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1 | /* Interprocedural scalar replacement of aggregates | |
2 | Copyright (C) 2008-2021 Free Software Foundation, Inc. | |
3 | ||
4 | Contributed by Martin Jambor <mjambor@suse.cz> | |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 3, or (at your option) any later | |
11 | version. | |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GCC; see the file COPYING3. If not see | |
20 | <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | /* IPA-SRA is an interprocedural pass that removes unused function return | |
23 | values (turning functions returning a value which is never used into void | |
24 | functions), removes unused function parameters. It can also replace an | |
25 | aggregate parameter by a set of other parameters representing part of the | |
26 | original, turning those passed by reference into new ones which pass the | |
27 | value directly. | |
28 | ||
29 | The pass is a true IPA one, which means that it works in three stages in | |
30 | order to be able to take advantage of LTO. First, summaries about functions | |
31 | and each calls are generated. Function summaries (often called call graph | |
32 | node summaries) contain mainly information about which parameters are | |
33 | potential transformation candidates and which bits of candidates are | |
34 | accessed. We differentiate between accesses done as a part of a call | |
35 | statement (which might be not necessary if the callee is also transformed) | |
36 | and others (which are mandatory). Call summaries (often called call graph | |
37 | edge summaries) contain information about which function formal parameters | |
38 | feed into which actual call arguments so that if two parameters are only | |
39 | used in a sum which is then passed to another function which then however | |
40 | does not use this parameter, all three parameters of the two functions can | |
41 | be eliminated. Edge summaries also have flags whether the return value is | |
42 | used or if it is only returned in the caller too. In LTO mode these | |
43 | summaries are then streamed to the object file in the compilation phase and | |
44 | streamed back in in the WPA analysis stage. | |
45 | ||
46 | The interprocedural analysis phase traverses the graph in topological order | |
47 | in two sweeps, one in each direction. First, from callees to callers for | |
48 | parameter removal and splitting. Each strongly-connected component is | |
49 | processed iteratively until the situation in it stabilizes. The pass from | |
50 | callers to callees is then carried out to remove unused return values in a | |
51 | very similar fashion. | |
52 | ||
53 | Because parameter manipulation has big implications for call redirection | |
54 | which is done only after all call graph nodes materialize, the | |
55 | transformation phase is not part of this patch but is carried out by the | |
56 | clone materialization and edge redirection itself, see comments in | |
57 | ipa-param-manipulation.h for more details. */ | |
58 | ||
59 | ||
60 | ||
61 | #include "config.h" | |
62 | #include "system.h" | |
63 | #include "coretypes.h" | |
64 | #include "backend.h" | |
65 | #include "tree.h" | |
66 | #include "gimple.h" | |
67 | #include "predict.h" | |
68 | #include "tree-pass.h" | |
69 | #include "ssa.h" | |
70 | #include "cgraph.h" | |
71 | #include "gimple-pretty-print.h" | |
72 | #include "alias.h" | |
73 | #include "tree-eh.h" | |
74 | #include "gimple-iterator.h" | |
75 | #include "gimple-walk.h" | |
76 | #include "tree-dfa.h" | |
77 | #include "tree-sra.h" | |
78 | #include "alloc-pool.h" | |
79 | #include "symbol-summary.h" | |
80 | #include "dbgcnt.h" | |
81 | #include "tree-inline.h" | |
82 | #include "ipa-utils.h" | |
83 | #include "builtins.h" | |
84 | #include "cfganal.h" | |
85 | #include "tree-streamer.h" | |
86 | #include "internal-fn.h" | |
87 | #include "symtab-clones.h" | |
88 | ||
89 | static void ipa_sra_summarize_function (cgraph_node *); | |
90 | ||
91 | /* Bits used to track size of an aggregate in bytes interprocedurally. */ | |
92 | #define ISRA_ARG_SIZE_LIMIT_BITS 16 | |
93 | #define ISRA_ARG_SIZE_LIMIT (1 << ISRA_ARG_SIZE_LIMIT_BITS) | |
94 | /* How many parameters can feed into a call actual argument and still be | |
95 | tracked. */ | |
96 | #define IPA_SRA_MAX_PARAM_FLOW_LEN 7 | |
97 | ||
98 | /* Structure describing accesses to a specific portion of an aggregate | |
99 | parameter, as given by the offset and size. Any smaller accesses that occur | |
100 | within a function that fall within another access form a tree. The pass | |
101 | cannot analyze parameters with only partially overlapping accesses. */ | |
102 | ||
103 | struct GTY(()) param_access | |
104 | { | |
105 | /* Type that a potential replacement should have. This field only has | |
106 | meaning in the summary building and transformation phases, when it is | |
107 | reconstructed from the body. Must not be touched in IPA analysis | |
108 | stage. */ | |
109 | tree type; | |
110 | ||
111 | /* Alias reference type to be used in MEM_REFs when adjusting caller | |
112 | arguments. */ | |
113 | tree alias_ptr_type; | |
114 | ||
115 | /* Values returned by get_ref_base_and_extent but converted to bytes and | |
116 | stored as unsigned ints. */ | |
117 | unsigned unit_offset; | |
118 | unsigned unit_size : ISRA_ARG_SIZE_LIMIT_BITS; | |
119 | ||
120 | /* Set once we are sure that the access will really end up in a potentially | |
121 | transformed function - initially not set for portions of formal parameters | |
122 | that are only used as actual function arguments passed to callees. */ | |
123 | unsigned certain : 1; | |
124 | /* Set if the access has a reversed scalar storage order. */ | |
125 | unsigned reverse : 1; | |
126 | }; | |
127 | ||
128 | /* This structure has the same purpose as the one above and additionally it | |
129 | contains some fields that are only necessary in the summary generation | |
130 | phase. */ | |
131 | ||
132 | struct gensum_param_access | |
133 | { | |
134 | /* Values returned by get_ref_base_and_extent. */ | |
135 | HOST_WIDE_INT offset; | |
136 | HOST_WIDE_INT size; | |
137 | ||
138 | /* if this access has any children (in terms of the definition above), this | |
139 | points to the first one. */ | |
140 | struct gensum_param_access *first_child; | |
141 | /* In intraprocedural SRA, pointer to the next sibling in the access tree as | |
142 | described above. */ | |
143 | struct gensum_param_access *next_sibling; | |
144 | ||
145 | /* Type that a potential replacement should have. This field only has | |
146 | meaning in the summary building and transformation phases, when it is | |
147 | reconstructed from the body. Must not be touched in IPA analysis | |
148 | stage. */ | |
149 | tree type; | |
150 | /* Alias reference type to be used in MEM_REFs when adjusting caller | |
151 | arguments. */ | |
152 | tree alias_ptr_type; | |
153 | ||
154 | /* Have there been writes to or reads from this exact location except for as | |
155 | arguments to a function call that can be tracked. */ | |
156 | bool nonarg; | |
157 | ||
158 | /* Set if the access has a reversed scalar storage order. */ | |
159 | bool reverse; | |
160 | }; | |
161 | ||
162 | /* Summary describing a parameter in the IPA stages. */ | |
163 | ||
164 | struct GTY(()) isra_param_desc | |
165 | { | |
166 | /* List of access representatives to the parameters, sorted according to | |
167 | their offset. */ | |
168 | vec <param_access *, va_gc> *accesses; | |
169 | ||
170 | /* Unit size limit of total size of all replacements. */ | |
171 | unsigned param_size_limit : ISRA_ARG_SIZE_LIMIT_BITS; | |
172 | /* Sum of unit sizes of all certain replacements. */ | |
173 | unsigned size_reached : ISRA_ARG_SIZE_LIMIT_BITS; | |
174 | ||
175 | /* A parameter that is used only in call arguments and can be removed if all | |
176 | concerned actual arguments are removed. */ | |
177 | unsigned locally_unused : 1; | |
178 | /* An aggregate that is a candidate for breaking up or complete removal. */ | |
179 | unsigned split_candidate : 1; | |
180 | /* Is this a parameter passing stuff by reference? */ | |
181 | unsigned by_ref : 1; | |
182 | }; | |
183 | ||
184 | /* Structure used when generating summaries that describes a parameter. */ | |
185 | ||
186 | struct gensum_param_desc | |
187 | { | |
188 | /* Roots of param_accesses. */ | |
189 | gensum_param_access *accesses; | |
190 | /* Number of accesses in the access tree rooted in field accesses. */ | |
191 | unsigned access_count; | |
192 | ||
193 | /* If the below is non-zero, this is the number of uses as actual arguments. */ | |
194 | int call_uses; | |
195 | /* Number of times this parameter has been directly passed to. */ | |
196 | unsigned ptr_pt_count; | |
197 | ||
198 | /* Size limit of total size of all replacements. */ | |
199 | unsigned param_size_limit; | |
200 | /* Sum of sizes of nonarg accesses. */ | |
201 | unsigned nonarg_acc_size; | |
202 | ||
203 | /* A parameter that is used only in call arguments and can be removed if all | |
204 | concerned actual arguments are removed. */ | |
205 | bool locally_unused; | |
206 | /* An aggregate that is a candidate for breaking up or a pointer passing data | |
207 | by reference that is a candidate for being converted to a set of | |
208 | parameters passing those data by value. */ | |
209 | bool split_candidate; | |
210 | /* Is this a parameter passing stuff by reference? */ | |
211 | bool by_ref; | |
212 | ||
213 | /* The number of this parameter as they are ordered in function decl. */ | |
214 | int param_number; | |
215 | /* For parameters passing data by reference, this is parameter index to | |
216 | compute indices to bb_dereferences. */ | |
217 | int deref_index; | |
218 | }; | |
219 | ||
220 | /* Properly deallocate accesses of DESC. TODO: Since this data structure is | |
221 | not in GC memory, this is not necessary and we can consider removing the | |
222 | function. */ | |
223 | ||
224 | static void | |
225 | free_param_decl_accesses (isra_param_desc *desc) | |
226 | { | |
227 | unsigned len = vec_safe_length (desc->accesses); | |
228 | for (unsigned i = 0; i < len; ++i) | |
229 | ggc_free ((*desc->accesses)[i]); | |
230 | vec_free (desc->accesses); | |
231 | } | |
232 | ||
233 | /* Class used to convey information about functions from the | |
234 | intra-procedural analysis stage to inter-procedural one. */ | |
235 | ||
236 | class GTY((for_user)) isra_func_summary | |
237 | { | |
238 | public: | |
239 | /* initialize the object. */ | |
240 | ||
241 | isra_func_summary () | |
