This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [patch, libfortran, RFC] Speed up cshift with array shift
- From: Dominique d'Humières <dominiq at lps dot ens dot fr>
- To: Thomas Koenig <tkoenig at netcologne dot de>
- Cc: gfortran <fortran at gcc dot gnu dot org>, gcc-patches <gcc-patches at gcc dot gnu dot org>
- Date: Tue, 20 Jun 2017 16:25:10 +0200
- Subject: Re: [patch, libfortran, RFC] Speed up cshift with array shift
- Authentication-results: sourceware.org; auth=none
Hi Thomas,
On my machine I get the following timings without the patch
cpu time cshift dim=1 0.490763009
cpu time do loop dim=1 5.57969809E-02
cpu time cshift dim=2 0.416319966
cpu time do loop dim=2 0.187106013
cpu time cshift dim=3 1.37362707
cpu time do loop dim=3 1.39690399
and
cpu time cshift dim=1 0.166012987
cpu time do loop dim=1 5.48990071E-02
cpu time cshift dim=2 0.183587968
cpu time do loop dim=2 0.191835046
cpu time cshift dim=3 1.35024190
cpu time do loop dim=3 1.42215610
with the patch. Do you understand why cshift is so slow for dim=3?
Thanks for working on this issue.
Dominique
PS See also pr45689.