mirror of
https://github.com/vale981/arb
synced 2025-03-06 01:41:39 -05:00
110 lines
3.1 KiB
C
110 lines
3.1 KiB
C
/*=============================================================================
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This file is part of ARB.
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ARB is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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ARB is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with ARB; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2012 Fredrik Johansson
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******************************************************************************/
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#include "fmprb.h"
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int
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fmprb_get_unique_fmpz(fmpz_t z, const fmprb_t x)
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{
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if (fmpr_is_inf(fmprb_radref(x)) || fmpr_is_nan(fmprb_radref(x)))
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{
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return 0;
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}
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else if (fmpr_is_zero(fmprb_radref(x)))
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{
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/* x = b*2^e, e >= 0 */
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if (fmpz_sgn(fmpr_expref(fmprb_midref(x))) >= 0)
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{
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if (!fmpz_fits_si(fmpr_expref(fmprb_midref(x))))
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{
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printf("fmprb_get_unique_fmpz: too large shift\n");
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abort();
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}
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fmpz_mul_2exp(z, fmpr_manref(fmprb_midref(x)),
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fmpz_get_si(fmpr_expref(fmprb_midref(x))));
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return 1;
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}
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else
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{
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return 0;
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}
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}
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/* if the radius is >= 1, there are at least two integers */
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else if (fmpr_cmp_2exp_si(fmprb_radref(x), 0) >= 0)
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{
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return 0;
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}
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/* there are 0 or 1 integers if the radius is < 1 */
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else
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{
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/* if the midpoint is exactly an integer, it is what we want */
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if (fmpz_sgn(fmpr_expref(fmprb_midref(x))) >= 0)
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{
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if (!fmpz_fits_si(fmpr_expref(fmprb_midref(x))))
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{
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printf("fmprb_get_unique_fmpz: too large shift\n");
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abort();
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}
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fmpz_mul_2exp(z, fmpr_manref(fmprb_midref(x)),
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fmpz_get_si(fmpr_expref(fmprb_midref(x))));
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return 1;
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}
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/* if the radius is tiny, it can't be an integer */
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else if (!fmpz_fits_si(fmpr_expref(fmprb_radref(x))))
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{
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return 0;
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}
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else
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{
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fmpz_t a, b, exp;
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int res;
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fmpz_init(a);
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fmpz_init(b);
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fmpz_init(exp);
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fmprb_get_interval_fmpz_2exp(a, b, exp, x);
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fmpz_cdiv_q_2exp(a, a, -fmpz_get_si(exp));
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fmpz_fdiv_q_2exp(b, b, -fmpz_get_si(exp));
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res = fmpz_equal(a, b);
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if (res)
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fmpz_set(z, a);
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fmpz_clear(a);
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fmpz_clear(b);
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fmpz_clear(exp);
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return res;
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}
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}
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}
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