Re: [Xen-devel] test_x86_emulator

[Don Slutz <dslutz@xxxxxxxxxxx>]

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@xxxxxxxx>
> Acked-by: Keir Fraser <keir@xxxxxxx>
And it works for me so:

Tested-by: Don Slutz <dslutz@xxxxxxxxxxx>

   -Don Slutz

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