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* RE: c++/8684: ABI Issue: gcc3.2 is not reusing tail-padding..
@ 2002-12-03 12:36 Wolfgang Bangerth
0 siblings, 0 replies; 4+ messages in thread
From: Wolfgang Bangerth @ 2002-12-03 12:36 UTC (permalink / raw)
To: nobody; +Cc: gcc-prs
The following reply was made to PR c++/8684; it has been noted by GNATS.
From: Wolfgang Bangerth <bangerth@ticam.utexas.edu>
To: gcc-gnats@gcc.gnu.org
Cc:
Subject: RE: c++/8684: ABI Issue: gcc3.2 is not reusing tail-padding..
Date: Tue, 3 Dec 2002 14:35:00 -0600 (CST)
---------- Forwarded message ----------
Date: Tue, 3 Dec 2002 12:08:57 -0800
From: "Davasam, Sunil K" <sunil.k.davasam@intel.com>
To: bangerth@dealii.org
Subject: RE: c++/8684: ABI Issue: gcc3.2 is not reusing tail-padding..
Sorry for the late reply. I tried with intel 6.0,7.0 compilers on Linux.
In both cases I am getting same result. Here are the details.
[skdavasa@crystal tmp]$ cat t4.cpp
#include <stdio.h>
struct C1 {
int i;
char c;
};
struct C2 : C1 {
char c;
};
int main()
{
printf("sizeof (C1) = %d\n", sizeof (C1) );
printf("sizeof (C2) = %d\n", sizeof (C2) );
return 0;
}
[skdavasa@crystal tmp]$ icpc t4.cpp
t4.cpp
[skdavasa@crystal tmp]$ a.out
sizeof (C1) = 8
sizeof (C2) = 8
[skdavasa@crystal ~/tmp]$ icpc -V
Intel(R) C++ Compiler for 32-bit applications, Version 6.0.1 Build 20021018Z
Copyright (C) 1985-2002 Intel Corporation. All rights reserved.
[skdavasa@crystal ~/tmp]$ source ~/.ia32_productrc 70
[skdavasa@crystal ~/tmp]$ icpc -V
Intel(R) C++ Compiler for 32-bit applications, Version 7.0 Build 20021021Z
Copyright (C) 1985-2002 Intel Corporation. All rights reserved.
[skdavasa@crystal ~/tmp]$ icpc t4.cpp
[skdavasa@crystal ~/tmp]$ a.out
sizeof (C1) = 8
sizeof (C2) = 8
---
Thanks & Regards,
-Sunil.
-----Original Message-----
From: bangerth@dealii.org [mailto:bangerth@dealii.org]
Sent: Tuesday, November 26, 2002 7:30 PM
To: gcc-bugs@gcc.gnu.org; gcc-prs@gcc.gnu.org; nobody@gcc.gnu.org;
Davasam, Sunil K
Subject: Re: c++/8684: ABI Issue: gcc3.2 is not reusing tail-padding..
Synopsis: ABI Issue: gcc3.2 is not reusing tail-padding..
State-Changed-From-To: open->feedback
State-Changed-By: bangerth
State-Changed-When: Tue Nov 26 19:29:32 2002
State-Changed-Why:
Between 3.1.1 and 3.2, a number of ABI bugs have been fixed.
This may be one of them. The question I have for you, is
which version of the Intel compiler you have been using?
If I use icc 6.0 on Linux, I get 8 and 12, so exactly
the same results as with gcc3.2. So to me it seems as if
they were now compatible in this respect.
Thanks
Wolfgang
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8684
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: c++/8684: ABI Issue: gcc3.2 is not reusing tail-padding..
@ 2003-01-24 17:17 nathan
0 siblings, 0 replies; 4+ messages in thread
From: nathan @ 2003-01-24 17:17 UTC (permalink / raw)
To: gcc-bugs, gcc-prs, mmitchel, nathan, sunil.k.davasam
Synopsis: ABI Issue: gcc3.2 is not reusing tail-padding..
Responsible-Changed-From-To: mmitchel->nathan
Responsible-Changed-By: nathan
Responsible-Changed-When: Fri Jan 24 17:17:17 2003
Responsible-Changed-Why:
analyzer
State-Changed-From-To: analyzed->closed
State-Changed-By: nathan
State-Changed-When: Fri Jan 24 17:17:17 2003
State-Changed-Why:
yup, not a bug. C1 is POD
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8684
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: c++/8684: ABI Issue: gcc3.2 is not reusing tail-padding..
@ 2003-01-24 16:56 Giovanni Bajo
0 siblings, 0 replies; 4+ messages in thread
From: Giovanni Bajo @ 2003-01-24 16:56 UTC (permalink / raw)
To: mmitchel; +Cc: gcc-prs
The following reply was made to PR c++/8684; it has been noted by GNATS.
From: "Giovanni Bajo" <giovannibajo@libero.it>
To: <gcc-gnats@gcc.gnu.org>,
<sunil.k.davasam@intel.com>,
<gcc-bugs@gcc.gnu.org>,
<mmitchel@gcc.gnu.org>,
<gcc-prs@gcc.gnu.org>
Cc:
Subject: Re: c++/8684: ABI Issue: gcc3.2 is not reusing tail-padding..
Date: Fri, 24 Jan 2003 17:54:49 +0100
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&p
r=8684
GCC is correct here because C1 is of POD type, and tail padding can be
reused only in non-POD types. Comeau agrees, I don't know why ICC does not.
Besides, Mark already commented this very code snippet:
http://gcc.gnu.org/ml/gcc/2002-11/msg00474.html
IMO, this is not a bug and should be closed.
Giovanni Bajo
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: c++/8684: ABI Issue: gcc3.2 is not reusing tail-padding..
@ 2002-12-03 12:44 bangerth
0 siblings, 0 replies; 4+ messages in thread
From: bangerth @ 2002-12-03 12:44 UTC (permalink / raw)
To: gcc-bugs, gcc-prs, mmitchel, nobody, sunil.k.davasam
Synopsis: ABI Issue: gcc3.2 is not reusing tail-padding..
Responsible-Changed-From-To: unassigned->mmitchel
Responsible-Changed-By: bangerth
Responsible-Changed-When: Tue Dec 3 12:44:29 2002
Responsible-Changed-Why:
The person who probably knows the most about this part
of the standard
State-Changed-From-To: feedback->analyzed
State-Changed-By: bangerth
State-Changed-When: Tue Dec 3 12:44:29 2002
State-Changed-Why:
Yes, this is wicked. gcc 2.95, 3.2, 3.2.2 and 3.3 do indeed not reuse
the tail padding in this example; it does also not matter
whether I specifiy -fabi-version=0 or 1 or 2. Also, icc6.0
does not. But gcc3.0.4 and icc7 do! I don't know what the standard
says, but it seems like worth someone knowledgable check
this.
http://gcc.gnu.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gcc&pr=8684
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2003-01-24 17:17 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2002-12-03 12:36 c++/8684: ABI Issue: gcc3.2 is not reusing tail-padding Wolfgang Bangerth
2002-12-03 12:44 bangerth
2003-01-24 16:56 Giovanni Bajo
2003-01-24 17:17 nathan
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