gcc/tree-ssa-propagate.h

   1 /* Data structures and function declarations for the SSA value propagation
   2    engine.
   3    Copyright (C) 2004, 2005, 2007, 2008, 2010, 2011
   4    Free Software Foundation, Inc.
   5    Contributed by Diego Novillo <dnovillo@redhat.com>
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 3, or (at your option)
  12 any later version.
  13
  14 GCC is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 #ifndef _TREE_SSA_PROPAGATE_H
  24 #define _TREE_SSA_PROPAGATE_H 1
  25
  26 /* If SIM_P is true, statement S will be simulated again.  */
  27
  28 static inline void
  29 prop_set_simulate_again (gimple s, bool visit_p)
  30 {
  31   gimple_set_visited (s, visit_p);
  32 }
  33
  34 /* Return true if statement T should be simulated again.  */
  35
  36 static inline bool
  37 prop_simulate_again_p (gimple s)
  38 {
  39   return gimple_visited_p (s);
  40 }
  41
  42 /* Lattice values used for propagation purposes.  Specific instances
  43    of a propagation engine must return these values from the statement
  44    and PHI visit functions to direct the engine.  */
  45 enum ssa_prop_result {
  46     /* The statement produces nothing of interest.  No edges will be
  47        added to the work lists.  */
  48     SSA_PROP_NOT_INTERESTING,
  49
  50     /* The statement produces an interesting value.  The set SSA_NAMEs
  51        returned by SSA_PROP_VISIT_STMT should be added to
  52        INTERESTING_SSA_EDGES.  If the statement being visited is a
  53        conditional jump, SSA_PROP_VISIT_STMT should indicate which edge
  54        out of the basic block should be marked executable.  */
  55     SSA_PROP_INTERESTING,
  56
  57     /* The statement produces a varying (i.e., useless) value and
  58        should not be simulated again.  If the statement being visited
  59        is a conditional jump, all the edges coming out of the block
  60        will be considered executable.  */
  61     SSA_PROP_VARYING
  62 };
  63
  64
  65 /* Call-back functions used by the value propagation engine.  */
  66 typedef enum ssa_prop_result (*ssa_prop_visit_stmt_fn) (gimple, edge *, tree *);
  67 typedef enum ssa_prop_result (*ssa_prop_visit_phi_fn) (gimple);
  68 typedef bool (*ssa_prop_fold_stmt_fn) (gimple_stmt_iterator *gsi);
  69 typedef tree (*ssa_prop_get_value_fn) (tree);
  70
  71
  72 /* In tree-ssa-propagate.c  */
  73 void ssa_propagate (ssa_prop_visit_stmt_fn, ssa_prop_visit_phi_fn);
  74 bool valid_gimple_rhs_p (tree);
  75 void move_ssa_defining_stmt_for_defs (gimple, gimple);
  76 bool update_gimple_call (gimple_stmt_iterator *, tree, int, ...);
  77 bool update_call_from_tree (gimple_stmt_iterator *, tree);
  78 bool stmt_makes_single_store (gimple);
  79 bool substitute_and_fold (ssa_prop_get_value_fn, ssa_prop_fold_stmt_fn, bool);
  80
  81 #endif /* _TREE_SSA_PROPAGATE_H  */