1 | /* Round float to integer away from zero. |
2 | Copyright (C) 1997-2018 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 | #include <libm-alias-float.h> |
24 | |
25 | |
26 | float |
27 | __roundf (float x) |
28 | { |
29 | int32_t i0, j0; |
30 | |
31 | GET_FLOAT_WORD (i0, x); |
32 | j0 = ((i0 >> 23) & 0xff) - 0x7f; |
33 | if (j0 < 23) |
34 | { |
35 | if (j0 < 0) |
36 | { |
37 | i0 &= 0x80000000; |
38 | if (j0 == -1) |
39 | i0 |= 0x3f800000; |
40 | } |
41 | else |
42 | { |
43 | uint32_t i = 0x007fffff >> j0; |
44 | if ((i0 & i) == 0) |
45 | /* X is integral. */ |
46 | return x; |
47 | |
48 | i0 += 0x00400000 >> j0; |
49 | i0 &= ~i; |
50 | } |
51 | } |
52 | else |
53 | { |
54 | if (j0 == 0x80) |
55 | /* Inf or NaN. */ |
56 | return x + x; |
57 | else |
58 | return x; |
59 | } |
60 | |
61 | SET_FLOAT_WORD (x, i0); |
62 | return x; |
63 | } |
64 | libm_alias_float (__round, round) |
65 | |