text: /* Tree based alias analysis and alias oracle.
     Copyright (C) 2008-2014 Free Software Foundation, Inc.
     Contributed by Richard Guenther  <rguenther@suse.de>
  
     This file is part of GCC.
  
     GCC is free software; you can redistribute it and/or modify
     under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 3 of the License, or
     (at your option) any later version.
  
     GCC is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with GCC; see the file COPYING3.  If not see
     <http://www.gnu.org/licenses/>.  */
  
  #ifndef TREE_SSA_ALIAS_H
  #define TREE_SSA_ALIAS_H
  
  /* The points-to solution.
  
     The points-to solution is a union of pt_vars and the abstract
     sets specified by the flags.  */
  struct GTY(()) pt_solution
  {
    /* Nonzero if points-to analysis couldn't determine where this pointer
       is pointing to.  */
    unsigned int anything : 1;
  
    /* Nonzero if the points-to set includes any global memory.  Note that
       even if this is zero pt_vars can still include global variables.  */
    unsigned int nonlocal : 1;
  
    /* Nonzero if the points-to set includes the local escaped solution by
       reference.  */
    unsigned int escaped : 1;
  
    /* Nonzero if the points-to set includes the IPA escaped solution by
       reference.  */
    unsigned int ipa_escaped : 1;
  
    /* Nonzero if the points-to set includes 'nothing', the points-to set
       includes memory at address NULL.  */
    unsigned int null : 1;
  
  
    /* Nonzero if the vars bitmap includes a variable included in 'nonlocal'.  */
    unsigned int vars_contains_nonlocal : 1;
    /* Nonzero if the vars bitmap includes a variable included in 'escaped'.  */
    unsigned int vars_contains_escaped : 1;
    /* Nonzero if the vars bitmap includes a anonymous heap variable that
       escaped the function and thus became global.  */
    unsigned int vars_contains_escaped_heap : 1;
  
    /* Set of variables that this pointer may point to.  */
    bitmap vars;
  };
  
  
  /* Simplified and cached information about a memory reference tree.
     Used by the alias-oracle internally and externally in alternate
     interfaces.  */
  struct ao_ref
  {
    /* The original full memory reference tree or NULL_TREE if that is
       not available.  */
    tree ref;
  
    /* The following fields are the decomposed reference as returned
       by get_ref_base_and_extent.  */
    /* The base object of the memory reference or NULL_TREE if all of
       the following fields are not yet computed.  */
    tree base;
    /* The offset relative to the base.  */
    HOST_WIDE_INT offset;
    /* The size of the access.  */
    HOST_WIDE_INT size;
    /* The maximum possible extent of the access or -1 if unconstrained.  */
    HOST_WIDE_INT max_size;
  
    /* The alias set of the access or -1 if not yet computed.  */
    alias_set_type ref_alias_set;
  
    /* The alias set of the base object or -1 if not yet computed.  */
    alias_set_type base_alias_set;
  
    /* Whether the memory is considered a volatile access.  */
    bool volatile_p;
  };
  
  
  /* In tree-ssa-alias.c  */
  extern void ao_ref_init (ao_ref *, tree);
  extern void ao_ref_init_from_ptr_and_size (ao_ref *, tree, tree);
  extern tree ao_ref_base (ao_ref *);
  extern alias_set_type ao_ref_alias_set (ao_ref *);
  extern bool ptr_deref_may_alias_global_p (tree);
  extern bool ptr_derefs_may_alias_p (tree, tree);
  extern bool ref_may_alias_global_p (tree);
  extern bool refs_may_alias_p (tree, tree);
  extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool);
  extern bool refs_anti_dependent_p (tree, tree);
  extern bool refs_output_dependent_p (tree, tree);
  extern bool ref_maybe_used_by_stmt_p (gimple, tree);
  extern bool stmt_may_clobber_global_p (gimple);
  extern bool stmt_may_clobber_ref_p (gimple, tree);
  extern bool stmt_may_clobber_ref_p_1 (gimple, ao_ref *);
  extern bool call_may_clobber_ref_p (gimple, tree);
  extern bool stmt_kills_ref_p (gimple, tree);
  extern tree get_continuation_for_phi (gimple, ao_ref *,
  				      unsigned int *, bitmap *, bool);
  extern void *walk_non_aliased_vuses (ao_ref *, tree,
  				     void *(*)(ao_ref *, tree,
  					       unsigned int, void *),
  				     void *(*)(ao_ref *, tree, void *), void *);
  extern unsigned int walk_aliased_vdefs (ao_ref *, tree,
  					bool (*)(ao_ref *, tree, void *),
  					void *, bitmap *);
  extern void dump_alias_info (FILE *);
  extern void debug_alias_info (void);
  extern void dump_points_to_solution (FILE *, struct pt_solution *);
  extern void debug (pt_solution &ref);
  extern void debug (pt_solution *ptr);
  extern void dump_points_to_info_for (FILE *, tree);
  extern void debug_points_to_info_for (tree);
  extern void dump_alias_stats (FILE *);
  
  
  /* In tree-ssa-structalias.c  */
  extern unsigned int compute_may_aliases (void);
  extern bool pt_solution_empty_p (struct pt_solution *);
  extern bool pt_solution_singleton_p (struct pt_solution *, unsigned *);
  extern bool pt_solution_includes_global (struct pt_solution *);
  extern bool pt_solution_includes (struct pt_solution *, const_tree);
  extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution *);
  extern void pt_solution_reset (struct pt_solution *);
  extern void pt_solution_set (struct pt_solution *, bitmap, bool);
  extern void pt_solution_set_var (struct pt_solution *, tree);
  
  extern void dump_pta_stats (FILE *);
  
  extern GTY(()) struct pt_solution ipa_escaped_pt;
  
  /* Return true, if the two ranges [POS1, SIZE1] and [POS2, SIZE2]
     overlap.  SIZE1 and/or SIZE2 can be (unsigned)-1 in which case the
     range is open-ended.  Otherwise return false.  */
  
  static inline bool
  ranges_overlap_p (HOST_WIDE_INT pos1,
  		  unsigned HOST_WIDE_INT size1,
  		  HOST_WIDE_INT pos2,
  		  unsigned HOST_WIDE_INT size2)
  {
    if (pos1 >= pos2
        && (size2 == (unsigned HOST_WIDE_INT)-1
  	  || pos1 < (pos2 + (HOST_WIDE_INT) size2)))
      return true;
    if (pos2 >= pos1
        && (size1 == (unsigned HOST_WIDE_INT)-1
  	  || pos2 < (pos1 + (HOST_WIDE_INT) size1)))
      return true;
  
    return false;
  }
  
  
  
  #endif /* TREE_SSA_ALIAS_H  */
  