gcc/tree-hash-traits.h

   1 /* Traits for hashing trees.
   2    Copyright (C) 2014-2015 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef tree_hash_traits_h
  21 #define tree_hash_traits_h
  22
  23 /* Hash for trees based on operand_equal_p.  */
  24 struct tree_operand_hash : ggc_ptr_hash <tree_node>
  25 {
  26   static inline hashval_t hash (const_tree);
  27   static inline bool equal_keys (const_tree, const_tree);
  28 };
  29
  30 inline hashval_t
  31 tree_operand_hash::hash (const_tree t)
  32 {
  33   return iterative_hash_expr (t, 0);
  34 }
  35
  36 inline bool
  37 tree_operand_hash::equal_keys (const_tree t1, const_tree t2)
  38 {
  39   return operand_equal_p (t1, t2, 0);
  40 }
  41
  42 /* Hasher for tree decls.  Pointer equality is enough here, but the DECL_UID
  43    is a better hash than the pointer value and gives a predictable traversal
  44    order.  */
  45 struct tree_decl_hash : ggc_ptr_hash <tree_node>
  46 {
  47   static inline hashval_t hash (tree);
  48 };
  49
  50 inline hashval_t
  51 tree_decl_hash::hash (tree t)
  52 {
  53   return DECL_UID (t);
  54 }
  55
  56 /* Hash for SSA_NAMEs in the same function.  Pointer equality is enough
  57    here, but the SSA_NAME_VERSION is a better hash than the pointer
  58    value and gives a predictable traversal order.  */
  59 struct tree_ssa_name_hash : ggc_ptr_hash <tree_node>
  60 {
  61   static inline hashval_t hash (tree);
  62 };
  63
  64 inline hashval_t
  65 tree_ssa_name_hash::hash (tree t)
  66 {
  67   return SSA_NAME_VERSION (t);
  68 }
  69
  70 /* Hasher for general trees, based on their TREE_HASH.  */
  71 struct tree_hash : ggc_ptr_hash <tree_node>
  72 {
  73   static hashval_t hash (tree);
  74 };
  75
  76 inline hashval_t
  77 tree_hash::hash (tree t)
  78 {
  79   return TREE_HASH (t);
  80 }
  81
  82 #endif