Karim BELABAS on Fri, 6 Dec 2002 15:12:55 +0100 (MET)

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Re: 2 changes in the CVS

On Fri, 6 Dec 2002, Bill Allombert wrote:
> I have commited two change to the CVS.

While we are at it: I have enabled Karatsuba multiplication for t_REAL (code
has been here for at least 2 years, but was unused). It is not properly tuned
yet, but at least it seems to give correct (and correctly rounded) results.

The speedup is not that impressive: a factor 2 for exp(1) at \p20000, a
factor 4 at \p100000. I have not implemented Mulders or Hanrot-Zimmermann
short products (maybe a further 30%, on average ??).

Karim Belabas                    Tel: (+33) (0)1 69 15 57 48
Dép. de Mathématiques, Bât. 425  Fax: (+33) (0)1 69 15 60 19
Université Paris-Sud             Email: Karim.Belabas@math.u-psud.fr
F-91405 Orsay (France)           http://www.math.u-psud.fr/~belabas/
PARI/GP Home Page: http://www.parigp-home.de/