From: Toon Moene <toon@moene.org>
To: Richard Biener <richard.guenther@gmail.com>
Cc: gcc mailing list <gcc@gcc.gnu.org>
Subject: Re: Loop fusion.
Date: Wed, 25 Apr 2018 08:06:00 -0000 [thread overview]
Message-ID: <7db072b0-a22f-3327-7eaf-f90a3431b357@moene.org> (raw)
In-Reply-To: <CAFiYyc0DprGVbBzKXgckPkz+9Z3mnjzcMCSVa1tkh=BJzJUsGA@mail.gmail.com>
On 04/24/2018 09:18 AM, Richard Biener wrote:
> On Mon, Apr 23, 2018 at 8:35 PM, Toon Moene <toon@moene.org> wrote:
>> On 04/23/2018 01:00 PM, Richard Biener wrote:
>>> Note that while it looks "obvious" in the above source fragment the IL
>>> that is presented to optimizers may make things a lot less "low-hanging".
>>
>>
>> Well, the loops are generated by the front end, so I *assume* they are
>> basically the same ...
>
> The issue will be boiler-plate code like duplicated loop header checks.
> That said, it's perfectly understandable that other Fortran compilers have
> high-level loop opts deeply embedded within their frontends...
I agree that this would be more easily handled in the Fortran front end.
However, for that it would first have to get a (high level) basic block
finder, because it has to be established that consecutive array
expressions are part of the same basic block.
I discussed high (i.e., Fortran-) level basic blocks briefly in my 2007
GCC Summit talk (http://moene.org/~toon/GCCSummit-2007.pdf, paragraph
7), but I do not think anyone really worked on it.
--
Toon Moene - e-mail: toon@moene.org - phone: +31 346 214290
Saturnushof 14, 3738 XG Maartensdijk, The Netherlands
At home: http://moene.org/~toon/; weather: http://moene.org/~hirlam/
Progress of GNU Fortran: http://gcc.gnu.org/wiki/GFortran#news
next prev parent reply other threads:[~2018-04-25 6:04 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-22 15:23 Toon Moene
2018-04-23 11:00 ` Bin.Cheng
2018-04-23 12:31 ` Richard Biener
2018-04-23 12:47 ` Janne Blomqvist
2018-04-23 14:11 ` Richard Biener
2018-04-23 11:02 ` Richard Biener
2018-04-24 2:22 ` Toon Moene
2018-04-24 12:58 ` Richard Biener
2018-04-25 8:06 ` Toon Moene [this message]
-- strict thread matches above, loose matches on Subject: below --
2015-04-22 19:19 Toon Moene
2015-04-22 20:05 ` Steven Bosscher
2015-04-23 4:58 ` Toon Moene
2015-04-23 17:17 ` Richard Biener
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=7db072b0-a22f-3327-7eaf-f90a3431b357@moene.org \
--to=toon@moene.org \
--cc=gcc@gcc.gnu.org \
--cc=richard.guenther@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).