GCC Middle and Back End API Reference
alias.h
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1 /* Exported functions from alias.c
2  Copyright (C) 2004-2013 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10 
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15 
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19 
20 #ifndef GCC_ALIAS_H
21 #define GCC_ALIAS_H
22 
23 /* The type of an alias set. Code currently assumes that variables of
24  this type can take the values 0 (the alias set which aliases
25  everything) and -1 (sometimes indicating that the alias set is
26  unknown, sometimes indicating a memory barrier) and -2 (indicating
27  that the alias set should be set to a unique value but has not been
28  set yet). */
29 typedef int alias_set_type;
30 
31 extern alias_set_type new_alias_set (void);
32 extern alias_set_type get_alias_set (tree);
33 extern alias_set_type get_deref_alias_set (tree);
34 extern alias_set_type get_varargs_alias_set (void);
35 extern alias_set_type get_frame_alias_set (void);
36 extern bool component_uses_parent_alias_set (const_tree);
37 extern bool alias_set_subset_of (alias_set_type, alias_set_type);
38 extern void record_alias_subset (alias_set_type, alias_set_type);
39 extern void record_component_aliases (tree);
40 extern int alias_sets_conflict_p (alias_set_type, alias_set_type);
41 extern int alias_sets_must_conflict_p (alias_set_type, alias_set_type);
42 extern int objects_must_conflict_p (tree, tree);
43 extern int nonoverlapping_memrefs_p (const_rtx, const_rtx, bool);
44 
45 /* This alias set can be used to force a memory to conflict with all
46  other memories, creating a barrier across which no memory reference
47  can move. Note that there are other legacy ways to create such
48  memory barriers, including an address of SCRATCH. */
49 #define ALIAS_SET_MEMORY_BARRIER ((alias_set_type) -1)
50 
51 #endif /* GCC_ALIAS_H */