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* [Bug c/19798] New: Prefix ++ doing wrong in an addition
@ 2005-02-07 6:26 ceniza666 at yahoo dot com
2005-02-07 6:45 ` [Bug c/19798] " pcarlini at suse dot de
0 siblings, 1 reply; 2+ messages in thread
From: ceniza666 at yahoo dot com @ 2005-02-07 6:26 UTC (permalink / raw)
To: gcc-bugs
A program as simple as:
int b = 10;
int a;
a = (++b) + (++b) + (++b);
printf("%d", a);
shows the wrong answer.
It should be 36, it shows 37. Optimisations on or off throw the same result.
Source of the problem: Generated code.
Pseudo C/asm code:
++b;
++b;
%eax = b;
%edx = b;
%edx += %eax;
++b;
%edx += b
a = %edx
So, when it should be doing "a = 11 + 12 + 13;" it's doing "a = 12 + 12 + 13;".
--
Summary: Prefix ++ doing wrong in an addition
Product: gcc
Version: 3.4.3
Status: UNCONFIRMED
Severity: normal
Priority: P2
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: ceniza666 at yahoo dot com
CC: gcc-bugs at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19798
^ permalink raw reply [flat|nested] 2+ messages in thread
* [Bug c/19798] Prefix ++ doing wrong in an addition
2005-02-07 6:26 [Bug c/19798] New: Prefix ++ doing wrong in an addition ceniza666 at yahoo dot com
@ 2005-02-07 6:45 ` pcarlini at suse dot de
0 siblings, 0 replies; 2+ messages in thread
From: pcarlini at suse dot de @ 2005-02-07 6:45 UTC (permalink / raw)
To: gcc-bugs
------- Additional Comments From pcarlini at suse dot de 2005-02-07 00:19 -------
*** 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=19798
^ permalink raw reply [flat|nested] 2+ messages in thread
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2005-02-07 6:26 [Bug c/19798] New: Prefix ++ doing wrong in an addition ceniza666 at yahoo dot com
2005-02-07 6:45 ` [Bug c/19798] " pcarlini at suse dot de
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