1 | /* Test for signaling NaN. |
2 | Copyright (C) 2013-2016 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 | <http://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <math.h> |
20 | #include <math_private.h> |
21 | |
22 | int |
23 | __issignalingl (long double x) |
24 | { |
25 | u_int32_t exi, hxi, lxi; |
26 | GET_LDOUBLE_WORDS (exi, hxi, lxi, x); |
27 | #ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN |
28 | # error not implemented |
29 | #else |
30 | /* To keep the following comparison simple, toggle the quiet/signaling bit, |
31 | so that it is set for sNaNs. This is inverse to IEEE 754-2008 (as well as |
32 | common practice for IEEE 754-1985). */ |
33 | hxi ^= 0x40000000; |
34 | /* If lxi != 0, then set any suitable bit of the significand in hxi. */ |
35 | hxi |= (lxi | -lxi) >> 31; |
36 | /* We do not recognize a pseudo NaN as sNaN; they're invalid on 80387 and |
37 | later. */ |
38 | /* We have to compare for greater (instead of greater or equal), because x's |
39 | significand being all-zero designates infinity not NaN. */ |
40 | return ((exi & 0x7fff) == 0x7fff) && (hxi > 0xc0000000); |
41 | #endif |
42 | } |
43 | libm_hidden_def (__issignalingl) |
44 | |