242 | : m_parameters (NULL), m_candidate (false), m_returns_value (false), | |
243 | m_return_ignored (false), m_queued (false) | |
244 | {} | |
245 | ||
246 | /* Destroy m_parameters. */ | |
247 | ||
248 | ~isra_func_summary (); | |
249 | ||
250 | /* Mark the function as not a candidate for any IPA-SRA transformation. | |
251 | Return true if it was a candidate until now. */ | |
252 | ||
253 | bool zap (); | |
254 | ||
255 | /* Vector of parameter descriptors corresponding to the function being | |
256 | analyzed. */ | |
257 | vec<isra_param_desc, va_gc> *m_parameters; | |
258 | ||
259 | /* Whether the node is even a candidate for any IPA-SRA transformation at | |
260 | all. */ | |
261 | unsigned m_candidate : 1; | |
262 | ||
263 | /* Whether the original function returns any value. */ | |
264 | unsigned m_returns_value : 1; | |
265 | ||
266 | /* Set to true if all call statements do not actually use the returned | |
267 | value. */ | |
268 | ||
269 | unsigned m_return_ignored : 1; | |
270 | ||
271 | /* Whether the node is already queued in IPA SRA stack during processing of | |
272 | call graphs SCCs. */ | |
273 | ||
274 | unsigned m_queued : 1; | |
275 | }; | |
276 | ||
277 | /* Clean up and deallocate isra_func_summary points to. TODO: Since this data | |
278 | structure is not in GC memory, this is not necessary and we can consider | |
279 | removing the destructor. */ | |
280 | ||
281 | isra_func_summary::~isra_func_summary () | |
282 | { | |
283 | unsigned len = vec_safe_length (m_parameters); | |
284 | for (unsigned i = 0; i < len; ++i) | |
285 | free_param_decl_accesses (&(*m_parameters)[i]); | |
286 | vec_free (m_parameters); | |
287 | } | |
288 | ||
289 | ||
290 | /* Mark the function as not a candidate for any IPA-SRA transformation. Return | |
291 | true if it was a candidate until now. */ | |
292 | ||
293 | bool | |
294 | isra_func_summary::zap () | |
295 | { | |
296 | bool ret = m_candidate; | |
297 | m_candidate = false; | |
298 | ||
299 | unsigned len = vec_safe_length (m_parameters); | |
300 | for (unsigned i = 0; i < len; ++i) | |
301 | free_param_decl_accesses (&(*m_parameters)[i]); | |
302 | vec_free (m_parameters); | |
303 | ||
304 | return ret; | |
305 | } | |
306 | ||
307 | /* Structure to describe which formal parameters feed into a particular actual | |
308 | arguments. */ | |
309 | ||
310 | struct isra_param_flow | |
311 | { | |
312 | /* Number of elements in array inputs that contain valid data. */ | |
313 | char length; | |
314 | /* Indices of formal parameters that feed into the described actual argument. | |
315 | If aggregate_pass_through or pointer_pass_through below are true, it must | |
316 | contain exactly one element which is passed through from a formal | |
317 | parameter if the given number. Otherwise, the array contains indices of | |
318 | callee's formal parameters which are used to calculate value of this | |
319 | actual argument. */ | |
320 | unsigned char inputs[IPA_SRA_MAX_PARAM_FLOW_LEN]; | |
321 | ||
322 | /* Offset within the formal parameter. */ | |
323 | unsigned unit_offset; | |
324 | /* Size of the portion of the formal parameter that is being passed. */ | |
325 | unsigned unit_size : ISRA_ARG_SIZE_LIMIT_BITS; | |
326 | ||
327 | /* True when the value of this actual copy is a portion of a formal | |
328 | parameter. */ | |
329 | unsigned aggregate_pass_through : 1; | |
330 | /* True when the value of this actual copy is a verbatim pass through of an | |
331 | obtained pointer. */ | |
332 | unsigned pointer_pass_through : 1; | |
333 | /* True when it is safe to copy access candidates here from the callee, which | |
334 | would mean introducing dereferences into callers of the caller. */ | |
335 | unsigned safe_to_import_accesses : 1; | |
336 | }; | |
337 | ||
338 | /* Structure used to convey information about calls from the intra-procedural | |
339 | analysis stage to inter-procedural one. */ | |
340 | ||
341 | class isra_call_summary | |
342 | { | |
343 | public: | |
344 | isra_call_summary () | |
345 | : m_arg_flow (), m_return_ignored (false), m_return_returned (false), | |
346 | m_bit_aligned_arg (false), m_before_any_store (false) | |
347 | {} | |
348 | ||
349 | void init_inputs (unsigned arg_count); | |
350 | void dump (FILE *f); | |
351 | ||
352 | /* Information about what formal parameters of the caller are used to compute | |
353 | individual actual arguments of this call. */ | |
354 | auto_vec <isra_param_flow> m_arg_flow; | |
355 | ||
356 | /* Set to true if the call statement does not have a LHS. */ | |
357 | unsigned m_return_ignored : 1; | |
358 | ||
359 | /* Set to true if the LHS of call statement is only used to construct the | |
360 | return value of the caller. */ | |
361 | unsigned m_return_returned : 1; | |
362 | ||
363 | /* Set when any of the call arguments are not byte-aligned. */ | |
364 | unsigned m_bit_aligned_arg : 1; | |
365 | ||
366 | /* Set to true if the call happend before any (other) store to memory in the | |
367 | caller. */ | |
368 | unsigned m_before_any_store : 1; | |
369 | }; | |
370 | ||
371 | /* Class to manage function summaries. */ | |
372 | ||
373 | class GTY((user)) ipa_sra_function_summaries | |
374 | : public function_summary <isra_func_summary *> | |
375 | { | |
376 | public: | |
377 | ipa_sra_function_summaries (symbol_table *table, bool ggc): | |
378 | function_summary<isra_func_summary *> (table, ggc) { } | |
379 | ||
380 | virtual void duplicate (cgraph_node *, cgraph_node *, | |
381 | isra_func_summary *old_sum, | |
382 | isra_func_summary *new_sum); | |
383 | virtual void insert (cgraph_node *, isra_func_summary *); | |
384 | }; | |
385 | ||
386 | /* Hook that is called by summary when a node is duplicated. */ | |
387 | ||
388 | void | |
389 | ipa_sra_function_summaries::duplicate (cgraph_node *, cgraph_node *, | |
390 | isra_func_summary *old_sum, | |
391 | isra_func_summary *new_sum) | |
392 | { | |
393 | /* TODO: Somehow stop copying when ISRA is doing the cloning, it is | |
394 | useless. */ | |
395 | new_sum->m_candidate = old_sum->m_candidate; | |
396 | new_sum->m_returns_value = old_sum->m_returns_value; | |
397 | new_sum->m_return_ignored = old_sum->m_return_ignored; | |
398 | gcc_assert (!old_sum->m_queued); | |
399 | new_sum->m_queued = false; | |
400 | ||
401 | unsigned param_count = vec_safe_length (old_sum->m_parameters); | |
402 | if (!param_count) | |
403 | return; | |
404 | vec_safe_reserve_exact (new_sum->m_parameters, param_count); | |
405 | new_sum->m_parameters->quick_grow_cleared (param_count); | |
406 | for (unsigned i = 0; i < param_count; i++) | |
407 | { | |
408 | isra_param_desc *s = &(*old_sum->m_parameters)[i]; | |
409 | isra_param_desc *d = &(*new_sum->m_parameters)[i]; | |
410 | ||
411 | d->param_size_limit = s->param_size_limit; | |
412 | d->size_reached = s->size_reached; | |
413 | d->locally_unused = s->locally_unused; | |
414 | d->split_candidate = s->split_candidate; | |
415 | d->by_ref = s->by_ref; | |
416 | ||
417 | unsigned acc_count = vec_safe_length (s->accesses); | |
418 | vec_safe_reserve_exact (d->accesses, acc_count); | |
419 | for (unsigned j = 0; j < acc_count; j++) | |
420 | { | |
421 | param_access *from = (*s->accesses)[j]; | |
422 | param_access *to = ggc_cleared_alloc<param_access> (); | |
423 | to->type = from->type; | |
424 | to->alias_ptr_type = from->alias_ptr_type; | |
425 | to->unit_offset = from->unit_offset; | |
426 | to->unit_size = from->unit_size; | |
427 | to->certain = from->certain; | |
428 | d->accesses->quick_push (to); | |
429 | } | |
430 | } | |
431 | } | |
432 | ||
433 | /* Pointer to the pass function summary holder. */ | |
434 | ||
435 | static GTY(()) ipa_sra_function_summaries *func_sums; | |
436 | ||
437 | /* Hook that is called by summary when new node appears. */ | |
438 | ||
439 | void | |
440 | ipa_sra_function_summaries::insert (cgraph_node *node, isra_func_summary *) | |
441 | { | |
442 | if (opt_for_fn (node->decl, flag_ipa_sra)) | |
443 | { | |
444 | push_cfun (DECL_STRUCT_FUNCTION (node->decl)); | |
445 | ipa_sra_summarize_function (node); | |
446 | pop_cfun (); | |
447 | } | |
448 | else | |
449 | func_sums->remove (node); | |
450 | } | |
451 | ||
452 | /* Class to manage call summaries. */ | |
453 | ||
454 | class ipa_sra_call_summaries: public call_summary <isra_call_summary *> | |
455 | { | |
456 | public: | |
457 | ipa_sra_call_summaries (symbol_table *table): | |
458 | call_summary<isra_call_summary *> (table) { } | |
459 | ||
460 | /* Duplicate info when an edge is cloned. */ | |
461 | virtual void duplicate (cgraph_edge *, cgraph_edge *, | |
462 | isra_call_summary *old_sum, | |
463 | isra_call_summary *new_sum); | |
464 | }; | |
465 | ||
466 | static ipa_sra_call_summaries *call_sums; | |
467 | ||
468 | ||
469 | /* Initialize m_arg_flow of a particular instance of isra_call_summary. | |
470 | ARG_COUNT is the number of actual arguments passed. */ | |
471 | ||
472 | void | |
473 | isra_call_summary::init_inputs (unsigned arg_count) | |
474 | { | |
475 | if (arg_count == 0) | |
476 | { | |
477 | gcc_checking_assert (m_arg_flow.length () == 0); | |
478 | return; | |
479 | } | |
480 | if (m_arg_flow.length () == 0) | |
481 | { | |
482 | m_arg_flow.reserve_exact (arg_count); | |
483 | m_arg_flow.quick_grow_cleared (arg_count); | |
484 | } | |
485 | else | |
486 | gcc_checking_assert (arg_count == m_arg_flow.length ()); | |
487 | } | |
488 | ||
489 | /* Dump all information in call summary to F. */ | |
490 | ||
491 | void | |
492 | isra_call_summary::dump (FILE *f) | |
493 | { | |
494 | if (m_return_ignored) | |
495 | fprintf (f, " return value ignored\n"); | |
496 | if (m_return_returned) | |
497 | fprintf (f, " return value used only to compute caller return value\n"); | |
498 | if (m_before_any_store) | |
499 | fprintf (f, " happens before any store to memory\n"); | |
500 | for (unsigned i = 0; i < m_arg_flow.length (); i++) | |
501 | { | |
502 | fprintf (f, " Parameter %u:\n", i); | |
503 | isra_param_flow *ipf = &m_arg_flow[i]; | |
504 | ||
505 | if (ipf->length) | |
506 | { | |
507 | bool first = true; | |
508 | fprintf (f, " Scalar param sources: "); | |
509 | for (int j = 0; j < ipf->length; j++) | |
510 | { | |
511 | if (!first) | |
512 | fprintf (f, ", "); | |
513 | else | |
514 | first = false; | |
515 | fprintf (f, "%i", (int) ipf->inputs[j]); | |
516 | } | |
517 | fprintf (f, "\n"); | |
518 | } | |
519 | if (ipf->aggregate_pass_through) | |
520 | fprintf (f, " Aggregate pass through from the param given above, " | |
521 | "unit offset: %u , unit size: %u\n", | |
522 | ipf->unit_offset, ipf->unit_size); | |
