GMP 4.3 multiplication performance
tg at gmplib.org
Sun Jun 7 15:06:09 CEST 2009
David Harvey <dmharvey at cims.nyu.edu> writes:
One case in which I am particularly interested is the 2n * n
unbalanced multiplication. This should be no more expensive than
twice the cost of an n * n multiplication, plus O(n) overhead that
should be negligible for large n.
I think it should be slightly cheaper than twice the cost of two n * n
But here is what I get for current 4.3 stable (changeset 85a941ada149
checked out this morning, on core 2 duo, mac OS X, after running
tuneup, using the attached python script). Columns are n, cost for
2n*n mult, cost for two n*n mults, ratio.
The numbers around 700-3000 limbs are not good.
Thanks, this was an eye opening comparison.
Let's address this for GMP 4.4!
More information about the gmp-devel