hashtable_policy.h (_Prime_rehash_policy): Use __builtin_floor rather than __builtin_ceil to compute next resize value.

2011-07-24  François Dumont  <francois.cppdevs@free.fr>

        * include/bits/hashtable_policy.h (_Prime_rehash_policy): Use
        __builtin_floor rather than __builtin_ceil to compute next resize
        value.
        * testsuite/23_containers/unordered_set/hash_policy/load_factor.cc:
        New.

From-SVN: r176717

1 files changed, 58 insertions, 0 deletions

diff --git a/libstdc++-v3/testsuite/23_containers/unordered_set/hash_policy/load_factor.cc b/libstdc++-v3/testsuite/23_containers/unordered_set/hash_policy/load_factor.cc
new file mode 100644
index 0000000..818274a
--- /dev/null
+++ b/libstdc++-v3/testsuite/23_containers/unordered_set/hash_policy/load_factor.cc
@@ -0,0 +1,58 @@
+// Copyright (C) 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.
+//
+// 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++0x" }
+
+#include <unordered_set>
+#include <testsuite_hooks.h>
+
+void test01()
+{
+  bool test __attribute__((unused)) = true;
+  {
+    std::unordered_set<int> us;
+    for (int i = 0; i != 100000; ++i)
+    {
+      us.insert(i);
+      VERIFY( us.load_factor() <= us.max_load_factor() );
+    }
+  }
+  {
+    std::unordered_set<int> us;
+    us.max_load_factor(3.f);
+    for (int i = 0; i != 100000; ++i)
+    {
+      us.insert(i);
+      VERIFY( us.load_factor() <= us.max_load_factor() );
+    }
+  }
+  {
+    std::unordered_set<int> us;
+    us.max_load_factor(.3f);
+    for (int i = 0; i != 100000; ++i)
+    {
+      us.insert(i);
+      VERIFY( us.load_factor() <= us.max_load_factor() );
+    }
+  }
+}
+
+int main()
+{
+  test01();
+  return 0;
+}