1 | /* Round float to integer away from zero. |
2 | Copyright (C) 1997-2017 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 | |
25 | float |
26 | __roundf (float x) |
27 | { |
28 | int32_t i0, j0; |
29 | |
30 | GET_FLOAT_WORD (i0, x); |
31 | j0 = ((i0 >> 23) & 0xff) - 0x7f; |
32 | if (j0 < 23) |
33 | { |
34 | if (j0 < 0) |
35 | { |
36 | i0 &= 0x80000000; |
37 | if (j0 == -1) |
38 | i0 |= 0x3f800000; |
39 | } |
40 | else |
41 | { |
42 | u_int32_t i = 0x007fffff >> j0; |
43 | if ((i0 & i) == 0) |
44 | /* X is integral. */ |
45 | return x; |
46 | |
47 | i0 += 0x00400000 >> j0; |
48 | i0 &= ~i; |
49 | } |
50 | } |
51 | else |
52 | { |
53 | if (j0 == 0x80) |
54 | /* Inf or NaN. */ |
55 | return x + x; |
56 | else |
57 | return x; |
58 | } |
59 | |
60 | SET_FLOAT_WORD (x, i0); |
61 | return x; |
62 | } |
63 | weak_alias (__roundf, roundf) |
64 | |