gcc/analyzer/state-purge.h

   1 /* Classes for purging state at function_points.
   2    Copyright (C) 2019-2024 Free Software Foundation, Inc.
   3    Contributed by David Malcolm <dmalcolm@redhat.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it
   8 under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 3, or (at your option)
  10 any later version.
  11
  12 GCC is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 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 GCC_ANALYZER_STATE_PURGE_H
  22 #define GCC_ANALYZER_STATE_PURGE_H
  23
  24 /* Hash traits for function_point.  */
  25
  26 template <> struct default_hash_traits<function_point>
  27 : public pod_hash_traits<function_point>
  28 {
  29   static const bool empty_zero_p = false;
  30 };
  31
  32 template <>
  33 inline hashval_t
  34 pod_hash_traits<function_point>::hash (value_type v)
  35 {
  36   return v.hash ();
  37 }
  38
  39 template <>
  40 inline bool
  41 pod_hash_traits<function_point>::equal (const value_type &existing,
  42                                  const value_type &candidate)
  43 {
  44   return existing == candidate;
  45 }
  46 template <>
  47 inline void
  48 pod_hash_traits<function_point>::mark_deleted (value_type &v)
  49 {
  50   v = function_point::deleted ();
  51 }
  52 template <>
  53 inline void
  54 pod_hash_traits<function_point>::mark_empty (value_type &v)
  55 {
  56   v = function_point::empty ();
  57 }
  58 template <>
  59 inline bool
  60 pod_hash_traits<function_point>::is_deleted (value_type v)
  61 {
  62   return v.get_kind () == PK_DELETED;
  63 }
  64 template <>
  65 inline bool
  66 pod_hash_traits<function_point>::is_empty (value_type v)
  67 {
  68   return v.get_kind () == PK_EMPTY;
  69 }
  70
  71 namespace ana {
  72
  73 /* The result of analyzing which decls and SSA names can be purged from state at
  74    different points in the program, so that we can simplify program_state
  75    objects, in the hope of reducing state-blowup.  */
  76
  77 class state_purge_map : public log_user
  78 {
  79 public:
  80   typedef ordered_hash_map<tree, state_purge_per_ssa_name *> ssa_map_t;
  81   typedef ssa_map_t::iterator ssa_iterator;
  82
  83   typedef ordered_hash_map<tree, state_purge_per_decl *> decl_map_t;
  84   typedef decl_map_t::iterator decl_iterator;
  85
  86   state_purge_map (const supergraph &sg,
  87                    region_model_manager *mgr,
  88                    logger *logger);
  89   ~state_purge_map ();
  90
  91   const state_purge_per_ssa_name &get_data_for_ssa_name (tree name) const
  92   {
  93     gcc_assert (TREE_CODE (name) == SSA_NAME);
  94     if (tree var = SSA_NAME_VAR (name))
  95       if (TREE_CODE (var) == VAR_DECL)
  96         gcc_assert (!VAR_DECL_IS_VIRTUAL_OPERAND (var));
  97
  98     state_purge_per_ssa_name **slot
  99       = const_cast <ssa_map_t&> (m_ssa_map).get (name);
 100     return **slot;
 101   }
 102
 103   const state_purge_per_decl *get_any_data_for_decl (tree decl) const
 104   {
 105     gcc_assert (TREE_CODE (decl) == VAR_DECL
 106                 || TREE_CODE (decl) == PARM_DECL
 107                 || TREE_CODE (decl) == RESULT_DECL);
 108     if (state_purge_per_decl **slot
 109         = const_cast <decl_map_t&> (m_decl_map).get (decl))
 110       return *slot;
 111     else
 112       return NULL;
 113   }
 114
 115   state_purge_per_decl &
 116   get_or_create_data_for_decl (const function &fun, tree decl);
 117
 118   const supergraph &get_sg () const { return m_sg; }
 119
 120   ssa_iterator begin_ssas () const { return m_ssa_map.begin (); }
 121   ssa_iterator end_ssas () const { return m_ssa_map.end (); }
 122
 123   decl_iterator begin_decls () const { return m_decl_map.begin (); }
 124   decl_iterator end_decls () const { return m_decl_map.end (); }
 125
 126 private:
 127   DISABLE_COPY_AND_ASSIGN (state_purge_map);
 128
 129   const supergraph &m_sg;
 130   ssa_map_t m_ssa_map;
 131   decl_map_t m_decl_map;
 132 };
 133
 134   /* Base class for state_purge_per_ssa_name and state_purge_per_decl.  */
 135
 136 class state_purge_per_tree
 137 {
 138 public:
 139   const function &get_function () const { return m_fun; }
 140   tree get_fndecl () const { return m_fun.decl; }
 141
 142 protected:
 143   typedef hash_set<function_point> point_set_t;
 144
 145   state_purge_per_tree (const function &fun)
 146   : m_fun (fun)
 147   {
 148   }
 149
 150 private:
 151   const function &m_fun;
 152 };
 153
 154 /* The part of a state_purge_map relating to a specific SSA name.
