Floating-Point Numbers and Internal Representation

[Matthias Kretschmer <mccratch@gmx.net>]

Hello,

I had a problem in one of my programs, that was caused by the internal
representation of floating-point numbers in the fpu. Concrete:
calculating the value of an optimum for some large number of objects,
then in a second doing something with all optimal objects. The problem
was, that when doing the calculation the second time, the compiler left
the floating-point number in the fpu which had a higher precision than
the representation I choosed, so comparing for equality returns always
"False". The problem would be solved by some operation truncating the
floating-point number to the precision I orginally wanted or used. I
could of course put all the values in an array or list and then finding
optimum and optimal objects, but I don't want to go this way. In C iirc
I could use a volatile variable to ensure the compiler will put the
value in and read from the variable before comparing, but to achieve
something similiar (truncating the precision to that of the type used)
in Ada?

My current solution is to enhance precision to compiler maximum which
seems to be the machine maximum. But I would like to know if there are
any better solutions?

-- 
Matthias Kretschmer