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.
Uros.
