x86: Add support for Intel AMX instructions

[H.J. Lu]

On Mon, Jun 29, 2020 at 11:29 PM Jan Beulich <jbeulich@suse.com> wrote:
>
> On 28.06.2020 09:43, Cui, Lili via Binutils wrote:
> > @@ -3153,6 +3201,16 @@ static const char *att_names_zmm[] = {
> >    "%zmm28", "%zmm29", "%zmm30", "%zmm31"
> >  };
> >
> > +static const char **names_tmm;
> > +static const char *intel_names_tmm[] = {
> > +  "tmm0", "tmm1", "tmm2", "tmm3",
> > +  "tmm4", "tmm5", "tmm6", "tmm7"
> > +};
> > +static const char *att_names_tmm[] = {
> > +  "%tmm0", "%tmm1", "%tmm2", "%tmm3",
> > +  "%tmm4", "%tmm5", "%tmm6", "%tmm7"
> > +};
>
> Upon further consideration I don't think this and ...
>
> > --- a/opcodes/i386-reg.tbl
> > +++ b/opcodes/i386-reg.tbl
> > @@ -278,6 +278,15 @@ zmm28, Class=RegSIMD|Zmmword, RegVRex|RegRex, 4, Dw2Inval, Dw2Inval
> >  zmm29, Class=RegSIMD|Zmmword, RegVRex|RegRex, 5, Dw2Inval, Dw2Inval
> >  zmm30, Class=RegSIMD|Zmmword, RegVRex|RegRex, 6, Dw2Inval, Dw2Inval
> >  zmm31, Class=RegSIMD|Zmmword, RegVRex|RegRex, 7, Dw2Inval, Dw2Inval
> > +// TMM registers for AMX
> > +tmm0, Class=RegSIMD|Tmmword, 0, 0, Dw2Inval, Dw2Inval
> > +tmm1, Class=RegSIMD|Tmmword, 0, 1, Dw2Inval, Dw2Inval
> > +tmm2, Class=RegSIMD|Tmmword, 0, 2, Dw2Inval, Dw2Inval
> > +tmm3, Class=RegSIMD|Tmmword, 0, 3, Dw2Inval, Dw2Inval
> > +tmm4, Class=RegSIMD|Tmmword, 0, 4, Dw2Inval, Dw2Inval
> > +tmm5, Class=RegSIMD|Tmmword, 0, 5, Dw2Inval, Dw2Inval
> > +tmm6, Class=RegSIMD|Tmmword, 0, 6, Dw2Inval, Dw2Inval
> > +tmm7, Class=RegSIMD|Tmmword, 0, 7, Dw2Inval, Dw2Inval
>
> ... this is quite sufficient: How many registers there are depends on
> the selected palette, and I don't think gas should needlessly restrict
> encoding options. The disassembler needs to handle the high bits of
> the register encoding fields in any event - whether by properly
> decoding the high bits or by properly considering the encodings as
> (bad) is secondary there (but should of course be in line with the
> choice on the assembler side).
>

Disassembler should check the high bits of the register encoding fields.
But i386-reg.tbl is used by assembler.   I don't see anything wrong with
tmm in i386-reg.tbl.

-- 
H.J.