public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: "Dominique d'Humières" <dominiq@lps.ens.fr>
To: Thomas Koenig <tkoenig@netcologne.de>
Cc: gfortran <fortran@gcc.gnu.org>, gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: [patch, libfortran, RFC] Speed up cshift with array shift
Date: Tue, 20 Jun 2017 14:25:00 -0000	[thread overview]
Message-ID: <CAF215C5-17D0-48A4-AD1B-14671F84253A@lps.ens.fr> (raw)

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.

             reply	other threads:[~2017-06-20 14:25 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-20 14:25 Dominique d'Humières [this message]
  -- strict thread matches above, loose matches on Subject: below --
2017-06-19 22:34 Thomas Koenig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAF215C5-17D0-48A4-AD1B-14671F84253A@lps.ens.fr \
    --to=dominiq@lps.ens.fr \
    --cc=fortran@gcc.gnu.org \
    --cc=gcc-patches@gcc.gnu.org \
    --cc=tkoenig@netcologne.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).