From: Paul Koning <paul_koning@dell.com>
To: Richard Guenther <richard.guenther@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>,
Andreas Schwab <schwab@linux-m68k.org>, Jim <jim876@xs4all.nl>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
gcc@gcc.gnu.org
Subject: Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
Date: Mon, 8 Nov 2010 06:47:59 -0500 [thread overview]
Message-ID: <E1D1023D-4F2D-4EF4-8E97-CC5685B57A19@dell.com> (raw)
In-Reply-To: <AANLkTi=tC01jshWAr_HyVs6-HKK-Puarb6cLpxZyg-Kr@mail.gmail.com>
On Nov 8, 2010, at 6:20 AM, Richard Guenther wrote:
> On Mon, Nov 8, 2010 at 12:20 PM, Andi Kleen <andi@firstfloor.org> wrote:
>> Richard Guenther <richard.guenther@gmail.com> writes:
>>
>>> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen <andi@firstfloor.org> wrote:
>>>> Andreas Schwab <schwab@linux-m68k.org> writes:
>>>>>
>>>>> The asm fails to mention that it modifies *regs.
>>>>
>>>> It has a memory clobber, that should be enough, no?
>>>
>>> No. A memory clobber does not cover automatic storage.
>>
>> That's a separate problem.
>>
>>> Btw, I can't see a testcase anywhere so I just assume Andreas got
>>> it right as usual.
>>
>> An asm with live inputs and outputs should never be optimized
>> way. If 4.5.1 started doing that it's seriously broken.
>
> Please provide a testcase, such asms can be optimized if the
> outputs are dead.
I don't know about 4.5, but I noticed that with 4.6 (trunk), testcasese like gcc.c-torture/compile/20000804-1.c optimize away the asm and all the operand generation except for -O0.
paul
next prev parent reply other threads:[~2010-11-08 11:48 UTC|newest]
Thread overview: 129+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-06 11:15 gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? Jim
2010-11-07 21:31 ` Andi Kleen
2010-11-07 22:41 ` Andreas Schwab
2010-11-07 23:03 ` Andi Kleen
2010-11-08 10:49 ` Richard Guenther
2010-11-08 11:20 ` Andi Kleen
2010-11-08 11:20 ` Richard Guenther
2010-11-08 11:47 ` Paul Koning [this message]
2010-11-08 11:53 ` Jakub Jelinek
2010-11-08 12:20 ` Michael Matz
2010-11-08 18:39 ` Dave Korn
2010-11-09 13:00 ` Michael Matz
2010-11-09 13:48 ` Andi Kleen
2010-11-09 13:57 ` Andreas Schwab
2010-11-09 16:43 ` Jim
2010-11-13 11:13 ` [PATCH] i8k: Tell gcc that *regs gets clobbered Jim Bos
2010-11-15 0:52 ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? James Cloos
2010-11-15 3:21 ` Linus Torvalds
2010-11-15 8:56 ` Jakub Jelinek
2010-11-15 9:12 ` Andi Kleen
2010-11-15 9:20 ` Jakub Jelinek
2010-11-15 10:03 ` Jakub Jelinek
2010-11-15 10:54 ` Andi Kleen
2010-11-15 11:16 ` Jakub Jelinek
2010-11-15 11:37 ` Andi Kleen
2010-11-15 17:36 ` Jim Bos
2010-11-15 17:44 ` Jakub Jelinek
2010-11-15 18:17 ` Jim Bos
2010-11-15 18:26 ` Jakub Jelinek
2010-11-15 19:10 ` Jim Bos
2010-11-15 16:04 ` Linus Torvalds
2010-11-15 17:40 ` Jim Bos
2010-11-15 18:08 ` Linus Torvalds
2010-11-15 18:30 ` Jim Bos
2010-11-15 18:37 ` Jim Bos
2010-11-15 18:56 ` Linus Torvalds
2010-11-15 18:58 ` Jakub Jelinek
2010-11-15 19:12 ` Jakub Jelinek
2010-11-15 19:21 ` Linus Torvalds
2010-11-15 19:51 ` Jakub Jelinek