523 | if (ipf->pointer_pass_through) | |
524 | fprintf (f, " Pointer pass through from the param given above, " | |
525 | "safe_to_import_accesses: %u\n", ipf->safe_to_import_accesses); | |
526 | } | |
527 | } | |
528 | ||
529 | /* Duplicate edge summary when an edge is cloned. */ | |
530 | ||
531 | void | |
532 | ipa_sra_call_summaries::duplicate (cgraph_edge *, cgraph_edge *, | |
533 | isra_call_summary *old_sum, | |
534 | isra_call_summary *new_sum) | |
535 | { | |
536 | unsigned arg_count = old_sum->m_arg_flow.length (); | |
537 | new_sum->init_inputs (arg_count); | |
538 | for (unsigned i = 0; i < arg_count; i++) | |
539 | new_sum->m_arg_flow[i] = old_sum->m_arg_flow[i]; | |
540 | ||
541 | new_sum->m_return_ignored = old_sum->m_return_ignored; | |
542 | new_sum->m_return_returned = old_sum->m_return_returned; | |
543 | new_sum->m_bit_aligned_arg = old_sum->m_bit_aligned_arg; | |
544 | new_sum->m_before_any_store = old_sum->m_before_any_store; | |
545 | } | |
546 | ||
547 | ||
548 | /* With all GTY stuff done, we can move to anonymous namespace. */ | |
549 | namespace { | |
550 | /* Quick mapping from a decl to its param descriptor. */ | |
551 | ||
552 | hash_map<tree, gensum_param_desc *> *decl2desc; | |
553 | ||
554 | /* Countdown of allowed Alias analysis steps during summary building. */ | |
555 | ||
556 | int aa_walking_limit; | |
557 | ||
558 | /* This is a table in which for each basic block and parameter there is a | |
559 | distance (offset + size) in that parameter which is dereferenced and | |
560 | accessed in that BB. */ | |
561 | HOST_WIDE_INT *bb_dereferences = NULL; | |
562 | /* How many by-reference parameters there are in the current function. */ | |
563 | int by_ref_count; | |
564 | ||
565 | /* Bitmap of BBs that can cause the function to "stop" progressing by | |
566 | returning, throwing externally, looping infinitely or calling a function | |
567 | which might abort etc.. */ | |
568 | bitmap final_bbs; | |
569 | ||
570 | /* Obstack to allocate various small structures required only when generating | |
571 | summary for a function. */ | |
572 | struct obstack gensum_obstack; | |
573 | ||
574 | /* Return false the function is apparently unsuitable for IPA-SRA based on it's | |
575 | attributes, return true otherwise. NODE is the cgraph node of the current | |
576 | function. */ | |
577 | ||
578 | static bool | |
579 | ipa_sra_preliminary_function_checks (cgraph_node *node) | |
580 | { | |
581 | if (!node->can_change_signature) | |
582 | { | |
583 | if (dump_file) | |
584 | fprintf (dump_file, "Function cannot change signature.\n"); | |
585 | return false; | |
586 | } | |
587 | ||
588 | if (!tree_versionable_function_p (node->decl)) | |
589 | { | |
590 | if (dump_file) | |
591 | fprintf (dump_file, "Function is not versionable.\n"); | |
592 | return false; | |
593 | } | |
594 | ||
595 | if (!opt_for_fn (node->decl, optimize) | |
596 | || !opt_for_fn (node->decl, flag_ipa_sra)) | |
597 | { | |
598 | if (dump_file) | |
599 | fprintf (dump_file, "Not optimizing or IPA-SRA turned off for this " | |
600 | "function.\n"); | |
601 | return false; | |
602 | } | |
603 | ||
604 | if (DECL_VIRTUAL_P (node->decl)) | |
605 | { | |
606 | if (dump_file) | |
607 | fprintf (dump_file, "Function is a virtual method.\n"); | |
608 | return false; | |
609 | } | |
610 | ||
611 | struct function *fun = DECL_STRUCT_FUNCTION (node->decl); | |
612 | if (fun->stdarg) | |
613 | { | |
614 | if (dump_file) | |
615 | fprintf (dump_file, "Function uses stdarg. \n"); | |
616 | return false; | |
617 | } | |
618 | ||
619 | if (TYPE_ATTRIBUTES (TREE_TYPE (node->decl))) | |
620 | { | |
621 | if (dump_file) | |
622 | fprintf (dump_file, "Function type has attributes. \n"); | |
623 | return false; | |
624 | } | |
625 | ||
626 | if (DECL_DISREGARD_INLINE_LIMITS (node->decl)) | |
627 | { | |
628 | if (dump_file) | |
629 | fprintf (dump_file, "Always inline function will be inlined " | |
630 | "anyway. \n"); | |
631 | return false; | |
632 | } | |
633 | ||
634 | return true; | |
635 | } | |
636 | ||
637 | /* Print access tree starting at ACCESS to F. */ | |
638 | ||
639 | static void | |
640 | dump_gensum_access (FILE *f, gensum_param_access *access, unsigned indent) | |
641 | { | |
642 | fprintf (f, " "); | |
643 | for (unsigned i = 0; i < indent; i++) | |
644 | fprintf (f, " "); | |
645 | fprintf (f, " * Access to offset: " HOST_WIDE_INT_PRINT_DEC, | |
646 | access->offset); | |
647 | fprintf (f, ", size: " HOST_WIDE_INT_PRINT_DEC, access->size); | |
648 | fprintf (f, ", type: "); | |
649 | print_generic_expr (f, access->type); | |
650 | fprintf (f, ", alias_ptr_type: "); | |
651 | print_generic_expr (f, access->alias_ptr_type); | |
652 | fprintf (f, ", nonarg: %u, reverse: %u\n", access->nonarg, access->reverse); | |
653 | for (gensum_param_access *ch = access->first_child; | |
654 | ch; | |
655 | ch = ch->next_sibling) | |
656 | dump_gensum_access (f, ch, indent + 2); | |
657 | } | |
658 | ||
659 | ||
660 | /* Print access tree starting at ACCESS to F. */ | |
661 | ||
662 | static void | |
663 | dump_isra_access (FILE *f, param_access *access) | |
664 | { | |
665 | fprintf (f, " * Access to unit offset: %u", access->unit_offset); | |
666 | fprintf (f, ", unit size: %u", access->unit_size); | |
667 | fprintf (f, ", type: "); | |
668 | print_generic_expr (f, access->type); | |
669 | fprintf (f, ", alias_ptr_type: "); | |
670 | print_generic_expr (f, access->alias_ptr_type); | |
671 | if (access->certain) | |
672 | fprintf (f, ", certain"); | |
673 | else | |
674 | fprintf (f, ", not-certain"); | |
675 | if (access->reverse) | |
676 | fprintf (f, ", reverse"); | |
677 | fprintf (f, "\n"); | |
678 | } | |
679 | ||
680 | /* Dump access tree starting at ACCESS to stderr. */ | |
681 | ||
682 | DEBUG_FUNCTION void | |
683 | debug_isra_access (param_access *access) | |
684 | { | |
685 | dump_isra_access (stderr, access); | |
686 | } | |
687 | ||
688 | /* Dump DESC to F. */ | |
689 | ||
690 | static void | |
691 | dump_gensum_param_descriptor (FILE *f, gensum_param_desc *desc) | |
692 | { | |
693 | if (desc->locally_unused) | |
694 | fprintf (f, " unused with %i call_uses\n", desc->call_uses); | |
695 | if (!desc->split_candidate) | |
696 | { | |
697 | fprintf (f, " not a candidate\n"); | |
698 | return; | |
699 | } | |
700 | if (desc->by_ref) | |
701 | fprintf (f, " by_ref with %u pass throughs\n", desc->ptr_pt_count); | |
702 | ||
703 | for (gensum_param_access *acc = desc->accesses; acc; acc = acc->next_sibling) | |
704 | dump_gensum_access (f, acc, 2); | |
705 | } | |
706 | ||
707 | /* Dump all parameter descriptors in IFS, assuming it describes FNDECL, to | |
708 | F. */ | |
709 | ||
710 | static void | |
711 | dump_gensum_param_descriptors (FILE *f, tree fndecl, | |
712 | vec<gensum_param_desc> *param_descriptions) | |
713 | { | |
714 | tree parm = DECL_ARGUMENTS (fndecl); | |
715 | for (unsigned i = 0; | |
716 | i < param_descriptions->length (); | |
717 | ++i, parm = DECL_CHAIN (parm)) | |
718 | { | |
719 | fprintf (f, " Descriptor for parameter %i ", i); | |
720 | print_generic_expr (f, parm, TDF_UID); | |
721 | fprintf (f, "\n"); | |
722 | dump_gensum_param_descriptor (f, &(*param_descriptions)[i]); | |
723 | } | |
724 | } | |
725 | ||
726 | ||
727 | /* Dump DESC to F. */ | |
728 | ||
729 | static void | |
730 | dump_isra_param_descriptor (FILE *f, isra_param_desc *desc) | |
731 | { | |
732 | if (desc->locally_unused) | |
733 | { | |
734 | fprintf (f, " (locally) unused\n"); | |
735 | } | |
736 | if (!desc->split_candidate) | |
737 | { | |
738 | fprintf (f, " not a candidate for splitting\n"); | |
739 | return; | |
740 | } | |
741 | fprintf (f, " param_size_limit: %u, size_reached: %u%s\n", | |
742 | desc->param_size_limit, desc->size_reached, | |
743 | desc->by_ref ? ", by_ref" : ""); | |
744 | ||
745 | for (unsigned i = 0; i < vec_safe_length (desc->accesses); ++i) | |
746 | { | |
747 | param_access *access = (*desc->accesses)[i]; | |
748 | dump_isra_access (f, access); | |
749 | } | |
750 | } | |
751 | ||
752 | /* Dump all parameter descriptors in IFS, assuming it describes FNDECL, to | |
753 | F. */ | |
754 | ||
755 | static void | |
756 | dump_isra_param_descriptors (FILE *f, tree fndecl, | |
757 | isra_func_summary *ifs) | |
758 | { | |
759 | tree parm = DECL_ARGUMENTS (fndecl); | |
760 | if (!ifs->m_parameters) | |
761 | { | |
762 | fprintf (f, " parameter descriptors not available\n"); | |
763 | return; | |
764 | } | |
765 | ||
766 | for (unsigned i = 0; | |
767 | i < ifs->m_parameters->length (); | |
768 | ++i, parm = DECL_CHAIN (parm)) | |
769 | { | |
770 | fprintf (f, " Descriptor for parameter %i ", i); | |
771 | print_generic_expr (f, parm, TDF_UID); | |
772 | fprintf (f, "\n"); | |
773 | dump_isra_param_descriptor (f, &(*ifs->m_parameters)[i]); | |
774 | } | |
775 | } | |
776 | ||
777 | /* Add SRC to inputs of PARAM_FLOW, unless it would exceed storage. If the | |
778 | function fails return false, otherwise return true. SRC must fit into an | |
779 | unsigned char. Used for purposes of transitive unused parameter | |
780 | removal. */ | |
781 | ||
782 | static bool | |
783 | add_src_to_param_flow (isra_param_flow *param_flow, int src) | |
784 | { | |
785 | gcc_checking_assert (src >= 0 && src <= UCHAR_MAX); | |
786 | if (param_flow->length == IPA_SRA_MAX_PARAM_FLOW_LEN) | |
787 | return false; | |
788 | ||
789 | param_flow->inputs[(int) param_flow->length] = src; | |
790 | param_flow->length++; | |
791 | return true; | |
792 | } | |
793 | ||
794 | /* Add a SRC to the inputs of PARAM_FLOW unless it is already there and assert | |
795 | it is the only input. Used for purposes of transitive parameter | |
796 | splitting. */ | |
797 | ||
798 | static void | |
799 | set_single_param_flow_source (isra_param_flow *param_flow, int src) | |
800 | { | |
801 | gcc_checking_assert (src >= 0 && src <= UCHAR_MAX); | |
802 | if (param_flow->length == 0) | |
803 | { | |
804 | param_flow->inputs[0] = src; | |
805 | param_flow->length = 1; | |
806 | } | |
807 | else if (param_flow->length == 1) | |
808 | gcc_assert (param_flow->inputs[0] == src); | |
809 | else | |
810 | gcc_unreachable (); | |
811 | } | |
812 | ||
813 | /* Assert that there is only a single value in PARAM_FLOW's inputs and return | |
814 | it. */ | |
815 | ||
816 | static unsigned | |
817 | get_single_param_flow_source (const isra_param_flow *param_flow) | |
818 | { | |
819 | gcc_assert (param_flow->length == 1); | |
820 | return param_flow->inputs[0]; | |
821 | } | |
822 | ||
823 | /* Inspect all uses of NAME and simple arithmetic calculations involving NAME | |
