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27d020cf | 1 | /* IPA function body analysis. |
99dee823 | 2 | Copyright (C) 2003-2021 Free Software Foundation, Inc. |
27d020cf JH |
3 | Contributed by Jan Hubicka |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 3, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | 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_IPA_SUMMARY_H | |
22 | #define GCC_IPA_SUMMARY_H | |
23 | ||
24 | #include "sreal.h" | |
25 | #include "ipa-predicate.h" | |
26 | ||
27 | ||
e4112065 | 28 | /* Hints are reasons why IPA heuristics should prefer specializing given |
956d615d | 29 | function. They are represented as bitmap of the following values. */ |
0bceb671 JH |
30 | enum ipa_hints_vals { |
31 | /* When specialization turns indirect call into a direct call, | |
27d020cf JH |
32 | it is good idea to do so. */ |
33 | INLINE_HINT_indirect_call = 1, | |
34 | /* Inlining may make loop iterations or loop stride known. It is good idea | |
956d615d | 35 | to do so because it enables loop optimizations. */ |
27d020cf JH |
36 | INLINE_HINT_loop_iterations = 2, |
37 | INLINE_HINT_loop_stride = 4, | |
38 | /* Inlining within same strongly connected component of callgraph is often | |
39 | a loss due to increased stack frame usage and prologue setup costs. */ | |
40 | INLINE_HINT_same_scc = 8, | |
41 | /* Inlining functions in strongly connected component is not such a great | |
42 | win. */ | |
43 | INLINE_HINT_in_scc = 16, | |
44 | /* If function is declared inline by user, it may be good idea to inline | |
0bceb671 | 45 | it. Set by simple_edge_hints in ipa-inline-analysis.c. */ |
27d020cf JH |
46 | INLINE_HINT_declared_inline = 32, |
47 | /* Programs are usually still organized for non-LTO compilation and thus | |
48 | if functions are in different modules, inlining may not be so important. | |
0bceb671 | 49 | Set by simple_edge_hints in ipa-inline-analysis.c. */ |
27d020cf | 50 | INLINE_HINT_cross_module = 64, |
27d020cf | 51 | /* We know that the callee is hot by profile. */ |
caaa218f JH |
52 | INLINE_HINT_known_hot = 128, |
53 | /* There is builtin_constant_p dependent on parameter which is usually | |
54 | a strong hint to inline. */ | |
55 | INLINE_HINT_builtin_constant_p = 256 | |
27d020cf JH |
56 | }; |
57 | ||
0bceb671 | 58 | typedef int ipa_hints; |
27d020cf JH |
59 | |
60 | /* Simple description of whether a memory load or a condition refers to a load | |
61 | from an aggregate and if so, how and where from in the aggregate. | |
62 | Individual fields have the same meaning like fields with the same name in | |
63 | struct condition. */ | |
64 | ||
65 | struct agg_position_info | |
66 | { | |
67 | HOST_WIDE_INT offset; | |
68 | bool agg_contents; | |
69 | bool by_ref; | |
70 | }; | |
71 | ||
0bceb671 | 72 | /* Representation of function body size and time depending on the call |
27d020cf | 73 | context. We keep simple array of record, every containing of predicate |
0bceb671 | 74 | and time/size to account. */ |
366099ff | 75 | class size_time_entry |
27d020cf | 76 | { |
6c1dae73 | 77 | public: |
27d020cf JH |
78 | /* Predicate for code to be executed. */ |
79 | predicate exec_predicate; | |
80 | /* Predicate for value to be constant and optimized out in a specialized copy. | |
81 | When deciding on specialization this makes it possible to see how much | |
82 | the executed code paths will simplify. */ | |
83 | predicate nonconst_predicate; | |
84 | int size; | |
366099ff | 85 | sreal time; |
27d020cf JH |
86 | }; |
87 | ||
f658ad30 JH |
88 | /* Summary about function and stack frame sizes. We keep this info |
89 | for inline clones and also for WPA streaming. For this reason this is not | |
90 | part of ipa_fn_summary which exists only for offline functions. */ | |
91 | class ipa_size_summary | |
92 | { | |
93 | public: | |
94 | /* Estimated stack frame consumption by the function. */ | |
95 | HOST_WIDE_INT estimated_self_stack_size; | |
