[PATCH] x86: Support BHI_CTRL instruction

[Christian Ludloff]

On Thu, Jun 4, 2026 at 11:02 PM Jiang, Haochen <haochen.jiang@intel.com> wrote:
> > > > Arguably RDSSP{D,Q} is a litmus test – can it REX2 or EVEX?
> > >
> > > I suppose it should be a REX2, not EVEX MAP4.
> >
> > From the perspective of the ISA, the W for D-vs-Q
> > can come from REX or REX2 or EVEX – it should
> > not matter which of the three encodings gets used
> > for RDSSP. If that is not the case, then please get
> > it documented too, together with IBHF behavior.
>
> APX documentation has mentioned which instructions could be
> promoted to EVEX MAP4. Only the inst mentioned in chart could
> use EVEX MAP4. Actually, those EVEX MAP4 insts are all listed
> one by one in EAS since the encoding are quite different.

Sure, MAP4 is documented as a "no".

But MAP1 otoh...  :-)

0x62,0xF9,0x7E,0x08,0x1E,0xC8
0x62,0xF9,0xFE,0x08,0x1E,0xC8

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C.