void fmpz_poly_sqrlow(fmpz_poly_t res, const fmpz_poly_t poly, long n) { const long len = poly->length; if (len == 0 || n == 0) { fmpz_poly_zero(res); return; } if (res == poly) { fmpz_poly_t t; fmpz_poly_init2(t, n); fmpz_poly_sqrlow(t, poly, n); fmpz_poly_swap(res, t); fmpz_poly_clear(t); return; } n = FLINT_MIN(2 * len - 1, n); fmpz_poly_fit_length(res, n); _fmpz_poly_sqrlow(res->coeffs, poly->coeffs, len, n); _fmpz_poly_set_length(res, n); _fmpz_poly_normalise(res); }
void fmpz_poly_mat_sqrlow(fmpz_poly_mat_t B, const fmpz_poly_mat_t A, slong len) { slong n = A->r; if (n == 0) return; if (len < 1) { fmpz_poly_mat_zero(B); return; } if (n == 1) { fmpz_poly_sqrlow(E(B, 0, 0), E(A, 0, 0), len); return; } if (n == 2) { fmpz_poly_t t, u; fmpz_poly_init(t); fmpz_poly_init(u); fmpz_poly_addlow(t, E(A, 0, 0), E(A, 1, 1), len); fmpz_poly_mullow(u, E(A, 0, 1), E(A, 1, 0), len); fmpz_poly_sqrlow(E(B, 0, 0), E(A, 0, 0), len); fmpz_poly_addlow(E(B, 0, 0), E(B, 0, 0), u, len); fmpz_poly_sqrlow(E(B, 1, 1), E(A, 1, 1), len); fmpz_poly_addlow(E(B, 1, 1), E(B, 1, 1), u, len); fmpz_poly_mullow(E(B, 0, 1), E(A, 0, 1), t, len); fmpz_poly_mullow(E(B, 1, 0), E(A, 1, 0), t, len); fmpz_poly_clear(t); fmpz_poly_clear(u); return; } fmpz_poly_mat_mullow(B, A, A, len); }