public inbox for gcc-bugs@sourceware.org
help / color / mirror / Atom feed
From: "hubicka at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/45791] Missed devirtualization
Date: Tue, 14 Dec 2010 23:15:00 -0000	[thread overview]
Message-ID: <bug-45791-4-tlExjZeCs2@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-45791-4@http.gcc.gnu.org/bugzilla/>

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45791

--- Comment #9 from Jan Hubicka <hubicka at gcc dot gnu.org> 2010-12-14 23:15:16 UTC ---
OK, main() code seems to optimize out that is an imrovement. Is it optimized
away with your patch pre-IPA too? 

Derived() is also devirtualizable:

Derived::Derived() (struct Derived * const this)
{
  int (*__vtbl_ptr_type) (void) * D.2237;
  int (*__vtbl_ptr_type) (void) D.2236;
  struct Base * D.2215;

<bb 2>:
  D.2215_2 = &this_1(D)->D.2115;
  D.2215_2->_vptr.Base = &_ZTV4Base[2];
  this_1(D)->D.2115._vptr.Base = &_ZTV7Derived[2];
  D.2215_3 = &this_1(D)->D.2115;
  D.2237_9 = D.2215_3->_vptr.Base;
  D.2236_10 = MEM[(int (*__vtbl_ptr_type) (void) *)D.2237_9 + 16B];
  OBJ_TYPE_REF(D.2236_10;D.2215_3->2) (D.2215_3);

We fail to devirtualize pre-IPA.  After IPA we compile into:

<bb 2>:
  MEM[(struct Base *)this_1(D)]._vptr.Base = &_ZTV4Base[2];
  this_1(D)->D.2115._vptr.Base = &_ZTV7Derived[2];
  D.2215_3 = &this_1(D)->D.2115;
  D.2236_10 = (int (*__vtbl_ptr_type) (void)) f;

a type mismatch?


  parent reply	other threads:[~2010-12-14 23:15 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-09-25 17:28 [Bug tree-optimization/45791] New: " hubicka at gcc dot gnu.org
2010-09-25 19:50 ` [Bug tree-optimization/45791] " hubicka at gcc dot gnu.org
2010-09-26  3:33 ` hubicka at gcc dot gnu.org
2010-09-26  3:39 ` hubicka at gcc dot gnu.org
2010-09-26  6:02 ` hubicka at gcc dot gnu.org
2010-10-11 17:15 ` jamborm at gcc dot gnu.org
2010-10-11 18:40 ` jamborm at gcc dot gnu.org
2010-12-14 17:46 ` jamborm at gcc dot gnu.org
2010-12-14 23:15 ` hubicka at gcc dot gnu.org [this message]
2010-12-14 23:17 ` hubicka at gcc dot gnu.org
2010-12-14 23:35 ` jamborm at gcc dot gnu.org
2010-12-15  0:10 ` hubicka at gcc dot gnu.org
2010-12-15  0:13 ` hubicka at gcc dot gnu.org
2010-12-15 16:07 ` jamborm at gcc dot gnu.org
2014-02-24  9:44 ` matthijs at stdin dot nl
2014-09-25 20:29 ` hubicka at gcc dot gnu.org
2021-01-07 17:38 ` jamborm 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-45791-4-tlExjZeCs2@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).