Update.
[glibc.git] / sysdeps / libm-ieee754 / s_lrintf.c
blob210ffec50139b7e11e12f9cf9e09756ada60565c
1 /* Round argument to nearest integral value according to current rounding
2 direction.
3 Copyright (C) 1997 Free Software Foundation, Inc.
4 This file is part of the GNU C Library.
5 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Library General Public License as
9 published by the Free Software Foundation; either version 2 of the
10 License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Library General Public License for more details.
17 You should have received a copy of the GNU Library General Public
18 License along with the GNU C Library; see the file COPYING.LIB. If not,
19 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
22 #include <math.h>
24 #include "math_private.h"
26 static const double two23[2] =
28 8.3886080000e+06, /* 0x4B000000 */
29 -8.3886080000e+06, /* 0xCB000000 */
33 long int
34 __lrintf (float x)
36 int32_t j0;
37 u_int32_t i0;
38 volatile float w;
39 float t;
40 long int result;
41 int sx;
43 GET_FLOAT_WORD (i0, x);
45 sx = i0 >> 31;
46 j0 = ((i0 >> 23) & 0xff) - 0x7f;
47 i0 &= 0x7fffff;
48 i0 |= 0x800000;
50 if (j0 < (int32_t) (sizeof (long int) * 8) - 1)
52 if (j0 < -1)
53 return 0;
54 else if (j0 >= 23)
55 result = (long int) i0 << (j0 - 23);
56 else
58 w = two23[sx] + x;
59 t = w - two23[sx];
60 GET_FLOAT_WORD (i0, t);
61 j0 = ((i0 >> 23) & 0xff) - 0x7f;
62 i0 &= 0x7fffff;
63 i0 |= 0x800000;
65 result = i0 >> (23 - j0);
68 else
70 /* The number is too large. It is left implementation defined
71 what happens. */
72 return (long int) x;
75 return sx ? -result : result;
78 weak_alias (__lrintf, lrintf)