| /* Test for signaling NaN. |
| Copyright (C) 2013-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <math.h> |
| #include <math_private.h> |
| |
| int |
| __issignalingl (long double x) |
| { |
| uint64_t xi; |
| /* For inspecting NaN status, we only have to look at the first of the pair |
| of IEEE 754 64-bit precision numbers. */ |
| double xhi; |
| |
| xhi = ldbl_high (x); |
| EXTRACT_WORDS64 (xi, xhi); |
| #ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN |
| # error untested |
| /* We only have to care about the high-order bit of x's significand, because |
| having it set (sNaN) already makes the significand different from that |
| used to designate infinity. */ |
| return (xi & UINT64_C (0x7ff8000000000000)) == UINT64_C (0x7ff8000000000000); |
| #else |
| /* To keep the following comparison simple, toggle the quiet/signaling bit, |
| so that it is set for sNaNs. This is inverse to IEEE 754-2008 (as well as |
| common practice for IEEE 754-1985). */ |
| xi ^= UINT64_C (0x0008000000000000); |
| /* We have to compare for greater (instead of greater or equal), because x's |
| significand being all-zero designates infinity not NaN. */ |
| return (xi & UINT64_C (0x7fffffffffffffff)) > UINT64_C (0x7ff8000000000000); |
| #endif |
| } |
| libm_hidden_def (__issignalingl) |
