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Re: powerpc-ibm-aix4.3.3.0 bootstrap issue


On Oct  5, 2001, David Edelsohn <dje@watson.ibm.com> wrote:

> 	Using a debugger on the compiler producing different output caused
> the compiler to stop emitting different output.

Gee!  I suppose the cat is neither dead nor alive, then :-)


If you run the compiler outside the debugger, does it reliably produce
different output?  Given that timing doesn't play a role in GCC, I
really don't see how a debugger could affect the output of the
program, assuming you're not issuing commands to modify the state of
the inferior program, such as setting variables, issuing calls, etc.

This makes me wonder whether there's some kernel problem that fails to
preserve the upper 32 bits of 64-bit registers in certain corner cases
on context switches, or something like that.  This would explain the
irreproducibility of the failures, and the reason why it was when
HOST_WIDE_INT became `long long' that it started showing up.

Does this make any sense to you?

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                  aoliva@{cygnus.com, redhat.com}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist    *Please* write to mailing lists, not to me


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