public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/63844] [4.8/4.9/5 Regression] open mp parallelization prevents vectorization
Date: Tue, 18 Nov 2014 11:43:00 -0000	[thread overview]
Message-ID: <bug-63844-4-z8guh3ijlx@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-63844-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63844

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #9)
> Valid testcase (well, assign sth useful to g...)
> 
> #define N 10000000
> int a[N], b[N], c[N];
> 
> main()
> {
> 
>   int i, g;
> 
> #pragma omp parallel for num_threads(4)
>   for (i = 0; i < N; i++) {
>       a[i] = b[i] + c[i] + g;
>   }
> }
> 
> in the OMP fn we fail to hoist the load of .omp_child_i->g out of the
> loop and thus generate inferior code.

And does making receiver_decl restrict and/or reference type help with that?
BTW, we probably should add some IPA omp pass that would try to constant
propagate across from GOMP_parallel*/GOMP_task* callers to the *.omp_fn.*
functions (or teach IPA-SRA to do that?).


  parent reply	other threads:[~2014-11-18 11:43 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-13  4:20 [Bug tree-optimization/63844] New: " andi-gcc at firstfloor dot org
2014-11-13  9:16 ` [Bug tree-optimization/63844] " rguenth at gcc dot gnu.org
2014-11-17 18:52 ` andi-gcc at firstfloor dot org
2014-11-18 10:59 ` [Bug tree-optimization/63844] [4.8/4.9/5 Regression] " rguenth at gcc dot gnu.org
2014-11-18 11:03 ` jakub at gcc dot gnu.org
2014-11-18 11:13 ` rguenth at gcc dot gnu.org
2014-11-18 11:34 ` rguenth at gcc dot gnu.org
2014-11-18 11:38 ` rguenth at gcc dot gnu.org
2014-11-18 11:43 ` jakub at gcc dot gnu.org [this message]
2014-11-18 12:09 ` rguenther at suse dot de
2014-11-18 13:42 ` andi-gcc at firstfloor dot org
2014-11-18 13:44 ` andi-gcc at firstfloor dot org
2014-11-19  9:47 ` rguenth at gcc dot gnu.org
2014-11-19  9:48 ` [Bug tree-optimization/63844] [4.8/4.9 " rguenth at gcc dot gnu.org
2014-12-10 13:17 ` rguenth at gcc dot gnu.org
2014-12-19 13:33 ` jakub at gcc dot gnu.org
2015-02-23 12:06 ` rguenth at gcc dot gnu.org
2015-02-24 15:54 ` [Bug tree-optimization/63844] [4.8 " rguenth at gcc dot gnu.org
2015-02-24 16:14 ` rguenth at gcc dot gnu.org

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=bug-63844-4-z8guh3ijlx@http.gcc.gnu.org/bugzilla/ \
    --to=gcc-bugzilla@gcc.gnu.org \
    --cc=gcc-bugs@gcc.gnu.org \
    /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).