Allocating 64 bits

[Paulo Matos]

Hi all,

I'd like to have access to 64 bits. I think unsigned long long is 64
bits in g++ although I'm not sure. Is there a way to know which type is
64 bits long or not?
Still, even if I know that unsigned long long is 64 bits long, how can
I know that it will occupy only two registers in a 32bit PC, or 1
register in a 64bit PC? Is there a way to make sure a 64 bit value, be
it an unsigned long long or a unsigned char v[8] to be kept on 2
registers or 1 in 32 bit or 64 bit PC respectively?

Cheers,

Paulo Matos