From: Richard Biener <rguenther@suse.de>
To: VandeVondele Joost <joost.vandevondele@mat.ethz.ch>
Cc: "hiraditya@gmail.com" <hiraditya@gmail.com>,
"sebpop@gmail.com" <sebpop@gmail.com>,
"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] RFC: Enable graphite at -O3 -fprofile_use
Date: Fri, 13 Nov 2015 11:32:00 -0000 [thread overview]
Message-ID: <alpine.LSU.2.11.1511131230240.4884@t29.fhfr.qr> (raw)
In-Reply-To: <908103EDB4893A42920B21D3568BFD9339F0AD26@MBX13.d.ethz.ch>
On Fri, 13 Nov 2015, VandeVondele Joost wrote:
> I'm all in favour of requiring isl and enabling graphite by default, but
> would suggest to enable it with -Ofast instead.
>
> One reason is that certainly extracting testcases from a PGO build is
> more difficult, and initially there will certainly be miscompiles with
> graphite (CP2K is right now).
>
> Furthermore, unless graphite is particularly effective with PGO (does it
> use average loop trip counts already?), I don't see a particular
> connection.
The reason to choose FDO was so GRAPHITE can concentrate its computing
budget on the hot parts of a program (which profile estimation isn't
good enough identifying), reducing its compile-time cost.
-Ofast isn't supposed to enable passes over -O3 so you're suggesting
to enable it with -O3 which I think is a bit premature. But we can
try doing that and revert at the end of stage3 if problems are just
too big.
Richard.
next prev parent reply other threads:[~2015-11-13 11:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-13 11:19 VandeVondele Joost
2015-11-13 11:32 ` Richard Biener [this message]
2015-11-13 13:25 ` aditya kumar
-- strict thread matches above, loose matches on Subject: below --
2015-11-13 10:30 Richard Biener
2015-11-09 5:16 hiraditya
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=alpine.LSU.2.11.1511131230240.4884@t29.fhfr.qr \
--to=rguenther@suse.de \
--cc=gcc-patches@gcc.gnu.org \
--cc=hiraditya@gmail.com \
--cc=joost.vandevondele@mat.ethz.ch \
--cc=sebpop@gmail.com \
/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).