1/* Round float to integer away from zero.
2 Copyright (C) 1997-2016 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
19
20#include <math.h>
21
22#include <math_private.h>
23
24
25static const float huge = 1.0e30;
26
27
28float
29__roundf (float x)
30{
31 int32_t i0, j0;
32
33 GET_FLOAT_WORD (i0, x);
34 j0 = ((i0 >> 23) & 0xff) - 0x7f;
35 if (j0 < 23)
36 {
37 if (j0 < 0)
38 {
39 math_force_eval (huge + x);
40
41 i0 &= 0x80000000;
42 if (j0 == -1)
43 i0 |= 0x3f800000;
44 }
45 else
46 {
47 u_int32_t i = 0x007fffff >> j0;
48 if ((i0 & i) == 0)
49 /* X is integral. */
50 return x;
51 math_force_eval (huge + x);
52
53 /* Raise inexact if x != 0. */
54 i0 += 0x00400000 >> j0;
55 i0 &= ~i;
56 }
57 }
58 else
59 {
60 if (j0 == 0x80)
61 /* Inf or NaN. */
62 return x + x;
63 else
64 return x;
65 }
66
67 SET_FLOAT_WORD (x, i0);
68 return x;
69}
70weak_alias (__roundf, roundf)
71