optimization/8613: -O3 optimisation of ++ generates wrong code
mark.odonohue@cytopia.com.au
mark.odonohue@cytopia.com.au
Sun Nov 17 06:28:00 GMT 2002
>Number: 8613
>Category: optimization
>Synopsis: -O3 optimisation of ++ generates wrong code
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: unassigned
>State: open
>Class: sw-bug
>Submitter-Id: net
>Arrival-Date: Sun Nov 17 05:46:06 PST 2002
>Closed-Date:
>Last-Modified:
>Originator: mark.odonohue@cytopia.com.au
>Release: gcc 3.2
>Organization:
>Environment:
mandrake linux 9.0
>Description:
In the provided code,
*dpb++ = strlen(userName)
dpb is incorrectly incremented by two bytes, not one.
The output buffer should result in:
1, 35, 6, 'sysdba'.
Instead it results in:
1, 35, 6, x, 'sysdba'
where x is random.
Tracing in gdb shows that dpb is incremented by a value of two.
>How-To-Repeat:
g++ -O2 -march=i686 -fPIC test1.cpp
./a.out 1
>Fix:
-O1 seems to work.
>Release-Note:
>Audit-Trail:
>Unformatted:
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