Annotation of OpenXM_contrib/gmp/mpfr/set_ui.c, Revision 1.1.1.1
1.1 ohara 1: /* mpfr_set_ui -- set a MPFR number from a machine unsigned integer
2:
3: Copyright 1999, 2000, 2001 Free Software Foundation.
4:
5: This file is part of the MPFR Library.
6:
7: The MPFR Library is free software; you can redistribute it and/or modify
8: it under the terms of the GNU Lesser General Public License as published by
9: the Free Software Foundation; either version 2.1 of the License, or (at your
10: option) any later version.
11:
12: The MPFR Library is distributed in the hope that it will be useful, but
13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14: or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
15: License for more details.
16:
17: You should have received a copy of the GNU Lesser General Public License
18: along with the MPFR Library; see the file COPYING.LIB. If not, write to
19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
20: MA 02111-1307, USA. */
21:
22: #include "gmp.h"
23: #include "gmp-impl.h"
24: #include "longlong.h"
25: #include "mpfr.h"
26: #include "mpfr-impl.h"
27:
28: int
29: mpfr_set_ui (mpfr_ptr x, unsigned long i, mp_rnd_t rnd_mode)
30: {
31: int inex = 0;
32:
33: MPFR_CLEAR_FLAGS(x);
34: if (i == 0)
35: MPFR_SET_ZERO(x); /* the sign will be set later */
36: else
37: {
38: mp_size_t xn;
39: unsigned int cnt, nbits;
40: mp_limb_t *xp;
41:
42: xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB;
43: count_leading_zeros(cnt, (mp_limb_t) i);
44:
45: xp = MPFR_MANT(x);
46: xp[xn] = ((mp_limb_t) i) << cnt;
47: /* don't forget to put zero in lower limbs */
48: MPN_ZERO(xp, xn);
49:
50: MPFR_EXP(x) = nbits = BITS_PER_MP_LIMB - cnt;
51: inex = mpfr_check_range(x, rnd_mode);
52: if (inex)
53: return inex; /* underflow or overflow */
54:
55: /* round if MPFR_PREC(x) smaller than length of i */
56: if (MPFR_PREC(x) < nbits)
57: {
58: int carry;
59: carry = mpfr_round_raw(xp+xn, xp+xn, nbits, 0, MPFR_PREC(x),
60: rnd_mode, &inex);
61: if (carry)
62: {
63: mp_exp_t exp = MPFR_EXP(x);
64:
65: if (exp == __mpfr_emax)
66: return mpfr_set_overflow(x, rnd_mode, 1);
67:
68: MPFR_EXP(x)++;
69: xp[xn] = GMP_LIMB_HIGHBIT;
70: }
71: }
72: }
73:
74: MPFR_SET_POS(x);
75:
76: MPFR_RET(inex);
77: }
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