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From: Paolo Bonzini <pbonzini@redhat.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Blue Swirl <blauwirbel@gmail.com>, qemu-devel@nongnu.org
Subject: [Qemu-devel] Re: [PATCH v2 2/2] get rid of hostregs_helper.h
Date: Thu, 25 Feb 2010 13:50:56 +0100	[thread overview]
Message-ID: <4B867230.60708@redhat.com> (raw)
In-Reply-To: <20100225114048.GB9116@redhat.com>

On 02/25/2010 12:40 PM, Michael S. Tsirkin wrote:
> On Thu, Feb 18, 2010 at 11:28:14PM +0200, Blue Swirl wrote:
>>>      /* restore global registers */
>>> -#include "hostregs_helper.h"
>>> +    asm("");
>>> +    env = (void *) saved_env_reg;
>>>
>
> Is this sufficient?
> I see __asm__ __volatile__("": : :"memory") in virtio.
> Is memory clobber implied? What about volatile?

All asms without colons ("old-style") are volatile.  Clobbering memory 
is not necessary since we are only caring about blocking assignments of 
"env", which is by definition in a register (hostregs_helper.h wasn't 
clobbering memory either).

Paolo

  reply	other threads:[~2010-02-25 12:51 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-02-10 23:26 [Qemu-devel] [PATCH 0/2] simplify global register save/restore Paolo Bonzini
2010-02-10 23:26 ` [Qemu-devel] [PATCH 1/2] remove dead m68k global register definitions Paolo Bonzini
2010-02-10 23:26 ` [Qemu-devel] [PATCH 2/2] get rid of hostregs_helper.h Paolo Bonzini
2010-02-18 19:07   ` Blue Swirl
2010-02-18 20:25     ` [Qemu-devel] [PATCH v2 1/2] remove dead m68k definitions Paolo Bonzini
2010-02-18 20:25       ` [Qemu-devel] [PATCH v2 2/2] get rid of hostregs_helper.h Paolo Bonzini
2010-02-18 21:28         ` [Qemu-devel] " Blue Swirl
2010-02-25 11:40           ` Michael S. Tsirkin
2010-02-25 12:50             ` Paolo Bonzini [this message]
2010-02-25 13:04               ` Michael S. Tsirkin
2010-02-25 13:11                 ` Paolo Bonzini
2010-02-13 17:58 ` [Qemu-devel] [PATCH 0/2] simplify global register save/restore Blue Swirl
2010-02-13 20:26   ` [Qemu-devel] " Paolo Bonzini
2010-02-13 20:57     ` Blue Swirl
2010-02-13 20:58       ` Paolo Bonzini
2010-02-26 11:30 ` [Qemu-devel] " Paul Brook
2010-02-26 13:05   ` Paolo Bonzini
2010-02-26 18:32     ` Paul Brook
2010-03-01 12:30       ` Paolo Bonzini
2010-03-01 14:02         ` Paul Brook

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