 155
 156    The result of analyzing a given SSA name, recording which
 157    function_points need to retain state information about it to handle
 158    their successor states, so that we can simplify program_state objects,
 159    in the hope of reducing state-blowup.  */
 160
 161 class state_purge_per_ssa_name : public state_purge_per_tree
 162 {
 163 public:
 164   state_purge_per_ssa_name (const state_purge_map &map,
 165                             tree name,
 166                             const function &fun);
 167
 168   bool needed_at_point_p (const function_point &point) const;
 169
 170 private:
 171   static function_point before_use_stmt (const state_purge_map &map,
 172                                          const gimple *use_stmt);
 173
 174   void add_to_worklist (const function_point &point,
 175                         auto_vec<function_point> *worklist,
 176                         logger *logger);
 177
 178   void process_point (const function_point &point,
 179                       auto_vec<function_point> *worklist,
 180                       const state_purge_map &map);
 181
 182   point_set_t m_points_needing_name;
 183   tree m_name;
 184 };
 185
 186 /* The part of a state_purge_map relating to a specific decl.
 187
 188    Analogous to state_purge_per_ssa_name, but for local decls.
 189
 190    This is more involved than the SSA name case, because we also need
 191    to handle pointers and components.  */
 192
 193 class state_purge_per_decl : public state_purge_per_tree
 194 {
 195 public:
 196   state_purge_per_decl (const state_purge_map &map,
 197                         tree decl,
 198                         const function &fun);
 199
 200   bool needed_at_point_p (const function_point &point) const;
 201
 202   void add_needed_at (const function_point &point);
 203   void add_pointed_to_at (const function_point &point);
 204   void process_worklists (const state_purge_map &map,
 205                           region_model_manager *mgr);
 206
 207 private:
 208   static function_point before_use_stmt (const state_purge_map &map,
 209                                          const gimple *use_stmt);
 210
 211   void add_to_worklist (const function_point &point,
 212                         auto_vec<function_point> *worklist,
 213                         point_set_t *seen,
 214                         logger *logger);
 215
 216   void process_point_backwards (const function_point &point,
 217                                 auto_vec<function_point> *worklist,
 218                                 point_set_t *seen,
 219                                 const state_purge_map &map,
 220                                 const region_model &model);
 221   void process_point_forwards (const function_point &point,
 222                                auto_vec<function_point> *worklist,
 223                                point_set_t *seen,
 224                                const state_purge_map &map);
 225
 226   point_set_t m_points_needing_decl;
 227   point_set_t m_points_taking_address;
 228   tree m_decl;
 229 };
 230
 231 /* Subclass of dot_annotator for use by -fdump-analyzer-state-purge.
 232    Annotate the .dot output with state-purge information.  */
 233
 234 class state_purge_annotator : public dot_annotator
 235 {
 236 public:
 237   state_purge_annotator (const state_purge_map *map) : m_map (map) {}
 238
 239   bool add_node_annotations (graphviz_out *gv, const supernode &n, bool)
 240     const final override;
 241
 242   void add_stmt_annotations (graphviz_out *gv, const gimple *stmt,
 243                              bool within_row)
 244     const final override;
 245
 246 private:
 247   void print_needed (graphviz_out *gv,
 248                      const function_point &point,
 249                      bool within_table) const;
 250
 251   const state_purge_map *m_map;
 252 };
 253
 254 } // namespace ana
 255
 256 #endif /* GCC_ANALYZER_STATE_PURGE_H */