1/* Return classification value corresponding to argument.
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
26int
27__fpclassify (double x)
28{
29  u_int32_t hx, lx;
30  int retval = FP_NORMAL;
31
32  EXTRACT_WORDS (hx, lx, x);
33  lx |= hx & 0xfffff;
34  hx &= 0x7ff00000;
35  if ((hx | lx) == 0)
36    retval = FP_ZERO;
37  else if (hx == 0)
38    retval = FP_SUBNORMAL;
39  else if (hx == 0x7ff00000)
40    retval = lx != 0 ? FP_NAN : FP_INFINITE;
41
42  return retval;
43}
44