1 /* mpfr_get_ui -- convert a floating-point number to an unsigned long.
3 Copyright 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 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_get_ui (mpfr_srcptr f
, mpfr_rnd_t rnd
)
34 if (MPFR_UNLIKELY (!mpfr_fits_ulong_p (f
, rnd
)))
37 return MPFR_IS_NAN (f
) || MPFR_IS_NEG (f
) ?
38 (unsigned long) 0 : ULONG_MAX
;
42 return (unsigned long) 0;
44 for (s
= ULONG_MAX
, prec
= 0; s
!= 0; s
/= 2, prec
++)
47 /* first round to prec bits */
49 mpfr_rint (x
, f
, rnd
);
51 /* warning: if x=0, taking its exponent is illegal */
56 /* now the result is in the most significant limb of x */
57 exp
= MPFR_GET_EXP (x
); /* since |x| >= 1, exp >= 1 */
58 n
= MPFR_LIMB_SIZE(x
);
59 s
= MPFR_MANT(x
)[n
- 1] >> (GMP_NUMB_BITS
- exp
);