2010-11-15 20:22 ` Jim Bos
2011-06-03 13:05 ` 2.6.39.1 immediately reboots/resets on EFI system Jim Bos
2011-06-03 13:33 ` Matthew Garrett
2011-06-03 14:26 ` Jim Bos
2011-06-03 14:46 ` Matthew Garrett
2011-06-05 10:40 ` Jim Bos
2011-06-05 12:57 ` Maarten Lankhorst
2011-06-06 15:01 ` Maarten Lankhorst
2011-06-06 15:40 ` Jim Bos
2011-06-06 15:44 ` Matthew Garrett
2011-06-06 15:27 ` Maarten Lankhorst
2011-06-06 16:11 ` Jim Bos
2011-06-06 16:43 ` Maarten Lankhorst
2011-06-07 0:19 ` Yinghai Lu
2011-06-07 1:41 ` Matthew Garrett
2011-06-07 2:05 ` Yinghai Lu
2011-06-07 8:25 ` Maarten Lankhorst
2011-06-07 15:14 ` Yinghai Lu
2011-06-07 9:08 ` Maarten Lankhorst
2011-06-07 12:22 ` Maarten Lankhorst
2011-06-07 22:25 ` Yinghai Lu
2011-06-08 16:44 ` Jim Bos
2011-06-08 19:17 ` Yinghai Lu
2011-06-08 19:23 ` Matthew Garrett
2011-06-08 19:27 ` Yinghai Lu
2011-06-08 19:29 ` Matthew Garrett
2011-06-08 19:35 ` Yinghai Lu
2011-06-08 19:38 ` Matthew Garrett
2011-06-08 19:46 ` Yinghai Lu
2011-06-08 19:52 ` Matthew Garrett
2011-06-08 19:48 ` Yinghai Lu
2011-06-08 19:52 ` Matthew Garrett
2011-06-08 20:03 ` Yinghai Lu
2011-06-08 20:09 ` Matthew Garrett
2011-06-08 20:23 ` Yinghai Lu
2011-06-08 20:30 ` Matthew Garrett
2011-06-08 20:36 ` Yinghai Lu
2011-06-08 20:42 ` Matthew Garrett
2011-06-08 20:46 ` Yinghai Lu
2011-06-08 21:06 ` Matthew Garrett
2011-06-08 21:06 ` Linus Torvalds
2011-06-08 21:28 ` Matthew Garrett
2011-06-08 21:31 ` H. Peter Anvin
2011-06-08 21:36 ` Matthew Garrett
2011-06-08 21:31 ` Linus Torvalds
2011-06-08 21:42 ` Matthew Garrett
2011-06-08 21:51 ` H. Peter Anvin
2011-06-08 22:57 ` Linus Torvalds
2011-06-08 23:54 ` Maarten Lankhorst
2011-06-08 21:38 ` Yinghai Lu
2011-06-10 16:47 ` Matthew Garrett
2011-06-10 17:51 ` Maarten Lankhorst
2011-06-10 17:54 ` Matthew Garrett
2011-06-10 22:45 ` Maarten Lankhorst
2011-06-10 22:58 ` Yinghai Lu
2011-06-10 23:03 ` Matthew Garrett
2011-06-10 23:17 ` Greg KH
2011-06-10 23:22 ` Maarten Lankhorst
2011-06-10 23:25 ` H. Peter Anvin
2011-06-10 23:26 ` Yinghai Lu
2011-06-10 23:32 ` H. Peter Anvin
2011-06-10 23:55 ` Yinghai Lu
2011-06-11 0:00 ` H. Peter Anvin
2011-06-11 0:19 ` Yinghai Lu
2011-06-14 18:06 ` H. Peter Anvin
2011-06-11 15:29 ` Matthew Garrett
2011-06-10 23:00 ` Yinghai Lu
2011-06-13 16:47 ` Matthew Garrett
2011-06-13 17:52 ` Maarten Lankhorst
2011-06-13 18:00 ` Matthew Garrett
2011-06-13 18:14 ` Maarten Lankhorst
2011-06-13 18:17 ` Matthew Garrett
2011-06-13 18:23 ` Maarten Lankhorst
2011-06-13 18:33 ` Matthew Garrett
2011-06-13 18:45 ` Maarten Lankhorst
2011-06-14 14:34 ` Maarten Lankhorst
2011-06-14 14:50 ` Maarten Lankhorst
2011-06-14 14:55 ` Matthew Garrett
2010-11-15 22:43 ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? Andi Kleen
2010-11-15 22:46 ` Jakub Jelinek
2010-11-15 19:53 ` Richard Henderson
2010-11-15 10:24 ` Richard Guenther
2010-11-15 18:45 ` Jeff Law
2010-11-15 19:04 ` Linus Torvalds
2010-11-15 22:07 ` Richard Guenther
2010-11-15 22:58 ` Jeff Law
2010-11-15 23:07 ` Richard Guenther
2010-11-16 4:10 ` Jeff Law
2010-11-15 18:42 ` Jeff Law
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