1/* Tree based alias analysis and alias oracle.
2   Copyright (C) 2008 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#include "coretypes.h"
25
26
27/* The points-to solution.
28
29   The points-to solution is a union of pt_vars and the abstract
30   sets specified by the flags.  */
31struct GTY(()) pt_solution
32{
33  /* Nonzero if points-to analysis couldn't determine where this pointer
34     is pointing to.  */
35  unsigned int anything : 1;
36
37  /* Nonzero if the points-to set includes any global memory.  Note that
38     even if this is zero pt_vars can still include global variables.  */
39  unsigned int nonlocal : 1;
40
41  /* Nonzero if the points-to set includes any escaped local variable.  */
42  unsigned int escaped : 1;
43
44  /* Nonzero if the points-to set includes 'nothing', the points-to set
45     includes memory at address NULL.  */
46  unsigned int null : 1;
47
48
49  /* Nonzero if the pt_vars bitmap includes a global variable.  */
50  unsigned int vars_contains_global : 1;
51
52  /* Nonzero if the pt_vars bitmap includes a restrict tag variable.  */
53  unsigned int vars_contains_restrict : 1;
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} ao_ref;
87
88
89/* In tree-ssa-alias.c  */
90extern void ao_ref_init (ao_ref *, tree);
91extern void ao_ref_init_from_ptr_and_size (ao_ref *, tree, tree);
92extern tree ao_ref_base (ao_ref *);
93extern alias_set_type ao_ref_alias_set (ao_ref *);
94extern bool ptr_deref_may_alias_global_p (tree);
95extern bool refs_may_alias_p (tree, tree);
96extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool);
97extern bool refs_anti_dependent_p (tree, tree);
98extern bool refs_output_dependent_p (tree, tree);
99extern bool ref_maybe_used_by_stmt_p (gimple, tree);
100extern bool stmt_may_clobber_ref_p (gimple, tree);
101extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *);
102extern tree get_continuation_for_phi (gimple, ao_ref *, bitmap *);
103extern void *walk_non_aliased_vuses (ao_ref *, tree,
104				     void *(*)(ao_ref *, tree, void *),
105				     void *(*)(ao_ref *, tree, void *), void *);
106extern unsigned int walk_aliased_vdefs (ao_ref *, tree,
107					bool (*)(ao_ref *, tree, void *),
108					void *, bitmap *);
109extern struct ptr_info_def *get_ptr_info (tree);
110extern void dump_alias_info (FILE *);
111extern void debug_alias_info (void);
112extern void dump_points_to_solution (FILE *, struct pt_solution *);
113extern void dump_points_to_info_for (FILE *, tree);
114extern void debug_points_to_info_for (tree);
115extern void dump_alias_stats (FILE *);
116
117
118/* In tree-ssa-structalias.c  */
119extern unsigned int compute_may_aliases (void);
120extern void delete_alias_heapvars (void);
121extern bool pt_solution_includes_global (struct pt_solution *);
122extern bool pt_solution_includes (struct pt_solution *, const_tree);
123extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution *);
124extern bool pt_solutions_same_restrict_base (struct pt_solution *,
125					     struct pt_solution *);
126extern void pt_solution_reset (struct pt_solution *);
127extern void pt_solution_set (struct pt_solution *, bitmap);
128extern void dump_pta_stats (FILE *);
129
130
131#endif /* TREE_SSA_ALIAS_H  */
132