[PATCH v2] Support Intel FRED LKGS

[Jiang, Haochen]

> > Well, there are two ways of approaching this, but imo in either case
> > via a prereq change to the other insns that use this operand
> > descriptor in a questionable manner. We could split decode at the
> > ModR/M.mod level, but perhaps better is to follow MOV to/from sreg,
> > SLDT, and STR in using a D suffix and an Sv operand.
> 
> I suppose the latter is better since Sv will go back to OP_E then split decode
> ad ModR/M.mod level.
> 
> I will go through that to make the change.
> 
> Thx,
> Haochen

I just take a look at the whole thing.

From my perspective, if we are going to use the same pattern like
SLDT and STR. Does that mean for the instruction below:

lldt %ax

We will need to add a 66 prefix for gas to make it happen or it will drop to %eax?

It will change the current assembler behavior. Is my understanding correct?

Haochen

> 
> >
> > If, however, you're not happy about making the prereq change first,
> > I'd be kind of okay with the change being committed as is, and I'd
> > then try to remember to follow up accordingly. One minor adjustment
> > request,
> > though: In the opcode table comments, can you please use singular for
> > LKGS (while plural is fine for FRED)?
> >
> > Jan