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* [Bug c++/15012] New: Unexpected behaviour on i--
@ 2004-04-19 15:08 mdeluigi at student dot ethz dot ch
2004-04-19 15:15 ` [Bug c++/15012] " pinskia at gcc dot gnu dot org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: mdeluigi at student dot ethz dot ch @ 2004-04-19 15:08 UTC (permalink / raw)
To: gcc-bugs
Try that code:
---8<---
int j = 2;
int i = 2;
i = i-- + ++j;
cout << i;
--->8---
The suprising result is that i == 1.
I tried this on pc (intel), powerpc and sparc.
The result is because the compiler does something like:
---8<---
tmp1 = i--;
tmp2 = ++j;
i = i + tmp2;
i = tmp1;
--->8---
(check the asm-code for more details).
That's not what the programer expects.
--
Summary: Unexpected behaviour on i--
Product: gcc
Version: 3.3
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: mdeluigi at student dot ethz dot ch
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15012
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/15012] Unexpected behaviour on i--
2004-04-19 15:08 [Bug c++/15012] New: Unexpected behaviour on i-- mdeluigi at student dot ethz dot ch
@ 2004-04-19 15:15 ` pinskia at gcc dot gnu dot org
2004-08-05 14:57 ` bangerth at dealii dot org
2004-08-05 15:01 ` bangerth at dealii dot org
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2004-04-19 15:15 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pinskia at gcc dot gnu dot org 2004-04-19 14:56 -------
Invalid as you are modifing i twice without a sequence point inbetween.
i = i-- + ++j;
^ ^
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |INVALID
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15012
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/15012] Unexpected behaviour on i--
2004-04-19 15:08 [Bug c++/15012] New: Unexpected behaviour on i-- mdeluigi at student dot ethz dot ch
2004-04-19 15:15 ` [Bug c++/15012] " pinskia at gcc dot gnu dot org
@ 2004-08-05 14:57 ` bangerth at dealii dot org
2004-08-05 15:01 ` bangerth at dealii dot org
2 siblings, 0 replies; 4+ messages in thread
From: bangerth at dealii dot org @ 2004-08-05 14:57 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From bangerth at dealii dot org 2004-08-05 14:57 -------
Reopen these bugs...
--
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Resolution|INVALID |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15012
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug c++/15012] Unexpected behaviour on i--
2004-04-19 15:08 [Bug c++/15012] New: Unexpected behaviour on i-- mdeluigi at student dot ethz dot ch
2004-04-19 15:15 ` [Bug c++/15012] " pinskia at gcc dot gnu dot org
2004-08-05 14:57 ` bangerth at dealii dot org
@ 2004-08-05 15:01 ` bangerth at dealii dot org
2 siblings, 0 replies; 4+ messages in thread
From: bangerth at dealii dot org @ 2004-08-05 15:01 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From bangerth at dealii dot org 2004-08-05 15:01 -------
...mark as duplicate of PR 11751.
*** This bug has been marked as a duplicate of 11751 ***
--
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15012
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2004-08-05 15:01 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-04-19 15:08 [Bug c++/15012] New: Unexpected behaviour on i-- mdeluigi at student dot ethz dot ch
2004-04-19 15:15 ` [Bug c++/15012] " pinskia at gcc dot gnu dot org
2004-08-05 14:57 ` bangerth at dealii dot org
2004-08-05 15:01 ` bangerth at dealii dot org
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