xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/analyzer/state-purge.h (revision 4c3eb207d36f67d31994830c0a694161fc1ca39b)
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   bool add_node_annotations (graphviz_out *gv, const supernode &n, bool)
155     const FINAL OVERRIDE;
156 
157   void add_stmt_annotations (graphviz_out *gv, const gimple *stmt,
158 			     bool within_row)
159     const FINAL OVERRIDE;
160 
161 private:
162   const state_purge_map *m_map;
163 };
164 
165 } // namespace ana
166 
167 #endif /* GCC_ANALYZER_STATE_PURGE_H */
168