gcc/tree-ssa-alias.h

   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.  */
  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 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.  */
  63 typedef 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  */
  90 extern void ao_ref_init (ao_ref *, tree);
  91 extern void ao_ref_init_from_ptr_and_size (ao_ref *, tree, tree);
  92 extern tree ao_ref_base (ao_ref *);
  93 extern alias_set_type ao_ref_alias_set (ao_ref *);
  94 extern bool ptr_deref_may_alias_global_p (tree);
  95 extern bool refs_may_alias_p (tree, tree);
  96 extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool);
  97 extern bool refs_anti_dependent_p (tree, tree);
  98 extern bool refs_output_dependent_p (tree, tree);
  99 extern bool ref_maybe_used_by_stmt_p (gimple, tree);
 100 extern bool stmt_may_clobber_ref_p (gimple, tree);
 101 extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *);
 102 extern tree get_continuation_for_phi (gimple, ao_ref *, bitmap *);
 103 extern void *walk_non_aliased_vuses (ao_ref *, tree,
 104                                      void *(*)(ao_ref *, tree, void *),
 105                                      void *(*)(ao_ref *, tree, void *), void *);
 106 extern unsigned int walk_aliased_vdefs (ao_ref *, tree,
 107                                         bool (*)(ao_ref *, tree, void *),
 108                                         void *, bitmap *);
 109 extern struct ptr_info_def *get_ptr_info (tree);
 110 extern void dump_alias_info (FILE *);
 111 extern void debug_alias_info (void);
 112 extern void dump_points_to_solution (FILE *, struct pt_solution *);
 113 extern void dump_points_to_info_for (FILE *, tree);
 114 extern void debug_points_to_info_for (tree);
 115 extern void dump_alias_stats (FILE *);
 116
 117
 118 /* In tree-ssa-structalias.c  */
 119 extern unsigned int compute_may_aliases (void);
 120 extern void delete_alias_heapvars (void);
 121 extern bool pt_solution_includes_global (struct pt_solution *);
 122 extern bool pt_solution_includes (struct pt_solution *, const_tree);
 123 extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution *);
 124 extern bool pt_solutions_same_restrict_base (struct pt_solution *,
 125                                              struct pt_solution *);
 126 extern void pt_solution_reset (struct pt_solution *);
 127 extern void pt_solution_set (struct pt_solution *, bitmap);
 128 extern void dump_pta_stats (FILE *);
 129
 130
 131 #endif /* TREE_SSA_ALIAS_H  */