1/* Return classification value corresponding to argument.
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 <math.h>
20
21#include <math_private.h>
22
23
24int
25__fpclassifyl (long double x)
26{
27 uint32_t ex, hx, lx;
28 int retval = FP_NORMAL;
29
30 GET_LDOUBLE_WORDS (ex, hx, lx, x);
31 ex &= 0x7fff;
32 if ((ex | lx | hx) == 0)
33 retval = FP_ZERO;
34 else if (ex == 0 && (hx & 0x80000000) == 0)
35 retval = FP_SUBNORMAL;
36 /* Pseudo-normals, i.e. pseudo-zero, pseudo-infinity and un-normals. They
37 behave like NaNs, so categorize them as such. */
38 else if ((hx & 0x80000000) == 0)
39 retval = FP_NAN;
40 else if (ex == 0x7fff)
41 retval = ((hx & 0x7fffffff) | lx) != 0 ? FP_NAN : FP_INFINITE;
42
43 return retval;
44}
45libm_hidden_def (__fpclassifyl)
46

source code of glibc/sysdeps/x86/fpu/s_fpclassifyl.c