Help required in gcc 3.2.3 optimization

[Pradeep Kumar]

Hi,

        We are finding the output differences between O2 flagged , optimized 
version and a –g3 –gdwarf-2 flagged debugable version 
        of a C++ application , which does some very heavy floating point 
xnumber crunching.   
We are noticing differences with very small numbers (close to 0) like 1.234E-11

        The optimized and debugable binaries built on the same platform 
generate different outputs.  This we are observing on both the platforms 
mentioned below:

        Platform A:  Linux 2.1 AS, gcc 2.96, RW SourcePro  3.0
        Platform B:  Linux 3.0 AS, gcc 3.2.3 , RW SourcePro 6.1

        However the debuggable binaries generated on these two platforms give 
the same output.

        http://gcc.gnu.org/bugzilla/show_bug.cgi?id=8613 – a link which talks 
about a bug with the –O2 flag.
        We need some detailed information of any issues related to the O2 flag 
used for optimization on any of the above platforms. 

        If anybody has faced similar issues or come across any doc which talks 
about this, please share with us.

Thanks,
Pradeep.