Getting a very large polynomial into pari/gp

[Neill Clift <neillclift@live.com>]

Hi,
I want to do a gcd with two polynomials with 16 million coefficients mod 
a large 64 bit prime.
Playing with gp with some sparse polynomials it looks like it can do the 
calculation.
If I try to read in a dense polynomial of large size though gp overflows 
its stack (runs out of thread stack space, not a buffer overflow or gp 
stack).
I assume your parser is putting a lot of data on the thread stack.
I am using a command like this:

gp > a = read("a.gp")

I am doing this on windows.
Is there some kind of raw read or similar that will let me get a large 
polynomial into gp? I can put the data into different formats rather 
than the symbolic format I am trying currently.
Thanks.
Neill.