Possible memory leak? (was: update on fast mult benchmark (fwd))

[Richard B. Kreckel]

Hi,

On Sun, 24 Mar 2002, Richard Fateman wrote:
> This seems to me to be a design that should be revisited.  For
> the univariate case it is particularly bad since multiplying polynomials
> of degree u and v gives you only degree u+v,  and you will have
> allocated (u+1)*(v+1) cells.

Sure.  Done now.

> When this problem works on GiNaC I'd like to know its speed!

Here are timings on a P-III, 1GHz, 512kB cache, running Linux, with
approximate memory usage:

System                                               time     Memory
--------------------------------------------------+--------+---------
GiNaC-1.0.8 (from CVS), using GCC-3.1 prerelease:    57.3s       8MB
MuPAD 1.4.2:                                        119.2s      25MB
MuPAD 2.0:                                          117.0s      30MB
Form 3.0:                                             0.5s       6MB
Maxima 5.6 (GCL 2.4.0):                              51.0s       8MB
MapleVR3:                                            16.7s       7MB
MapleVR4:                                            17.9s       8MB
MapleVR5:                                            18.4s       8MB
Mathematica 4.1:                                     80.5s      11MB
Reduce 3.6:                                       Segmentation Fault
Yacas 1.0.48:            N/A (smaller examples fail to expand fully)

Richard, I noticed a mistake in the printed version of the Mathematica
program (missing Expand[]) and the MockMMA doesn't seem right to me
either.  Note that Form can really only do ring operations like in this
test, but its speed there should come as no surprise.  You probably just
cannot beat it with any more general system.

Regards
    -richy.
-- 
Richard B. Kreckel
<Richard.Kreckel at Uni-Mainz.DE>
<http://wwwthep.physik.uni-mainz.de/~kreckel/>