gcc/analyzer/state-purge.h

   1 /* Classes for purging state at function_points.
   2    Copyright (C) 2019-2020 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 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 *> map_t;
  81   typedef map_t::iterator iterator;
  82
  83   state_purge_map (const supergraph &sg, logger *logger);
  84   ~state_purge_map ();
  85
  86   const state_purge_per_ssa_name &get_data_for_ssa_name (tree name) const
  87   {
  88     gcc_assert (TREE_CODE (name) == SSA_NAME);
  89     if (tree var = SSA_NAME_VAR (name))
  90       if (TREE_CODE (var) == VAR_DECL)
  91         gcc_assert (!VAR_DECL_IS_VIRTUAL_OPERAND (var));
  92
  93     state_purge_per_ssa_name **slot
  94       = const_cast <map_t&> (m_map).get (name);
  95     return **slot;
  96   }
  97
  98   const supergraph &get_sg () const { return m_sg; }
  99
 100   iterator begin () const { return m_map.begin (); }
 101   iterator end () const { return m_map.end (); }
 102
 103 private:
 104   DISABLE_COPY_AND_ASSIGN (state_purge_map);
 105
 106   const supergraph &m_sg;
 107   map_t m_map;
 108 };
 109
 110 /* The part of a state_purge_map relating to a specific SSA name.
 111
 112    The result of analyzing a given SSA name, recording which
 113    function_points need to retain state information about it to handle
 114    their successor states, so that we can simplify program_state objects,
 115    in the hope of reducing state-blowup.  */
 116
 117 class state_purge_per_ssa_name
 118 {
 119 public:
 120   state_purge_per_ssa_name (const state_purge_map &map,
 121                             tree name,
 122                             function *fun);
 123
 124   bool needed_at_point_p (const function_point &point) const;
 125
 126   function *get_function () const { return m_fun; }
 127
 128 private:
 129   static function_point before_use_stmt (const state_purge_map &map,
 130                                          const gimple *use_stmt);
 131
 132   void add_to_worklist (const function_point &point,
 133                         auto_vec<function_point> *worklist,
 134                         logger *logger);
 135
 136   void process_point (const function_point &point,
 137                       auto_vec<function_point> *worklist,
 138                       const state_purge_map &map);
 139
 140   typedef hash_set<function_point> point_set_t;
 141   point_set_t m_points_needing_name;
 142   tree m_name;
 143   function *m_fun;
 144 };
 145
 146 /* Subclass of dot_annotator for use by -fdump-analyzer-state-purge.
 147    Annotate the .dot output with state-purge information.  */
 148
 149 class state_purge_annotator : public dot_annotator
 150 {
 151 public:
 152   state_purge_annotator (const state_purge_map *map) : m_map (map) {}
 153
 154   void add_node_annotations (graphviz_out *gv, const supernode &n)
 155     const FINAL OVERRIDE;
 156
 157   void add_stmt_annotations (graphviz_out *gv, const gimple *stmt)
 158     const FINAL OVERRIDE;
 159
 160 private:
 161   const state_purge_map *m_map;
 162 };
 163
 164 } // namespace ana
 165
 166 #endif /* GCC_ANALYZER_STATE_PURGE_H */