[patch, fortran] Implement blocked eoshift for eoshift0

[Paul Richard Thomas]

Hi Thomas,

The timings are impressive! OK for trunk.

Thanks

Paul

On 1 July 2017 at 14:48, Thomas Koenig <tkoenig@netcologne.de> wrote:
> Hello world,
>
> the attached patch implements the blocked algorithm for
> constant shift for dim > 1 for eoshift0 (which handles
> the case of constant shift and constant fill value).
>
> Speedup, as for cshift, is large.  Moving a 500*500*500
> array by -3 with eo_bench.f90 (also attached):
>
> $ gfortran -O3 eo_bench.f90 && ./a.out
>  dim =            1  t =   0.451796889
>  dim =            2  t =   0.183514118
>  dim =            3  t =   0.184015989
> $ gfortran-7 -static-libgfortran -O3 eo_bench.f90 && ./a.out
>  dim =            1  t =   0.955736041
>  dim =            2  t =    1.42228103
>  dim =            3  t =    3.00043702
>
> Regression-tested.  OK for trunk?
>
> Regards
>
>         Thomas
>
> 2017-07-01  Thomas Koenig  <tkoenig@gcc.gnu.org>
>
>         * intrinsics/eoshift0.c:  For contiguous arrays, use
>         block algorithm.  Use memcpy where possible.
>
> 2017-07-01  Thomas Koenig  <tkoenig@gcc.gnu.org>
>
>         * gfortran/eoshift_3.f90:  New test.



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