1 files changed, 56 insertions, 0 deletions
diff --git a/libstdc++-v3/src/hash-long-double-tr1-aux.cc b/libstdc++-v3/src/hash-long-double-tr1-aux.cc
new file mode 100644
index 00000000000..70ed45bbfbe
--- /dev/null
+++ b/libstdc++-v3/src/hash-long-double-tr1-aux.cc
@@ -0,0 +1,56 @@
+// std::tr1::hash definitions, long double bits -*- C++ -*-
+
+// Copyright (C) 2010, 2011 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.
+
+// Under Section 7 of GPL version 3, you are granted additional
+// permissions described in the GCC Runtime Library Exception, version
+// 3.1, as published by the Free Software Foundation.
+
+// You should have received a copy of the GNU General Public License and
+// a copy of the GCC Runtime Library Exception along with this program;
+// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+  namespace tr1 
+  {
+    // For long double, careful with random padding bits (e.g., on x86,
+    // 10 bytes -> 12 bytes) and resort to frexp.
+    template<>
+      size_t
+      hash<long double>::operator()(long double __val) const
+      {
+	// 0 and -0 both hash to zero.
+	if (__val == 0.0L)
+	  return 0;
+
+	int __exponent;
+	__val = __builtin_frexpl(__val, &__exponent);
+	__val = __val < 0.0l ? -(__val + 0.5l) : __val;
+
+	const long double __mult = __SIZE_MAX__ + 1.0l;
+	__val *= __mult;
+
+	// Try to use all the bits of the mantissa (really necessary only
+	// on 32-bit targets, at least for 80-bit floating point formats).
+	const size_t __hibits = (size_t)__val;
+	__val = (__val - (long double)__hibits) * __mult;
+
+	const size_t __coeff = __SIZE_MAX__ / __LDBL_MAX_EXP__;
+
+	return __hibits + (size_t)__val + __coeff * __exponent;
+      }
+  }
+}