1 /* Classes for purging state at function_points.
2 Copyright (C) 2019-2023 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 &get_or_create_data_for_decl (function *fun, tree decl);
116
117 const supergraph &get_sg () const { return m_sg; }
118
119 ssa_iterator begin_ssas () const { return m_ssa_map.begin (); }
120 ssa_iterator end_ssas () const { return m_ssa_map.end (); }
121
122 decl_iterator begin_decls () const { return m_decl_map.begin (); }
123 decl_iterator end_decls () const { return m_decl_map.end (); }
124
125 private:
126 DISABLE_COPY_AND_ASSIGN (state_purge_map);
127
128 const supergraph &m_sg;
129 ssa_map_t m_ssa_map;
130 decl_map_t m_decl_map;
131 };
132
133 /* Base class for state_purge_per_ssa_name and state_purge_per_decl. */
134
135 class state_purge_per_tree
136 {
137 public:
138 function *get_function () const { return m_fun; }
139 tree get_fndecl () const { return m_fun->decl; }
140
141 protected:
142 typedef hash_set<function_point> point_set_t;
143
144 state_purge_per_tree (function *fun)
145 : m_fun (fun)
146 {
147 }
148
149 private:
150 function *m_fun;
151 };
152
153 /* The part of a state_purge_map relating to a specific SSA name.
154
155 The result of analyzing a given SSA name, recording which
156 function_points need to retain state information about it to handle
157 their successor states, so that we can simplify program_state objects,
158 in the hope of reducing state-blowup. */
159
160 class state_purge_per_ssa_name : public state_purge_per_tree
161 {
162 public:
163 state_purge_per_ssa_name (const state_purge_map &map,
164 tree name,
165 function *fun);
166
167 bool needed_at_point_p (const function_point &point) const;
168
169 private:
170 static function_point before_use_stmt (const state_purge_map &map,
171 const gimple *use_stmt);
172
173 void add_to_worklist (const function_point &point,
174 auto_vec<function_point> *worklist,
175 logger *logger);
176
177 void process_point (const function_point &point,
178 auto_vec<function_point> *worklist,
179 const state_purge_map &map);
180
181 point_set_t m_points_needing_name;
182 tree m_name;
183 };
184
185 /* The part of a state_purge_map relating to a specific decl.
186
187 Analogous to state_purge_per_ssa_name, but for local decls.
188
189 This is more involved than the SSA name case, because we also need
190 to handle pointers and components. */
191
192 class state_purge_per_decl : public state_purge_per_tree
193 {
194 public:
195 state_purge_per_decl (const state_purge_map &map,
196 tree decl,
197 function *fun);
198
199 bool needed_at_point_p (const function_point &point) const;
200
201 void add_needed_at (const function_point &point);
202 void add_pointed_to_at (const function_point &point);
203 void process_worklists (const state_purge_map &map,
204 region_model_manager *mgr);
205
206 private:
207 static function_point before_use_stmt (const state_purge_map &map,
208 const gimple *use_stmt);
209
210 void add_to_worklist (const function_point &point,
211 auto_vec<function_point> *worklist,
212 point_set_t *seen,
213 logger *logger);
214
215 void process_point_backwards (const function_point &point,
216 auto_vec<function_point> *worklist,
217 point_set_t *seen,
218 const state_purge_map &map,
219 const region_model &model);
220 void process_point_forwards (const function_point &point,
221 auto_vec<function_point> *worklist,
222 point_set_t *seen,
223 const state_purge_map &map);
224
225 point_set_t m_points_needing_decl;
226 point_set_t m_points_taking_address;
227 tree m_decl;
228 };
229
230 /* Subclass of dot_annotator for use by -fdump-analyzer-state-purge.
231 Annotate the .dot output with state-purge information. */
232
233 class state_purge_annotator : public dot_annotator
234 {
235 public:
236 state_purge_annotator (const state_purge_map *map) : m_map (map) {}
237
238 bool add_node_annotations (graphviz_out *gv, const supernode &n, bool)
239 const final override;
240
241 void add_stmt_annotations (graphviz_out *gv, const gimple *stmt,
242 bool within_row)
243 const final override;
244
245 private:
246 void print_needed (graphviz_out *gv,
247 const function_point &point,
248 bool within_table) const;
249
250 const state_purge_map *m_map;
251 };
252
253 } // namespace ana
254
255 #endif /* GCC_ANALYZER_STATE_PURGE_H */