From: James Cowgill <James.Cowgill@imgtec.com>
To: "Maciej W. Rozycki" <macro@imgtec.com>
Cc: <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] [PR rtl-optimization/65618] Fix MIPS ADA bootstrap failure
Date: Wed, 11 Jan 2017 17:00:00 -0000 [thread overview]
Message-ID: <1a6da0f4-a48c-2bf2-1243-1e264af1ca9a@imgtec.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1701111641440.6936@tp.orcam.me.uk>
Hi,
On 11/01/17 16:49, Maciej W. Rozycki wrote:
> On Mon, 19 Dec 2016, James Cowgill wrote:
>> This bug causes the ADA bootstrap comparison failure in a-except.o
>> because the branch delay scheduling operates slightly differently for
>> that file if debug information is turned on.
>
> This looks like a bug to me -- actual code produced is supposed to be the
> same regardless of the amount of debug information requested. This is
> important for some debugging scenarios, such as when a binary originally
> produced with no debug information crashes and a core file is obtained so
> that the program can be rebuilt with debug information included and then
> matched to the core file previously produced, which may not be easy to
> recreate with the rebuilt binary.
>
> From this consideration I gather you have a program source which can be
> used as a test case to reproduce the issue, so can you please file a
> problem report and include the source and a recipe to reproduce it? Is
> this a GCC issue with generated assembly or a GAS issue with interpreting
> it?
Yes I had a testcase which I used to debug this, but it was pretty huge
(and written in ADA). When debugging I just diffed it with the debug
information toggled to see if the patch fixed it. I'll see if I can find
it anyway.
The issue was about the assembly GCC generated.
James
next prev parent reply other threads:[~2017-01-11 17:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-19 15:44 James Cowgill
2016-12-19 21:47 ` Jeff Law
2016-12-20 14:45 ` James Cowgill
2017-01-01 22:27 ` Jeff Law
2017-01-03 11:04 ` James Cowgill
2017-01-03 18:41 ` Jeff Law
2017-01-11 16:50 ` Maciej W. Rozycki
2017-01-11 17:00 ` James Cowgill [this message]
2017-01-11 17:22 ` Maciej W. Rozycki
2017-01-12 11:12 ` James Cowgill
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=1a6da0f4-a48c-2bf2-1243-1e264af1ca9a@imgtec.com \
--to=james.cowgill@imgtec.com \
--cc=gcc-patches@gcc.gnu.org \
--cc=macro@imgtec.com \
/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).