1/* Tree based alias analysis and alias oracle. 2 Copyright (C) 2008-2022 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. */ 28struct 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. */ 71class ao_ref 72{ 73public: 74 /* The original full memory reference tree or NULL_TREE if that is 75 not available. */ 76 tree ref; 77 78 /* The following fields are the decomposed reference as returned 79 by get_ref_base_and_extent. */ 80 /* The base object of the memory reference or NULL_TREE if all of 81 the following fields are not yet computed. */ 82 tree base; 83 /* The offset relative to the base. */ 84 poly_int64 offset; 85 /* The size of the access. */ 86 poly_int64 size; 87 /* The maximum possible extent of the access or -1 if unconstrained. */ 88 poly_int64 max_size; 89 90 /* The alias set of the access or -1 if not yet computed. */ 91 alias_set_type ref_alias_set; 92 93 /* The alias set of the base object or -1 if not yet computed. */ 94 alias_set_type base_alias_set; 95 96 /* Whether the memory is considered a volatile access. */ 97 bool volatile_p; 98 99 bool max_size_known_p () const; 100}; 101 102/* Return true if the maximum size is known, rather than the special -1 103 marker. */ 104 105inline bool 106ao_ref::max_size_known_p () const 107{ 108 return known_size_p (max_size); 109} 110 111/* In tree-ssa-alias.cc */ 112extern void ao_ref_init (ao_ref *, tree); 113extern void ao_ref_init_from_ptr_and_size (ao_ref *, tree, tree); 114extern void ao_ref_init_from_ptr_and_range (ao_ref *, tree, bool, 115 poly_int64, poly_int64, 116 poly_int64); 117extern tree ao_ref_base (ao_ref *); 118extern alias_set_type ao_ref_alias_set (ao_ref *); 119extern alias_set_type ao_ref_base_alias_set (ao_ref *); 120extern tree ao_ref_alias_ptr_type (ao_ref *); 121extern tree ao_ref_base_alias_ptr_type (ao_ref *); 122extern bool ao_ref_alignment (ao_ref *, unsigned int *, 123 unsigned HOST_WIDE_INT *); 124extern bool ptr_deref_may_alias_global_p (tree, bool); 125extern bool ptr_derefs_may_alias_p (tree, tree); 126extern bool ptrs_compare_unequal (tree, tree); 127extern bool ref_may_alias_global_p (tree, bool); 128extern bool ref_may_alias_global_p (ao_ref *, bool); 129extern bool refs_may_alias_p (tree, tree, bool = true); 130extern bool refs_may_alias_p_1 (ao_ref *, ao_ref *, bool); 131extern bool refs_anti_dependent_p (tree, tree); 132extern bool refs_output_dependent_p (tree, tree); 133extern bool ref_maybe_used_by_stmt_p (gimple *, tree, bool = true); 134extern bool ref_maybe_used_by_stmt_p (gimple *, ao_ref *, bool = true); 135extern bool stmt_may_clobber_global_p (gimple *, bool); 136extern bool stmt_may_clobber_ref_p (gimple *, tree, bool = true); 137extern bool stmt_may_clobber_ref_p_1 (gimple *, ao_ref *, bool = true); 138extern bool call_may_clobber_ref_p (gcall *, tree, bool = true); 139extern bool call_may_clobber_ref_p_1 (gcall *, ao_ref *, bool = true); 140extern bool stmt_kills_ref_p (gimple *, tree); 141extern bool stmt_kills_ref_p (gimple *, ao_ref *); 142enum translate_flags 143 { TR_TRANSLATE, TR_VALUEIZE_AND_DISAMBIGUATE, TR_DISAMBIGUATE }; 144extern tree get_continuation_for_phi (gimple *, ao_ref *, bool, 145 unsigned int &, bitmap *, bool, 146 void *(*)(ao_ref *, tree, void *, 147 translate_flags *), 148 void *, translate_flags 149 = TR_VALUEIZE_AND_DISAMBIGUATE); 150extern void *walk_non_aliased_vuses (ao_ref *, tree, bool, 151 void *(*)(ao_ref *, tree, void *), 152 void *(*)(ao_ref *, tree, void *, 153 translate_flags *), 154 tree (*)(tree), unsigned &, void *); 155extern int walk_aliased_vdefs (ao_ref *, tree, 156 bool (*)(ao_ref *, tree, void *), 157 void *, bitmap *, 158 bool *function_entry_reached = NULL, 159 unsigned int limit = 0); 160extern void dump_alias_info (FILE *); 161extern void debug_alias_info (void); 162extern void dump_points_to_solution (FILE *, struct pt_solution *); 163extern void debug (pt_solution &ref); 164extern void debug (pt_solution *ptr); 165extern void dump_points_to_info_for (FILE *, tree); 166extern void debug_points_to_info_for (tree); 167extern void dump_alias_stats (FILE *); 168 169 170/* In tree-ssa-structalias.cc */ 171extern unsigned int compute_may_aliases (void); 172extern bool pt_solution_empty_p (const pt_solution *); 173extern bool pt_solution_singleton_or_null_p (struct pt_solution *, unsigned *); 174extern bool pt_solution_includes_global (struct pt_solution *, bool); 175extern bool pt_solution_includes (struct pt_solution *, const_tree); 176extern bool pt_solutions_intersect (struct pt_solution *, struct pt_solution *); 177extern void pt_solution_reset (struct pt_solution *); 178extern void pt_solution_set (struct pt_solution *, bitmap, bool); 179extern void pt_solution_set_var (struct pt_solution *, tree); 180 181extern void dump_pta_stats (FILE *); 182 183extern GTY(()) struct pt_solution ipa_escaped_pt; 184 185/* Return true, if the two ranges [POS1, SIZE1] and [POS2, SIZE2] 186 overlap. SIZE1 and/or SIZE2 can be (unsigned)-1 in which case the 187 range is open-ended. Otherwise return false. */ 188 189static inline bool 190ranges_overlap_p (HOST_WIDE_INT pos1, 191 unsigned HOST_WIDE_INT size1, 192 HOST_WIDE_INT pos2, 193 unsigned HOST_WIDE_INT size2) 194{ 195 if (size1 == 0 || size2 == 0) 196 return false; 197 if (pos1 >= pos2 198 && (size2 == (unsigned HOST_WIDE_INT)-1 199 || pos1 < (pos2 + (HOST_WIDE_INT) size2))) 200 return true; 201 if (pos2 >= pos1 202 && (size1 == (unsigned HOST_WIDE_INT)-1 203 || pos2 < (pos1 + (HOST_WIDE_INT) size1))) 204 return true; 205 206 return false; 207} 208 209 210 211#endif /* TREE_SSA_ALIAS_H */ 212