1/* Interprocedural semantic function equality pass
2 Copyright (C) 2014-2017 Free Software Foundation, Inc.
3
4 Contributed by Jan Hubicka <hubicka@ucw.cz> and Martin Liska <mliska@suse.cz>
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 3, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3. If not see
20<http://www.gnu.org/licenses/>. */
21
22/* Gimple identical code folding (class func_checker) is an infastructure
23 capable of comparing two given functions. The class compares every
24 gimple statement and uses many dictionaries to map source and target
25 SSA_NAMEs, declarations and other components.
26
27 To use the infrastructure, create an instanse of func_checker and call
28 a comparsion function based on type of gimple statement. */
29
30/* Prints string STRING to a FILE with a given number of SPACE_COUNT. */
31#define FPUTS_SPACES(file, space_count, string) \
32 fprintf (file, "%*s" string, space_count, " ");
33
34/* fprintf function wrapper that transforms given FORMAT to follow given
35 number for SPACE_COUNT and call fprintf for a FILE. */
36#define FPRINTF_SPACES(file, space_count, format, ...) \
37 fprintf (file, "%*s" format, space_count, " ", ##__VA_ARGS__);
38
39/* Prints a MESSAGE to dump_file if exists. FUNC is name of function and
40 LINE is location in the source file. */
41
42static inline void
43dump_message_1 (const char *message, const char *func, unsigned int line)
44{
45 if (dump_file && (dump_flags & TDF_DETAILS))
46 fprintf (dump_file, " debug message: %s (%s:%u)\n", message, func, line);
47}
48
49/* Prints a MESSAGE to dump_file if exists. */
50#define dump_message(message) dump_message_1 (message, __func__, __LINE__)
51
52/* Logs a MESSAGE to dump_file if exists and returns false. FUNC is name
53 of function and LINE is location in the source file. */
54
55static inline bool
56return_false_with_message_1 (const char *message, const char *func,
57 unsigned int line)
58{
59 if (dump_file && (dump_flags & TDF_DETAILS))
60 fprintf (dump_file, " false returned: '%s' (%s:%u)\n", message, func, line);
61 return false;
62}
63
64/* Logs a MESSAGE to dump_file if exists and returns false. */
65#define return_false_with_msg(message) \
66 return_false_with_message_1 (message, __func__, __LINE__)
67
68/* Return false and log that false value is returned. */
69#define return_false() return_false_with_msg ("")
70
71/* Logs return value if RESULT is false. FUNC is name of function and LINE
72 is location in the source file. */
73
74static inline bool
75return_with_result (bool result, const char *func, unsigned int line)
76{
77 if (!result && dump_file && (dump_flags & TDF_DETAILS))
78 fprintf (dump_file, " false returned: (%s:%u)\n", func, line);
79
80 return result;
81}
82
83/* Logs return value if RESULT is false. */
84#define return_with_debug(result) return_with_result (result, __func__, __LINE__)
85
86/* Verbose logging function logging statements S1 and S2 of a CODE.
87 FUNC is name of function and LINE is location in the source file. */
88
89static inline bool
90return_different_stmts_1 (gimple *s1, gimple *s2, const char *code,
91 const char *func, unsigned int line)
92{
93 if (dump_file && (dump_flags & TDF_DETAILS))
94 {
95 fprintf (dump_file, " different statement for code: %s (%s:%u):\n",
96 code, func, line);
97
98 print_gimple_stmt (dump_file, s1, 3, TDF_DETAILS);
99 print_gimple_stmt (dump_file, s2, 3, TDF_DETAILS);
100 }
101
102 return false;
103}
104
105/* Verbose logging function logging statements S1 and S2 of a CODE. */
106#define return_different_stmts(s1, s2, code) \
107 return_different_stmts_1 (s1, s2, code, __func__, __LINE__)
108
109namespace ipa_icf_gimple {
110
111/* Basic block struct for semantic equality pass. */
112class sem_bb
113{
114public:
115 sem_bb (basic_block bb_, unsigned nondbg_stmt_count_, unsigned edge_count_):
116 bb (bb_), nondbg_stmt_count (nondbg_stmt_count_), edge_count (edge_count_) {}
117
118 /* Basic block the structure belongs to. */
119 basic_block bb;
120
121 /* Number of non-debug statements in the basic block. */
122 unsigned nondbg_stmt_count;
123
124 /* Number of edges connected to the block. */
125 unsigned edge_count;
126};
127
128/* A class aggregating all connections and semantic equivalents
129 for a given pair of semantic function candidates. */
130class func_checker
131{
132public:
133 /* Initialize internal structures for a given SOURCE_FUNC_DECL and
134 TARGET_FUNC_DECL. Strict polymorphic comparison is processed if
135 an option COMPARE_POLYMORPHIC is true. For special cases, one can
136 set IGNORE_LABELS to skip label comparison.
