1 /* mpfr_set_prec -- reset the precision of a floating-point number
3 Copyright 1999, 2001-2002, 2004, 2006-2015 Free Software Foundation, Inc.
4 Contributed by the AriC and Caramel projects, INRIA.
6 This file is part of the GNU MPFR Library.
8 The GNU MPFR Library is free software; you can redistribute it and/or modify
9 it under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or (at your
11 option) any later version.
13 The GNU MPFR Library is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
16 License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
20 http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
21 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
23 #include "mpfr-impl.h"
26 mpfr_set_prec (mpfr_ptr x
, mpfr_prec_t p
)
28 mp_size_t xsize
, xoldsize
;
31 /* first, check if p is correct */
32 MPFR_ASSERTN (p
>= MPFR_PREC_MIN
&& p
<= MPFR_PREC_MAX
);
34 /* Calculate the new number of limbs */
35 xsize
= MPFR_PREC2LIMBS (p
);
37 /* Realloc only if the new size is greater than the old */
38 xoldsize
= MPFR_GET_ALLOC_SIZE (x
);
41 tmp
= (mpfr_limb_ptr
) (*__gmp_reallocate_func
)
42 (MPFR_GET_REAL_PTR(x
), MPFR_MALLOC_SIZE(xoldsize
), MPFR_MALLOC_SIZE(xsize
));
43 MPFR_SET_MANT_PTR(x
, tmp
);
44 MPFR_SET_ALLOC_SIZE(x
, xsize
);
47 MPFR_SET_NAN (x
); /* initializes to NaN */
52 mpfr_get_prec (mpfr_srcptr x
)