824 | in FUN represented with NODE and return a negative number if any of them is | |
825 | used for something else than either an actual call argument, simple | |
826 | arithmetic operation or debug statement. If there are no such uses, return | |
827 | the number of actual arguments that this parameter eventually feeds to (or | |
828 | zero if there is none). For any such parameter, mark PARM_NUM as one of its | |
829 | sources. ANALYZED is a bitmap that tracks which SSA names we have already | |
830 | started investigating. */ | |
831 | ||
832 | static int | |
833 | isra_track_scalar_value_uses (function *fun, cgraph_node *node, tree name, | |
834 | int parm_num, bitmap analyzed) | |
835 | { | |
836 | int res = 0; | |
837 | imm_use_iterator imm_iter; | |
838 | gimple *stmt; | |
839 | ||
840 | FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name) | |
841 | { | |
842 | if (is_gimple_debug (stmt)) | |
843 | continue; | |
844 | ||
845 | /* TODO: We could handle at least const builtin functions like arithmetic | |
846 | operations below. */ | |
847 | if (is_gimple_call (stmt)) | |
848 | { | |
849 | int all_uses = 0; | |
850 | use_operand_p use_p; | |
851 | FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) | |
852 | all_uses++; | |
853 | ||
854 | gcall *call = as_a <gcall *> (stmt); | |
855 | unsigned arg_count; | |
856 | if (gimple_call_internal_p (call) | |
857 | || (arg_count = gimple_call_num_args (call)) == 0) | |
858 | { | |
859 | res = -1; | |
860 | break; | |
861 | } | |
862 | ||
863 | cgraph_edge *cs = node->get_edge (stmt); | |
864 | gcc_checking_assert (cs); | |
865 | isra_call_summary *csum = call_sums->get_create (cs); | |
866 | csum->init_inputs (arg_count); | |
867 | ||
868 | int simple_uses = 0; | |
869 | for (unsigned i = 0; i < arg_count; i++) | |
870 | if (gimple_call_arg (call, i) == name) | |
871 | { | |
872 | if (!add_src_to_param_flow (&csum->m_arg_flow[i], parm_num)) | |
873 | { | |
874 | simple_uses = -1; | |
875 | break; | |
876 | } | |
877 | simple_uses++; | |
878 | } | |
879 | ||
880 | if (simple_uses < 0 | |
881 | || all_uses != simple_uses) | |
882 | { | |
883 | res = -1; | |
884 | break; | |
885 | } | |
886 | res += all_uses; | |
887 | } | |
888 | else if (!stmt_unremovable_because_of_non_call_eh_p (fun, stmt) | |
889 | && ((is_gimple_assign (stmt) && !gimple_has_volatile_ops (stmt)) | |
890 | || gimple_code (stmt) == GIMPLE_PHI)) | |
891 | { | |
892 | tree lhs; | |
893 | if (gimple_code (stmt) == GIMPLE_PHI) | |
894 | lhs = gimple_phi_result (stmt); | |
895 | else | |
896 | lhs = gimple_assign_lhs (stmt); | |
897 | ||
898 | if (TREE_CODE (lhs) != SSA_NAME) | |
899 | { | |
900 | res = -1; | |
901 | break; | |
902 | } | |
903 | gcc_assert (!gimple_vdef (stmt)); | |
904 | if (bitmap_set_bit (analyzed, SSA_NAME_VERSION (lhs))) | |
905 | { | |
906 | int tmp = isra_track_scalar_value_uses (fun, node, lhs, parm_num, | |
907 | analyzed); | |
908 | if (tmp < 0) | |
909 | { | |
910 | res = tmp; | |
911 | break; | |
912 | } | |
913 | res += tmp; | |
914 | } | |
915 | } | |
916 | else | |
917 | { | |
918 | res = -1; | |
919 | break; | |
920 | } | |
921 | } | |
922 | return res; | |
923 | } | |
924 | ||
925 | /* Inspect all uses of PARM, which must be a gimple register, in FUN (which is | |
926 | also described by NODE) and simple arithmetic calculations involving PARM | |
927 | and return false if any of them is used for something else than either an | |
928 | actual call argument, simple arithmetic operation or debug statement. If | |
929 | there are no such uses, return true and store the number of actual arguments | |
930 | that this parameter eventually feeds to (or zero if there is none) to | |
931 | *CALL_USES_P. For any such parameter, mark PARM_NUM as one of its | |
932 | sources. | |
933 | ||
934 | This function is similar to ptr_parm_has_nonarg_uses but its results are | |
935 | meant for unused parameter removal, as opposed to splitting of parameters | |
936 | passed by reference or converting them to passed by value. | |
937 | */ | |
938 | ||
939 | static bool | |
940 | isra_track_scalar_param_local_uses (function *fun, cgraph_node *node, tree parm, | |
941 | int parm_num, int *call_uses_p) | |
942 | { | |
943 | gcc_checking_assert (is_gimple_reg (parm)); | |
944 | ||
945 | tree name = ssa_default_def (fun, parm); | |
946 | if (!name || has_zero_uses (name)) | |
947 | { | |
948 | *call_uses_p = 0; | |
949 | return false; | |
950 | } | |
951 | ||
952 | /* Edge summaries can only handle callers with fewer than 256 parameters. */ | |
953 | if (parm_num > UCHAR_MAX) | |
954 | return true; | |
955 | ||
956 | bitmap analyzed = BITMAP_ALLOC (NULL); | |
957 | int call_uses = isra_track_scalar_value_uses (fun, node, name, parm_num, | |
958 | analyzed); | |
959 | BITMAP_FREE (analyzed); | |
960 | if (call_uses < 0) | |
961 | return true; | |
962 | *call_uses_p = call_uses; | |
963 | return false; | |
964 | } | |
965 | ||
966 | /* Scan immediate uses of a default definition SSA name of a parameter PARM and | |
967 | examine whether there are any nonarg uses that are not actual arguments or | |
968 | otherwise infeasible uses. If so, return true, otherwise return false. | |
969 | Create pass-through IPA flow records for any direct uses as argument calls | |
970 | and if returning false, store their number into *PT_COUNT_P. NODE and FUN | |
971 | must represent the function that is currently analyzed, PARM_NUM must be the | |
972 | index of the analyzed parameter. | |
973 | ||
974 | This function is similar to isra_track_scalar_param_local_uses but its | |
975 | results are meant for splitting of parameters passed by reference or turning | |
976 | them into bits passed by value, as opposed to generic unused parameter | |
977 | removal. | |
978 | */ | |
979 | ||
980 | static bool | |
981 | ptr_parm_has_nonarg_uses (cgraph_node *node, function *fun, tree parm, | |
982 | int parm_num, unsigned *pt_count_p) | |
983 | { | |
984 | imm_use_iterator ui; | |
985 | gimple *stmt; | |
986 | tree name = ssa_default_def (fun, parm); | |
987 | bool ret = false; | |
988 | unsigned pt_count = 0; | |
989 | ||
990 | if (!name || has_zero_uses (name)) | |
991 | return false; | |
992 | ||
993 | /* Edge summaries can only handle callers with fewer than 256 parameters. */ | |
994 | if (parm_num > UCHAR_MAX) | |
995 | return true; | |
996 | ||
997 | FOR_EACH_IMM_USE_STMT (stmt, ui, name) | |
998 | { | |
999 | unsigned uses_ok = 0; | |
1000 | use_operand_p use_p; | |
1001 | ||
1002 | if (is_gimple_debug (stmt)) | |
1003 | continue; | |
1004 | ||
1005 | if (gimple_assign_single_p (stmt)) | |
1006 | { | |
1007 | tree rhs = gimple_assign_rhs1 (stmt); | |
1008 | while (handled_component_p (rhs)) | |
1009 | rhs = TREE_OPERAND (rhs, 0); | |
1010 | if (TREE_CODE (rhs) == MEM_REF | |
1011 | && TREE_OPERAND (rhs, 0) == name | |
1012 | && integer_zerop (TREE_OPERAND (rhs, 1)) | |
1013 | && types_compatible_p (TREE_TYPE (rhs), | |
1014 | TREE_TYPE (TREE_TYPE (name))) | |
1015 | && !TREE_THIS_VOLATILE (rhs)) | |
1016 | uses_ok++; | |
1017 | } | |
1018 | else if (is_gimple_call (stmt)) | |
1019 | { | |
1020 | gcall *call = as_a <gcall *> (stmt); | |
1021 | unsigned arg_count; | |
1022 | if (gimple_call_internal_p (call) | |
1023 | || (arg_count = gimple_call_num_args (call)) == 0) | |
1024 | { | |
1025 | ret = true; | |
1026 | break; | |
1027 | } | |
1028 | ||
1029 | cgraph_edge *cs = node->get_edge (stmt); | |
1030 | gcc_checking_assert (cs); | |
1031 | isra_call_summary *csum = call_sums->get_create (cs); | |
1032 | csum->init_inputs (arg_count); | |
1033 | ||
1034 | for (unsigned i = 0; i < arg_count; ++i) | |
1035 | { | |
1036 | tree arg = gimple_call_arg (stmt, i); | |
1037 | ||
1038 | if (arg == name) | |
1039 | { | |
1040 | /* TODO: Allow &MEM_REF[name + offset] here, | |
1041 | ipa_param_body_adjustments::modify_call_stmt has to be | |
1042 | adjusted too. */ | |
1043 | csum->m_arg_flow[i].pointer_pass_through = true; | |
1044 | set_single_param_flow_source (&csum->m_arg_flow[i], parm_num); | |
1045 | pt_count++; | |
1046 | uses_ok++; | |
1047 | continue; | |
1048 | } | |
1049 | ||
1050 | while (handled_component_p (arg)) | |
1051 | arg = TREE_OPERAND (arg, 0); | |
1052 | if (TREE_CODE (arg) == MEM_REF | |
1053 | && TREE_OPERAND (arg, 0) == name | |
1054 | && integer_zerop (TREE_OPERAND (arg, 1)) | |
1055 | && types_compatible_p (TREE_TYPE (arg), | |
1056 | TREE_TYPE (TREE_TYPE (name))) | |
1057 | && !TREE_THIS_VOLATILE (arg)) | |
1058 | uses_ok++; | |
1059 | } | |
1060 | } | |
1061 | ||
1062 | /* If the number of valid uses does not match the number of | |
1063 | uses in this stmt there is an unhandled use. */ | |
1064 | unsigned all_uses = 0; | |
1065 | FOR_EACH_IMM_USE_ON_STMT (use_p, ui) | |
1066 | all_uses++; | |
1067 | ||
1068 | gcc_checking_assert (uses_ok <= all_uses); | |
1069 | if (uses_ok != all_uses) | |
1070 | { | |
1071 | ret = true; | |
1072 | break; | |
1073 | } | |
1074 | } | |
1075 | ||
1076 | *pt_count_p = pt_count; | |
1077 | return ret; | |
1078 | } | |
1079 | ||
1080 | /* Initialize vector of parameter descriptors of NODE. Return true if there | |
1081 | are any candidates for splitting or unused aggregate parameter removal (the | |
1082 | function may return false if there are candidates for removal of register | |
1083 | parameters) and function body must be scanned. */ | |
1084 | ||
1085 | static bool | |
1086 | create_parameter_descriptors (cgraph_node *node, | |
1087 | vec<gensum_param_desc> *param_descriptions) | |
1088 | { | |
1089 | function *fun = DECL_STRUCT_FUNCTION (node->decl); | |
1090 | bool ret = false; | |
1091 | ||
1092 | int num = 0; | |
1093 | for (tree parm = DECL_ARGUMENTS (node->decl); | |
1094 | parm; | |
1095 | parm = DECL_CHAIN (parm), num++) | |
1096 | { | |
1097 | const char *msg; | |
1098 | gensum_param_desc *desc = &(*param_descriptions)[num]; | |
1099 | /* param_descriptions vector is grown cleared in the caller. */ | |
1100 | desc->param_number = num; | |
1101 | decl2desc->put (parm, desc); | |
1102 | ||
1103 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1104 | print_generic_expr (dump_file, parm, TDF_UID); | |
1105 | ||
1106 | int scalar_call_uses; | |
1107 | tree type = TREE_TYPE (parm); | |
1108 | if (TREE_THIS_VOLATILE (parm)) | |
1109 | { | |
1110 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1111 | fprintf (dump_file, " not a candidate, is volatile\n"); | |
1112 | continue; | |
1113 | } | |
1114 | if (!is_gimple_reg_type (type) && is_va_list_type (type)) | |
1115 | { | |
1116 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1117 | fprintf (dump_file, " not a candidate, is a va_list type\n"); | |
