/* Test for signaling NaN. Copyright (C) 2013-2016 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 . */ #include #include int __issignalingl (_Float128 x) { u_int64_t hxi, lxi __attribute__ ((unused)); GET_LDOUBLE_WORDS64 (hxi, lxi, x); #ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN /* 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 & UINT64_C (0x7fff800000000000)) == UINT64_C (0x7fff800000000000)); #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). */ hxi ^= UINT64_C (0x0000800000000000); /* If lxi != 0, then set any suitable bit of the significand in hxi. */ hxi |= (lxi | -lxi) >> 63; /* We have to compare for greater (instead of greater or equal), because x's significand being all-zero designates infinity not NaN. */ return (hxi & UINT64_C (0x7fffffffffffffff)) > UINT64_C (0x7fff800000000000); #endif } libm_hidden_def (__issignalingl)