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
26float
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}
64libm_alias_float (__round, round)
65