Question

How to know the size of a declared variable in GMP??or how can we decide the size of an integer in GMP?

mpz_random(temp,1);

in manual it is given that this function allocates 1limb(=32bits for my comp) size to the “temp”….
but it is having 9 digit number only..
SO i dont think that 32 bit size number holds only 9 digits number..

So please help me to know the size of integer variable in GMP ..

thanks in adv..

Answer 1

32 bits (4 bytes) really can be used to store only 9 decimal digits

2^32 = 4 294 967 296

so only 9 full decimal digits here (the 10th is in interval from 0 up 4, so it is not full).

You can recompute this via logarithms:

log_10(2^32)

let’s ask google

log base 10(2^32) = 9.63295986

Everything is correct.