From: Richard Guenther <richard.guenther@gmail.com>
To: Jakub Jelinek <jakub@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
James Cloos <cloos@jhcloos.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Andreas Schwab <schwab@redhat.com>,
Andi Kleen <andi@firstfloor.org>, Michael Matz <matz@suse.de>,
Dave Korn <dave.korn.cygwin@gmail.com>,
gcc@gcc.gnu.org, Jim Bos <jim876@xs4all.nl>
Subject: Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
Date: Mon, 15 Nov 2010 11:24:48 +0100 [thread overview]
Message-ID: <AANLkTinAfq4HbPvEMDUM6230Qp41bJgZYPL1WtpkYHLN@mail.gmail.com> (raw)
In-Reply-To: <20101115085605.GE2583@sunsite.ms.mff.cuni.cz>
On Mon, Nov 15, 2010 at 9:56 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Sun, Nov 14, 2010 at 07:21:50PM -0800, Linus Torvalds wrote:
>> So when Richard Gunther says "a memory clobber doesn't cover automatic
>> storage", to me that very clearly spells "gcc is buggy as hell".
>> Because automatic storage with its address taken _very_ much gets
>> clobbered by things like memset etc. If the compiler doesn't
>> understand that, the compiler is just broken.
>
> I'll leave the discussion about meaning of "memory" clobber aside to
> Richard,
Of course GCC handles memset just fine. Note that I was refering
to non-address taken automatic storage for "memory" (even though
when double-checking the current implementation GCC even thinks
that all address-taken memory is clobbered by asms as soon as
they have at least one memory operand or a "memory" clobber).
It's just that in future we might want to improve this and I think
not covering non-address taken automatic storage for "memory"
is sensible. And I see that you don't see address-taken automatic
storage as a sensible choice to exclude from "memory", and I
have noted that.
Btw, I still haven't seen an testcase for the actual problem we are
talking about.
Richard.
next prev parent reply other threads:[~2010-11-15 10:24 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
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 [this message]
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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