RE: [PATCH v3 7/7] [X86]: Add Sub-byte element extration and Symmetric-signed saturation narrow support.

> From: Jiang, Haochen
> Sent: Monday, August 3, 2026 4:42 PM
> 
> > From: Dipesh Sharma <[email protected]>
> > Sent: Friday, July 31, 2026 6:08 PM
> > diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-
> expand.cc
> > index b82a4913b4e..98aab429062 100644
> > --- a/gcc/config/i386/i386-expand.cc
> > +++ b/gcc/config/i386/i386-expand.cc
> > @@ -13452,6 +13455,29 @@ ix86_expand_args_builtin (const struct
> > builtin_description *d,
> >        else if ((mask_pos && (nargs - i - mask_pos) == nargs_constant) ||
> >  	       (!mask_pos && (nargs - i) <= nargs_constant))
> >  	{
> > +	  switch (icode)
> 
> An if putting after "if(!match)" is well enough. No need for a switch. But
> the current code is also ok.
> 
> > +	    {
> > +	    case CODE_FOR_vunpackbv16qi_mask:
> > +	    case CODE_FOR_vunpackbv32qi_mask:
> > +	    case CODE_FOR_vunpackbv64qi_mask:
> > +	      if (CONST_INT_P (op))
> > +		{
> > +		  char val = INTVAL (op);
> > +		  if ((val & 0xc0)
> > +		      || (!(val & 0x18))
> > +		      || ((val & 0x02) && ((val & 0x1c) != 0x08))
> > +		      || ((val & 0x01) && (((val & 0x1c) >> 2) > 0x4)))
> > +		    {
> > +		      error ("the last argument must not use reserved value "
> > +			     "immediate");
> > +		      return const0_rtx;
> > +		    }
> > +		}
> > +	      break;
> > +	    default:
> > +	      break;
> > +	    }
> > +
> >  	  if (!match)
> >  	    switch (icode)
> >  	      {
> > diff --git a/gcc/config/i386/sse.md b/gcc/config/i386/sse.md
> > index 1625b8b18ca..cf07d7d2d37 100644
> > --- a/gcc/config/i386/sse.md
> > +++ b/gcc/config/i386/sse.md
> > +(define_insn "*avx10v2aux_sym_truncatev4siv4qi2"
> > +  [(set (match_operand:V16QI 0 "register_operand" "=v")
> 
> Do you meet any issues for changing this and similar patterns
> to nonimmediate_operand?
> 

Mine. For non-512, it should not be nonimmediate_operand in
one pattern. For 512, you could use nonimmediate_operand.

Thx,
Haochen

> Thx,
> Haochen
> 
> > +	(vec_concat:V16QI
> > +	  (unspec:V4QI
> > +	   [(match_operand:V4SI 1 "register_operand" "v")]
> > +	   UNSPEC_VPMOVSSDB)
> > +	(match_operand:V12QI 2 "const0_operand")))]
> > +  "TARGET_AVX10V2AUX"
> > +  "vpmovssdb\t{%1, %0|%0, %1}"
> > +  [(set_attr "type" "ssemov")
> > +   (set_attr "prefix" "evex")
> > +   (set_attr "mode" "TI")])