23:02 ` xinliangli at gmail dot com
2011-10-24 18:28 ` oleg at smolsky dot net
2011-10-24 18:28 ` oleg at smolsky dot net
2011-10-24 18:33 ` oleg at smolsky dot net
2011-10-24 19:34 ` xinliangli at gmail dot com
2011-10-24 19:50 ` oleg at smolsky dot net
2011-10-24 19:59 ` xinliangli at gmail dot com
2011-10-24 21:12 ` oleg at smolsky dot net
2011-10-24 23:00 ` xinliangli at gmail dot com
2011-10-24 23:03 ` xinliangli at gmail dot com
2012-01-10 18:07 ` oleg at smolsky dot net
2012-01-11  9:43 ` rguenth at gcc dot gnu.org
2012-01-11 17:27 ` xinliangli at gmail dot com
2012-03-02  0:56 ` oleg at smolsky dot net
2012-03-02  8:08 ` jakub at gcc dot gnu.org
2012-03-02  8:23 ` oleg at smolsky dot net
2012-03-02  8:29 ` jakub at gcc dot gnu.org [this message]
2012-03-02  9:14 ` jakub at gcc dot gnu.org
2012-03-03  2:20 ` oleg at smolsky dot net
2012-03-03  2:47 ` oleg at smolsky dot net
2012-03-03  3:00 ` oleg at smolsky dot net
2012-03-06 16:34 ` oleg at smolsky dot net
2012-03-06 17:27 ` jakub at gcc dot gnu.org
2012-03-06 19:40 ` oleg at smolsky dot net

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