96 | /* Size of the function body. */ | |
97 | int self_size; | |
98 | /* Estimated size of the function after inlining. */ | |
99 | int size; | |
100 | ||
101 | ipa_size_summary () | |
102 | : estimated_self_stack_size (0), self_size (0), size (0) | |
103 | { | |
104 | } | |
f658ad30 JH |
105 | }; |
106 | ||
67ce9099 MJ |
107 | /* Structure to capture how frequently some interesting events occur given a |
108 | particular predicate. The structure is used to estimate how often we | |
109 | encounter loops with known iteration count or stride in various | |
110 | contexts. */ | |
111 | ||
112 | struct GTY(()) ipa_freqcounting_predicate | |
113 | { | |
114 | /* The described event happens with this frequency... */ | |
115 | sreal freq; | |
116 | /* ...when this predicate evaluates to false. */ | |
117 | class predicate * GTY((skip)) predicate; | |
118 | }; | |
119 | ||
27d020cf | 120 | /* Function inlining information. */ |
6c1dae73 | 121 | class GTY(()) ipa_fn_summary |
27d020cf | 122 | { |
6c1dae73 | 123 | public: |
56f62793 ML |
124 | /* Keep all field empty so summary dumping works during its computation. |
125 | This is useful for debugging. */ | |
126 | ipa_fn_summary () | |
f658ad30 | 127 | : min_size (0), |
56f62793 | 128 | inlinable (false), single_caller (false), |
caaa218f JH |
129 | fp_expressions (false), |
130 | estimated_stack_size (false), | |
f658ad30 | 131 | time (0), conds (NULL), |
366099ff | 132 | size_time_table (), call_size_time_table (vNULL), |
67ce9099 | 133 | loop_iterations (NULL), loop_strides (NULL), |
caaa218f | 134 | builtin_constant_p_parms (vNULL), |
67ce9099 | 135 | growth (0), scc_no (0) |
56f62793 ML |
136 | { |
137 | } | |
138 | ||
139 | /* Copy constructor. */ | |
140 | ipa_fn_summary (const ipa_fn_summary &s) | |
f658ad30 | 141 | : min_size (s.min_size), |
56f62793 ML |
142 | inlinable (s.inlinable), single_caller (s.single_caller), |
143 | fp_expressions (s.fp_expressions), | |
144 | estimated_stack_size (s.estimated_stack_size), | |
366099ff JH |
145 | time (s.time), conds (s.conds), size_time_table (), |
146 | call_size_time_table (vNULL), | |
67ce9099 | 147 | loop_iterations (s.loop_iterations), loop_strides (s.loop_strides), |
caaa218f | 148 | builtin_constant_p_parms (s.builtin_constant_p_parms), |
a20f263b | 149 | growth (s.growth), scc_no (s.scc_no) |
56f62793 ML |
150 | {} |
151 | ||
152 | /* Default constructor. */ | |
153 | ~ipa_fn_summary (); | |
154 | ||
27d020cf JH |
155 | /* Information about the function body itself. */ |
156 | ||
27d020cf JH |
157 | /* Minimal size increase after inlining. */ |
158 | int min_size; | |
159 | ||
160 | /* False when there something makes inlining impossible (such as va_arg). */ | |
161 | unsigned inlinable : 1; | |
27d020cf JH |
162 | /* True wen there is only one caller of the function before small function |
163 | inlining. */ | |
164 | unsigned int single_caller : 1; | |
165 | /* True if function contains any floating point expressions. */ | |
166 | unsigned int fp_expressions : 1; | |
167 | ||
168 | /* Information about function that will result after applying all the | |
169 | inline decisions present in the callgraph. Generally kept up to | |
170 | date only for functions that are not inline clones. */ | |
171 | ||
172 | /* Estimated stack frame consumption by the function. */ | |
173 | HOST_WIDE_INT estimated_stack_size; | |
f658ad30 | 174 | /* Estimated runtime of function after inlining. */ |
27d020cf | 175 | sreal GTY((skip)) time; |
27d020cf JH |
176 | |
177 | /* Conditional size/time information. The summaries are being | |
178 | merged during inlining. */ | |
179 | conditions conds; | |
956d615d | 180 | /* Normal code is accounted in size_time_table, while calls are |
070e3489 JH |
181 | accounted in call_size_time_table. This is because calls |
182 | are often adjusted by IPA optimizations and thus this summary | |
183 | is generated from call summary information when needed. */ | |
366099ff JH |
