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/* mpfr_sqrt_ui -- square root of a machine integer
Copyright 2000-2004, 2006-2021 Free Software Foundation, Inc.
Contributed by the AriC and Caramba projects, INRIA.
This file is part of the GNU MPFR Library.
The GNU MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at your
option) any later version.
The GNU MPFR Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
#define MPFR_NEED_LONGLONG_H
#include "mpfr-impl.h"
int
mpfr_sqrt_ui (mpfr_ptr r, unsigned long u, mpfr_rnd_t rnd_mode)
{
int inex;
MPFR_LOG_FUNC
(("u=%lu rnd=%d", u, rnd_mode),
("y[%Pu]=%.*Rg inexact=%d",
mpfr_get_prec(r), mpfr_log_prec, r, inex));
if (u != 0)
{
mpfr_t uu;
#ifdef MPFR_LONG_WITHIN_LIMB
mp_limb_t up[1];
int cnt;
MPFR_SAVE_EXPO_DECL (expo);
MPFR_TMP_INIT1 (up, uu, GMP_NUMB_BITS);
MPFR_ASSERTN (u == (mp_limb_t) u);
count_leading_zeros (cnt, (mp_limb_t) u);
*up = (mp_limb_t) u << cnt;
MPFR_SAVE_EXPO_MARK (expo);
MPFR_SET_EXP (uu, GMP_NUMB_BITS - cnt);
inex = mpfr_sqrt (r, uu, rnd_mode);
#else
MPFR_SAVE_EXPO_DECL (expo);
mpfr_init2 (uu, sizeof (unsigned long) * CHAR_BIT);
/* Warning: u might be outside the current exponent range! */
MPFR_SAVE_EXPO_MARK (expo);
mpfr_set_ui (uu, u, MPFR_RNDZ);
inex = mpfr_sqrt (r, uu, rnd_mode);
mpfr_clear (uu);
#endif /* MPFR_LONG_WITHIN_LIMB */
MPFR_SAVE_EXPO_FREE (expo);
inex = mpfr_check_range (r, inex, rnd_mode);
return inex;
}
else /* sqrt(0) = 0 */
{
MPFR_SET_ZERO(r);
MPFR_SET_POS(r);
MPFR_RET(0);
}
}
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