1 | /* Round float to integer away from zero. |
2 | Copyright (C) 1997-2019 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 | #define NO_MATH_REDIRECT |
21 | #include <math.h> |
22 | |
23 | #include <math_private.h> |
24 | #include <libm-alias-float.h> |
25 | |
26 | |
27 | float |
28 | __roundf (float x) |
29 | { |
30 | int32_t i0, j0; |
31 | |
32 | GET_FLOAT_WORD (i0, x); |
33 | j0 = ((i0 >> 23) & 0xff) - 0x7f; |
34 | if (j0 < 23) |
35 | { |
36 | if (j0 < 0) |
37 | { |
38 | i0 &= 0x80000000; |
39 | if (j0 == -1) |
40 | i0 |= 0x3f800000; |
41 | } |
42 | else |
43 | { |
44 | uint32_t i = 0x007fffff >> j0; |
45 | if ((i0 & i) == 0) |
46 | /* X is integral. */ |
47 | return x; |
48 | |
49 | i0 += 0x00400000 >> j0; |
50 | i0 &= ~i; |
51 | } |
52 | } |
53 | else |
54 | { |
55 | if (j0 == 0x80) |
56 | /* Inf or NaN. */ |
57 | return x + x; |
58 | else |
59 | return x; |
60 | } |
61 | |
62 | SET_FLOAT_WORD (x, i0); |
63 | return x; |
64 | } |
65 | libm_alias_float (__round, round) |
66 | |