Re: [PATCH 12/43] i386: Emulate MMX vec_dupv2si with SSE

[H.J. Lu]

On Sun, Feb 10, 2019 at 1:49 PM Uros Bizjak <ubiz...@gmail.com> wrote:
>
> On Sun, Feb 10, 2019 at 10:45 PM Uros Bizjak <ubiz...@gmail.com> wrote:
>
> > > > > +  [(const_int 0)]
> > > > > +{
> > > > > +  /* Emulate MMX vec_dupv2si with SSE vec_dupv4si.  */
> > > > > +  rtx op0 = gen_rtx_REG (V4SImode, REGNO (operands[0]));
> > > > > +  rtx insn = gen_vec_dupv4si (op0, operands[1]);
> > > > > +  emit_insn (insn);
> > > > > +  DONE;
> > > >
> > > > Please write this simple RTX explicitly in the place of (const_int 0) 
> > > > above.
> > >
> > > rtx insn = gen_vec_dupv4si (op0, operands[1]);
> > >
> > > is easy.   How do I write
> > >
> > > rtx op0 = gen_rtx_REG (V4SImode, REGNO (operands[0]));
> > >
> > > in place of  (const_int 0)?
> >
> >   [(set (match_dup 2)
> >     (vec_duplicate:V4SI (match_dup 1)))]
> >
> > with
> >
> > "operands[2] = gen_rtx_REG (V4SImode, REGNO (operands[0]));"
> >
> > or even better:
> >
> > "operands[2] = gen_lowpart (V4SImode, operands[0]);"
> >
> > in the preparation statement.
>
> Even shorter is
>
> "operands[0] = gen_lowpart (V4SImode, operands[0]);"
>
> and use (match_dup 0) instead of (match_dup 2) in the RTX.
>
> There is plenty of examples throughout sse.md.
>

This works:

(define_insn_and_split "*vec_dupv2si"
  [(set (match_operand:V2SI 0 "register_operand" "=y,x,Yv")
        (vec_duplicate:V2SI
          (match_operand:SI 1 "register_operand" "0,0,Yv")))]
  "TARGET_MMX || TARGET_MMX_WITH_SSE"
  "@
   punpckldq\t%0, %0
   #
   #"
  "TARGET_MMX_WITH_SSE && reload_completed"
  [(set (match_dup 0)
        (vec_duplicate:V4SI (match_dup 1)))]
  "operands[0] = gen_rtx_REG (V4SImode, REGNO (operands[0]));"
  [(set_attr "mmx_isa" "native,x64_noavx,x64_avx")
   (set_attr "type" "mmxcvt,ssemov,ssemov")
   (set_attr "mode" "DI,TI,TI")])

Thanks.

-- 
H.J.