184 | auto_vec<size_time_entry> GTY((skip)) size_time_table; |
185 | /* Unlike size_time_table that is initialized for all summaries | |
186 | call_size_time_table is allocated only for functions with | |
187 | many calls. Use effecient vl_ptr storage. */ | |
188 | vec<size_time_entry, va_heap, vl_ptr> GTY((skip)) call_size_time_table; | |
27d020cf | 189 | |
67ce9099 MJ |
190 | /* Predicates on when some loops in the function can have known bounds. */ |
191 | vec<ipa_freqcounting_predicate, va_gc> *loop_iterations; | |
192 | /* Predicates on when some loops in the function can have known strides. */ | |
193 | vec<ipa_freqcounting_predicate, va_gc> *loop_strides; | |
caaa218f JH |
194 | /* Parameters tested by builtin_constant_p. */ |
195 | vec<int, va_heap, vl_ptr> GTY((skip)) builtin_constant_p_parms; | |
27d020cf JH |
196 | /* Estimated growth for inlining all copies of the function before start |
197 | of small functions inlining. | |
198 | This value will get out of date as the callers are duplicated, but | |
199 | using up-to-date value in the badness metric mean a lot of extra | |
200 | expenses. */ | |
201 | int growth; | |
202 | /* Number of SCC on the beginning of inlining process. */ | |
203 | int scc_no; | |
204 | ||
27d020cf | 205 | /* Record time and size under given predicates. */ |
070e3489 JH |
206 | void account_size_time (int, sreal, const predicate &, const predicate &, |
207 | bool call = false); | |
27d020cf | 208 | |
0bceb671 JH |
209 | /* We keep values scaled up, so fractional sizes can be accounted. */ |
210 | static const int size_scale = 2; | |
070e3489 JH |
211 | /* Maximal size of size_time_table before we start to be conservative. */ |
212 | static const int max_size_time_table_size = 256; | |
27d020cf JH |
213 | }; |
214 | ||
db30281f ML |
215 | class GTY((user)) ipa_fn_summary_t: |
216 | public fast_function_summary <ipa_fn_summary *, va_gc> | |
27d020cf JH |
217 | { |
218 | public: | |
db30281f ML |
219 | ipa_fn_summary_t (symbol_table *symtab): |
220 | fast_function_summary <ipa_fn_summary *, va_gc> (symtab) {} | |
27d020cf | 221 | |
0bceb671 | 222 | static ipa_fn_summary_t *create_ggc (symbol_table *symtab) |
27d020cf | 223 | { |
78cd68c0 ML |
224 | class ipa_fn_summary_t *summary |
225 | = new (ggc_alloc_no_dtor<ipa_fn_summary_t> ()) ipa_fn_summary_t (symtab); | |
27d020cf JH |
226 | summary->disable_insertion_hook (); |
227 | return summary; | |
228 | } | |
229 | ||
56f62793 ML |
230 | /* Remove ipa_fn_summary for all callees of NODE. */ |
231 | void remove_callees (cgraph_node *node); | |
27d020cf | 232 | |
0bceb671 | 233 | virtual void insert (cgraph_node *, ipa_fn_summary *); |
56f62793 ML |
234 | virtual void remove (cgraph_node *node, ipa_fn_summary *) |
235 | { | |
236 | remove_callees (node); | |
237 | } | |
238 | ||
27d020cf | 239 | virtual void duplicate (cgraph_node *src, cgraph_node *dst, |
0bceb671 | 240 | ipa_fn_summary *src_data, ipa_fn_summary *dst_data); |
27d020cf JH |
241 | }; |
242 | ||
db30281f ML |
243 | extern GTY(()) fast_function_summary <ipa_fn_summary *, va_gc> |
244 | *ipa_fn_summaries; | |
27d020cf | 245 | |
f658ad30 | 246 | class ipa_size_summary_t: |
44fca832 | 247 | public fast_function_summary <ipa_size_summary *, va_heap> |
f658ad30 JH |
248 | { |
249 | public: | |
250 | ipa_size_summary_t (symbol_table *symtab): | |
44fca832 JH |
251 | fast_function_summary <ipa_size_summary *, va_heap> (symtab) |
252 | { | |
253 | disable_insertion_hook (); | |
254 | } | |
f658ad30 | 255 | |
44fca832 JH |
256 | virtual void duplicate (cgraph_node *, cgraph_node *, |
257 | ipa_size_summary *src_data, | |
258 | ipa_size_summary *dst_data) | |
f658ad30 | 259 | { |
44fca832 | 260 | *dst_data = *src_data; |
f658ad30 JH |
261 | } |
262 | }; | |
263 | extern fast_function_summary <ipa_size_summary *, va_heap> | |
264 | *ipa_size_summaries; | |
265 | ||
27d020cf | 266 | /* Information kept about callgraph edges. */ |
6c1dae73 | 267 | class ipa_call_summary |
