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Import gmp 4.1.2

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

Copyright 1999, 2001 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., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */

#include <stdio.h>
#include "gmp.h"
#include "gmp-impl.h"
#include "mpfr.h"
#include "mpfr-impl.h"

int
mpfr_set_prec (mpfr_ptr x, mp_prec_t p)
{
  mp_size_t xsize;

  MPFR_ASSERTN(p >= MPFR_PREC_MIN && p <= MPFR_PREC_MAX);

  xsize = (p - 1) / BITS_PER_MP_LIMB + 1; /* new limb size */

  if (xsize > MPFR_ABSSIZE(x))
    {
      MPFR_MANT(x) = (mp_ptr) (*__gmp_reallocate_func)
        (MPFR_MANT(x), (size_t) MPFR_ABSSIZE(x) * BYTES_PER_MP_LIMB,
         (size_t) xsize * BYTES_PER_MP_LIMB);
      MPFR_SIZE(x) = xsize; /* new number of allocated limbs */
    }

  MPFR_PREC(x) = p;
  MPFR_SET_NAN(x); /* initializes to NaN */

  return MPFR_MANT(x) == NULL;
}

mp_prec_t
mpfr_get_prec (mpfr_srcptr x)
{
  return MPFR_PREC(x);
}