Re: [PATCH 1/3] New generic sincosf

[Rajalakshmi Srinivasaraghavan <raji at linux dot vnet dot ibm dot com>]

On 12/16/2017 08:13 PM, H.J. Lu wrote:
> On Sat, Dec 16, 2017 at 12:52 AM, Rajalakshmi Srinivasaraghavan
> <raji@linux.vnet.ibm.com> wrote:
> > On 12/16/2017 02:20 AM, Joseph Myers wrote:
> > > On Fri, 15 Dec 2017, H.J. Lu wrote:
> > >
> > > > One comment,  should sysdeps/ieee754/flt-32/s_sincos.h be renamed
> > > > to  sysdeps/ieee754/flt-32/s_sincosf.h?
> > >
> > >
> > > Yes, I think so.
> >
> > Pushed as 984ae9967b49830173490a33ae6130880f3f70d9 with the file
> > name changed as s_sincosf.h.  Thanks for the review.
>
> I noticed that sysdeps/x86_64/fpu/s_sincosf.S is still faster:
>
> Generic:
>
>      "max": 276.971,
>      "min": 10.813,
>      "mean": 29.3755
>
> SSE2:
>
>      "max": 138.795,
>      "min": 11.686,
>      "mean": 22.9463
>
> The SSE2 is 28% faster.  Do they use the same algorithm?

Yes, they are same. One small difference is generic version calls 
reduced_sin() and reduced_cos() whereas asm version handles both in the 
same branch for reconstruction.

>

--
Thanks
Rajalakshmi S