| /* 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 |
| __issignaling (double x) |
| { |
| #ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN |
| u_int32_t hxi; |
| GET_HIGH_WORD (hxi, x); |
| /* 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 (hxi & 0x7ff80000) == 0x7ff80000; |
| #else |
| u_int32_t hxi, lxi; |
| EXTRACT_WORDS (hxi, lxi, x); |
| /* 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). */ |
| hxi ^= 0x00080000; |
| /* If lxi != 0, then set any suitable bit of the significand in hxi. */ |
| hxi |= (lxi | -lxi) >> 31; |
| /* We have to compare for greater (instead of greater or equal), because x's |
| significand being all-zero designates infinity not NaN. */ |
| return (hxi & 0x7fffffff) > 0x7ff80000; |
| #endif |
| } |
| libm_hidden_def (__issignaling) |
