1 /* mpfr_fits_uintmax_p -- test whether an mpfr fits an uintmax_t.
3 Copyright 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. */
24 # include "config.h" /* for a build within gmp */
27 #include "mpfr-intmax.h"
28 #include "mpfr-impl.h"
30 #ifdef _MPFR_H_HAVE_INTMAX_T
32 /* We can't use fits_u.h <= mpfr_cmp_ui */
34 mpfr_fits_uintmax_p (mpfr_srcptr f
, mpfr_rnd_t rnd
)
42 if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (f
)))
44 return MPFR_IS_ZERO (f
) ? 1 : 0;
45 else if (MPFR_IS_NEG (f
))
46 /* Negative numbers don't fit */
50 (b) round(f, prec(slong), rnd) <= MAXIMUM */
54 /* first compute prec(MAXIMUM); fits in an int */
55 for (s
= MPFR_UINTMAX_MAX
, prec
= 0; s
!= 0; s
/= 2, prec
++);
57 /* MAXIMUM needs prec bits, i.e. MAXIMUM = 2^prec - 1 */
59 /* if e <= prec - 1, then f < 2^(prec-1) < MAXIMUM */
63 /* if e >= prec + 1, then f >= 2^prec > MAXIMUM */
67 MPFR_ASSERTD (e
== prec
);
69 /* hard case: first round to prec bits, then check */
72 res
= MPFR_GET_EXP (x
) == e
;