gcd problem



>>>>> "Stavros" == Stavros Macrakis <macrakis at alum.mit.edu> writes:

    Stavros> cache) bandwidth is the limiting factor, not processor speed.  I think there
    Stavros> are old published papers with timings of calculations.

Wang's (or Moses?) thesis on integration has some timing information.
I think some integrals took on the order of 1-5 sec.  On the machines
I've tried I think they take like 0.1 sec or less.  Surely a large
part is from the faster processor.  But some could also come from the
Lisp implementation itself.  

    Stavros> In the particular case of CRE exponents, I am not sure.  There are unlikely
    Stavros> to be many practical applications of exponents > 2^31, and certainly
    Stavros> Maxima's algorithms haven't been tuned for those cases.  On the other hand,
    Stavros> *silent* failure is almost always unacceptable.  *IF* we are going to use
    Stavros> integer arithmetic, we have to err out in the case of overflow.  I don't
    Stavros> think there are mechanisms for doing that in all (any?) of the Lisps we run
    Stavros> in without using generic arithmetic.

I agree that we need to do something.  An explicit check might be
necessary, but perhaps only for GCL.

Ray