gcc/tree-hasher.h

   1 /* Hash Table Helper for Trees
   2    Copyright (C) 2012-2020 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 struct int_tree_map {
  25   unsigned int uid;
  26   tree to;
  27 };
  28
  29 /* Hashtable helpers.  */
  30
  31 struct int_tree_hasher
  32 {
  33   typedef int_tree_map value_type;
  34   typedef int_tree_map compare_type;
  35   static inline hashval_t hash (const value_type &);
  36   static inline bool equal (const value_type &, const compare_type &);
  37   static bool is_deleted (const value_type &v)
  38     {
  39       return v.to == reinterpret_cast<tree> (1);
  40     }
  41   static void mark_deleted (value_type &v) { v.to = reinterpret_cast<tree> (0x1); }
  42   static bool is_empty (const value_type &v) { return v.to == NULL; }
  43   static const bool empty_zero_p = true;
  44   static void mark_empty (value_type &v) { v.to = NULL; }
  45   static void remove (value_type &) {}
  46 };
  47
  48 /* Hash a UID in a int_tree_map.  */
  49
  50 inline hashval_t
  51 int_tree_hasher::hash (const value_type &item)
  52 {
  53   return item.uid;
  54 }
  55
  56 /* Return true if the uid in both int tree maps are equal.  */
  57
  58 inline bool
  59 int_tree_hasher::equal (const value_type &a, const compare_type &b)
  60 {
  61   return (a.uid == b.uid);
  62 }
  63
  64 typedef hash_table <int_tree_hasher> int_tree_htab_type;
  65
  66 #endif /* GCC_TREE_HASHER_H  */