1118 | continue; | |
1119 | } | |
1120 | if (TREE_ADDRESSABLE (parm)) | |
1121 | { | |
1122 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1123 | fprintf (dump_file, " not a candidate, is addressable\n"); | |
1124 | continue; | |
1125 | } | |
1126 | if (TREE_ADDRESSABLE (type)) | |
1127 | { | |
1128 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1129 | fprintf (dump_file, " not a candidate, type cannot be split\n"); | |
1130 | continue; | |
1131 | } | |
1132 | ||
1133 | if (is_gimple_reg (parm) | |
1134 | && !isra_track_scalar_param_local_uses (fun, node, parm, num, | |
1135 | &scalar_call_uses)) | |
1136 | { | |
1137 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1138 | fprintf (dump_file, " is a scalar with only %i call uses\n", | |
1139 | scalar_call_uses); | |
1140 | ||
1141 | desc->locally_unused = true; | |
1142 | desc->call_uses = scalar_call_uses; | |
1143 | } | |
1144 | ||
1145 | if (POINTER_TYPE_P (type)) | |
1146 | { | |
1147 | type = TREE_TYPE (type); | |
1148 | ||
1149 | if (TREE_CODE (type) == FUNCTION_TYPE | |
1150 | || TREE_CODE (type) == METHOD_TYPE) | |
1151 | { | |
1152 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1153 | fprintf (dump_file, " not a candidate, reference to " | |
1154 | "a function\n"); | |
1155 | continue; | |
1156 | } | |
1157 | if (TYPE_VOLATILE (type)) | |
1158 | { | |
1159 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1160 | fprintf (dump_file, " not a candidate, reference to " | |
1161 | "a volatile type\n"); | |
1162 | continue; | |
1163 | } | |
1164 | if (TREE_CODE (type) == ARRAY_TYPE | |
1165 | && TYPE_NONALIASED_COMPONENT (type)) | |
1166 | { | |
1167 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1168 | fprintf (dump_file, " not a candidate, reference to " | |
1169 | "a nonaliased component array\n"); | |
1170 | continue; | |
1171 | } | |
1172 | if (!is_gimple_reg (parm)) | |
1173 | { | |
1174 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1175 | fprintf (dump_file, " not a candidate, a reference which is " | |
1176 | "not a gimple register (probably addressable)\n"); | |
1177 | continue; | |
1178 | } | |
1179 | if (is_va_list_type (type)) | |
1180 | { | |
1181 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1182 | fprintf (dump_file, " not a candidate, reference to " | |
1183 | "a va list\n"); | |
1184 | continue; | |
1185 | } | |
1186 | if (ptr_parm_has_nonarg_uses (node, fun, parm, num, | |
1187 | &desc->ptr_pt_count)) | |
1188 | { | |
1189 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1190 | fprintf (dump_file, " not a candidate, reference has " | |
1191 | "nonarg uses\n"); | |
1192 | continue; | |
1193 | } | |
1194 | desc->by_ref = true; | |
1195 | } | |
1196 | else if (!AGGREGATE_TYPE_P (type)) | |
1197 | { | |
1198 | /* This is in an else branch because scalars passed by reference are | |
1199 | still candidates to be passed by value. */ | |
1200 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1201 | fprintf (dump_file, " not a candidate, not an aggregate\n"); | |
1202 | continue; | |
1203 | } | |
1204 | ||
1205 | if (!COMPLETE_TYPE_P (type)) | |
1206 | { | |
1207 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1208 | fprintf (dump_file, " not a candidate, not a complete type\n"); | |
1209 | continue; | |
1210 | } | |
1211 | if (!tree_fits_uhwi_p (TYPE_SIZE (type))) | |
1212 | { | |
1213 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1214 | fprintf (dump_file, " not a candidate, size not representable\n"); | |
1215 | continue; | |
1216 | } | |
1217 | unsigned HOST_WIDE_INT type_size | |
1218 | = tree_to_uhwi (TYPE_SIZE (type)) / BITS_PER_UNIT; | |
1219 | if (type_size == 0 | |
1220 | || type_size >= ISRA_ARG_SIZE_LIMIT) | |
1221 | { | |
1222 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1223 | fprintf (dump_file, " not a candidate, has zero or huge size\n"); | |
1224 | continue; | |
1225 | } | |
1226 | if (type_internals_preclude_sra_p (type, &msg)) | |
1227 | { | |
1228 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1229 | fprintf (dump_file, " not a candidate, %s\n", msg); | |
1230 | continue; | |
1231 | } | |
1232 | ||
1233 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1234 | fprintf (dump_file, " is a candidate\n"); | |
1235 | ||
1236 | ret = true; | |
1237 | desc->split_candidate = true; | |
1238 | if (desc->by_ref) | |
1239 | desc->deref_index = by_ref_count++; | |
1240 | } | |
1241 | return ret; | |
1242 | } | |
1243 | ||
1244 | /* Return pointer to descriptor of parameter DECL or NULL if it cannot be | |
1245 | found, which happens if DECL is for a static chain. */ | |
1246 | ||
1247 | static gensum_param_desc * | |
1248 | get_gensum_param_desc (tree decl) | |
1249 | { | |
1250 | gcc_checking_assert (TREE_CODE (decl) == PARM_DECL); | |
1251 | gensum_param_desc **slot = decl2desc->get (decl); | |
1252 | if (!slot) | |
1253 | /* This can happen for static chains which we cannot handle so far. */ | |
1254 | return NULL; | |
1255 | gcc_checking_assert (*slot); | |
1256 | return *slot; | |
1257 | } | |
1258 | ||
1259 | ||
1260 | /* Remove parameter described by DESC from candidates for IPA-SRA splitting and | |
1261 | write REASON to the dump file if there is one. */ | |
1262 | ||
1263 | static void | |
1264 | disqualify_split_candidate (gensum_param_desc *desc, const char *reason) | |
1265 | { | |
1266 | if (!desc->split_candidate) | |
1267 | return; | |
1268 | ||
1269 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1270 | fprintf (dump_file, "! Disqualifying parameter number %i - %s\n", | |
1271 | desc->param_number, reason); | |
1272 | ||
1273 | desc->split_candidate = false; | |
1274 | } | |
1275 | ||
1276 | /* Remove DECL from candidates for IPA-SRA and write REASON to the dump file if | |
1277 | there is one. */ | |
1278 | ||
1279 | static void | |
1280 | disqualify_split_candidate (tree decl, const char *reason) | |
1281 | { | |
1282 | gensum_param_desc *desc = get_gensum_param_desc (decl); | |
1283 | if (desc) | |
1284 | disqualify_split_candidate (desc, reason); | |
1285 | } | |
1286 | ||
1287 | /* Allocate a new access to DESC and fill it in with OFFSET and SIZE. But | |
1288 | first, check that there are not too many of them already. If so, do not | |
1289 | allocate anything and return NULL. */ | |
1290 | ||
1291 | static gensum_param_access * | |
1292 | allocate_access (gensum_param_desc *desc, | |
1293 | HOST_WIDE_INT offset, HOST_WIDE_INT size) | |
1294 | { | |
1295 | if (desc->access_count | |
1296 | == (unsigned) param_ipa_sra_max_replacements) | |
1297 | { | |
1298 | disqualify_split_candidate (desc, "Too many replacement candidates"); | |
1299 | return NULL; | |
1300 | } | |
1301 | ||
1302 | gensum_param_access *access | |
1303 | = (gensum_param_access *) obstack_alloc (&gensum_obstack, | |
1304 | sizeof (gensum_param_access)); | |
1305 | memset (access, 0, sizeof (*access)); | |
1306 | access->offset = offset; | |
1307 | access->size = size; | |
1308 | return access; | |
1309 | } | |
1310 | ||
1311 | /* In what context scan_expr_access has been called, whether it deals with a | |
1312 | load, a function argument, or a store. Please note that in rare | |
1313 | circumstances when it is not clear if the access is a load or store, | |
1314 | ISRA_CTX_STORE is used too. */ | |
1315 | ||
1316 | enum isra_scan_context {ISRA_CTX_LOAD, ISRA_CTX_ARG, ISRA_CTX_STORE}; | |
1317 | ||
1318 | /* Return an access describing memory access to the variable described by DESC | |
1319 | at OFFSET with SIZE in context CTX, starting at pointer to the linked list | |
1320 | at a certain tree level FIRST. Attempt to create it and put into the | |
1321 | appropriate place in the access tree if does not exist, but fail and return | |
1322 | NULL if there are already too many accesses, if it would create a partially | |
1323 | overlapping access or if an access would end up within a pre-existing | |
1324 | non-call access. */ | |
1325 | ||
1326 | static gensum_param_access * | |
1327 | get_access_1 (gensum_param_desc *desc, gensum_param_access **first, | |
1328 | HOST_WIDE_INT offset, HOST_WIDE_INT size, isra_scan_context ctx) | |
1329 | { | |
1330 | gensum_param_access *access = *first, **ptr = first; | |
1331 | ||
1332 | if (!access) | |
1333 | { | |
1334 | /* No pre-existing access at this level, just create it. */ | |
1335 | gensum_param_access *a = allocate_access (desc, offset, size); | |
1336 | if (!a) | |
1337 | return NULL; | |
1338 | *first = a; | |
1339 | return *first; | |
1340 | } | |
1341 | ||
1342 | if (access->offset >= offset + size) | |
1343 | { | |
1344 | /* We want to squeeze it in front of the very first access, just do | |
1345 | it. */ | |
1346 | gensum_param_access *r = allocate_access (desc, offset, size); | |
1347 | if (!r) | |
1348 | return NULL; | |
1349 | r->next_sibling = access; | |
1350 | *first = r; | |
1351 | return r; | |
1352 | } | |
1353 | ||
1354 | /* Skip all accesses that have to come before us until the next sibling is | |
1355 | already too far. */ | |
1356 | while (offset >= access->offset + access->size | |
1357 | && access->next_sibling | |
1358 | && access->next_sibling->offset < offset + size) | |
1359 | { | |
1360 | ptr = &access->next_sibling; | |
1361 | access = access->next_sibling; | |
1362 | } | |
1363 | ||
1364 | /* At this point we know we do not belong before access. */ | |
1365 | gcc_assert (access->offset < offset + size); | |
1366 | ||
1367 | if (access->offset == offset && access->size == size) | |
1368 | /* We found what we were looking for. */ | |
1369 | return access; | |
1370 | ||
1371 | if (access->offset <= offset | |
1372 | && access->offset + access->size >= offset + size) | |
1373 | { | |
1374 | /* We fit into access which is larger than us. We need to find/create | |
1375 | something below access. But we only allow nesting in call | |
1376 | arguments. */ | |
1377 | if (access->nonarg) | |
1378 | return NULL; | |
1379 | ||
1380 | return get_access_1 (desc, &access->first_child, offset, size, ctx); | |
1381 | } | |
1382 | ||
1383 | if (offset <= access->offset | |
1384 | && offset + size >= access->offset + access->size) | |
1385 | /* We are actually bigger than access, which fully fits into us, take its | |
1386 | place and make all accesses fitting into it its children. */ | |
1387 | { | |
1388 | /* But first, we only allow nesting in call arguments so check if that is | |
1389 | what we are trying to represent. */ | |
1390 | if (ctx != ISRA_CTX_ARG) | |
1391 | return NULL; | |
1392 | ||
1393 | gensum_param_access *r = allocate_access (desc, offset, size); | |
