On Thu, May 28, 2026 at 11:48 AM Jakub Jelinek <[email protected]> wrote:
>
> On Thu, May 28, 2026 at 11:31:27AM +0200, Uros Bizjak wrote:
> > Hm, OTOH, is this condition correct:
> >
> >     case TYPE_LEA:
> >       if (TARGET_APX_NDD && <nf_applied>)
> >     return "%{nf%} add{<imodesuffix>}\t{%2, %1, %0|%0, %1, %2}";
> >       else
> >     return "#";
> >
> > Should it be "TARGET_APX_NDD || <nf_applied>"?
>
> The pattern is weird, but TARGET_APX_NDD || <nf_applied> would be wrong.
> Without TARGET_APX_NDD there is no 3 operand add, so we can't use that.
> Of course, question is if there will be CPUs with just APX-NF and not
> APX-NDD or with just APX-NDD and not APX-NF.
>
> I'd say it is a bad idea to have the "lea" variant come before the
> 3 apx_ndd variants, if the lea variant came last, then at least the r <- r, l
> case would be covered for TARGET_APX_NDD by the earlier (but now later)
> r <- rje, r variant and could then emit either the 3 operand add or 3
> operand add with {nf}.  Anyway, with the current position it could also be
>   if (TARGET_APX_NDD)
>     return "<nf_prefix>add{<imodesuffix>}\t{%2, %1, %0|%0, %1, %2}";
>   else
>     {
>       operands[3] = gen_rtx_PLUS (<MODE>mode, operands[1], operands[2]);
>       return "lea{<imodesuffix>}\t{%E3, %0|%0, %E3}";
>     }

I think that the correct solution is to put LEA at the end. LEA
alternative is intended for non-NDD cases to allow two-register
operation, but NDD should override it, w/ or w/o NF. Let's ask
Hongtao.

Uros.

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