1 /* Round float to integer away from zero.
2    Copyright (C) 1997-2022 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 
27 float
__roundf(float x)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 }
70 libm_alias_float (__round, round)
71