1394 | if (!r) | |
1395 | return NULL; | |
1396 | r->first_child = access; | |
1397 | ||
1398 | while (access->next_sibling | |
1399 | && access->next_sibling->offset < offset + size) | |
1400 | access = access->next_sibling; | |
1401 | if (access->offset + access->size > offset + size) | |
1402 | { | |
1403 | /* This must be a different access, which are sorted, so the | |
1404 | following must be true and this signals a partial overlap. */ | |
1405 | gcc_assert (access->offset > offset); | |
1406 | return NULL; | |
1407 | } | |
1408 | ||
1409 | r->next_sibling = access->next_sibling; | |
1410 | access->next_sibling = NULL; | |
1411 | *ptr = r; | |
1412 | return r; | |
1413 | } | |
1414 | ||
1415 | if (offset >= access->offset + access->size) | |
1416 | { | |
1417 | /* We belong after access. */ | |
1418 | gensum_param_access *r = allocate_access (desc, offset, size); | |
1419 | if (!r) | |
1420 | return NULL; | |
1421 | r->next_sibling = access->next_sibling; | |
1422 | access->next_sibling = r; | |
1423 | return r; | |
1424 | } | |
1425 | ||
1426 | if (offset < access->offset) | |
1427 | { | |
1428 | /* We know the following, otherwise we would have created a | |
1429 | super-access. */ | |
1430 | gcc_checking_assert (offset + size < access->offset + access->size); | |
1431 | return NULL; | |
1432 | } | |
1433 | ||
1434 | if (offset + size > access->offset + access->size) | |
1435 | { | |
1436 | /* Likewise. */ | |
1437 | gcc_checking_assert (offset > access->offset); | |
1438 | return NULL; | |
1439 | } | |
1440 | ||
1441 | gcc_unreachable (); | |
1442 | } | |
1443 | ||
1444 | /* Return an access describing memory access to the variable described by DESC | |
1445 | at OFFSET with SIZE in context CTX, mark it as used in context CTX. Attempt | |
1446 | to create if it does not exist, but fail and return NULL if there are | |
1447 | already too many accesses, if it would create a partially overlapping access | |
1448 | or if an access would end up in a non-call access. */ | |
1449 | ||
1450 | static gensum_param_access * | |
1451 | get_access (gensum_param_desc *desc, HOST_WIDE_INT offset, HOST_WIDE_INT size, | |
1452 | isra_scan_context ctx) | |
1453 | { | |
1454 | gcc_checking_assert (desc->split_candidate); | |
1455 | ||
1456 | gensum_param_access *access = get_access_1 (desc, &desc->accesses, offset, | |
1457 | size, ctx); | |
1458 | if (!access) | |
1459 | { | |
1460 | disqualify_split_candidate (desc, | |
1461 | "Bad access overlap or too many accesses"); | |
1462 | return NULL; | |
1463 | } | |
1464 | ||
1465 | switch (ctx) | |
1466 | { | |
1467 | case ISRA_CTX_STORE: | |
1468 | gcc_assert (!desc->by_ref); | |
1469 | /* Fall-through */ | |
1470 | case ISRA_CTX_LOAD: | |
1471 | access->nonarg = true; | |
1472 | break; | |
1473 | case ISRA_CTX_ARG: | |
1474 | break; | |
1475 | } | |
1476 | ||
1477 | return access; | |
1478 | } | |
1479 | ||
1480 | /* Verify that parameter access tree starting with ACCESS is in good shape. | |
1481 | PARENT_OFFSET and PARENT_SIZE are the corresponding fields of parent of | |
1482 | ACCESS or zero if there is none. */ | |
1483 | ||
1484 | static bool | |
1485 | verify_access_tree_1 (gensum_param_access *access, HOST_WIDE_INT parent_offset, | |
1486 | HOST_WIDE_INT parent_size) | |
1487 | { | |
1488 | while (access) | |
1489 | { | |
1490 | gcc_assert (access->offset >= 0 && access->size >= 0); | |
1491 | ||
1492 | if (parent_size != 0) | |
1493 | { | |
1494 | if (access->offset < parent_offset) | |
1495 | { | |
1496 | error ("Access offset before parent offset"); | |
1497 | return true; | |
1498 | } | |
1499 | if (access->size >= parent_size) | |
1500 | { | |
1501 | error ("Access size greater or equal to its parent size"); | |
1502 | return true; | |
1503 | } | |
1504 | if (access->offset + access->size > parent_offset + parent_size) | |
1505 | { | |
1506 | error ("Access terminates outside of its parent"); | |
1507 | return true; | |
1508 | } | |
1509 | } | |
1510 | ||
1511 | if (verify_access_tree_1 (access->first_child, access->offset, | |
1512 | access->size)) | |
1513 | return true; | |
1514 | ||
1515 | if (access->next_sibling | |
1516 | && (access->next_sibling->offset < access->offset + access->size)) | |
1517 | { | |
1518 | error ("Access overlaps with its sibling"); | |
1519 | return true; | |
1520 | } | |
1521 | ||
1522 | access = access->next_sibling; | |
1523 | } | |
1524 | return false; | |
1525 | } | |
1526 | ||
1527 | /* Verify that parameter access tree starting with ACCESS is in good shape, | |
1528 | halt compilation and dump the tree to stderr if not. */ | |
1529 | ||
1530 | DEBUG_FUNCTION void | |
1531 | isra_verify_access_tree (gensum_param_access *access) | |
1532 | { | |
1533 | if (verify_access_tree_1 (access, 0, 0)) | |
1534 | { | |
1535 | for (; access; access = access->next_sibling) | |
1536 | dump_gensum_access (stderr, access, 2); | |
1537 | internal_error ("IPA-SRA access verification failed"); | |
1538 | } | |
1539 | } | |
1540 | ||
1541 | ||
1542 | /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine | |
1543 | GIMPLE_ASM operands with memory constrains which cannot be scalarized. */ | |
1544 | ||
1545 | static bool | |
1546 | asm_visit_addr (gimple *, tree op, tree, void *) | |
1547 | { | |
1548 | op = get_base_address (op); | |
1549 | if (op | |
1550 | && TREE_CODE (op) == PARM_DECL) | |
1551 | disqualify_split_candidate (op, "Non-scalarizable GIMPLE_ASM operand."); | |
1552 | ||
1553 | return false; | |
1554 | } | |
1555 | ||
1556 | /* Mark a dereference of parameter identified by DESC of distance DIST in a | |
1557 | basic block BB, unless the BB has already been marked as a potentially | |
1558 | final. */ | |
1559 | ||
1560 | static void | |
1561 | mark_param_dereference (gensum_param_desc *desc, HOST_WIDE_INT dist, | |
1562 | basic_block bb) | |
1563 | { | |
1564 | gcc_assert (desc->by_ref); | |
1565 | gcc_checking_assert (desc->split_candidate); | |
1566 | ||
1567 | if (bitmap_bit_p (final_bbs, bb->index)) | |
1568 | return; | |
1569 | ||
1570 | int idx = bb->index * by_ref_count + desc->deref_index; | |
1571 | if (bb_dereferences[idx] < dist) | |
1572 | bb_dereferences[idx] = dist; | |
1573 | } | |
1574 | ||
1575 | /* Return true, if any potential replacements should use NEW_TYPE as opposed to | |
1576 | previously recorded OLD_TYPE. */ | |
1577 | ||
1578 | static bool | |
1579 | type_prevails_p (tree old_type, tree new_type) | |
1580 | { | |
1581 | if (old_type == new_type) | |
1582 | return false; | |
1583 | ||
1584 | /* Non-aggregates are always better. */ | |
1585 | if (!is_gimple_reg_type (old_type) | |
1586 | && is_gimple_reg_type (new_type)) | |
1587 | return true; | |
1588 | if (is_gimple_reg_type (old_type) | |
1589 | && !is_gimple_reg_type (new_type)) | |
1590 | return false; | |
1591 | ||
1592 | /* Prefer any complex or vector type over any other scalar type. */ | |
1593 | if (TREE_CODE (old_type) != COMPLEX_TYPE | |
1594 | && TREE_CODE (old_type) != VECTOR_TYPE | |
1595 | && (TREE_CODE (new_type) == COMPLEX_TYPE | |
1596 | || TREE_CODE (new_type) == VECTOR_TYPE)) | |
1597 | return true; | |
1598 | if ((TREE_CODE (old_type) == COMPLEX_TYPE | |
1599 | || TREE_CODE (old_type) == VECTOR_TYPE) | |
1600 | && TREE_CODE (new_type) != COMPLEX_TYPE | |
1601 | && TREE_CODE (new_type) != VECTOR_TYPE) | |
1602 | return false; | |
1603 | ||
1604 | /* Use the integral type with the bigger precision. */ | |
1605 | if (INTEGRAL_TYPE_P (old_type) | |
1606 | && INTEGRAL_TYPE_P (new_type)) | |
1607 | return (TYPE_PRECISION (new_type) > TYPE_PRECISION (old_type)); | |
1608 | ||
1609 | /* Attempt to disregard any integral type with non-full precision. */ | |
1610 | if (INTEGRAL_TYPE_P (old_type) | |
1611 | && (TREE_INT_CST_LOW (TYPE_SIZE (old_type)) | |
1612 | != TYPE_PRECISION (old_type))) | |
1613 | return true; | |
1614 | if (INTEGRAL_TYPE_P (new_type) | |
1615 | && (TREE_INT_CST_LOW (TYPE_SIZE (new_type)) | |
1616 | != TYPE_PRECISION (new_type))) | |
1617 | return false; | |
1618 | /* Stabilize the selection. */ | |
1619 | return TYPE_UID (old_type) < TYPE_UID (new_type); | |
1620 | } | |
1621 | ||
1622 | /* When scanning an expression which is a call argument, this structure | |
1623 | specifies the call and the position of the argument. */ | |
1624 | ||
1625 | struct scan_call_info | |
1626 | { | |
1627 | /* Call graph edge representing the call. */ | |
1628 | cgraph_edge *cs; | |
1629 | /* Total number of arguments in the call. */ | |
1630 | unsigned argument_count; | |
1631 | /* Number of the actual argument being scanned. */ | |
1632 | unsigned arg_idx; | |
1633 | }; | |
1634 | ||
1635 | /* Record use of ACCESS which belongs to a parameter described by DESC in a | |
1636 | call argument described by CALL_INFO. */ | |
1637 | ||
1638 | static void | |
1639 | record_nonregister_call_use (gensum_param_desc *desc, | |
1640 | scan_call_info *call_info, | |
1641 | unsigned unit_offset, unsigned unit_size) | |
1642 | { | |
1643 | isra_call_summary *csum = call_sums->get_create (call_info->cs); | |
1644 | csum->init_inputs (call_info->argument_count); | |
1645 | ||
1646 | isra_param_flow *param_flow = &csum->m_arg_flow[call_info->arg_idx]; | |
1647 | param_flow->aggregate_pass_through = true; | |
1648 | set_single_param_flow_source (param_flow, desc->param_number); | |
1649 | param_flow->unit_offset = unit_offset; | |
1650 | param_flow->unit_size = unit_size; | |
1651 | desc->call_uses++; | |
1652 | } | |
1653 | ||
1654 | /* Callback of walk_aliased_vdefs, just mark that there was a possible | |
1655 | modification. */ | |
1656 | ||
1657 | static bool | |
1658 | mark_maybe_modified (ao_ref *, tree, void *data) | |
1659 | { | |
1660 | bool *maybe_modified = (bool *) data; | |
1661 | *maybe_modified = true; | |
1662 | return true; | |
1663 | } | |
1664 | ||
1665 | /* Analyze expression EXPR from GIMPLE for accesses to parameters. CTX | |
1666 | specifies whether EXPR is used in a load, store or as an argument call. BB | |
1667 | must be the basic block in which expr resides. If CTX specifies call | |
1668 | argument context, CALL_INFO must describe that call and argument position, | |
1669 | otherwise it is ignored. */ | |
1670 | ||
1671 | static void | |
1672 | scan_expr_access (tree expr, gimple *stmt, isra_scan_context ctx, | |
1673 | basic_block bb, scan_call_info *call_info = NULL) | |
1674 | { | |
1675 | poly_int64 poffset, psize, pmax_size; | |
1676 | HOST_WIDE_INT offset, size, max_size; | |
1677 | tree base; | |
1678 | bool deref = false; | |
1679 | bool reverse; | |
1680 | ||
1681 | if (TREE_CODE (expr) == BIT_FIELD_REF | |
