Ciao,
While we are looking at gcd, I propose a shorter version for gcd_11 in
mini-gmp.
Meanwhile, we can also define a gcd_1 function... even if this is not
really useful. It would not make sense to give public access to mpn_gcd_1,
because we don't have any division function for the mpn level in mini-gmp
:-)
*** /tmp/extdiff.qIjJF7/gmp.643c931da9bd/mini-gmp/mini-gmp.c 2019-08-22
15:14:09.000000000 +0200
--- /home/bodrato/gmp/mini-gmp/mini-gmp.c 2019-08-22 21:40:30.144348034
+0200
***************
*** 2652,2680 ****
while ( (v & 1) == 0)
v >>= 1;
while (u != v)
{
if (u > v)
! {
! u -= v;
! do
! u >>= 1;
! while ( (u & 1) == 0);
! }
! else
! {
! v -= u;
! do
! v >>= 1;
! while ( (v & 1) == 0);
! }
}
return u << shift;
}
unsigned long
mpz_gcd_ui (mpz_t g, const mpz_t u, unsigned long v)
{
mpz_t t;
mpz_init_set_ui(t, v);
mpz_gcd (t, u, t);
--- 2652,2679 ----
while ( (v & 1) == 0)
v >>= 1;
while (u != v)
{
if (u > v)
! MP_LIMB_T_SWAP (u, v);
! v -= u;
! do
! v >>= 1;
! while ( (v & 1) == 0);
}
return u << shift;
}
+ static mp_limb_t
+ mpn_gcd_1 (mp_srcptr up, mp_size_t un, mp_limb_t v)
+ {
+ mpz_t t;
+ return mpn_gcd_11 (mpz_tdiv_ui (mpz_roinit_n (t, up, un), v), v);
+ }
+
unsigned long
mpz_gcd_ui (mpz_t g, const mpz_t u, unsigned long v)
{
mpz_t t;
mpz_init_set_ui(t, v);
mpz_gcd (t, u, t);
***************
*** 2750,2764 ****
}
if (c < 0)
mpz_swap (tu, tv);
if (tv->_mp_size == 1)
{
! mp_limb_t vl = tv->_mp_d[0];
! mp_limb_t ul = mpz_tdiv_ui (tu, vl);
! mpz_set_ui (g, mpn_gcd_11 (ul, vl));
break;
}
mpz_sub (tu, tu, tv);
}
mpz_clear (tu);
mpz_clear (tv);
--- 2749,2761 ----
}
if (c < 0)
mpz_swap (tu, tv);
if (tv->_mp_size == 1)
{
! mpz_set_ui (g, mpn_gcd_1 (tu->_mp_d, tu->_mp_size, tv->_mp_d[0]));
break;
}
mpz_sub (tu, tu, tv);
}
mpz_clear (tu);
mpz_clear (tv);
Ĝis,
m
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