[PATCH 1/3] Support Intel AMX-TRANSPOSE

[Jiang, Haochen]

> From: Jan Beulich <jbeulich@suse.com>
> Sent: Thursday, December 19, 2024 7:21 PM
> 
> On 18.12.2024 07:32, Haochen Jiang wrote:
> > @@ -10750,25 +10752,43 @@ process_operands (void)
> >        unsigned int op, extra;
> >        const reg_entry *first;
> >
> > -      /* The second operand must be {x,y,z}mmN. */
> > -      gas_assert (i.operands == 3 && i.types[1].bitfield.class == RegSIMD);
> > +      /* The second operand must be {x,y,z,t}mmN */
> > +      gas_assert ((i.operands == 2 || i.operands == 3)
> > +		  && i.types[1].bitfield.class == RegSIMD);
> >
> > -      switch (i.types[2].bitfield.class)
> > +      if (i.operands == 3)
> >  	{
> > -	case RegSIMD:
> > -	  /* AVX512-{4FMAPS,4VNNIW} operand 2: N must be a multiple of
> 4. */
> > -	  op = 1;
> > -	  extra = 3;
> > -	  break;
> > +	  switch (i.types[2].bitfield.class)
> > +	    {
> > +	    case RegSIMD:
> > +	      /* AVX512-{4FMAPS,4VNNIW} operand 2: N must be a multiple of
> 4. */
> > +	      op = 1;
> > +	      extra = 3;
> > +	      break;
> >
> > -	case RegMask:
> > -	  /* AVX512-VP2INTERSECT operand 3: N must be a multiple of 2. */
> > -	  op = 2;
> > -	  extra = 1;
> > -	  break;
> > +	    case RegMask:
> > +	      /* AVX512-VP2INTERSECT operand 3: N must be a multiple of 2. */
> > +	      op = 2;
> > +	      extra = 1;
> > +	      break;
> >
> > -	default:
> > -	  abort ();
> > +	    default:
> > +	      abort ();
> > +	    }
> > +	}
> > +      else
> > +	{
> > +	  switch (i.types[1].bitfield.class)
> > +	    {
> > +	    case RegSIMD:
> > +	      /* AMX-TRANSPOSE operand 2: N must be a multiple of 2. */
> > +	      op = 1;
> > +	      extra = 1;
> > +	      break;
> > +
> > +	    default:
> > +	      abort ();
> > +	    }
> >  	}
> 
> This could have been done with less churn, also making it easier to review.
> There's imo no need to wrap an operand count check around the switch().
> Instead in the RegSIMD case you can check the register type (Tmmword), thus
> likely making the new code a simple insertion. That's what I had in mind when
> originally laying out the code that you're now fully re-indenting.
> 

Let me have a try. I am not sure if it could be done.

I need to mention here the AMX-TRANSPOSE related inst only got two operands.
There are no types[2] here. Then you have to use types[1] in switch. However, we
could not distinguish the original AVX512-VP2INTERSECT and AVX512_4FMAPS with
types[1].

Thx,
Haochen