27d020cf | 268 | { |
6c1dae73 | 269 | public: |
56f62793 ML |
270 | /* Keep all field empty so summary dumping works during its computation. |
271 | This is useful for debugging. */ | |
272 | ipa_call_summary () | |
273 | : predicate (NULL), param (vNULL), call_stmt_size (0), call_stmt_time (0), | |
274 | loop_depth (0), is_return_callee_uncaptured (false) | |
275 | { | |
276 | } | |
277 | ||
278 | /* Copy constructor. */ | |
279 | ipa_call_summary (const ipa_call_summary &s): | |
280 | predicate (s.predicate), param (s.param), call_stmt_size (s.call_stmt_size), | |
281 | call_stmt_time (s.call_stmt_time), loop_depth (s.loop_depth), | |
282 | is_return_callee_uncaptured (s.is_return_callee_uncaptured) | |
283 | { | |
284 | } | |
285 | ||
286 | /* Default destructor. */ | |
287 | ~ipa_call_summary (); | |
288 | ||
27d020cf JH |
289 | class predicate *predicate; |
290 | /* Vector indexed by parameters. */ | |
291 | vec<inline_param_summary> param; | |
292 | /* Estimated size and time of the call statement. */ | |
293 | int call_stmt_size; | |
294 | int call_stmt_time; | |
295 | /* Depth of loop nest, 0 means no nesting. */ | |
296 | unsigned int loop_depth; | |
0fab169b PK |
297 | /* Indicates whether the caller returns the value of it's callee. */ |
298 | bool is_return_callee_uncaptured; | |
27d020cf JH |
299 | }; |
300 | ||
db30281f | 301 | class ipa_call_summary_t: public fast_call_summary <ipa_call_summary *, va_heap> |
27d020cf JH |
302 | { |
303 | public: | |
db30281f ML |
304 | ipa_call_summary_t (symbol_table *symtab): |
305 | fast_call_summary <ipa_call_summary *, va_heap> (symtab) {} | |
27d020cf | 306 | |
27d020cf JH |
307 | /* Hook that is called by summary when an edge is duplicated. */ |
308 | virtual void duplicate (cgraph_edge *src, cgraph_edge *dst, | |
309 | ipa_call_summary *src_data, | |
310 | ipa_call_summary *dst_data); | |
311 | }; | |
312 | ||
1e7fdc02 MJ |
313 | /* Estimated execution times, code sizes and other information about the |
314 | code executing a call described by ipa_call_context. */ | |
315 | ||
316 | struct ipa_call_estimates | |
317 | { | |
318 | /* Estimated size needed to execute call in the given context. */ | |
319 | int size; | |
320 | ||
321 | /* Minimal size needed for the call that is + independent on the call context | |
322 | and can be used for fast estimates. */ | |
323 | int min_size; | |
324 | ||
325 | /* Estimated time needed to execute call in the given context. */ | |
326 | sreal time; | |
327 | ||
328 | /* Estimated time needed to execute the function when not ignoring | |
329 | computations known to be constant in this context. */ | |
330 | sreal nonspecialized_time; | |
331 | ||
332 | /* Further discovered reasons why to inline or specialize the give calls. */ | |
333 | ipa_hints hints; | |
67ce9099 MJ |
334 | |
335 | /* Frequency how often a loop with known number of iterations is encountered. | |
336 | Calculated with hints. */ | |
337 | sreal loops_with_known_iterations; | |
338 | ||
339 | /* Frequency how often a loop with known strides is encountered. Calculated | |
340 | with hints. */ | |
341 | sreal loops_with_known_strides; | |
1e7fdc02 MJ |
342 | }; |
343 | ||
7d2cb275 MJ |
344 | class ipa_cached_call_context; |
345 | ||
1532500e JH |
346 | /* This object describe a context of call. That is a summary of known |
347 | information about its parameters. Main purpose of this context is | |
956d615d | 348 | to give more realistic estimations of function runtime, size and |
1532500e JH |
349 | inline hints. */ |
350 | class ipa_call_context | |
351 | { | |
352 | public: | |
353 | ipa_call_context (cgraph_node *node, | |
354 | clause_t possible_truths, | |
355 | clause_t nonspec_possible_truths, | |
9d5af1db MJ |
356 | vec<inline_param_summary> inline_param_summary, |
357 | ipa_auto_call_arg_values *arg_values); | |
ac6f2e59 JH |
358 | ipa_call_context () |
359 | : m_node(NULL) | |
360 | { | |
361 | } | |
1e7fdc02 MJ |
