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From: "rth at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/16269] g++ doesn't reuse stack space
Date: Sat, 04 Sep 2004 00:06:00 -0000	[thread overview]
Message-ID: <20040904000641.19127.qmail@sourceware.org> (raw)
In-Reply-To: <20040629144215.16269.mrs@apple.com>


------- Additional Comments From rth at gcc dot gnu dot org  2004-09-04 00:06 -------
No, not related to 9997.  In this case we have 

  struct A <D1614>;
  struct A <D1615>;
  ...                                                                              
  <D1614> = foo ();
  operator= (&a, &<D1614>);
  <D1615> = foo ();
  operator= (&a, &<D1615>);

These two compiler temporaries are in the same scope, and thus the code that
lays out stack space will not be given an opportunity to share the memory.
In order for this to work as you expect, the front end would have to be 
changed to generate

  {
    struct A <D1614>;
    <D1614> = foo ();
    operator= (&a, &<D1614>);
  }
  {
    struct A <D1615>;
    <D1615> = foo ();
    operator= (&a, &<D1615>);
  }

In other words, be more explicit about the lifetimes of the temporaries
that it creates.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2004-07-10 02:50:38         |2004-09-04 00:06:38
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16269


  parent reply	other threads:[~2004-09-04  0:06 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-06-29 14:49 [Bug c++/16269] New: " mrs at apple dot com
2004-06-29 15:08 ` [Bug c++/16269] " pinskia at gcc dot gnu dot org
2004-07-10  2:50 ` giovannibajo at libero dot it
2004-09-03 23:52 ` rth at gcc dot gnu dot org
2004-09-04  0:06 ` rth at gcc dot gnu dot org [this message]
     [not found] <bug-16269-1447@http.gcc.gnu.org/bugzilla/>
2006-09-06 20:56 ` jason at gcc dot gnu dot org
2009-04-22 21:12 ` pinskia at gcc dot gnu dot org

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