1/* Classes for purging state at function_points.
2 Copyright (C) 2019-2025 Free Software Foundation, Inc.
3 Contributed by David Malcolm <dmalcolm@redhat.com>.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it
8under the terms of the GNU General Public License as published by
9the Free Software Foundation; either version 3, or (at your option)
10any later version.
11
12GCC is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of
14MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15General Public License for more details.
16
17You should have received a copy of the GNU General Public License
18along 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
26template <> struct default_hash_traits<function_point>
27: public pod_hash_traits<function_point>
28{
29 static const bool empty_zero_p = false;
30};
31
32template <>
33inline hashval_t
34pod_hash_traits<function_point>::hash (value_type v)
35{
36 return v.hash ();
37}
38
39template <>
40inline bool
41pod_hash_traits<function_point>::equal (const value_type &existing,
42 const value_type &candidate)
43{
44 return existing == candidate;
45}
46template <>
47inline void
48pod_hash_traits<function_point>::mark_deleted (value_type &v)
49{
50 v = function_point::deleted ();
51}
52template <>
53inline void
54pod_hash_traits<function_point>::mark_empty (value_type &v)
55{
56 v = function_point::empty ();
57}
58template <>
59inline bool
60pod_hash_traits<function_point>::is_deleted (value_type v)
61{
62 return v.get_kind () == PK_DELETED;
63}
64template <>
65inline bool
66pod_hash_traits<function_point>::is_empty (value_type v)
67{
68 return v.get_kind () == PK_EMPTY;
69}
70
71namespace 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
77class state_purge_map : public log_user
78{
79public:
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 (k: 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 (k: 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
126private:
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
136class state_purge_per_tree
137{
138public:
139 const function &get_function () const { return m_fun; }
140 tree get_fndecl () const { return m_fun.decl; }
141
142protected:
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
150private:
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
161class state_purge_per_ssa_name : public state_purge_per_tree
162{
163public:
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
170private:
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
193class state_purge_per_decl : public state_purge_per_tree
194{
195public:
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
207private:
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
234class state_purge_annotator : public dot_annotator
235{
236public:
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
246private:
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 */
257

source code of gcc/analyzer/state-purge.h