1 /* Tree based alias analysis and alias oracle. 2 Copyright (C) 2008-2018 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 /* Nonzero if the vars bitmap includes a variable included in 'nonlocal'. */ 51 unsigned int vars_contains_nonlocal : 1; 52 /* Nonzero if the vars bitmap includes a variable included in 'escaped'. */ 53 unsigned int vars_contains_escaped : 1; 54 /* Nonzero if the vars bitmap includes a anonymous heap variable that 55 escaped the function and thus became global. */ 56 unsigned int vars_contains_escaped_heap : 1; 57 /* Nonzero if the vars bitmap includes a anonymous variable used to 58 represent storage pointed to by a restrict qualified pointer. */ 59 unsigned int vars_contains_restrict : 1; 60 /* Nonzero if the vars bitmap includes an interposable variable. */ 61 unsigned int vars_contains_interposable : 1; 62 63 /* Set of variables that this pointer may point to. */ 64 bitmap vars; 65 }; 66 67 68 /* Simplified and cached information about a memory reference tree. 69 Used by the alias-oracle internally and externally in alternate 70 interfaces. */ 71 struct ao_ref 72 { 73 /* The original full memory reference tree or NULL_TREE if that is 74 not available. */ 75 tree ref; 76 77 /* The following fields are the decomposed reference as returned 78 by get_ref_base_and_extent. */ 79 /* The base object of the memory reference or NULL_TREE if all of 80 the following fields are not yet computed. */ 81 tree base; 82 /* The offset relative to the base. */ 83 poly_int64 offset; 84 /* The size of the access. */ 85 poly_int64 size; 86 /* The maximum possible extent of the access or -1 if unconstrained. */ 87 poly_int64 max_size; 88 89 /* The alias set of the access or -1 if not yet computed. */ 90 alias_set_type ref_alias_set; 91 92 /* The alias set of the base object or -1 if not yet computed. */ 93 alias_set_type base_alias_set; 94 95 /* Whether the memory is considered a volatile access. */ 96 bool volatile_p; 97 98 bool max_size_known_p () const; 99 }; 100 101 /* Return true if the maximum size is known, rather than the special -1 102 marker. */ 103 104 inline bool 105 ao_ref::max_size_known_p () const 106 { 107 return known_size_p (max_size); 108 } 109 110 /* In tree-ssa-alias.c */ 111 extern void ao_ref_init (ao_ref *, tree); 112 extern void ao_ref_init_from_ptr_and_size (ao_ref *, tree, tree); 113 extern tree ao_ref_base (ao_ref *); 114 extern alias_set_type ao_ref_alias_set (ao_ref *); 115 extern alias_set_type ao_ref_base_alias_set (ao_ref *); 116 extern bool ptr_deref_may_alias_global_p (tree); 117 extern bool ptr_derefs_may_alias_p (tree, tree); 118 extern bool ptrs_compare_unequal (tree, tree); 119 extern bool ref_may_alias_global_p (tree); 120 extern bool ref_may_alias_global_p (ao_ref *); 121 extern bool refs_may_alias_p (tree, tree); 122 extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool); 123 extern bool refs_anti_dependent_p (tree, tree); 124 extern bool refs_output_dependent_p (tree, tree); 125 extern bool ref_maybe_used_by_stmt_p (gimple *, tree); 126 extern bool ref_maybe_used_by_stmt_p (gimple *, ao_ref *); 127 extern bool stmt_may_clobber_global_p (gimple *); 128 extern bool stmt_may_clobber_ref_p (gimple *, tree); 129 extern bool stmt_may_clobber_ref_p_1 (gimple *, ao_ref *); 130 extern bool call_may_clobber_ref_p (gcall *, tree); 131 extern bool call_may_clobber_ref_p_1 (gcall *, ao_ref *); 132 extern bool stmt_kills_ref_p (gimple *, tree); 133 extern bool stmt_kills_ref_p (gimple *, ao_ref *); 134 extern tree get_continuation_for_phi (gimple *, ao_ref *, 135 unsigned int *, bitmap *, bool, 136 void *(*)(ao_ref *, tree, void *, bool *), 137 void *); 138 extern void *walk_non_aliased_vuses (ao_ref *, tree, 139 void *(*)(ao_ref *, tree, 140 unsigned int, void *), 141 void *(*)(ao_ref *, tree, void *, bool *), 142 tree (*)(tree), 143 void *); 144 extern int walk_aliased_vdefs (ao_ref *, tree, 145 bool (*)(ao_ref *, tree, void *), 146 void *, bitmap *, 147 bool *function_entry_reached = NULL, 148 unsigned int limit = 0); 149 extern void dump_alias_info (FILE *); 150 extern void debug_alias_info (void); 151 extern void dump_points_to_solution (FILE *, struct pt_solution *); 152 extern void debug (pt_solution &ref); 153 extern void debug (pt_solution *ptr); 154 extern void dump_points_to_info_for (FILE *, tree); 155 extern void debug_points_to_info_for (tree); 156 extern void dump_alias_stats (FILE *); 157 158 159 /* In tree-ssa-structalias.c */ 160 extern unsigned int compute_may_aliases (void); 161 extern bool pt_solution_empty_p (struct pt_solution *); 162 extern bool pt_solution_singleton_or_null_p (struct pt_solution *, unsigned *); 163 extern bool pt_solution_includes_global (struct pt_solution *); 164 extern bool pt_solution_includes (struct pt_solution *, const_tree); 165 extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution *); 166 extern void pt_solution_reset (struct pt_solution *); 167 extern void pt_solution_set (struct pt_solution *, bitmap, bool); 168 extern void pt_solution_set_var (struct pt_solution *, tree); 169 170 extern void dump_pta_stats (FILE *); 171 172 extern GTY(()) struct pt_solution ipa_escaped_pt; 173 174 /* Return true, if the two ranges [POS1, SIZE1] and [POS2, SIZE2] 175 overlap. SIZE1 and/or SIZE2 can be (unsigned)-1 in which case the 176 range is open-ended. Otherwise return false. */ 177 178 static inline bool 179 ranges_overlap_p (HOST_WIDE_INT pos1, 180 unsigned HOST_WIDE_INT size1, 181 HOST_WIDE_INT pos2, 182 unsigned HOST_WIDE_INT size2) 183 { 184 if (size1 == 0 || size2 == 0) 185 return false; 186 if (pos1 >= pos2 187 && (size2 == (unsigned HOST_WIDE_INT)-1 188 || pos1 < (pos2 + (HOST_WIDE_INT) size2))) 189 return true; 190 if (pos2 >= pos1 191 && (size1 == (unsigned HOST_WIDE_INT)-1 192 || pos2 < (pos1 + (HOST_WIDE_INT) size1))) 193 return true; 194 195 return false; 196 } 197 198 199 200 #endif /* TREE_SSA_ALIAS_H */ 201