Re: [PATCH] ix86/Intel: don't require memory operand size specifier for PTWRITE

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Wed, Nov 15, 2017 at 5:58 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>> On 15.11.17 at 14:24, <hjl.tools@gmail.com> wrote:
>> On Wed, Nov 15, 2017 at 5:16 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>> Other than in 64-bit mode, in 32- and 16-bit modes operand size isn't
>>> ambiguous.
>
> With this ...
>
>>> --- 2017-11-10/gas/testsuite/gas/i386/ptwrite.s
>>> +++ 2017-11-10/gas/testsuite/gas/i386/ptwrite.s
>>> @@ -9,4 +9,5 @@ _start:
>>>
>>>         .intel_syntax noprefix
>>>         ptwrite ecx
>>> +       ptwrite [ecx]
>>
>> Do we also need such a test in x86-64-ptwrite.s?
>
> ... the answer is clearly no: The operand size _is_ ambiguous
> there. In fact I have (as part of the larger patch talked about in
> the other thread) queued an adjustment removing the suffix-less
> AT&T variant there.
>

Why isn't

      ptwrite (%ecx)

ambiguous in 64-bit? Is that because the `l' suffix is implied?

OK.

Thanks.

-- 
H.J.