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diff --git a/sysdeps/ieee754/ldbl-96/s_issignalingl.c b/sysdeps/ieee754/ldbl-96/s_issignalingl.c
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+/* Test for signaling NaN.
+ Copyright (C) 2013 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)
+{
+ u_int32_t exi, hxi, lxi;
+ GET_LDOUBLE_WORDS (exi, hxi, lxi, x);
+#ifdef HIGH_ORDER_BIT_IS_SET_FOR_SNAN
+# error not implemented
+#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 ^= 0x40000000;
+ /* If lxi != 0, then set any suitable bit of the significand in hxi. */
+ hxi |= (lxi | -lxi) >> 31;
+ /* We do not recognize a pseudo NaN as sNaN; they're invalid on 80387 and
+ later. */
+ /* We have to compare for greater (instead of greater or equal), because x's
+ significand being all-zero designates infinity not NaN. */
+ return ((exi & 0x7fff) == 0x7fff) && (hxi > 0xc0000000);
+#endif
+}
+libm_hidden_def (__issignalingl)