Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 47 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/ieee754/dbl-64/s_issignaling.c b/REORG.TODO/sysdeps/ieee754/dbl-64/s_issignaling.c
new file mode 100644
index 0000000000..09e12f9a6a
--- /dev/null
+++ b/REORG.TODO/sysdeps/ieee754/dbl-64/s_issignaling.c
@@ -0,0 +1,47 @@
+/* Test for signaling NaN.
+   Copyright (C) 2013-2017 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>
+#include <nan-high-order-bit.h>
+
+int
+__issignaling (double x)
+{
+#if 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)