1682 | || TREE_CODE (expr) == IMAGPART_EXPR | |
1683 | || TREE_CODE (expr) == REALPART_EXPR) | |
1684 | expr = TREE_OPERAND (expr, 0); | |
1685 | ||
1686 | base = get_ref_base_and_extent (expr, &poffset, &psize, &pmax_size, &reverse); | |
1687 | ||
1688 | if (TREE_CODE (base) == MEM_REF) | |
1689 | { | |
1690 | tree op = TREE_OPERAND (base, 0); | |
1691 | if (TREE_CODE (op) != SSA_NAME | |
1692 | || !SSA_NAME_IS_DEFAULT_DEF (op)) | |
1693 | return; | |
1694 | base = SSA_NAME_VAR (op); | |
1695 | if (!base) | |
1696 | return; | |
1697 | deref = true; | |
1698 | } | |
1699 | if (TREE_CODE (base) != PARM_DECL) | |
1700 | return; | |
1701 | ||
1702 | gensum_param_desc *desc = get_gensum_param_desc (base); | |
1703 | if (!desc || !desc->split_candidate) | |
1704 | return; | |
1705 | ||
1706 | if (!poffset.is_constant (&offset) | |
1707 | || !psize.is_constant (&size) | |
1708 | || !pmax_size.is_constant (&max_size)) | |
1709 | { | |
1710 | disqualify_split_candidate (desc, "Encountered a polynomial-sized " | |
1711 | "access."); | |
1712 | return; | |
1713 | } | |
1714 | if (size < 0 || size != max_size) | |
1715 | { | |
1716 | disqualify_split_candidate (desc, "Encountered a variable sized access."); | |
1717 | return; | |
1718 | } | |
1719 | if (TREE_CODE (expr) == COMPONENT_REF | |
1720 | && DECL_BIT_FIELD (TREE_OPERAND (expr, 1))) | |
1721 | { | |
1722 | disqualify_split_candidate (desc, "Encountered a bit-field access."); | |
1723 | return; | |
1724 | } | |
1725 | if (offset < 0) | |
1726 | { | |
1727 | disqualify_split_candidate (desc, "Encountered an access at a " | |
1728 | "negative offset."); | |
1729 | return; | |
1730 | } | |
1731 | gcc_assert ((offset % BITS_PER_UNIT) == 0); | |
1732 | gcc_assert ((size % BITS_PER_UNIT) == 0); | |
1733 | if ((offset / BITS_PER_UNIT) >= (UINT_MAX - ISRA_ARG_SIZE_LIMIT) | |
1734 | || (size / BITS_PER_UNIT) >= ISRA_ARG_SIZE_LIMIT) | |
1735 | { | |
1736 | disqualify_split_candidate (desc, "Encountered an access with too big " | |
1737 | "offset or size"); | |
1738 | return; | |
1739 | } | |
1740 | ||
1741 | tree type = TREE_TYPE (expr); | |
1742 | unsigned int exp_align = get_object_alignment (expr); | |
1743 | ||
1744 | if (exp_align < TYPE_ALIGN (type)) | |
1745 | { | |
1746 | disqualify_split_candidate (desc, "Underaligned access."); | |
1747 | return; | |
1748 | } | |
1749 | ||
1750 | if (deref) | |
1751 | { | |
1752 | if (!desc->by_ref) | |
1753 | { | |
1754 | disqualify_split_candidate (desc, "Dereferencing a non-reference."); | |
1755 | return; | |
1756 | } | |
1757 | else if (ctx == ISRA_CTX_STORE) | |
1758 | { | |
1759 | disqualify_split_candidate (desc, "Storing to data passed by " | |
1760 | "reference."); | |
1761 | return; | |
1762 | } | |
1763 | ||
1764 | if (!aa_walking_limit) | |
1765 | { | |
1766 | disqualify_split_candidate (desc, "Out of alias analysis step " | |
1767 | "limit."); | |
1768 | return; | |
1769 | } | |
1770 | ||
1771 | gcc_checking_assert (gimple_vuse (stmt)); | |
1772 | bool maybe_modified = false; | |
1773 | ao_ref ar; | |
1774 | ||
1775 | ao_ref_init (&ar, expr); | |
1776 | bitmap visited = BITMAP_ALLOC (NULL); | |
1777 | int walked = walk_aliased_vdefs (&ar, gimple_vuse (stmt), | |
1778 | mark_maybe_modified, &maybe_modified, | |
1779 | &visited, NULL, aa_walking_limit); | |
1780 | BITMAP_FREE (visited); | |
1781 | if (walked > 0) | |
1782 | { | |
1783 | gcc_assert (aa_walking_limit > walked); | |
1784 | aa_walking_limit = aa_walking_limit - walked; | |
1785 | } | |
1786 | if (walked < 0) | |
1787 | aa_walking_limit = 0; | |
1788 | if (maybe_modified || walked < 0) | |
1789 | { | |
1790 | disqualify_split_candidate (desc, "Data passed by reference possibly " | |
1791 | "modified through an alias."); | |
1792 | return; | |
1793 | } | |
1794 | else | |
1795 | mark_param_dereference (desc, offset + size, bb); | |
1796 | } | |
1797 | else | |
1798 | /* Pointer parameters with direct uses should have been ruled out by | |
1799 | analyzing SSA default def when looking at the parameters. */ | |
1800 | gcc_assert (!desc->by_ref); | |
1801 | ||
1802 | gensum_param_access *access = get_access (desc, offset, size, ctx); | |
1803 | if (!access) | |
1804 | return; | |
1805 | ||
1806 | if (ctx == ISRA_CTX_ARG) | |
1807 | { | |
1808 | gcc_checking_assert (call_info); | |
1809 | ||
1810 | if (!deref) | |
1811 | record_nonregister_call_use (desc, call_info, offset / BITS_PER_UNIT, | |
1812 | size / BITS_PER_UNIT); | |
1813 | else | |
1814 | /* This is not a pass-through of a pointer, this is a use like any | |
1815 | other. */ | |
1816 | access->nonarg = true; | |
1817 | } | |
1818 | ||
1819 | if (!access->type) | |
1820 | { | |
1821 | access->type = type; | |
1822 | access->alias_ptr_type = reference_alias_ptr_type (expr); | |
1823 | access->reverse = reverse; | |
1824 | } | |
1825 | else | |
1826 | { | |
1827 | if (exp_align < TYPE_ALIGN (access->type)) | |
1828 | { | |
1829 | disqualify_split_candidate (desc, "Reference has lower alignment " | |
1830 | "than a previous one."); | |
1831 | return; | |
1832 | } | |
1833 | if (access->alias_ptr_type != reference_alias_ptr_type (expr)) | |
1834 | { | |
1835 | disqualify_split_candidate (desc, "Multiple alias pointer types."); | |
1836 | return; | |
1837 | } | |
1838 | if (access->reverse != reverse) | |
1839 | { | |
1840 | disqualify_split_candidate (desc, "Both normal and reverse " | |
1841 | "scalar storage order."); | |
1842 | return; | |
1843 | } | |
1844 | if (!deref | |
1845 | && (AGGREGATE_TYPE_P (type) || AGGREGATE_TYPE_P (access->type)) | |
1846 | && (TYPE_MAIN_VARIANT (access->type) != TYPE_MAIN_VARIANT (type))) | |
1847 | { | |
1848 | /* We need the same aggregate type on all accesses to be able to | |
1849 | distinguish transformation spots from pass-through arguments in | |
1850 | the transformation phase. */ | |
1851 | disqualify_split_candidate (desc, "We do not support aggregate " | |
1852 | "type punning."); | |
1853 | return; | |
1854 | } | |
1855 | ||
1856 | if (type_prevails_p (access->type, type)) | |
1857 | access->type = type; | |
1858 | } | |
1859 | } | |
1860 | ||
1861 | /* Scan body function described by NODE and FUN and create access trees for | |
1862 | parameters. */ | |
1863 | ||
1864 | static void | |
1865 | scan_function (cgraph_node *node, struct function *fun) | |
1866 | { | |
1867 | basic_block bb; | |
1868 | ||
1869 | FOR_EACH_BB_FN (bb, fun) | |
1870 | { | |
1871 | gimple_stmt_iterator gsi; | |
1872 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1873 | { | |
1874 | gimple *stmt = gsi_stmt (gsi); | |
1875 | ||
1876 | if (stmt_can_throw_external (fun, stmt)) | |
1877 | bitmap_set_bit (final_bbs, bb->index); | |
1878 | switch (gimple_code (stmt)) | |
1879 | { | |
1880 | case GIMPLE_RETURN: | |
1881 | { | |
1882 | tree t = gimple_return_retval (as_a <greturn *> (stmt)); | |
1883 | if (t != NULL_TREE) | |
1884 | scan_expr_access (t, stmt, ISRA_CTX_LOAD, bb); | |
1885 | bitmap_set_bit (final_bbs, bb->index); | |
1886 | } | |
1887 | break; | |
1888 | ||
1889 | case GIMPLE_ASSIGN: | |
1890 | if (gimple_assign_single_p (stmt) | |
1891 | && !gimple_clobber_p (stmt)) | |
1892 | { | |
1893 | tree rhs = gimple_assign_rhs1 (stmt); | |
1894 | scan_expr_access (rhs, stmt, ISRA_CTX_LOAD, bb); | |
1895 | tree lhs = gimple_assign_lhs (stmt); | |
1896 | scan_expr_access (lhs, stmt, ISRA_CTX_STORE, bb); | |
1897 | } | |
1898 | break; | |
1899 | ||
1900 | case GIMPLE_CALL: | |
1901 | { | |
1902 | unsigned argument_count = gimple_call_num_args (stmt); | |
1903 | isra_scan_context ctx = ISRA_CTX_ARG; | |
1904 | scan_call_info call_info, *call_info_p = &call_info; | |
1905 | if (gimple_call_internal_p (stmt)) | |
1906 | { | |
1907 | call_info_p = NULL; | |
1908 | ctx = ISRA_CTX_LOAD; | |
1909 | internal_fn ifn = gimple_call_internal_fn (stmt); | |
1910 | if (internal_store_fn_p (ifn)) | |
1911 | ctx = ISRA_CTX_STORE; | |
1912 | } | |
1913 | else | |
1914 | { | |
1915 | call_info.cs = node->get_edge (stmt); | |
1916 | call_info.argument_count = argument_count; | |
1917 | } | |
1918 | ||
1919 | for (unsigned i = 0; i < argument_count; i++) | |
1920 | { | |
1921 | call_info.arg_idx = i; | |
1922 | scan_expr_access (gimple_call_arg (stmt, i), stmt, | |
1923 | ctx, bb, call_info_p); | |
1924 | } | |
1925 | ||
1926 | tree lhs = gimple_call_lhs (stmt); | |
1927 | if (lhs) | |
1928 | scan_expr_access (lhs, stmt, ISRA_CTX_STORE, bb); | |
1929 | int flags = gimple_call_flags (stmt); | |
1930 | if ((flags & (ECF_CONST | ECF_PURE)) == 0) | |
1931 | bitmap_set_bit (final_bbs, bb->index); | |
1932 | } | |
1933 | break; | |
1934 | ||
1935 | case GIMPLE_ASM: | |
1936 | { | |
1937 | gasm *asm_stmt = as_a <gasm *> (stmt); | |
1938 | walk_stmt_load_store_addr_ops (asm_stmt, NULL, NULL, NULL, | |
1939 | asm_visit_addr); | |
1940 | bitmap_set_bit (final_bbs, bb->index); | |
1941 | ||
1942 | for (unsigned i = 0; i < gimple_asm_ninputs (asm_stmt); i++) | |
1943 | { | |
1944 | tree t = TREE_VALUE (gimple_asm_input_op (asm_stmt, i)); | |
1945 | scan_expr_access (t, stmt, ISRA_CTX_LOAD, bb); | |
1946 | } | |
1947 | for (unsigned i = 0; i < gimple_asm_noutputs (asm_stmt); i++) | |
1948 | { | |
1949 | tree t = TREE_VALUE (gimple_asm_output_op (asm_stmt, i)); | |
1950 | scan_expr_access (t, stmt, ISRA_CTX_STORE, bb); | |
1951 | } | |
1952 | } | |
1953 | break; | |
1954 | ||
1955 | default: | |
1956 | break; | |
1957 | } | |
1958 | } | |
1959 | } | |
1960 | } | |
1961 | ||
1962 | /* Return true if SSA_NAME NAME of function described by FUN is only used in | |
1963 | return statements, or if results of any operations it is involved in are | |
1964 | only used in return statements. ANALYZED is a bitmap that tracks which SSA | |
1965 | names we have already started investigating. */ | |
1966 | ||
1967 | static bool | |
1968 | ssa_name_only_returned_p (function *fun, tree name, bitmap analyzed) | |
1969 | { | |
1970 | bool res = true; | |
1971 | imm_use_iterator imm_iter; | |
1972 | gimple *stmt; | |
1973 | ||
1974 | FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name) | |
1975 | { | |
1976 | if (is_gimple_debug (stmt)) | |
1977 | continue; | |
1978 | ||
1979 | if (gimple_code (stmt) == GIMPLE_RETURN) | |
1980 | { | |
1981 | tree t = gimple_return_retval (as_a <greturn *> (stmt)); | |
1982 | if (t != name) | |
1983 | { | |
1984 | res = false; | |
1985 | break; | |
1986 | } | |
1987 | } | |
1988 | else if (!stmt_unremovable_because_of_non_call_eh_p (fun, stmt) | |
1989 | && ((is_gimple_assign (stmt) && !gimple_has_volatile_ops (stmt)) | |
1990 | || gimple_code (stmt) == GIMPLE_PHI)) | |
1991 | { | |
1992 | /* TODO: And perhaps for const function calls too? */ | |
