1/* Test for signaling NaN.
2 Copyright (C) 2013-2020 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#include <math_private.h>
21#include <nan-high-order-bit.h>
22
23int
24__issignalingl (long double x)
25{
26 uint32_t exi, hxi, lxi;
27 GET_LDOUBLE_WORDS (exi, hxi, lxi, x);
28#if HIGH_ORDER_BIT_IS_SET_FOR_SNAN
29# error not implemented
30#else
31 /* To keep the following comparison simple, toggle the quiet/signaling bit,
32 so that it is set for sNaNs. This is inverse to IEEE 754-2008 (as well as
33 common practice for IEEE 754-1985). */
34 hxi ^= 0x40000000;
35 /* If lxi != 0, then set any suitable bit of the significand in hxi. */
36 hxi |= (lxi | -lxi) >> 31;
37 /* We do not recognize a pseudo NaN as sNaN; they're invalid on 80387 and
38 later. */
39 /* We have to compare for greater (instead of greater or equal), because x's
40 significand being all-zero designates infinity not NaN. */
41 return ((exi & 0x7fff) == 0x7fff) && (hxi > 0xc0000000);
42#endif
43}
44libm_hidden_def (__issignalingl)
45