/* mpfr_set_prec -- reset the precision of a floating-point number

Copyright 1999, 2001, 2002, 2004, 2006 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 St, 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);
}