1*86d7f5d3SJohn Marino /* mpf_trunc -- truncate an mpf to an integer.
2*86d7f5d3SJohn Marino
3*86d7f5d3SJohn Marino Copyright 2001 Free Software Foundation, Inc.
4*86d7f5d3SJohn Marino
5*86d7f5d3SJohn Marino This file is part of the GNU MP Library.
6*86d7f5d3SJohn Marino
7*86d7f5d3SJohn Marino The GNU MP Library is free software; you can redistribute it and/or modify
8*86d7f5d3SJohn Marino it under the terms of the GNU Lesser General Public License as published by
9*86d7f5d3SJohn Marino the Free Software Foundation; either version 3 of the License, or (at your
10*86d7f5d3SJohn Marino option) any later version.
11*86d7f5d3SJohn Marino
12*86d7f5d3SJohn Marino The GNU MP Library is distributed in the hope that it will be useful, but
13*86d7f5d3SJohn Marino WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14*86d7f5d3SJohn Marino or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
15*86d7f5d3SJohn Marino License for more details.
16*86d7f5d3SJohn Marino
17*86d7f5d3SJohn Marino You should have received a copy of the GNU Lesser General Public License
18*86d7f5d3SJohn Marino along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
19*86d7f5d3SJohn Marino
20*86d7f5d3SJohn Marino #include "gmp.h"
21*86d7f5d3SJohn Marino #include "gmp-impl.h"
22*86d7f5d3SJohn Marino
23*86d7f5d3SJohn Marino
24*86d7f5d3SJohn Marino /* Notice the use of prec+1 ensures mpf_trunc is equivalent to mpf_set if u
25*86d7f5d3SJohn Marino is already an integer. */
26*86d7f5d3SJohn Marino
27*86d7f5d3SJohn Marino void
mpf_trunc(mpf_ptr r,mpf_srcptr u)28*86d7f5d3SJohn Marino mpf_trunc (mpf_ptr r, mpf_srcptr u)
29*86d7f5d3SJohn Marino {
30*86d7f5d3SJohn Marino mp_ptr rp;
31*86d7f5d3SJohn Marino mp_srcptr up;
32*86d7f5d3SJohn Marino mp_size_t size, asize, prec;
33*86d7f5d3SJohn Marino mp_exp_t exp;
34*86d7f5d3SJohn Marino
35*86d7f5d3SJohn Marino exp = EXP(u);
36*86d7f5d3SJohn Marino size = SIZ(u);
37*86d7f5d3SJohn Marino if (size == 0 || exp <= 0)
38*86d7f5d3SJohn Marino {
39*86d7f5d3SJohn Marino /* u is only a fraction */
40*86d7f5d3SJohn Marino SIZ(r) = 0;
41*86d7f5d3SJohn Marino EXP(r) = 0;
42*86d7f5d3SJohn Marino return;
43*86d7f5d3SJohn Marino }
44*86d7f5d3SJohn Marino
45*86d7f5d3SJohn Marino up = PTR(u);
46*86d7f5d3SJohn Marino EXP(r) = exp;
47*86d7f5d3SJohn Marino asize = ABS (size);
48*86d7f5d3SJohn Marino up += asize;
49*86d7f5d3SJohn Marino
50*86d7f5d3SJohn Marino /* skip fraction part of u */
51*86d7f5d3SJohn Marino asize = MIN (asize, exp);
52*86d7f5d3SJohn Marino
53*86d7f5d3SJohn Marino /* don't lose precision in the copy */
54*86d7f5d3SJohn Marino prec = PREC(r) + 1;
55*86d7f5d3SJohn Marino
56*86d7f5d3SJohn Marino /* skip excess over target precision */
57*86d7f5d3SJohn Marino asize = MIN (asize, prec);
58*86d7f5d3SJohn Marino
59*86d7f5d3SJohn Marino up -= asize;
60*86d7f5d3SJohn Marino rp = PTR(r);
61*86d7f5d3SJohn Marino SIZ(r) = (size >= 0 ? asize : -asize);
62*86d7f5d3SJohn Marino if (rp != up)
63*86d7f5d3SJohn Marino MPN_COPY_INCR (rp, up, asize);
64*86d7f5d3SJohn Marino }
65