From mboxrd@z Thu Jan  1 00:00:00 1970
From: Don Slutz <dslutz@verizon.com>
Subject: Re: test_x86_emulator
Date: Wed, 16 Apr 2014 11:21:20 -0400
Message-ID: <534E9FF0.5000209@terremark.com>
References: <1396967094-29484-1-git-send-email-dslutz@verizon.com>
	<1396967094-29484-2-git-send-email-dslutz@verizon.com>
	<53458CB40200007800007598@nat28.tlf.novell.com>
	<534592D7.2020805@terremark.com>
	<534652300200007800007727@nat28.tlf.novell.com>
	<53475944.3060100@terremark.com>
	<5347B9BD0200007800007DDB@nat28.tlf.novell.com>
	<5347D8C4.8080500@terremark.com>
	<5347F7A10200007800007F74@nat28.tlf.novell.com>
	<5347E4B1.3080505@terremark.com>
	<534822E202000078000080AC@nat28.tlf.novell.com>
	<5348292B.5000102@terremark.com>
	<534BAD0F0200007800008407@nat28.tlf.novell.com>
	<534C1AF0.3060707@terremark.com>
	<534CF2950200007800008C62@nat28.tlf.novell.com>
	<534D4108.2020100@terremark.com>
	<534E5AE40200007800009550@nat28.tlf.novell.com>
	<534E4E39.50105@gmail.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"; Format="flowed"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <534E4E39.50105@gmail.com>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Keir Fraser <keir.xen@gmail.com>, Jan Beulich <JBeulich@suse.com>
Cc: Don Slutz <dslutz@verizon.com>, xen-devel@lists.xen.org
List-Id: xen-devel@lists.xenproject.org

On 04/16/14 05:32, Keir Fraser wrote:
> Jan Beulich wrote:
>> x86: fix instruction emulator test's xgetbv constraints
>>
>> The "A" constraint, while documented up to gcc4.5  as "The a and d
>> registers, as a pair (for instructions that return half the result in
>> one and half in the other)," never really behaved that (natural) way,
>> but always meant (and is now also documented so) %eax_or_  %edx (%rax
>> _or_  %rdx on x86-64) unless the operand was wide enough to require both
>> (i.e. more than 32 bits on ix86 and more than 64 bits on x86-64).
>>
>> Interestingly something internal to the compiler changed between4.4
>> and4.5  to actually expose the difference - up to gcc4.4  I was unable
>> to construct a case where, when only the low half of the result is
>> actually looked at, the result would be considered to be in %edx/%rdx
>> (and %eax/%rax would be treated as unmodified by the instruction).
>>
>> Signed-off-by: Jan Beulich<jbeulich@suse.com>
>
> Acked-by: Keir Fraser <keir@xen.org>

And it works for me so:

Tested-by: Don Slutz <dslutz@verizon.com>

    -Don Slutz