1/* Data structures and function declarations for the SSA value propagation
2   engine.
3   Copyright (C) 2004-2015 Free Software Foundation, Inc.
4   Contributed by Diego Novillo <dnovillo@redhat.com>
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 3, or (at your option)
11any later version.
12
13GCC is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3.  If not see
20<http://www.gnu.org/licenses/>.  */
21
22#ifndef _TREE_SSA_PROPAGATE_H
23#define _TREE_SSA_PROPAGATE_H 1
24
25/* If SIM_P is true, statement S will be simulated again.  */
26
27static inline void
28prop_set_simulate_again (gimple s, bool visit_p)
29{
30  gimple_set_visited (s, visit_p);
31}
32
33/* Return true if statement T should be simulated again.  */
34
35static inline bool
36prop_simulate_again_p (gimple s)
37{
38  return gimple_visited_p (s);
39}
40
41/* Lattice values used for propagation purposes.  Specific instances
42   of a propagation engine must return these values from the statement
43   and PHI visit functions to direct the engine.  */
44enum ssa_prop_result {
45    /* The statement produces nothing of interest.  No edges will be
46       added to the work lists.  */
47    SSA_PROP_NOT_INTERESTING,
48
49    /* The statement produces an interesting value.  The set SSA_NAMEs
50       returned by SSA_PROP_VISIT_STMT should be added to
51       INTERESTING_SSA_EDGES.  If the statement being visited is a
52       conditional jump, SSA_PROP_VISIT_STMT should indicate which edge
53       out of the basic block should be marked executable.  */
54    SSA_PROP_INTERESTING,
55
56    /* The statement produces a varying (i.e., useless) value and
57       should not be simulated again.  If the statement being visited
58       is a conditional jump, all the edges coming out of the block
59       will be considered executable.  */
60    SSA_PROP_VARYING
61};
62
63
64/* Call-back functions used by the value propagation engine.  */
65typedef enum ssa_prop_result (*ssa_prop_visit_stmt_fn) (gimple, edge *, tree *);
66typedef enum ssa_prop_result (*ssa_prop_visit_phi_fn) (gphi *);
67typedef bool (*ssa_prop_fold_stmt_fn) (gimple_stmt_iterator *gsi);
68typedef tree (*ssa_prop_get_value_fn) (tree);
69
70
71extern bool valid_gimple_rhs_p (tree);
72extern void move_ssa_defining_stmt_for_defs (gimple, gimple);
73extern bool update_gimple_call (gimple_stmt_iterator *, tree, int, ...);
74extern bool update_call_from_tree (gimple_stmt_iterator *, tree);
75extern void ssa_propagate (ssa_prop_visit_stmt_fn, ssa_prop_visit_phi_fn);
76extern bool stmt_makes_single_store (gimple);
77extern bool substitute_and_fold (ssa_prop_get_value_fn, ssa_prop_fold_stmt_fn,
78				 bool);
79extern bool may_propagate_copy (tree, tree);
80extern bool may_propagate_copy_into_stmt (gimple, tree);
81extern bool may_propagate_copy_into_asm (tree);
82extern void propagate_value (use_operand_p, tree);
83extern void replace_exp (use_operand_p, tree);
84extern void propagate_tree_value (tree *, tree);
85extern void propagate_tree_value_into_stmt (gimple_stmt_iterator *, tree);
86
87#endif /* _TREE_SSA_PROPAGATE_H  */
88