Re: Expansion of narrowing math built-ins into power instructions

[Tejas Joshi <tejasjoshi9673@gmail.com>]

Hi.
It took some time for me to finish with the folding part for fadd
variants and till it is reviewed, I want to move ahead with power8/9
expansions on top of the current fadd patch.

> In GCC (in rs6000.md) we have the "*add<mode>3_fpr" and similar insns,
> which could be extended to allow DF inputs with an SF output; it doesn't
> yet allow it.

This might be very lousy but I am confused with the optabs and insn
name rn, the comments in obtabs.def says that these patterns are
present in md as insn names. How can fadd function be mapped with the
"fadd<mode>3_fpr" pattern name?
Also, faddl and daddl functions take long double as argument, can they
also be expanded on DF to SF mode or only on QP float on power9?

I have built GCC and applied my current patches on gcc112 and yes, on
gcc135 too.

Thanks,
Tejas


On Wed, 31 Jul 2019 at 20:17, Segher Boessenkool
<segher@kernel.crashing.org> wrote:
>
> On Wed, Jul 31, 2019 at 12:23:18PM +0530, Tejas Joshi wrote:
> > > In GCC (in rs6000.md) we have the "*add<mode>3_fpr" and similar insns,
> > > which could be extended to allow DF inputs with an SF output; it doesn't
> > > yet allow it.
> >
> > Thanks for the inputs, I will try to address these points now. I have
> > built GCC on gcc112 and will apply patch and test testcases there.
>
> For the QP float (binary128, KFmode, take your pick) you need Power9 or
> newer, so gcc135.
>
>
> Segher