gcc/tree-ssa-sccvn.h

   1 /* Tree SCC value numbering
   2    Copyright (C) 2007 Free Software Foundation, Inc.
   3    Contributed by Daniel Berlin <dberlin@dberlin.org>
   4
   5    This file is part of GCC.
   6
   7    GCC is free software; you can redistribute it and/or modify
   8    under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) 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 TREE_SSA_SCCVN_H
  22 #define TREE_SSA_SCCVN_H
  23
  24 /* TOP of the VN lattice.  */
  25 extern tree VN_TOP;
  26
  27 typedef struct vn_ssa_aux
  28 {
  29   /* Value number. This may be an SSA name or a constant.  */
  30   tree valnum;
  31   /* Representative expression, if not a direct constant. */
  32   tree expr;
  33
  34   /* SCC information.  */
  35   unsigned int dfsnum;
  36   unsigned int low;
  37   unsigned visited : 1;
  38   unsigned on_sccstack : 1;
  39
  40   /* Whether the representative expression contains constants.  */
  41   unsigned has_constants : 1;
  42   /* Whether the SSA_NAME has been value numbered already.  This is
  43      only saying whether visit_use has been called on it at least
  44      once.  It cannot be used to avoid visitation for SSA_NAME's
  45      involved in non-singleton SCC's.  */
  46   unsigned use_processed : 1;
  47
  48   /* Whether the SSA_NAME has no defining statement and thus an
  49      insertion of such with EXPR as definition is required before
  50      a use can be created of it.  */
  51   unsigned needs_insertion : 1;
  52 } *vn_ssa_aux_t;
  53
  54 /* Return the value numbering info for an SSA_NAME.  */
  55 extern vn_ssa_aux_t VN_INFO (tree);
  56 extern vn_ssa_aux_t VN_INFO_GET (tree);
  57 bool run_scc_vn (bool);
  58 void free_scc_vn (void);
  59 void switch_to_PRE_table (void);
  60 tree vn_nary_op_lookup (tree);
  61 void vn_nary_op_insert (tree, tree);
  62 tree vn_reference_lookup (tree, VEC (tree, gc) *, bool);
  63 void vn_reference_insert (tree, tree, VEC (tree, gc) *);
  64 VEC (tree, gc) *shared_vuses_from_stmt (tree);
  65 VEC (tree, gc) *copy_vuses_from_stmt (tree);
  66
  67
  68 #endif /* TREE_SSA_SCCVN_H  */