tree-ssa-alias.h revision 1.1.1.2 
1/* Tree based alias analysis and alias oracle.
2   Copyright (C) 2008-2013 Free Software Foundation, Inc.
3   Contributed by Richard Guenther  <rguenther@suse.de>
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_ALIAS_H
22#define TREE_SSA_ALIAS_H
23
24/* The points-to solution.
25
26   The points-to solution is a union of pt_vars and the abstract
27   sets specified by the flags.  */
28struct GTY(()) pt_solution
29{
30  /* Nonzero if points-to analysis couldn't determine where this pointer
31     is pointing to.  */
32  unsigned int anything : 1;
33
34  /* Nonzero if the points-to set includes any global memory.  Note that
35     even if this is zero pt_vars can still include global variables.  */
36  unsigned int nonlocal : 1;
37
38  /* Nonzero if the points-to set includes the local escaped solution by
39     reference.  */
40  unsigned int escaped : 1;
41
42  /* Nonzero if the points-to set includes the IPA escaped solution by
43     reference.  */
44  unsigned int ipa_escaped : 1;
45
46  /* Nonzero if the points-to set includes 'nothing', the points-to set
47     includes memory at address NULL.  */
48  unsigned int null : 1;
49
50
51  /* Nonzero if the pt_vars bitmap includes a global variable.  */
52  unsigned int vars_contains_global : 1;
53
54
55  /* Set of variables that this pointer may point to.  */
56  bitmap vars;
57};
58
59
60/* Simplified and cached information about a memory reference tree.
61   Used by the alias-oracle internally and externally in alternate
62   interfaces.  */
63typedef struct ao_ref_s
64{
65  /* The original full memory reference tree or NULL_TREE if that is
66     not available.  */
67  tree ref;
68
69  /* The following fields are the decomposed reference as returned
70     by get_ref_base_and_extent.  */
71  /* The base object of the memory reference or NULL_TREE if all of
72     the following fields are not yet computed.  */
73  tree base;
74  /* The offset relative to the base.  */
75  HOST_WIDE_INT offset;
76  /* The size of the access.  */
77  HOST_WIDE_INT size;
78  /* The maximum possible extent of the access or -1 if unconstrained.  */
79  HOST_WIDE_INT max_size;
80
81  /* The alias set of the access or -1 if not yet computed.  */
82  alias_set_type ref_alias_set;
83
84  /* The alias set of the base object or -1 if not yet computed.  */
85  alias_set_type base_alias_set;
86
87  /* Whether the memory is considered a volatile access.  */
88  bool volatile_p;
89} ao_ref;
90
91
92/* In tree-ssa-alias.c  */
93extern void ao_ref_init (ao_ref *, tree);
94extern void ao_ref_init_from_ptr_and_size (ao_ref *, tree, tree);
95extern tree ao_ref_base (ao_ref *);
96extern alias_set_type ao_ref_alias_set (ao_ref *);
97extern bool ptr_deref_may_alias_global_p (tree);
98extern bool ptr_derefs_may_alias_p (tree, tree);
99extern bool ref_may_alias_global_p (tree);
100extern bool refs_may_alias_p (tree, tree);
101extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool);
102extern bool refs_anti_dependent_p (tree, tree);
103extern bool refs_output_dependent_p (tree, tree);
104extern bool ref_maybe_used_by_stmt_p (gimple, tree);
105extern bool stmt_may_clobber_global_p (gimple);
106extern bool stmt_may_clobber_ref_p (gimple, tree);
107extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *);
108extern bool call_may_clobber_ref_p (gimple, tree);
109extern bool stmt_kills_ref_p (gimple, tree);
110extern tree get_continuation_for_phi (gimple, ao_ref *,
111				      unsigned int *, bitmap *, bool);
112extern void *walk_non_aliased_vuses (ao_ref *, tree,
113				     void *(*)(ao_ref *, tree,
114					       unsigned int, void *),
115				     void *(*)(ao_ref *, tree, void *), void *);
116extern unsigned int walk_aliased_vdefs (ao_ref *, tree,
117					bool (*)(ao_ref *, tree, void *),
118					void *, bitmap *);
119extern struct ptr_info_def *get_ptr_info (tree);
120extern void dump_alias_info (FILE *);
121extern void debug_alias_info (void);
122extern void dump_points_to_solution (FILE *, struct pt_solution *);
123extern void dump_points_to_info_for (FILE *, tree);
124extern void debug_points_to_info_for (tree);
125extern void dump_alias_stats (FILE *);
126
127
128/* In tree-ssa-structalias.c  */
129extern unsigned int compute_may_aliases (void);
130extern bool pt_solution_empty_p (struct pt_solution *);
131extern bool pt_solution_singleton_p (struct pt_solution *, unsigned *);
132extern bool pt_solution_includes_global (struct pt_solution *);
133extern bool pt_solution_includes (struct pt_solution *, const_tree);
134extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution *);
135extern void pt_solution_reset (struct pt_solution *);
136extern void pt_solution_set (struct pt_solution *, bitmap, bool);
137extern void pt_solution_set_var (struct pt_solution *, tree);
138
139extern void dump_pta_stats (FILE *);
140
141extern GTY(()) struct pt_solution ipa_escaped_pt;
142
143
144#endif /* TREE_SSA_ALIAS_H  */
145