From 8c8d74fe1e1433597dc6e450c5c9ebe38a323461 Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Mon, 18 Jan 2016 16:28:48 +0000
Subject: [PATCH] Fix C++98 std::signbit<long double>

	PR libstdc++/60637
	* include/c_global/cmath (signbit) [__cplusplus < 201103L]: Use
	__builtin_signbitf or __builtin_signbitl as appropriate.
	* testsuite/26_numerics/headers/cmath/60637.cc: New.

From-SVN: r232532
---
 libstdc++-v3/ChangeLog                        |  7 ++++
 libstdc++-v3/include/c_global/cmath           |  6 +++-
 .../26_numerics/headers/cmath/60637.cc        | 35 +++++++++++++++++++
 3 files changed, 47 insertions(+), 1 deletion(-)
 create mode 100644 libstdc++-v3/testsuite/26_numerics/headers/cmath/60637.cc

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index b9283e91445d..62450855d129 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,10 @@
+2016-01-18  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/60637
+	* include/c_global/cmath (signbit) [__cplusplus < 201103L]: Use
+	__builtin_signbitf or __builtin_signbitl as appropriate.
+	* testsuite/26_numerics/headers/cmath/60637.cc: New.
+
 2016-01-16  H.J. Lu  <hongjiu.lu@intel.com>
 
 	Backport from mainline
diff --git a/libstdc++-v3/include/c_global/cmath b/libstdc++-v3/include/c_global/cmath
index 4cafe5f7fe3a..d3fc8b7f39cf 100644
--- a/libstdc++-v3/include/c_global/cmath
+++ b/libstdc++-v3/include/c_global/cmath
@@ -880,7 +880,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     signbit(_Tp __f)
     {
       typedef typename __gnu_cxx::__promote<_Tp>::__type __type;
-      return __builtin_signbit(__type(__f));
+      return sizeof(__type) == sizeof(float)
+	? __builtin_signbitf(__type(__f))
+	: sizeof(__type) == sizeof(double)
+	? __builtin_signbit(__type(__f))
+	: __builtin_signbitl(__type(__f));
     }
 
   template<typename _Tp>
diff --git a/libstdc++-v3/testsuite/26_numerics/headers/cmath/60637.cc b/libstdc++-v3/testsuite/26_numerics/headers/cmath/60637.cc
new file mode 100644
index 000000000000..16a78963e6cb
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/headers/cmath/60637.cc
@@ -0,0 +1,35 @@
+// Copyright (C) 2016 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This 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 General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++98 -ffast-math" }
+// { dg-do run { target i?86-*-* x86_64-*-* } }
+
+#include <cmath>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  long double ld = -5.3165867831218916301793863361917824e-2467L;
+  VERIFY( std::signbit(ld) == 1 );
+}
+
+int
+main()
+{
+  test01();
+}