From: Claus Fischer <claus.fischer@clausfischer.com>
To: Andrew Haley <aph-gcc@littlepinkcloud.COM>
Cc: gcc-help@gcc.gnu.org
Subject: Re: Likely code generation bug in GCC 4.0.1
Date: Mon, 14 May 2007 09:50:00 -0000 [thread overview]
Message-ID: <20070514095013.GB19170@clausfischer.com> (raw)
In-Reply-To: <17992.11645.386076.975611@zebedee.pink>
On Mon, May 14, 2007 at 10:35:57AM +0100, Andrew Haley wrote:
: Claus Fischer writes:
: > On Mon, May 14, 2007 at 10:18:26AM +0100, Andrew Haley wrote:
: > : Claus Fischer writes:
: > : >
: > : > I think I found a code generation bug in GCC 4.0.1.
: > : >
: > : > I'm sending this mail to make sure this bug is known and
: > : > is or will be removed in newer versions.
: > : > On a quick glance I couldn't find it in the bug database,
: > : > so it may not be known.
: > :
: > : Redirected to gcc-help.
: > :
: > : Please send a full test case that can be run, with full information
: > : about the expected effect.
: >
: >
: > The full test case is way too big to run and contains data
: > which I don't have authority to disclose publicly.
:
: I'm not asking for your full code. If you believe that the bug is in
: the code generated for the source you posted, presumably you can
: create a test wrapper.
I can, but it's likely to take me more than five times as long
as someone who knows assembler to take a (quick) glance. If that
quick glance doesn't get us further, I'm very willing to do my
homework/test case, even though just switching to gcc 4.1 would
probably solve MY problem completely. It's just out of desire to
help gcc people keep gcc bug-free that I have tried to "isolate"
this bug.
I have already spent a lot of time tracking this down, and I feel
I have reached a point where the imbalance of time I'd have to
spend to create a complete test case, and of the time required to
look at the assembly, is grossly in favor of learning assembly
myself :-)
[ Unfortunately, creating the MINGW cross compilation environment
itself is a task that would probably keep most gcc developers from
examining the case, even if I posted the instructions. ]
: Experience over meny years has shown us that this is the bet way to
: find and fix bugs in gcc. It's much more productive than staring at
: thousands of lines of assembly language.
I know and understand. I typically try to do that. But that's easier
for a recent GCC as shipped with Linux, than for a cross-compilation
environment that involves Mingw and an older GCC.
: The problem is that gcc reorders and reorganizes code to such an
: extent that it can be exceedingly hard to find the equivalent code.
I understand that.
Claus
--
Claus Fischer <claus.fischer@clausfischer.com>
http://www.clausfischer.com/
next prev parent reply other threads:[~2007-05-14 9:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20070513221443.GA3660@clausfischer.com>
2007-05-14 9:18 ` Andrew Haley
2007-05-14 9:29 ` Claus Fischer
2007-05-14 9:36 ` Andrew Haley
2007-05-14 9:50 ` Claus Fischer [this message]
2007-05-14 9:59 ` Andrew Haley
2007-05-14 10:15 ` Claus Fischer
2007-05-14 19:56 ` Claus Fischer
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=20070514095013.GB19170@clausfischer.com \
--to=claus.fischer@clausfischer.com \
--cc=aph-gcc@littlepinkcloud.COM \
--cc=gcc-help@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).