Jacobi symbol using Lehmer's algorithm.
tg at gmplib.org
Thu Feb 25 17:04:40 CET 2010
nisse at lysator.liu.se (Niels Möller) writes:
Other mpz functions used are mpz_fdiv_r, mpz_sub_ui, mpz_fdiv_q_2exp,
mpz_cmp, mpz_sub, mpz_cmpabs_ui, mpz_sgn. Should any of those also be
replaced by refmpz functions? I don't fully understand the logic here.
Me neither. :-)
Some guidelines I try to follow:
o The ref functions should be conservatively implemented.
o We must not make the ref functions so slow that they seriously hurt
the amont of testing possible. E.g., we should avoid \Omega(n f(n))
complexity where the tested function is O(f(n)).
o We should either use other ref functions for our implementation,
alternatively non-ref functions in a different way than the library
o It is OK to use the library functions if we don't have a ref function
or if the ref function's slowness is a serious problem, but then we
have to make sure we don't use it the same way as the library function
for which we're implementing a ref function.
> You're planning to start using refmpz_legendre? (If the function is
> unused, we might as well remove it, or ifdef it out.)
Yes. For a start, I'm adding support in try.c, so I can get some testing
of the reference function before I check it in...
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