From: "Jan Beulich" <jbeulich@novell.com>
Subject: Re: [PATCH] x86: usercopy assembly constraints
Date: Wed, 14 Nov 2007 07:37:01 +0000
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	<C35FB77E.185D0%Keir.Fraser@cl.cam.ac.uk>
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>>> Keir Fraser <Keir.Fraser@cl.cam.ac.uk> 13.11.07 21:20 >>>
>On 13/11/07 16:02, "Jan Beulich" <jbeulich@novell.com> wrote:
>
>> Besides only being correct this way, this helps work around a gcc 4.3
>> issue.
>> At the same time, add some white space, re-order the inputs, and remove
>> a bogus cast.
>
>What's the bug? Does some gcc allocate the 4th output parameter into one =
of
>the other used registers (cx,si,di) if we don't use '=3D&'?

No, the effect is an 'impossible constraint' error, so there's not much =
reason
to be afraid I think. But as said, the constraint was wrong.

Jan