Error, error, unsupported BITS_PER_MP_LIMB
#endif
int
mpz_kronecker_ui (mpz_srcptr a, unsigned long b)
{
mp_srcptr a_ptr = PTR(a);
mp_size_t a_size;
mp_limb_t a_rem;
int result_bit1;
a_size = SIZ(a);
if (a_size == 0)
return JACOBI_0U (b);
if (b > GMP_NUMB_MAX)
{
mp_limb_t blimbs[2];
mpz_t bz;
ALLOC(bz) = numberof (blimbs);
PTR(bz) = blimbs;
mpz_set_ui (bz, b);
return mpz_kronecker (a, bz);
}
if ((b & 1) != 0)
{
result_bit1 = JACOBI_ASGN_SU_BIT1 (a_size, b);
}
else
{
mp_limb_t a_low = a_ptr[0];
int twos;
if (b == 0)
return JACOBI_LS0 (a_low, a_size); /* (a/0) */
if (! (a_low & 1))
return 0; /* (even/even)=0 */
/* (a/2)=(2/a) for a odd */
count_trailing_zeros (twos, b);
b >>= twos;
result_bit1 = (JACOBI_TWOS_U_BIT1 (twos, a_low)
^ JACOBI_ASGN_SU_BIT1 (a_size, b));
}
if (b == 1)
return JACOBI_BIT1_TO_PN (result_bit1); /* (a/1)=1 for any a */
a_size = ABS(a_size);
/* (a/b) = (a mod b / b) */
JACOBI_MOD_OR_MODEXACT_1_ODD (result_bit1, a_rem, a_ptr, a_size, b);
return mpn_jacobi_base (a_rem, (mp_limb_t) b, result_bit1);
}
int
mpn_jacobi_n (mp_ptr ap, mp_ptr bp, mp_size_t n, unsigned bits)
{
mp_size_t scratch;
mp_size_t matrix_scratch;
mp_ptr tp;
TMP_DECL;
ASSERT (n > 0);
ASSERT ( (ap[n-1] | bp[n-1]) > 0);
ASSERT ( (bp[0] | ap[0]) & 1);
/* FIXME: Check for small sizes first, before setting up temporary
storage etc. */
scratch = MPN_GCD_SUBDIV_STEP_ITCH(n);
if (ABOVE_THRESHOLD (n, GCD_DC_THRESHOLD))
{
mp_size_t hgcd_scratch;
mp_size_t update_scratch;
mp_size_t p = CHOOSE_P (n);
mp_size_t dc_scratch;
matrix_scratch = MPN_HGCD_MATRIX_INIT_ITCH (n - p);
hgcd_scratch = mpn_hgcd_itch (n - p);
update_scratch = p + n - 1;
dc_scratch = matrix_scratch + MAX(hgcd_scratch, update_scratch);
if (dc_scratch > scratch)
scratch = dc_scratch;
}
TMP_MARK;
tp = TMP_ALLOC_LIMBS(scratch);
while (ABOVE_THRESHOLD (n, JACOBI_DC_THRESHOLD))
{
struct hgcd_matrix M;
mp_size_t p = 2*n/3;
mp_size_t matrix_scratch = MPN_HGCD_MATRIX_INIT_ITCH (n - p);
mp_size_t nn;
mpn_hgcd_matrix_init (&M, n - p, tp);
nn = mpn_hgcd_jacobi (ap + p, bp + p, n - p, &M, &bits,
tp + matrix_scratch);
if (nn > 0)
{
ASSERT (M.n <= (n - p - 1)/2);
ASSERT (M.n + p <= (p + n - 1) / 2);
/* Temporary storage 2 (p + M->n) <= p + n - 1. */
n = mpn_hgcd_matrix_adjust (&M, p + nn, ap, bp, p, tp + matrix_scratch);
}
else
{
/* Temporary storage n */
n = mpn_gcd_subdiv_step (ap, bp, n, 0, jacobi_hook, &bits, tp);
if (!n)
{
TMP_FREE;
return bits == BITS_FAIL ? 0 : mpn_jacobi_finish (bits);
}
}
}
while (n > 2)
{
struct hgcd_matrix1 M;
mp_limb_t ah, al, bh, bl;
mp_limb_t mask;
mask = ap[n-1] | bp[n-1];
ASSERT (mask > 0);
if (mask & GMP_NUMB_HIGHBIT)
{
ah = ap[n-1]; al = ap[n-2];
bh = bp[n-1]; bl = bp[n-2];
}
else
{
int shift;
count_leading_zeros (shift, mask);
ah = MPN_EXTRACT_NUMB (shift, ap[n-1], ap[n-2]);
al = MPN_EXTRACT_NUMB (shift, ap[n-2], ap[n-3]);
bh = MPN_EXTRACT_NUMB (shift, bp[n-1], bp[n-2]);
bl = MPN_EXTRACT_NUMB (shift, bp[n-2], bp[n-3]);
}
/* Try an mpn_nhgcd2 step */
if (mpn_hgcd2_jacobi (ah, al, bh, bl, &M, &bits))
{
n = mpn_matrix22_mul1_inverse_vector (&M, tp, ap, bp, n);
MP_PTR_SWAP (ap, tp);
}
else
{
/* mpn_hgcd2 has failed. Then either one of a or b is very
small, or the difference is very small. Perform one
subtraction followed by one division. */
n = mpn_gcd_subdiv_step (ap, bp, n, 0, &jacobi_hook, &bits, tp);
if (!n)
{
TMP_FREE;
return bits == BITS_FAIL ? 0 : mpn_jacobi_finish (bits);
}
}
}
if (bits >= 16)
MP_PTR_SWAP (ap, bp);
ASSERT (bp[0] & 1);
if (n == 1)
{
mp_limb_t al, bl;
al = ap[0];
bl = bp[0];
TMP_FREE;
if (bl == 1)
return 1 - 2*(bits & 1);
else
return mpn_jacobi_base (al, bl, bits << 1);
}
else
{
int res = mpn_jacobi_2 (ap, bp, bits & 1);
TMP_FREE;
return res;
}
}
