/**
* @brief Compute Aberth correction for the j-th root,
* but only with other roots of the <code>jc</code>-th
* cluster.
*/
void
mps_faberth_s (mps_context * s, mps_approximation * ab_root, mps_cluster * cluster, cplx_t abcorr)
{
cplx_t z;
mps_root * root;
cplx_set (abcorr, cplx_zero);
for (root = cluster->first; root != NULL; root = root->next)
{
mps_approximation * appr = s->root[root->k];
if (appr == ab_root)
continue;
cplx_sub (z, ab_root->fvalue, appr->fvalue);
cplx_inv_eq (z);
cplx_add_eq (abcorr, z);
}
}
/**
* @brief Compute Aberth correction for j-th root, without
* selective correction.
*/
void
mps_faberth (mps_context * s, mps_approximation * root, cplx_t abcorr)
{
cplx_t z;
int i;
cplx_set (abcorr, cplx_zero);
for (i = 0; i < s->n; i++)
{
if (s->root[i] == root)
continue;
cplx_sub (z, root->fvalue, s->root[i]->fvalue);
cplx_inv_eq (z);
cplx_add_eq (abcorr, z);
}
}
void
cplx_pow_eq_si (cplx_t x, register signed long int i)
/* x = x ^ i , i integer */
{
cplx_t t;
cplx_Move (t, x);
cplx_Move (x, cplx_one);
if (i < 0)
{
cplx_inv_eq (t);
i = -i;
}
while (i)
{
if (i & 1)
cplx_mul_eq (x, t);
cplx_sqr_eq (t);
i >>= 1; /* divide i by 2 */
}
}
void
mps_faberth_wl (mps_context * s, int j, cplx_t abcorr, pthread_mutex_t * aberth_mutexes)
{
int i;
cplx_t z, froot;
pthread_mutex_lock (&aberth_mutexes[j]);
cplx_set (froot, s->root[j]->fvalue);
pthread_mutex_unlock (&aberth_mutexes[j]);
cplx_set (abcorr, cplx_zero);
for (i = 0; i < s->n; i++)
{
if (i == j)
continue;
pthread_mutex_lock (&aberth_mutexes[i]);
cplx_sub (z, froot, s->root[i]->fvalue);
pthread_mutex_unlock (&aberth_mutexes[i]);
cplx_inv_eq (z);
cplx_add_eq (abcorr, z);
}
}
