[PATCH v3 3/7] x86: re-work insn/suffix recognition

[H.J. Lu]

On Wed, Oct 5, 2022 at 11:58 PM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 06.10.2022 08:15, Jan Beulich via Binutils wrote:
> > On 06.10.2022 01:52, H.J. Lu wrote:
> >> Does the new assembler work on Linux kernel which has "rep movsd"?
> >
> > No. And it shouldn't, as they should never have used MOVSD. The only valid
> > mnemonic (in AT&T syntax) is MOVSL. If you're meaning to suggest that we
> > continue to support MOVSD in AT&T mode, then this will - once again for
> > consistency - need extending to _all_ other D-suffixable insns the SDM
> > specifies. I can only repeat what I've said before: Consistency is a
> > requirement such that users can predict assembler behavior.
>
> Note how Clang's integrated assembler doesn't even support CMPSD as a
> string instruction - that's imo yet more odd behavior, and likely
> attributed _solely_ to the goal of wanting to work around code wrongly
> using such.

I think we should avoid changing assembly sources if possible.  Should we keep
CMPSD/MOVSD without any operands? This won't cause any confusion.


-- 
H.J.