arb/fmpr/get_fmpz_fixed.c
2016-04-26 17:20:05 +02:00

49 lines
1 KiB
C

/*
Copyright (C) 2012 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 "fmpr.h"
int
fmpr_get_fmpz_fixed_fmpz(fmpz_t y, const fmpr_t x, const fmpz_t exp)
{
slong shift;
if (fmpr_is_zero(x))
{
fmpz_zero(y);
return 0;
}
shift = _fmpz_sub_small(fmpr_expref(x), exp);
if (shift >= 0)
{
fmpz_mul_2exp(y, fmpr_manref(x), shift);
return 0;
}
else
{
fmpz_tdiv_q_2exp(y, fmpr_manref(x), -shift);
return 1;
}
}
int
fmpr_get_fmpz_fixed_si(fmpz_t y, const fmpr_t x, slong exp)
{
int result;
fmpz_t t;
fmpz_init(t);
fmpz_set_si(t, exp);
result = fmpr_get_fmpz_fixed_fmpz(y, x, t);
fmpz_clear(t);
return result;
}