From: Richard Earnshaw <rearnsha@arm.com>
To: Yao Qi <yao@codesourcery.com>
Cc: Terry Guo <Terry.Guo@arm.com>,
"gdb-patches@sourceware.org" <gdb-patches@sourceware.org>,
"pedro@codesourcery.com" <pedro@codesourcery.com>
Subject: Re: [PATCH] Fix that different function breakpoints are set at same pc address (PR gdb/12703)
Date: Fri, 01 Jul 2011 08:59:00 -0000 [thread overview]
Message-ID: <4E0D8C5B.2090407@arm.com> (raw)
In-Reply-To: <4E0AF7A6.1040800@codesourcery.com>
On 29/06/11 11:00, Yao Qi wrote:
> On 06/29/2011 04:47 PM, Terry Guo wrote:
>> Hi,
>>
>> First if you look at the generated binary code, I thought it is a valid case. After performing the function test, it will fall into function bar which is a normal function. At least my case can run correctly on QEMU. It is very likely for people to write program in assembly code like:
>>
>> main:
>> b test
>>
>> test:
>> movs r5, #10
>> bar:
>> push.......
>> .........
>>
>
> We are lucky here GCC places bar next to function test physically, but
> gcc may also place function test and bar in other layout, like
>
> main:
> b test
>
> bar:
> push ...
>
> test:
> moves r5, #10
>
> After test, processor will run some instructions that we don't know.
> IMO, it is incorrect.
>
Which is one of the reasons why GCC has the option -fno-toplevel-reorder
to prevent such reordering.
R.
next prev parent reply other threads:[~2011-07-01 8:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-27 11:26 Terry Guo
2011-06-29 1:26 ` Terry Guo
2011-06-29 5:36 ` Yao Qi
2011-06-29 7:00 ` Terry Guo
2011-06-29 8:00 ` Yao Qi
2011-06-29 8:49 ` Terry Guo
[not found] ` <45520D6299C11E4588128526465332BB0D0C8B1246@SAROVARA.Asiapac.Arm.com>
2011-06-29 10:00 ` Yao Qi
2011-06-29 10:17 ` Terry Guo
2011-07-01 8:59 ` Richard Earnshaw [this message]
2011-07-01 9:47 ` Pedro Alves
2011-07-13 13:21 ` Terry Guo
-- strict thread matches above, loose matches on Subject: below --
2011-06-24 2:31 Terry Guo
2011-06-24 3:55 ` Yao Qi
2011-06-24 8:59 ` Pedro Alves
2011-06-24 10:39 ` Yao Qi
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=4E0D8C5B.2090407@arm.com \
--to=rearnsha@arm.com \
--cc=Terry.Guo@arm.com \
--cc=gdb-patches@sourceware.org \
--cc=pedro@codesourcery.com \
--cc=yao@codesourcery.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