[PATCH] x86: Add .nop directive to assembler

[Jan Beulich]

>>> On 14.02.18 at 17:48, <matz@suse.de> wrote:
> On Wed, 14 Feb 2018, H.J. Lu wrote:
>> >> This requires much bigger changes.  Also I like ".not SIZE, LIMIT". 
>> >> But if everyone agrees that we should extend .skip, we can do that. 
>> >> This may also remove the size limit.
>> >
>> > If I may chime in, it didn't occur to me before Jan mentioned it, but yes,
>> > I also think extending .fill feels more natural.
>> >
>> 
>> No, .fill isn't what we want.
> 
> I fat-fingered that one, yes I meant .fill.

.fill again? Didn't you mean to write .skip this time?

>> We need to extend
>> 
>> .skip SIZE , FILL
>> 
>> So what should FILL look like?
> 
> @nop, $nop, %nop?  (I think only 'nop' without prefix would interact with 
> uses in macros?  The '@' prefix resembles a prefix for relocations, so 
> that might be the natural choice).  Perhaps also 'nop' should be 'anynop' 
> or so, to indicate it's not just the single-byte 0x90 filler).

Having thought about this some more - since currently FILL is
expected to be an expression, none of the above is really suitable.
How about "nop" (including the quotes) instead?

Jan