362 | void estimate_size_and_time (ipa_call_estimates *estimates, |
363 | bool est_times = true, bool est_hints = true); | |
ac6f2e59 JH |
364 | bool equal_to (const ipa_call_context &); |
365 | bool exists_p () | |
366 | { | |
367 | return m_node != NULL; | |
368 | } | |
1532500e JH |
369 | private: |
370 | /* Called function. */ | |
371 | cgraph_node *m_node; | |
372 | /* Clause describing what predicate conditionals can be satisfied | |
956d615d | 373 | in this context if function is inlined/specialized. */ |
1532500e JH |
374 | clause_t m_possible_truths; |
375 | /* Clause describing what predicate conditionals can be satisfied | |
376 | in this context if function is kept offline. */ | |
377 | clause_t m_nonspec_possible_truths; | |
378 | /* Inline summary maintains info about change probabilities. */ | |
379 | vec<inline_param_summary> m_inline_param_summary; | |
380 | ||
9d5af1db MJ |
381 | /* Even after having calculated clauses, the information about argument |
382 | values is used to resolve indirect calls. */ | |
383 | ipa_call_arg_values m_avals; | |
7d2cb275 MJ |
384 | |
385 | friend ipa_cached_call_context; | |
386 | }; | |
387 | ||
388 | /* Variant of ipa_call_context that is stored in a cache over a longer period | |
389 | of time. */ | |
390 | ||
391 | class ipa_cached_call_context : public ipa_call_context | |
392 | { | |
393 | public: | |
394 | void duplicate_from (const ipa_call_context &ctx); | |
395 | void release (); | |
1532500e JH |
396 | }; |
397 | ||
db30281f | 398 | extern fast_call_summary <ipa_call_summary *, va_heap> *ipa_call_summaries; |
27d020cf JH |
399 | |
400 | /* In ipa-fnsummary.c */ | |
0bceb671 JH |
401 | void ipa_debug_fn_summary (struct cgraph_node *); |
402 | void ipa_dump_fn_summaries (FILE *f); | |
403 | void ipa_dump_fn_summary (FILE *f, struct cgraph_node *node); | |
404 | void ipa_dump_hints (FILE *f, ipa_hints); | |
d2db2e6b | 405 | void ipa_free_fn_summary (void); |
f658ad30 | 406 | void ipa_free_size_summary (void); |
27d020cf | 407 | void inline_analyze_function (struct cgraph_node *node); |
1e7fdc02 MJ |
408 | void estimate_ipcp_clone_size_and_time (struct cgraph_node *node, |
409 | ipa_auto_call_arg_values *avals, | |
410 | ipa_call_estimates *estimates); | |
0bceb671 | 411 | void ipa_merge_fn_summary_after_inlining (struct cgraph_edge *edge); |
d2bcf46c | 412 | void ipa_update_overall_fn_summary (struct cgraph_node *node, bool reset = true); |
0bceb671 | 413 | void compute_fn_summary (struct cgraph_node *, bool); |
e977dd5e JH |
414 | bool refs_local_or_readonly_memory_p (tree); |
415 | bool points_to_local_or_readonly_memory_p (tree); | |
27d020cf JH |
416 | |
417 | ||
1532500e JH |
418 | void evaluate_properties_for_edge (struct cgraph_edge *e, |
419 | bool inline_p, | |
27d020cf JH |
420 | clause_t *clause_ptr, |
421 | clause_t *nonspec_clause_ptr, | |
9d5af1db MJ |
422 | ipa_auto_call_arg_values *avals, |
423 | bool compute_contexts); | |
27d020cf | 424 | |
de4381a4 | 425 | void ipa_fnsummary_c_finalize (void); |
f658ad30 | 426 | HOST_WIDE_INT ipa_get_stack_frame_offset (struct cgraph_node *node); |
7237f93e | 427 | void ipa_remove_from_growth_caches (struct cgraph_edge *edge); |
de4381a4 | 428 | |
b74d8dc4 JH |
429 | /* Return true if EDGE is a cross module call. */ |
430 | ||
431 | static inline bool | |
432 | cross_module_call_p (struct cgraph_edge *edge) | |
433 | { | |
434 | /* Here we do not want to walk to alias target becuase ICF may create | |
435 | cross-unit aliases. */ | |
436 | if (edge->caller->unit_id == edge->callee->unit_id) | |
437 | return false; | |
438 | /* If the call is to a (former) comdat function or s symbol with mutiple | |
439 | extern inline definitions then treat is as in-module call. */ | |
440 | if (edge->callee->merged_extern_inline || edge->callee->merged_comdat | |
441 | || DECL_COMDAT (edge->callee->decl)) | |
442 | return false; | |
443 | return true; | |
444 | } | |
445 | ||
27d020cf | 446 | #endif /* GCC_IPA_FNSUMMARY_H */ |