gcc/tree-hasher.h

   1 /* Hash Table Helper for Trees
   2    Copyright (C) 2012-2015 Free Software Foundation, Inc.
   3    Contributed by Lawrence Crowl <crowl@google.com>
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_TREE_HASHER_H
  22 #define GCC_TREE_HASHER_H 1
  23
  24 #include "hash-table.h"
  25
  26 struct int_tree_map {
  27   unsigned int uid;
  28   tree to;
  29 };
  30
  31 /* Hashtable helpers.  */
  32
  33 struct int_tree_hasher
  34 {
  35   typedef int_tree_map value_type;
  36   typedef int_tree_map compare_type;
  37   typedef int store_values_directly;
  38   static inline hashval_t hash (const value_type &);
  39   static inline bool equal (const value_type &, const compare_type &);
  40   static bool is_deleted (const value_type &v)
  41     {
  42       return v.to == reinterpret_cast<tree> (1);
  43     }
  44   static void mark_deleted (value_type &v) { v.to = reinterpret_cast<tree> (0x1); }
  45   static bool is_empty (const value_type &v) { return v.to == NULL; }
  46   static void mark_empty (value_type &v) { v.to = NULL; }
  47   static void remove (value_type &) {}
  48 };
  49
  50 /* Hash a UID in a int_tree_map.  */
  51
  52 inline hashval_t
  53 int_tree_hasher::hash (const value_type &item)
  54 {
  55   return item.uid;
  56 }
  57
  58 /* Return true if the uid in both int tree maps are equal.  */
  59
  60 inline bool
  61 int_tree_hasher::equal (const value_type &a, const compare_type &b)
  62 {
  63   return (a.uid == b.uid);
  64 }
  65
  66 typedef hash_table <int_tree_hasher> int_tree_htab_type;
  67
  68 #endif /* GCC_TREE_HASHER_H  */