1/* Round float to integer away from zero.
2   Copyright (C) 1997 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, write to the Free
18   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
19   02111-1307 USA.  */
20
21#include <math.h>
22
23#include "math_private.h"
24
25
26static const float huge = 1.0e30;
27
28
29float
30__roundf (float x)
31{
32  int32_t i0, j0;
33
34  GET_FLOAT_WORD (i0, x);
35  j0 = ((i0 >> 23) & 0xff) - 0x7f;
36  if (j0 < 23)
37    {
38      if (j0 < 0)
39	{
40	  if (huge + x > 0.0F)
41	    {
42	      i0 &= 0x80000000;
43	      if (j0 == -1)
44		i0 |= 0x3f800000;
45	    }
46	}
47      else
48	{
49	  u_int32_t i = 0x007fffff >> j0;
50	  if ((i0 & i) == 0)
51	    /* X is integral.  */
52	    return x;
53	  if (huge + x > 0.0F)
54	    {
55	      /* Raise inexact if x != 0.  */
56	      i0 += 0x00400000 >> j0;
57	      i0 &= ~i;
58	    }
59	}
60    }
61  else
62    {
63      if (j0 == 0x80)
64	/* Inf or NaN.  */
65	return x + x;
66      else
67	return x;
68    }
69
70  SET_FLOAT_WORD (x, i0);
71  return x;
72}
73weak_alias (__roundf, roundf)
74