1 /* Round float value to long int.
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 #include <fenv.h>
20 #include <limits.h>
21 #include <math.h>
22 
23 #include <math_private.h>
24 #include <libm-alias-float.h>
25 #include <fix-fp-int-convert-overflow.h>
26 
27 
28 long int
__lroundf(float x)29 __lroundf (float x)
30 {
31   int32_t j0;
32   uint32_t i;
33   long int result;
34   int sign;
35 
36   GET_FLOAT_WORD (i, x);
37   j0 = ((i >> 23) & 0xff) - 0x7f;
38   sign = (i & 0x80000000) != 0 ? -1 : 1;
39   i &= 0x7fffff;
40   i |= 0x800000;
41 
42   if (j0 < (int32_t) (8 * sizeof (long int)) - 1)
43     {
44       if (j0 < 0)
45 	return j0 < -1 ? 0 : sign;
46       else if (j0 >= 23)
47 	result = (long int) i << (j0 - 23);
48       else
49 	{
50 	  i += 0x400000 >> j0;
51 
52 	  result = i >> (23 - j0);
53 	}
54     }
55   else
56     {
57 #ifdef FE_INVALID
58       /* The number is too large.  Unless it rounds to LONG_MIN,
59 	 FE_INVALID must be raised and the return value is
60 	 unspecified.  */
61       if (FIX_FLT_LONG_CONVERT_OVERFLOW && x != (float) LONG_MIN)
62 	{
63 	  feraiseexcept (FE_INVALID);
64 	  return sign == 1 ? LONG_MAX : LONG_MIN;
65 	}
66 #endif
67       return (long int) x;
68     }
69 
70   return sign * result;
71 }
72 
73 libm_alias_float (__lround, lround)
74