mingw/lib/gcc/mingw32/4.3.3/include/c++/ext/pb_ds/detail/resize_policy/hash_prime_size_policy_imp.hpp

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2005, 2006 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 2, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free
  22 // software library without restriction.  Specifically, if other files
  23 // instantiate templates or use macros or inline functions from this
  24 // file, or you compile this file and link it with other files to
  25 // produce an executable, this file does not by itself cause the
  26 // resulting executable to be covered by the GNU General Public
  27 // License.  This exception does not however invalidate any other
  28 // reasons why the executable file might be covered by the GNU General
  29 // Public License.
  30
  31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  32
  33 // Permission to use, copy, modify, sell, and distribute this software
  34 // is hereby granted without fee, provided that the above copyright
  35 // notice appears in all copies, and that both that copyright notice
  36 // and this permission notice appear in supporting documentation. None
  37 // of the above authors, nor IBM Haifa Research Laboratories, make any
  38 // representation about the suitability of this software for any
  39 // purpose. It is provided "as is" without express or implied
  40 // warranty.
  41
  42 /**
  43  * @file hash_prime_size_policy_imp.hpp
  44  * Contains a resize size policy implementation.
  45  */
  46
  47 #pragma GCC system_header
  48
  49 namespace detail
  50 {
  51   enum
  52     {
  53       num_distinct_sizes_32_bit = 30,
  54       num_distinct_sizes_64_bit = 62,
  55       num_distinct_sizes = sizeof(std::size_t) != 8 ?
  56             num_distinct_sizes_32_bit : num_distinct_sizes_64_bit,
  57     };
  58
  59   // Originally taken from the SGI implementation; acknowledged in the docs.
  60   // Further modified (for 64 bits) from tr1's hashtable.
  61   static const std::size_t g_a_sizes[num_distinct_sizes_64_bit] =
  62     {
  63       /* 0     */              5ul,
  64       /* 1     */              11ul,
  65       /* 2     */              23ul,
  66       /* 3     */              47ul,
  67       /* 4     */              97ul,
  68       /* 5     */              199ul,
  69       /* 6     */              409ul,
  70       /* 7     */              823ul,
  71       /* 8     */              1741ul,
  72       /* 9     */              3469ul,
  73       /* 10    */              6949ul,
  74       /* 11    */              14033ul,
  75       /* 12    */              28411ul,
  76       /* 13    */              57557ul,
  77       /* 14    */              116731ul,
  78       /* 15    */              236897ul,
  79       /* 16    */              480881ul,
  80       /* 17    */              976369ul,
  81       /* 18    */              1982627ul,
  82       /* 19    */              4026031ul,
  83       /* 20    */              8175383ul,
  84       /* 21    */              16601593ul,
  85       /* 22    */              33712729ul,
  86       /* 23    */              68460391ul,
  87       /* 24    */              139022417ul,
  88       /* 25    */              282312799ul,
  89       /* 26    */              573292817ul,
  90       /* 27    */              1164186217ul,
  91       /* 28    */              2364114217ul,
  92       /* 29    */              4294967291ul,
  93       /* 30    */ (std::size_t)8589934583ull,
  94       /* 31    */ (std::size_t)17179869143ull,
  95       /* 32    */ (std::size_t)34359738337ull,
  96       /* 33    */ (std::size_t)68719476731ull,
  97       /* 34    */ (std::size_t)137438953447ull,
  98       /* 35    */ (std::size_t)274877906899ull,
  99       /* 36    */ (std::size_t)549755813881ull,
 100       /* 37    */ (std::size_t)1099511627689ull,
 101       /* 38    */ (std::size_t)2199023255531ull,
 102       /* 39    */ (std::size_t)4398046511093ull,
 103       /* 40    */ (std::size_t)8796093022151ull,
 104       /* 41    */ (std::size_t)17592186044399ull,
 105       /* 42    */ (std::size_t)35184372088777ull,
 106       /* 43    */ (std::size_t)70368744177643ull,
 107       /* 44    */ (std::size_t)140737488355213ull,
 108       /* 45    */ (std::size_t)281474976710597ull,
 109       /* 46    */ (std::size_t)562949953421231ull,
 110       /* 47    */ (std::size_t)1125899906842597ull,
 111       /* 48    */ (std::size_t)2251799813685119ull,
 112       /* 49    */ (std::size_t)4503599627370449ull,
 113       /* 50    */ (std::size_t)9007199254740881ull,
 114       /* 51    */ (std::size_t)18014398509481951ull,
 115       /* 52    */ (std::size_t)36028797018963913ull,
 116       /* 53    */ (std::size_t)72057594037927931ull,
 117       /* 54    */ (std::size_t)144115188075855859ull,
 118       /* 55    */ (std::size_t)288230376151711717ull,
 119       /* 56    */ (std::size_t)576460752303423433ull,
 120       /* 57    */ (std::size_t)1152921504606846883ull,
 121       /* 58    */ (std::size_t)2305843009213693951ull,
 122       /* 59    */ (std::size_t)4611686018427387847ull,
 123       /* 60    */ (std::size_t)9223372036854775783ull,
 124       /* 61    */ (std::size_t)18446744073709551557ull,
 125     };
 126
 127 } // namespace detail
 128
 129 PB_DS_CLASS_T_DEC
 130 inline
 131 PB_DS_CLASS_C_DEC::
 132 hash_prime_size_policy(size_type n) : m_start_size(n)
 133 { m_start_size = get_nearest_larger_size(n); }
 134
 135 PB_DS_CLASS_T_DEC
 136 inline void
 137 PB_DS_CLASS_C_DEC::
 138 swap(PB_DS_CLASS_C_DEC& other)
 139 { std::swap(m_start_size, other.m_start_size); }
 140
 141 PB_DS_CLASS_T_DEC
 142 inline PB_DS_CLASS_C_DEC::size_type
 143 PB_DS_CLASS_C_DEC::
 144 get_nearest_larger_size(size_type n) const
 145 {
 146   const std::size_t* const p_upper = std::upper_bound(detail::g_a_sizes,
 147                      detail::g_a_sizes + detail::num_distinct_sizes, n);
 148
 149   if (p_upper == detail::g_a_sizes + detail::num_distinct_sizes)
 150     __throw_resize_error();
 151   return *p_upper;
 152 }
 153
 154 PB_DS_CLASS_T_DEC
 155 inline PB_DS_CLASS_C_DEC::size_type
 156 PB_DS_CLASS_C_DEC::
 157 get_nearest_smaller_size(size_type n) const
 158 {
 159   const size_t* p_lower = std::lower_bound(detail::g_a_sizes,
 160                        detail::g_a_sizes + detail::num_distinct_sizes, n);
 161
 162   if (*p_lower >= n &&  p_lower != detail::g_a_sizes)
 163     --p_lower;
 164   if (*p_lower < m_start_size)
 165     return m_start_size;
 166   return *p_lower;
 167 }