[PATCH] x86: Add .nop directive to assembler

[Maciej W. Rozycki]

On Mon, 19 Feb 2018, H.J. Lu wrote:

> >>  I have a feeling the default should wire in HANDLE_ALIGN somehow.  For
> >> many targets, such as fixed instruction width RISC processors, there is
> >> only going to be one way of filling a given amount of space with no-op
> >> instructions, so I think there's no point in having code duplication
> >> here.  And even if there are more ways possible for a given target, then
> >> the `.align' way is still right even if suboptimal.
> >
> > How would you propose to express "I need three nop
> > instructions aka 12 bytes from here" with just .align?  (Note: no matter
> > how "here" is currently aligned!)
> >
> 
> .align isn't the same as .nop.   However, HANDLE_ALIGN can be updated
> to shared the same code with md_generate_nops, like what I did for x86.

 Yes, that's what I meant.  It's an internal code wiring thing, not to be 
something observable by the user.

  Maciej