[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Floating point problems
Michael van Acken wrote:
>
> Marco Oetken <Marco.Oetken@informatik.uni-oldenburg.de> writes:
>
> > Hello!
> >
> > I have a few problems with floating points!
> > I include three test modules which shall show the
> > problems I have. The occur in similar ways in
> > different places, too.
> > I can't find any rules in why the calculations
> > have errornous results. (E.g. in a different module
> > with slightly different MatrixMultPoint I made it
> > work by introducing output (Err) at the beginning of the
> > prcedure.)
>
> Adding a call to an external procedure can severely impact the
> compiler backend's instruction scheduling due to the added scheduling
> restraints. I will try to investigate if this really is a scheduler
> problem early next week. In the meantime, an empty external procedure
> call, like Out.String(""), may work miracles at the right place.
>
> -- mva
I should have added that I have tried to compare the c-files
generated by oo2c. I did it for another similar module. I
replaced the module name in the second file with that of the
first and then ran diff: the differences were the calls
for the output. I don't know if it helps you.
Sometimes I like to go back to my last computer: no miracles,
only deterministic software. Occasionally I take a look at
the magazines for it and regularly see that the manufacturer
promises to provide a faster and better one (a good idea after so
many years).
Marco