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/* mpfr_set_prec -- reset the precision of a floating-point number
Copyright 1999, 2001, 2002, 2004 Free Software Foundation, Inc.
This file is part of the MPFR Library.
The 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 2.1 of the License, or (at your
option) any later version.
The 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 MPFR Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Place, Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "mpfr-impl.h"
void
mpfr_set_prec (mpfr_ptr x, mpfr_prec_t p)
{
mp_size_t xsize, xoldsize;
mp_ptr tmp;
/* first, check if p is correct */
MPFR_ASSERTN (p >= MPFR_PREC_MIN && p <= MPFR_PREC_MAX);
/* Calculate the new number of limbs */
xsize = (p - 1) / BITS_PER_MP_LIMB + 1;
/* Realloc only if the new size is greater than the old */
xoldsize = MPFR_GET_ALLOC_SIZE (x);
if (xsize > xoldsize)
{
tmp = (mp_ptr) (*__gmp_reallocate_func)
(MPFR_GET_REAL_PTR(x), MPFR_MALLOC_SIZE(xoldsize), MPFR_MALLOC_SIZE(xsize));
MPFR_SET_MANT_PTR(x, tmp);
MPFR_SET_ALLOC_SIZE(x, xsize);
}
MPFR_PREC (x) = p;
MPFR_SET_NAN (x); /* initializes to NaN */
}
#undef mpfr_get_prec
mp_prec_t
mpfr_get_prec (mpfr_srcptr x)
{
return MPFR_PREC(x);
}
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