arb/arb_hypgeom/rising_ui_rec.c
2021-07-11 08:06:18 +02:00

46 lines
1.1 KiB
C

/*
Copyright (C) 2021 Fredrik Johansson
This file is part of Arb.
Arb is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version. See <http://www.gnu.org/licenses/>.
*/
#include "arb_hypgeom.h"
void
arb_hypgeom_rising_ui_rec(arb_t res, const arb_t x, ulong n, slong prec)
{
if (n <= 1)
{
if (n == 0)
arb_one(res);
else
arb_set_round(res, x, prec);
return;
}
if (n == 2 && prec <= 1024)
{
if (res != x)
arb_set(res, x);
arb_addmul(res, x, x, prec);
return;
}
if ((prec < 512 && n <= 20) || (n <= FLINT_MIN(80, 6000 / prec)))
{
arb_hypgeom_rising_ui_forward(res, x, n, prec);
}
else
{
if (n >= 20 && arb_bits(x) < prec / 8)
arb_hypgeom_rising_ui_bs(res, x, n, prec);
else
arb_hypgeom_rising_ui_rs(res, x, n, 0, prec);
}
}