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From: Richard Guenther <richard.guenther@gmail.com>
To: Michael Matz <matz@suse.de>
Cc: Andrew Haley <aph@redhat.com>, "H.J. Lu" <hjl.tools@gmail.com>,
	gcc-patches@gcc.gnu.org
Subject: Re: PATCH: Add pause intrinsic
Date: Wed, 25 May 2011 16:39:00 -0000	[thread overview]
Message-ID: <BANLkTinqdLoMfiRwCnYxNP3+B=EjcOB83g@mail.gmail.com> (raw)
In-Reply-To: <Pine.LNX.4.64.1105251719310.19219@wotan.suse.de>

On Wed, May 25, 2011 at 5:20 PM, Michael Matz <matz@suse.de> wrote:
> Hi,
>
> On Wed, 25 May 2011, Richard Guenther wrote:
>
>> >> asm volatile ("" : : : "memory") in fact will work as a full memory
>> >> barrier
>> >
>> > How?  You surely need MFENCE or somesuch, unless all you care about is
>> > a compiler barrier.  That's what I think needs to be clarified.
>>
>> Well, yes, I'm talking about the compiler memory barrier.
>
> Something that we conventionally call "optimization barrier" :)  memory
> barrier has a fixed meaning which we shouldn't use in this case, it's
> confusing.

Sure ;)

And to keep the info in a suitable thread what I'd like to improve here
is to make us disambiguate memory loads/stores against asms that
have no memory outputs/inputs.

Richard.

  reply	other threads:[~2011-05-25 15:27 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-05-24 19:35 H.J. Lu
2011-05-25 12:36 ` Andrew Haley
2011-05-25 13:20   ` Richard Guenther
2011-05-25 13:45     ` H.J. Lu
2011-05-25 13:40   ` H.J. Lu
2011-05-25 14:51     ` Andrew Haley
2011-05-25 15:19       ` H.J. Lu
2011-05-25 15:31         ` Andrew Haley
2011-05-25 15:32           ` Richard Guenther
2011-05-25 16:05             ` Andrew Haley
2011-05-25 16:16               ` Richard Guenther
2011-05-25 16:32                 ` Michael Matz
2011-05-25 16:39                   ` Richard Guenther [this message]
2011-05-25 16:53                     ` H.J. Lu
2011-05-25 17:30                       ` Andrew Haley
2011-05-25 17:56                         ` H.J. Lu
2011-05-25 18:09                           ` Andrew Pinski
2011-05-25 18:16                             ` Andrew Haley
2011-05-26 10:49                           ` Richard Guenther
2011-05-26 13:51                             ` Andrew Haley
2011-05-26 14:39                               ` Richard Guenther
2011-05-26 14:45                                 ` Andrew Haley
2011-05-26 15:19                                   ` Richard Guenther
2011-05-26 15:37                                     ` Jakub Jelinek
2011-05-26 15:42                                       ` Richard Guenther
2011-05-26 15:43                                     ` Andrew Haley
2011-05-26 15:58                                       ` Michael Matz
2011-05-26 17:36                                     ` Andi Kleen
2011-05-26 17:40                                       ` Jakub Jelinek
2011-05-26 18:23                                         ` Andi Kleen
2011-05-26 18:37                                           ` Paul Koning
2011-05-26 19:05                                             ` Andi Kleen
2011-05-26 21:56                                             ` Basile Starynkevitch
2011-05-30 10:39                                               ` Andrew Haley
2011-05-25 15:31         ` Richard Guenther
2011-05-25 19:53   ` Basile Starynkevitch
2011-05-25 20:03     ` H.J. Lu
2011-05-25 21:10       ` Basile Starynkevitch
2011-05-26  9:35     ` Andrew Haley
2011-05-26 17:37     ` Andi Kleen
2011-05-26 17:48       ` Basile Starynkevitch
2011-05-25 14:08 ` Uros Bizjak

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