gcc/tree-ssa-alias.h

   1 /* Tree based alias analysis and alias oracle.
   2    Copyright (C) 2008-2014 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 bool ptr_deref_may_alias_global_p (tree);
 102 extern bool ptr_derefs_may_alias_p (tree, tree);
 103 extern bool ref_may_alias_global_p (tree);
 104 extern bool refs_may_alias_p (tree, tree);
 105 extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool);
 106 extern bool refs_anti_dependent_p (tree, tree);
 107 extern bool refs_output_dependent_p (tree, tree);
 108 extern bool ref_maybe_used_by_stmt_p (gimple, tree);
 109 extern bool stmt_may_clobber_global_p (gimple);
 110 extern bool stmt_may_clobber_ref_p (gimple, tree);
 111 extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *);
 112 extern bool call_may_clobber_ref_p (gimple, tree);
 113 extern bool call_may_clobber_ref_p_1 (gimple, ao_ref *);
 114 extern bool stmt_kills_ref_p (gimple, tree);
 115 extern tree get_continuation_for_phi (gimple, ao_ref *,
 116                                       unsigned int *, bitmap *, bool,
 117                                       void *(*)(ao_ref *, tree, void *, bool),
 118                                       void *);
 119 extern void *walk_non_aliased_vuses (ao_ref *, tree,
 120                                      void *(*)(ao_ref *, tree,
 121                                                unsigned int, void *),
 122                                      void *(*)(ao_ref *, tree, void *, bool),
 123                                      void *);
 124 extern unsigned int walk_aliased_vdefs (ao_ref *, tree,
 125                                         bool (*)(ao_ref *, tree, void *),
 126                                         void *, bitmap *,
 127                                         bool *function_entry_reached = NULL);
 128 extern void dump_alias_info (FILE *);
 129 extern void debug_alias_info (void);
 130 extern void dump_points_to_solution (FILE *, struct pt_solution *);
 131 extern void debug (pt_solution &ref);
 132 extern void debug (pt_solution *ptr);
 133 extern void dump_points_to_info_for (FILE *, tree);
 134 extern void debug_points_to_info_for (tree);
 135 extern void dump_alias_stats (FILE *);
 136
 137
 138 /* In tree-ssa-structalias.c  */
 139 extern unsigned int compute_may_aliases (void);
 140 extern bool pt_solution_empty_p (struct pt_solution *);
 141 extern bool pt_solution_singleton_p (struct pt_solution *, unsigned *);
 142 extern bool pt_solution_includes_global (struct pt_solution *);
 143 extern bool pt_solution_includes (struct pt_solution *, const_tree);
 144 extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution *);
 145 extern void pt_solution_reset (struct pt_solution *);
 146 extern void pt_solution_set (struct pt_solution *, bitmap, bool);
 147 extern void pt_solution_set_var (struct pt_solution *, tree);
 148
 149 extern void dump_pta_stats (FILE *);
 150
 151 extern GTY(()) struct pt_solution ipa_escaped_pt;
 152
 153 /* Return true, if the two ranges [POS1, SIZE1] and [POS2, SIZE2]
 154    overlap.  SIZE1 and/or SIZE2 can be (unsigned)-1 in which case the
 155    range is open-ended.  Otherwise return false.  */
 156
 157 static inline bool
 158 ranges_overlap_p (HOST_WIDE_INT pos1,
 159                   unsigned HOST_WIDE_INT size1,
 160                   HOST_WIDE_INT pos2,
 161                   unsigned HOST_WIDE_INT size2)
 162 {
 163   if (pos1 >= pos2
 164       && (size2 == (unsigned HOST_WIDE_INT)-1
 165           || pos1 < (pos2 + (HOST_WIDE_INT) size2)))
 166     return true;
 167   if (pos2 >= pos1
 168       && (size1 == (unsigned HOST_WIDE_INT)-1
 169           || pos2 < (pos1 + (HOST_WIDE_INT) size1)))
 170     return true;
 171
 172   return false;
 173 }
 174
 175
 176
 177 #endif /* TREE_SSA_ALIAS_H  */