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From: Thomas Gleixner <tglx@linutronix.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jeff Law <law@redhat.com>,
	rostedt@goodmis.org,         "H. Peter Anvin" <hpa@zytor.com>,
	        David Daney <ddaney@caviumnetworks.com>,
	Andrew Haley <aph@redhat.com>,
	        Richard Guenther <richard.guenther@gmail.com>,
	        Ingo Molnar <mingo@elte.hu>,
	LKML <linux-kernel@vger.kernel.org>,
	        Andrew Morton <akpm@linux-foundation.org>,
	        Heiko Carstens <heiko.carstens@de.ibm.com>,
	feng.tang@intel.com,
	        Fr??d??ric Weisbecker <fweisbec@gmail.com>,
	        Peter Zijlstra <peterz@infradead.org>,
	jakub@redhat.com,         gcc@gcc.gnu.org
Subject: Re: BUG: GCC-4.4.x changes the function frame on some functions
Date: Fri, 20 Nov 2009 02:16:00 -0000	[thread overview]
Message-ID: <alpine.LFD.2.00.0911200307190.24119@localhost.localdomain> (raw)
In-Reply-To: <alpine.LFD.2.00.0911200206570.24119@localhost.localdomain>

On Fri, 20 Nov 2009, Thomas Gleixner wrote:

> On Thu, 19 Nov 2009, Linus Torvalds wrote:
> > On Fri, 20 Nov 2009, Thomas Gleixner wrote:
> > > 
> > > While testing various kernel configs we found out that the problem
> > > comes and goes. Finally I started to compare the gcc command line
> > > options and after some fiddling it turned out that the following
> > > minimal deltas change the code generator behaviour:
> > > 
> > > Bad:  -march=pentium-mmx                -Wa,-mtune=generic32
> > > Good: -march=i686        -mtune=generic -Wa,-mtune=generic32
> > > Good: -march=pentium-mmx -mtune-generic -Wa,-mtune=generic32

Found some more:

Bad:  -march=k6                   -Wa,-mtune=generic32
Bad:  -march=geode                -Wa,-mtune=generic32
Bad:  -march=c3                   -Wa,-mtune=generic32

That seems every thing which has MMX support but no SSE and is somehow
compatible to the pentium-mmx.

Looks like the code generator optimization for those was done after
consuming the secret gcc-shrooms.

Thanks,

	tglx

  reply	other threads:[~2009-11-20  2:16 UTC|newest]

Thread overview: 67+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-11-19 21:16 H. Peter Anvin
2009-11-19 21:26 ` Jeff Law
2009-11-19 22:44   ` Steven Rostedt
2009-11-20  0:00     ` Jeff Law
2009-11-20  0:37       ` Thomas Gleixner
2009-11-20  1:00         ` Linus Torvalds
2009-11-20  1:29           ` Thomas Gleixner
2009-11-20  2:16             ` Thomas Gleixner [this message]
2009-11-20  1:30           ` H. Peter Anvin
2009-11-20  5:40           ` Ingo Molnar
2009-11-20 12:06         ` Andrew Haley
2009-11-20 12:23           ` Andrew Haley
  -- strict thread matches above, loose matches on Subject: below --
2009-11-19 20:50 H. Peter Anvin
     [not found] <alpine.LFD.2.00.0911181933540.24119@localhost.localdomain>
     [not found] ` <tip-887a29f59b93cf54e21814869a4ab6e80b6fa623@git.kernel.org>
     [not found]   ` <20091119072040.GA23579@elte.hu>
     [not found]     ` <alpine.LFD.2.00.0911191053390.24119@localhost.localdomain>
     [not found]       ` <alpine.LFD.2.00.0911191423190.24119@localhost.localdomain>
2009-11-19 15:39         ` Thomas Gleixner
2009-11-19 15:45           ` Andrew Haley
2009-11-19 15:55             ` H. Peter Anvin
2009-11-19 15:59               ` Richard Guenther
2009-11-19 16:03             ` Steven Rostedt
2009-11-19 16:13               ` H. Peter Anvin
2009-11-19 16:20               ` Frederic Weisbecker
2009-11-19 16:07             ` Thomas Gleixner
2009-11-19 16:19               ` Andrew Haley
2009-11-19 16:45                 ` Thomas Gleixner
2009-11-19 16:13             ` Steven Rostedt
2009-11-19 15:46           ` H. Peter Anvin
2009-11-19 15:51             ` Richard Guenther
2009-11-19 15:53               ` Richard Guenther
2009-11-19 17:38               ` Andi Kleen
2009-11-19 17:41           ` Linus Torvalds
2009-11-19 17:52             ` Thomas Gleixner
2009-11-19 18:00             ` Steven Rostedt
2009-11-19 18:04               ` Richard Guenther
2009-11-19 18:23                 ` Andrew Haley
2009-11-19 18:42                   ` Linus Torvalds
2009-11-19 18:45                     ` Linus Torvalds
2009-11-19 18:56                       ` Linus Torvalds
2009-11-19 19:03                         ` Thomas Gleixner
2009-11-23  9:17                           ` Jakub Jelinek
2009-11-23  9:53                             ` Thomas Gleixner
2009-11-19 19:12                         ` David Daney
2009-11-19 19:29                           ` Steven Rostedt
2009-11-19 19:47                             ` Frederic Weisbecker
2009-11-19 19:55                               ` Kai Tietz
2009-11-19 20:06                                 ` Frederic Weisbecker
2009-11-19 20:06                               ` Steven Rostedt
2009-11-19 20:18                                 ` Steven Rostedt
2009-11-19 20:29                                   ` Frederic Weisbecker
2009-11-19 20:26                                 ` Frederic Weisbecker
2009-11-19 20:38                                   ` Linus Torvalds
2009-11-19 20:45                                     ` Steven Rostedt
2009-11-19 19:51                             ` H. Peter Anvin
2009-11-19 20:08                               ` Linus Torvalds
2009-11-19 21:13                                 ` Jeff Law
2009-11-19 20:11                               ` Steven Rostedt
2009-11-19 21:07                               ` Jeff Law
2009-11-19 18:34                 ` Thomas Gleixner
2009-11-19 18:40                 ` Linus Torvalds
2009-11-19 18:48                   ` Ingo Molnar
2009-11-19 19:08                     ` Steven Rostedt
2009-11-19 19:51                       ` Ingo Molnar
2009-11-19 20:37                   ` Thomas Gleixner
2009-11-19 18:22           ` Andrew Haley
2009-11-19 18:34             ` Steven Rostedt
2009-11-19 18:37               ` Andrew Pinski
2009-11-19 18:38               ` Andrew Haley
2009-11-19 18:38               ` H. Peter Anvin
2009-11-19 18:40             ` Thomas Gleixner

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