From: Richard Henderson <rth@twiddle.net>
To: Ulrich Drepper <drepper@redhat.com>
Cc: "John David Anglin" <dave@hiauly1.hia.nrc.ca>,
"\"Martin v. Löwis\"" <martin@v.loewis.de>,
jakub@redhat.com, aj@suse.de, gcc@gcc.gnu.org,
libc-alpha@sources.redhat.com
Subject: Re: Miscompilation of glibc with CVS mainline
Date: Thu, 02 Jan 2003 22:16:00 -0000 [thread overview]
Message-ID: <20030102141509.B20498@twiddle.net> (raw)
In-Reply-To: <3E149623.6000506@redhat.com>; from drepper@redhat.com on Thu, Jan 02, 2003 at 11:42:27AM -0800
On Thu, Jan 02, 2003 at 11:42:27AM -0800, Ulrich Drepper wrote:
> The problem here is that somebody thought s/he can be very clever and
> add one more optimization without knowing the history of gcc. We had
> problems with exactly this situation several times over the last years
> and always it has been the case that gcc was adjusted to *not* remove
> the test.
The history is not quite as you remember.
Once upon a time, GCC wasn't able to track whether or not a
particular symbol is or is not weak at the rtl level, and
thus we had to assume that all symbols were weak.
Now it is the case that we *can* track this, and so we do.
Note that the *only* way to subvert this scheme is to use
inline assembly to force the symbol weak behind gcc's back.
All I can say here is "Don't Do That".
r~
next prev parent reply other threads:[~2003-01-02 22:16 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-01-01 17:43 John David Anglin
2003-01-02 13:18 ` Andreas Jaeger
2003-01-02 13:27 ` Jakub Jelinek
2003-01-02 13:53 ` Andreas Jaeger
2003-01-02 14:41 ` Andreas Jaeger
2003-01-02 21:10 ` Andreas Jaeger
2003-01-02 17:38 ` John David Anglin
2003-01-02 17:48 ` "Martin v. Löwis"
2003-01-02 18:52 ` John David Anglin
2003-01-02 18:58 ` Paul Jarc
2003-01-02 19:10 ` Dale Johannesen
2003-01-02 19:16 ` John David Anglin
2003-01-02 19:26 ` Paul Jarc
2003-01-02 20:25 ` Martin v. Löwis
2003-01-02 22:11 ` Richard Henderson
2003-01-03 1:02 ` John David Anglin
2003-01-03 1:35 ` Richard Henderson
2003-01-02 19:42 ` Ulrich Drepper
2003-01-02 22:16 ` Richard Henderson [this message]
2003-01-03 0:14 ` Fergus Henderson
-- strict thread matches above, loose matches on Subject: below --
2003-01-04 18:54 Robert Dewar
2003-01-04 17:52 Robert Dewar
[not found] <no.id>
2003-01-02 17:48 ` John David Anglin
2003-01-02 17:54 ` Jakub Jelinek
2003-01-02 18:58 ` John David Anglin
2003-01-02 17:57 ` Daniel Jacobowitz
2003-01-01 13:37 Andreas Jaeger
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=20030102141509.B20498@twiddle.net \
--to=rth@twiddle.net \
--cc=aj@suse.de \
--cc=dave@hiauly1.hia.nrc.ca \
--cc=drepper@redhat.com \
--cc=gcc@gcc.gnu.org \
--cc=jakub@redhat.com \
--cc=libc-alpha@sources.redhat.com \
--cc=martin@v.loewis.de \
/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).