gcc/tree-ssa-alias.h

   1 /* Tree based alias analysis and alias oracle.
   2    Copyright (C) 2008, 2010 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.  */
  31 struct 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 the local escaped solution by
  42      reference.  */
  43   unsigned int escaped : 1;
  44
  45   /* Nonzero if the points-to set includes the IPA escaped solution by
  46      reference.  */
  47   unsigned int ipa_escaped : 1;
  48
  49   /* Nonzero if the points-to set includes 'nothing', the points-to set
  50      includes memory at address NULL.  */
  51   unsigned int null : 1;
  52
  53
  54   /* Nonzero if the pt_vars bitmap includes a global variable.  */
  55   unsigned int vars_contains_global : 1;
  56
  57   /* Nonzero if the pt_vars bitmap includes a restrict tag variable.  */
  58   unsigned int vars_contains_restrict : 1;
  59
  60   /* Set of variables that this pointer may point to.  */
  61   bitmap vars;
  62 };
  63
  64
  65 /* Simplified and cached information about a memory reference tree.
  66    Used by the alias-oracle internally and externally in alternate
  67    interfaces.  */
  68 typedef struct ao_ref_s
  69 {
  70   /* The original full memory reference tree or NULL_TREE if that is
  71      not available.  */
  72   tree ref;
  73
  74   /* The following fields are the decomposed reference as returned
  75      by get_ref_base_and_extent.  */
  76   /* The base object of the memory reference or NULL_TREE if all of
  77      the following fields are not yet computed.  */
  78   tree base;
  79   /* The offset relative to the base.  */
  80   HOST_WIDE_INT offset;
  81   /* The size of the access.  */
  82   HOST_WIDE_INT size;
  83   /* The maximum possible extent of the access or -1 if unconstrained.  */
  84   HOST_WIDE_INT max_size;
  85
  86   /* The alias set of the access or -1 if not yet computed.  */
  87   alias_set_type ref_alias_set;
  88
  89   /* The alias set of the base object or -1 if not yet computed.  */
  90   alias_set_type base_alias_set;
  91 } ao_ref;
  92
  93
  94 /* In tree-ssa-alias.c  */
  95 extern void ao_ref_init (ao_ref *, tree);
  96 extern void ao_ref_init_from_ptr_and_size (ao_ref *, tree, tree);
  97 extern tree ao_ref_base (ao_ref *);
  98 extern alias_set_type ao_ref_alias_set (ao_ref *);
  99 extern bool ptr_deref_may_alias_global_p (tree);
 100 extern bool ptr_derefs_may_alias_p (tree, tree);
 101 extern bool refs_may_alias_p (tree, tree);
 102 extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool);
 103 extern bool refs_anti_dependent_p (tree, tree);
 104 extern bool refs_output_dependent_p (tree, tree);
 105 extern bool ref_maybe_used_by_stmt_p (gimple, tree);
 106 extern bool stmt_may_clobber_ref_p (gimple, tree);
 107 extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *);
 108 extern bool call_may_clobber_ref_p (gimple, tree);
 109 extern bool stmt_kills_ref_p (gimple, tree);
 110 extern tree get_continuation_for_phi (gimple, ao_ref *, bitmap *);
 111 extern void *walk_non_aliased_vuses (ao_ref *, tree,
 112                                      void *(*)(ao_ref *, tree, void *),
 113                                      void *(*)(ao_ref *, tree, void *), void *);
 114 extern unsigned int walk_aliased_vdefs (ao_ref *, tree,
 115                                         bool (*)(ao_ref *, tree, void *),
 116                                         void *, bitmap *);
 117 extern struct ptr_info_def *get_ptr_info (tree);
 118 extern void dump_alias_info (FILE *);
 119 extern void debug_alias_info (void);
 120 extern void dump_points_to_solution (FILE *, struct pt_solution *);
 121 extern void dump_points_to_info_for (FILE *, tree);
 122 extern void debug_points_to_info_for (tree);
 123 extern void dump_alias_stats (FILE *);
 124
 125
 126 /* In tree-ssa-structalias.c  */
 127 extern unsigned int compute_may_aliases (void);
 128 extern bool pt_solution_empty_p (struct pt_solution *);
 129 extern bool pt_solution_includes_global (struct pt_solution *);
 130 extern bool pt_solution_includes (struct pt_solution *, const_tree);
 131 extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution *);
 132 extern bool pt_solutions_same_restrict_base (struct pt_solution *,
 133                                              struct pt_solution *);
 134 extern void pt_solution_reset (struct pt_solution *);
 135 extern void pt_solution_set (struct pt_solution *, bitmap, bool, bool);
 136 extern void pt_solution_set_var (struct pt_solution *, tree);
 137
 138 extern void dump_pta_stats (FILE *);
 139
 140 extern GTY(()) struct pt_solution ipa_escaped_pt;
 141
 142
 143 #endif /* TREE_SSA_ALIAS_H  */