137 Similarly, IGNORE_SOURCE_DECLS and IGNORE_TARGET_DECLS are sets
138 of declarations that can be skipped. */
139 func_checker (tree source_func_decl, tree target_func_decl,
140 bool compare_polymorphic,
141 bool ignore_labels = false,
142 hash_set<symtab_node *> *ignored_source_nodes = NULL,
143 hash_set<symtab_node *> *ignored_target_nodes = NULL);
144
145 /* Memory release routine. */
146 ~func_checker();
147
148 /* Function visits all gimple labels and creates corresponding
149 mapping between basic blocks and labels. */
150 void parse_labels (sem_bb *bb);
151
152 /* Basic block equivalence comparison function that returns true if
153 basic blocks BB1 and BB2 correspond. */
154 bool compare_bb (sem_bb *bb1, sem_bb *bb2);
155
156 /* Verifies that trees T1 and T2 are equivalent from perspective of ICF. */
157 bool compare_ssa_name (tree t1, tree t2);
158
159 /* Verification function for edges E1 and E2. */
160 bool compare_edge (edge e1, edge e2);
161
162 /* Verifies for given GIMPLEs S1 and S2 that
163 call statements are semantically equivalent. */
164 bool compare_gimple_call (gcall *s1, gcall *s2);
165
166 /* Verifies for given GIMPLEs S1 and S2 that
167 assignment statements are semantically equivalent. */
168 bool compare_gimple_assign (gimple *s1, gimple *s2);
169
170 /* Verifies for given GIMPLEs S1 and S2 that
171 condition statements are semantically equivalent. */
172 bool compare_gimple_cond (gimple *s1, gimple *s2);
173
174 /* Verifies for given GIMPLE_LABEL stmts S1 and S2 that
175 label statements are semantically equivalent. */
176 bool compare_gimple_label (const glabel *s1, const glabel *s2);
177
178 /* Verifies for given GIMPLE_SWITCH stmts S1 and S2 that
179 switch statements are semantically equivalent. */
180 bool compare_gimple_switch (const gswitch *s1, const gswitch *s2);
181
182 /* Verifies for given GIMPLE_RETURN stmts S1 and S2 that
183 return statements are semantically equivalent. */
184 bool compare_gimple_return (const greturn *s1, const greturn *s2);
185
186 /* Verifies for given GIMPLEs S1 and S2 that
187 goto statements are semantically equivalent. */
188 bool compare_gimple_goto (gimple *s1, gimple *s2);
189
190 /* Verifies for given GIMPLE_RESX stmts S1 and S2 that
191 resx statements are semantically equivalent. */
192 bool compare_gimple_resx (const gresx *s1, const gresx *s2);
193
194 /* Verifies for given GIMPLE_ASM stmts S1 and S2 that ASM statements
195 are equivalent.
196 For the beginning, the pass only supports equality for
197 '__asm__ __volatile__ ("", "", "", "memory")'. */
198 bool compare_gimple_asm (const gasm *s1, const gasm *s2);
199
200 /* Verification function for declaration trees T1 and T2. */
201 bool compare_decl (tree t1, tree t2);
202
203 /* Verifies that tree labels T1 and T2 correspond. */
204 bool compare_tree_ssa_label (tree t1, tree t2);
205
206 /* Function compare for equality given memory operands T1 and T2. */
207 bool compare_memory_operand (tree t1, tree t2);
208
209 /* Function compare for equality given trees T1 and T2 which
210 can be either a constant or a declaration type. */
211 bool compare_cst_or_decl (tree t1, tree t2);
212
213 /* Function responsible for comparison of various operands T1 and T2.
214 If these components, from functions FUNC1 and FUNC2, are equal, true
215 is returned. */
216 bool compare_operand (tree t1, tree t2);
217
218 /* Compares GIMPLE ASM inputs (or outputs) where we iterate tree chain
219 and compare both TREE_PURPOSEs and TREE_VALUEs. */
220 bool compare_asm_inputs_outputs (tree t1, tree t2);
221
222 /* Verifies that trees T1 and T2, representing function declarations
223 are equivalent from perspective of ICF. */
224 bool compare_function_decl (tree t1, tree t2);
225
226 /* Verifies that trees T1 and T2 do correspond. */
227 bool compare_variable_decl (tree t1, tree t2);
228
229 /* Return true if types are compatible for polymorphic call analysis.
230 COMPARE_PTR indicates if polymorphic type comparsion should be
231 done for pointers, too. */
232 static bool compatible_polymorphic_types_p (tree t1, tree t2,
233 bool compare_ptr);
234
235 /* Return true if types are compatible from perspective of ICF.
236 FIRST_ARGUMENT indicates if the comparison is called for
237 first parameter of a function. */
238 static bool compatible_types_p (tree t1, tree t2);
239
240
241private:
242 /* Vector mapping source SSA names to target ones. */
243 vec <int> m_source_ssa_names;
244
245 /* Vector mapping target SSA names to source ones. */
246 vec <int> m_target_ssa_names;
247
248 /* Source TREE function declaration. */
249 tree m_source_func_decl;
250
251 /* Target TREE function declaration. */
252 tree m_target_func_decl;
253
254 /* Source symbol nodes that should be skipped by
255 declaration comparison. */
256 hash_set<symtab_node *> *m_ignored_source_nodes;
257
258 /* Target symbol nodes that should be skipped by
259 declaration comparison. */
260 hash_set<symtab_node *> *m_ignored_target_nodes;
261
262 /* Source to target edge map. */
263 hash_map <edge, edge> m_edge_map;
264
265 /* Source to target declaration map. */
266 hash_map <tree, tree> m_decl_map;
267
268 /* Label to basic block index mapping. */
269 hash_map <tree, int> m_label_bb_map;
270
271 /* Flag if polymorphic comparison should be executed. */
272 bool m_compare_polymorphic;
273
274 /* Flag if ignore labels in comparison. */
275 bool m_ignore_labels;
276};
277
278} // ipa_icf_gimple namespace
279