1/* Round float to integer away from zero.
2 Copyright (C) 1997-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#define NO_MATH_REDIRECT
20#include <math.h>
21
22#include <math_private.h>
23#include <libm-alias-float.h>
24#include <math-use-builtins.h>
25
26
27float
28__roundf (float x)
29{
30#if USE_ROUNDF_BUILTIN
31 return __builtin_roundf (x);
32#else
33 /* Use generic implementation. */
34 int32_t i0, j0;
35
36 GET_FLOAT_WORD (i0, x);
37 j0 = ((i0 >> 23) & 0xff) - 0x7f;
38 if (j0 < 23)
39 {
40 if (j0 < 0)
41 {
42 i0 &= 0x80000000;
43 if (j0 == -1)
44 i0 |= 0x3f800000;
45 }
46 else
47 {
48 uint32_t i = 0x007fffff >> j0;
49 if ((i0 & i) == 0)
50 /* X is integral. */
51 return x;
52
53 i0 += 0x00400000 >> j0;
54 i0 &= ~i;
55 }
56 }
57 else
58 {
59 if (j0 == 0x80)
60 /* Inf or NaN. */
61 return x + x;
62 else
63 return x;
64 }
65
66 SET_FLOAT_WORD (x, i0);
67 return x;
68#endif /* ! USE_ROUNDF_BUILTIN */
69}
70libm_alias_float (__round, round)
71