mpz_set_str() question
hermann at stamm-wilbrandt.de
hermann at stamm-wilbrandt.de
Sat Feb 24 15:47:29 CET 2024
On 2024-02-23 14:00, niXman's Github wrote:
> ...
> in the process of studying the implementation of those functions I
> paid attention to the most obvious reasons slowing down parsing:
> 0) calls to `strlen()`/`strchr()` etc functions.
> 1) memory allocations and copying into, just to add the final '\0'
> char. (mpq_set_str)
> 2) preliminary memory allocations and copying into char-by-char just
> to full processing the input string. (mpz_set_str/mpf_set_str)
>
> let me explain with the simplest example on the `mpz_set_str()`
> function:
> ...
>
Hi,
yesterday 8.55 day 16 thread forced on chiplet0 of AMD 7950X CPU patched
LLR 4.0.5 software based on gwnum lib did compute sqrt(-1) (mod p) for
largest known prime p =1 (mod 4) known since 9/2023.
Today I added validation code for Python, Node and C++ in addition to
PARI/GP.
You might want to use 7462826 hexadecimal digits sqrt(-1) (mod p) in
sqrtm1.gp file:
https://github.com/Hermann-SW/RSA_numbers_factored/tree/main/llr/11%2C981%2C518#855-days-computation
hermann at 7950x:~/RSA_numbers_factored/llr/11,981,518$ make validate
g++ -O3 validate.cc -lgmpxx -lgmp -o validate.cc.out
./validate.cc.out
11981518 decimal digits prime p
0.008523s for mpz_set_str() of 7462826 hexadecimal digits sqrt(-1) (mod
p)
1.56775s for computing powm(_, sqrtm1, 2, p)
1 (sqrtm1*sqrtm1 % p == p-1)
0.00625s for mpz_set_str() of x and y
1 (x*x + y*y == p)
hermann at 7950x:~/RSA_numbers_factored/llr/11,981,518$
Regards,
Hermann.
More information about the gmp-discuss
mailing list