public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "hubicka at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/30354] -Os doesn't optimize a/CONST even if it saves size.
Date: Sat, 06 Jun 2009 13:41:00 -0000	[thread overview]
Message-ID: <20090606134124.11267.qmail@sourceware.org> (raw)
In-Reply-To: <bug-30354-12956@http.gcc.gnu.org/bugzilla/>



------- Comment #7 from hubicka at gcc dot gnu dot org  2009-06-06 13:41 -------
It seems to make sense to bump cost of idiv a bit, given the fact that there
are register pressure implications.

I would like to however understand what code sequences we produce that are
estimated to be long but ends up being shorter in practice.  Would be possible
to try to give me some examples of constants where it is important to bump cost
to 8?  It is possible we can simply fix cost estimation in divmod expansion
instead.

Honza 


-- 

hubicka at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2009-06-06 13:41:23
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30354


  parent reply	other threads:[~2009-06-06 13:41 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-02 22:09 [Bug rtl-optimization/30354] New: " vda dot linux at googlemail dot com
2007-01-02 22:45 ` [Bug target/30354] " pinskia at gcc dot gnu dot org
2007-07-25 15:05 ` vda dot linux at googlemail dot com
2007-07-25 15:09 ` vda dot linux at googlemail dot com
2007-07-25 15:17 ` vda dot linux at googlemail dot com
2007-07-25 15:22 ` vda dot linux at googlemail dot com
2009-06-05 16:19 ` aldot at gcc dot gnu dot org
2009-06-06 13:41 ` hubicka at gcc dot gnu dot org [this message]
2009-06-21 16:11 ` vda dot linux at googlemail dot com
2009-06-21 16:12 ` vda dot linux at googlemail dot com
2009-06-21 16:26 ` rguenth at gcc dot gnu dot org
2009-06-21 16:47 ` vda dot linux at googlemail dot com
2009-06-21 16:48 ` vda dot linux at googlemail dot com
2009-06-30 13:36 ` hubicka at gcc dot gnu dot org
2010-01-08  9:06 ` steven at gcc dot gnu dot org
     [not found] <bug-30354-4@http.gcc.gnu.org/bugzilla/>
2012-06-28 23:29 ` aldot at gcc dot gnu.org
2013-01-18 10:29 ` vda.linux at googlemail dot com
2021-12-21 11:42 ` pinskia 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=20090606134124.11267.qmail@sourceware.org \
    --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).