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[PATCH] x86: Add .nop directive to assembler

Michael Matz matz@suse.de
Mon Feb 19 14:17:00 GMT 2018 
Hi,

On Mon, 19 Feb 2018, Maciej W. Rozycki wrote:

> > OK, except for one quibble with the default md_generate_nops.  I think
> > that should error rather than filling with zeros (which is likely to
> > be an illegal instruction or trap).
> 
>  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!)


Ciao,
Michael.
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