gcc/tree-ssa-alias.h

   1 /* Tree based alias analysis and alias oracle.
   2    Copyright (C) 2008-2015 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.  */
  28 struct 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 vars bitmap includes a variable included in 'nonlocal'.  */
  52   unsigned int vars_contains_nonlocal : 1;
  53   /* Nonzero if the vars bitmap includes a variable included in 'escaped'.  */
  54   unsigned int vars_contains_escaped : 1;
  55   /* Nonzero if the vars bitmap includes a anonymous heap variable that
  56      escaped the function and thus became global.  */
  57   unsigned int vars_contains_escaped_heap : 1;
  58
  59   /* Set of variables that this pointer may point to.  */
  60   bitmap vars;
  61 };
  62
  63
  64 /* Simplified and cached information about a memory reference tree.
  65    Used by the alias-oracle internally and externally in alternate
  66    interfaces.  */
  67 struct ao_ref
  68 {
  69   /* The original full memory reference tree or NULL_TREE if that is
  70      not available.  */
  71   tree ref;
  72
  73   /* The following fields are the decomposed reference as returned
  74      by get_ref_base_and_extent.  */
  75   /* The base object of the memory reference or NULL_TREE if all of
  76      the following fields are not yet computed.  */
  77   tree base;
  78   /* The offset relative to the base.  */
  79   HOST_WIDE_INT offset;
  80   /* The size of the access.  */
  81   HOST_WIDE_INT size;
  82   /* The maximum possible extent of the access or -1 if unconstrained.  */
  83   HOST_WIDE_INT max_size;
  84
  85   /* The alias set of the access or -1 if not yet computed.  */
  86   alias_set_type ref_alias_set;
  87
  88   /* The alias set of the base object or -1 if not yet computed.  */
  89   alias_set_type base_alias_set;
  90
  91   /* Whether the memory is considered a volatile access.  */
  92   bool volatile_p;
  93 };
  94
  95
  96 /* In tree-ssa-alias.c  */
  97 extern void ao_ref_init (ao_ref *, tree);
  98 extern void ao_ref_init_from_ptr_and_size (ao_ref *, tree, tree);
  99 extern tree ao_ref_base (ao_ref *);
 100 extern alias_set_type ao_ref_alias_set (ao_ref *);
 101 extern alias_set_type ao_ref_base_alias_set (ao_ref *);
 102 extern bool ptr_deref_may_alias_global_p (tree);
 103 extern bool ptr_derefs_may_alias_p (tree, tree);
 104 extern bool ref_may_alias_global_p (tree);
 105 extern bool ref_may_alias_global_p (ao_ref *);
 106 extern bool refs_may_alias_p (tree, tree);
 107 extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool);
 108 extern bool refs_anti_dependent_p (tree, tree);
 109 extern bool refs_output_dependent_p (tree, tree);
 110 extern bool ref_maybe_used_by_stmt_p (gimple *, tree);
 111 extern bool ref_maybe_used_by_stmt_p (gimple *, ao_ref *);
 112 extern bool stmt_may_clobber_global_p (gimple *);
 113 extern bool stmt_may_clobber_ref_p (gimple *, tree);
 114 extern bool stmt_may_clobber_ref_p_1 (gimple *, ao_ref *);
 115 extern bool call_may_clobber_ref_p (gcall *, tree);
 116 extern bool call_may_clobber_ref_p_1 (gcall *, ao_ref *);
 117 extern bool stmt_kills_ref_p (gimple *, tree);
 118 extern bool stmt_kills_ref_p (gimple *, ao_ref *);
 119 extern tree get_continuation_for_phi (gimple *, ao_ref *,
 120                                       unsigned int *, bitmap *, bool,
 121                                       void *(*)(ao_ref *, tree, void *, bool *),
 122                                       void *);
 123 extern void *walk_non_aliased_vuses (ao_ref *, tree,
 124                                      void *(*)(ao_ref *, tree,
 125                                                unsigned int, void *),
 126                                      void *(*)(ao_ref *, tree, void *, bool *),
 127                                      tree (*)(tree),
 128                                      void *);
 129 extern unsigned int walk_aliased_vdefs (ao_ref *, tree,
 130                                         bool (*)(ao_ref *, tree, void *),
 131                                         void *, bitmap *,
 132                                         bool *function_entry_reached = NULL);
 133 extern void dump_alias_info (FILE *);
 134 extern void debug_alias_info (void);
 135 extern void dump_points_to_solution (FILE *, struct pt_solution *);
 136 extern void debug (pt_solution &ref);
 137 extern void debug (pt_solution *ptr);
 138 extern void dump_points_to_info_for (FILE *, tree);
 139 extern void debug_points_to_info_for (tree);
 140 extern void dump_alias_stats (FILE *);
 141
 142
 143 /* In tree-ssa-structalias.c  */
 144 extern unsigned int compute_may_aliases (void);
 145 extern bool pt_solution_empty_p (struct pt_solution *);
 146 extern bool pt_solution_singleton_p (struct pt_solution *, unsigned *);
 147 extern bool pt_solution_includes_global (struct pt_solution *);
 148 extern bool pt_solution_includes (struct pt_solution *, const_tree);
 149 extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution *);
 150 extern void pt_solution_reset (struct pt_solution *);
 151 extern void pt_solution_set (struct pt_solution *, bitmap, bool);
 152 extern void pt_solution_set_var (struct pt_solution *, tree);
 153
 154 extern void dump_pta_stats (FILE *);
 155
 156 extern GTY(()) struct pt_solution ipa_escaped_pt;
 157
 158 /* Return true, if the two ranges [POS1, SIZE1] and [POS2, SIZE2]
 159    overlap.  SIZE1 and/or SIZE2 can be (unsigned)-1 in which case the
 160    range is open-ended.  Otherwise return false.  */
 161
 162 static inline bool
 163 ranges_overlap_p (HOST_WIDE_INT pos1,
 164                   unsigned HOST_WIDE_INT size1,
 165                   HOST_WIDE_INT pos2,
 166                   unsigned HOST_WIDE_INT size2)
 167 {
 168   if (pos1 >= pos2
 169       && (size2 == (unsigned HOST_WIDE_INT)-1
 170           || pos1 < (pos2 + (HOST_WIDE_INT) size2)))
 171     return true;
 172   if (pos2 >= pos1
 173       && (size1 == (unsigned HOST_WIDE_INT)-1
 174           || pos2 < (pos1 + (HOST_WIDE_INT) size1)))
 175     return true;
 176
 177   return false;
 178 }
 179
 180
 181
 182 #endif /* TREE_SSA_ALIAS_H  */