1993 | tree lhs; | |
1994 | if (gimple_code (stmt) == GIMPLE_PHI) | |
1995 | lhs = gimple_phi_result (stmt); | |
1996 | else | |
1997 | lhs = gimple_assign_lhs (stmt); | |
1998 | ||
1999 | if (TREE_CODE (lhs) != SSA_NAME) | |
2000 | { | |
2001 | res = false; | |
2002 | break; | |
2003 | } | |
2004 | gcc_assert (!gimple_vdef (stmt)); | |
2005 | if (bitmap_set_bit (analyzed, SSA_NAME_VERSION (lhs)) | |
2006 | && !ssa_name_only_returned_p (fun, lhs, analyzed)) | |
2007 | { | |
2008 | res = false; | |
2009 | break; | |
2010 | } | |
2011 | } | |
2012 | else | |
2013 | { | |
2014 | res = false; | |
2015 | break; | |
2016 | } | |
2017 | } | |
2018 | return res; | |
2019 | } | |
2020 | ||
2021 | /* Inspect the uses of the return value of the call associated with CS, and if | |
2022 | it is not used or if it is only used to construct the return value of the | |
2023 | caller, mark it as such in call or caller summary. Also check for | |
2024 | misaligned arguments. */ | |
2025 | ||
2026 | static void | |
2027 | isra_analyze_call (cgraph_edge *cs) | |
2028 | { | |
2029 | gcall *call_stmt = cs->call_stmt; | |
2030 | unsigned count = gimple_call_num_args (call_stmt); | |
2031 | isra_call_summary *csum = call_sums->get_create (cs); | |
2032 | ||
2033 | for (unsigned i = 0; i < count; i++) | |
2034 | { | |
2035 | tree arg = gimple_call_arg (call_stmt, i); | |
2036 | if (is_gimple_reg (arg)) | |
2037 | continue; | |
2038 | ||
2039 | tree offset; | |
2040 | poly_int64 bitsize, bitpos; | |
2041 | machine_mode mode; | |
2042 | int unsignedp, reversep, volatilep = 0; | |
2043 | get_inner_reference (arg, &bitsize, &bitpos, &offset, &mode, | |
2044 | &unsignedp, &reversep, &volatilep); | |
2045 | if (!multiple_p (bitpos, BITS_PER_UNIT)) | |
2046 | { | |
2047 | csum->m_bit_aligned_arg = true; | |
2048 | break; | |
2049 | } | |
2050 | } | |
2051 | ||
2052 | tree lhs = gimple_call_lhs (call_stmt); | |
2053 | if (lhs) | |
2054 | { | |
2055 | /* TODO: Also detect aggregates on a LHS of a call that are only returned | |
2056 | from this function (without being read anywhere). */ | |
2057 | if (TREE_CODE (lhs) == SSA_NAME) | |
2058 | { | |
2059 | bitmap analyzed = BITMAP_ALLOC (NULL); | |
2060 | if (ssa_name_only_returned_p (DECL_STRUCT_FUNCTION (cs->caller->decl), | |
2061 | lhs, analyzed)) | |
2062 | csum->m_return_returned = true; | |
2063 | BITMAP_FREE (analyzed); | |
2064 | } | |
2065 | } | |
2066 | else | |
2067 | csum->m_return_ignored = true; | |
2068 | } | |
2069 | ||
2070 | /* Look at all calls going out of NODE, described also by IFS and perform all | |
2071 | analyses necessary for IPA-SRA that are not done at body scan time or done | |
2072 | even when body is not scanned because the function is not a candidate. */ | |
2073 | ||
2074 | static void | |
2075 | isra_analyze_all_outgoing_calls (cgraph_node *node) | |
2076 | { | |
2077 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) | |
2078 | isra_analyze_call (cs); | |
2079 | for (cgraph_edge *cs = node->indirect_calls; cs; cs = cs->next_callee) | |
2080 | isra_analyze_call (cs); | |
2081 | } | |
2082 | ||
2083 | /* Dump a dereferences table with heading STR to file F. */ | |
2084 | ||
2085 | static void | |
2086 | dump_dereferences_table (FILE *f, struct function *fun, const char *str) | |
2087 | { | |
2088 | basic_block bb; | |
2089 | ||
2090 | fprintf (dump_file, "%s", str); | |
2091 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (fun), | |
2092 | EXIT_BLOCK_PTR_FOR_FN (fun), next_bb) | |
2093 | { | |
2094 | fprintf (f, "%4i %i ", bb->index, bitmap_bit_p (final_bbs, bb->index)); | |
2095 | if (bb != EXIT_BLOCK_PTR_FOR_FN (fun)) | |
2096 | { | |
2097 | int i; | |
2098 | for (i = 0; i < by_ref_count; i++) | |
2099 | { | |
2100 | int idx = bb->index * by_ref_count + i; | |
2101 | fprintf (f, " %4" HOST_WIDE_INT_PRINT "d", bb_dereferences[idx]); | |
2102 | } | |
2103 | } | |
2104 | fprintf (f, "\n"); | |
2105 | } | |
2106 | fprintf (dump_file, "\n"); | |
2107 | } | |
2108 | ||
2109 | /* Propagate distances in bb_dereferences in the opposite direction than the | |
2110 | control flow edges, in each step storing the maximum of the current value | |
2111 | and the minimum of all successors. These steps are repeated until the table | |
2112 | stabilizes. Note that BBs which might terminate the functions (according to | |
2113 | final_bbs bitmap) never updated in this way. */ | |
2114 | ||
2115 | static void | |
2116 | propagate_dereference_distances (struct function *fun) | |
2117 | { | |
2118 | basic_block bb; | |
2119 | ||
2120 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2121 | dump_dereferences_table (dump_file, fun, | |
2122 | "Dereference table before propagation:\n"); | |
2123 | ||
2124 | auto_vec<basic_block> queue (last_basic_block_for_fn (fun)); | |
2125 | queue.quick_push (ENTRY_BLOCK_PTR_FOR_FN (fun)); | |
2126 | FOR_EACH_BB_FN (bb, fun) | |
2127 | { | |
2128 | queue.quick_push (bb); | |
2129 | bb->aux = bb; | |
2130 | } | |
2131 | ||
2132 | while (!queue.is_empty ()) | |
2133 | { | |
2134 | edge_iterator ei; | |
2135 | edge e; | |
2136 | bool change = false; | |
2137 | int i; | |
2138 | ||
2139 | bb = queue.pop (); | |
2140 | bb->aux = NULL; | |
2141 | ||
2142 | if (bitmap_bit_p (final_bbs, bb->index)) | |
2143 | continue; | |
2144 | ||
2145 | for (i = 0; i < by_ref_count; i++) | |
2146 | { | |
2147 | int idx = bb->index * by_ref_count + i; | |
2148 | bool first = true; | |
2149 | HOST_WIDE_INT inh = 0; | |
2150 | ||
2151 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2152 | { | |
2153 | int succ_idx = e->dest->index * by_ref_count + i; | |
2154 | ||
2155 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (fun)) | |
2156 | continue; | |
2157 | ||
2158 | if (first) | |
2159 | { | |
2160 | first = false; | |
2161 | inh = bb_dereferences [succ_idx]; | |
2162 | } | |
2163 | else if (bb_dereferences [succ_idx] < inh) | |
2164 | inh = bb_dereferences [succ_idx]; | |
2165 | } | |
2166 | ||
2167 | if (!first && bb_dereferences[idx] < inh) | |
2168 | { | |
2169 | bb_dereferences[idx] = inh; | |
2170 | change = true; | |
2171 | } | |
2172 | } | |
2173 | ||
2174 | if (change) | |
2175 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2176 | { | |
2177 | if (e->src->aux) | |
2178 | continue; | |
2179 | ||
2180 | e->src->aux = e->src; | |
2181 | queue.quick_push (e->src); | |
2182 | } | |
2183 | } | |
2184 | ||
2185 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2186 | dump_dereferences_table (dump_file, fun, | |
2187 | "Dereference table after propagation:\n"); | |
2188 | } | |
2189 | ||
2190 | /* Perform basic checks on ACCESS to PARM described by DESC and all its | |
2191 | children, return true if the parameter cannot be split, otherwise return | |
2192 | true and update *TOTAL_SIZE and *ONLY_CALLS. ENTRY_BB_INDEX must be the | |
2193 | index of the entry BB in the function of PARM. */ | |
2194 | ||
2195 | static bool | |
2196 | check_gensum_access (tree parm, gensum_param_desc *desc, | |
2197 | gensum_param_access *access, | |
2198 | HOST_WIDE_INT *nonarg_acc_size, bool *only_calls, | |
2199 | int entry_bb_index) | |
2200 | { | |
2201 | if (access->nonarg) | |
2202 | { | |
2203 | *only_calls = false; | |
2204 | *nonarg_acc_size += access->size; | |
2205 | ||
2206 | if (access->first_child) | |
2207 | { | |
2208 | disqualify_split_candidate (desc, "Overlapping non-call uses."); | |
2209 | return true; | |
2210 | } | |
2211 | } | |
2212 | /* Do not decompose a non-BLKmode param in a way that would create | |
2213 | BLKmode params. Especially for by-reference passing (thus, | |
2214 | pointer-type param) this is hardly worthwhile. */ | |
2215 | if (DECL_MODE (parm) != BLKmode | |
2216 | && TYPE_MODE (access->type) == BLKmode) | |
2217 | { | |
2218 | disqualify_split_candidate (desc, "Would convert a non-BLK to a BLK."); | |
2219 | return true; | |
2220 | } | |
2221 | ||
2222 | if (desc->by_ref) | |
2223 | { | |
2224 | int idx = (entry_bb_index * by_ref_count + desc->deref_index); | |
2225 | if ((access->offset + access->size) > bb_dereferences[idx]) | |
2226 | { | |
2227 | disqualify_split_candidate (desc, "Would create a possibly " | |
2228 | "illegal dereference in a caller."); | |
2229 | return true; | |
2230 | } | |
2231 | } | |
2232 | ||
2233 | for (gensum_param_access *ch = access->first_child; | |
2234 | ch; | |
2235 | ch = ch->next_sibling) | |
2236 | if (check_gensum_access (parm, desc, ch, nonarg_acc_size, only_calls, | |
2237 | entry_bb_index)) | |
2238 | return true; | |
2239 | ||
2240 | return false; | |
2241 | } | |
2242 | ||
2243 | /* Copy data from FROM and all of its children to a vector of accesses in IPA | |
2244 | descriptor DESC. */ | |
2245 | ||
2246 | static void | |
2247 | copy_accesses_to_ipa_desc (gensum_param_access *from, isra_param_desc *desc) | |
2248 | { | |
2249 | param_access *to = ggc_cleared_alloc<param_access> (); | |
2250 | gcc_checking_assert ((from->offset % BITS_PER_UNIT) == 0); | |
2251 | gcc_checking_assert ((from->size % BITS_PER_UNIT) == 0); | |
2252 | to->unit_offset = from->offset / BITS_PER_UNIT; | |
2253 | to->unit_size = from->size / BITS_PER_UNIT; | |
2254 | to->type = from->type; | |
2255 | to->alias_ptr_type = from->alias_ptr_type; | |
2256 | to->certain = from->nonarg; | |
2257 | to->reverse = from->reverse; | |
2258 | vec_safe_push (desc->accesses, to); | |
2259 | ||
2260 | for (gensum_param_access *ch = from->first_child; | |
2261 | ch; | |
2262 | ch = ch->next_sibling) | |
2263 | copy_accesses_to_ipa_desc (ch, desc); | |
2264 | } | |
2265 | ||
2266 | /* Analyze function body scan results stored in param_accesses and | |
2267 | param_accesses, detect possible transformations and store information of | |
2268 | those in function summary. NODE, FUN and IFS are all various structures | |
2269 | describing the currently analyzed function. */ | |
2270 | ||
2271 | static void | |
2272 | process_scan_results (cgraph_node *node, struct function *fun, | |
2273 | isra_func_summary *ifs, | |
2274 | vec<gensum_param_desc> *param_descriptions) | |
2275 | { | |
2276 | bool check_pass_throughs = false; | |
2277 | bool dereferences_propagated = false; | |
2278 | tree parm = DECL_ARGUMENTS (node->decl); | |
2279 | unsigned param_count = param_descriptions->length(); | |
2280 | ||
2281 | for (unsigned desc_index = 0; | |
2282 | desc_index < param_count; | |
2283 | desc_index++, parm = DECL_CHAIN (parm)) | |
2284 | { | |
2285 | gensum_param_desc *desc = &(*param_descriptions)[desc_index]; | |
2286 | if (!desc->split_candidate) | |
2287 | continue; | |
2288 | ||
2289 | if (flag_checking) | |
2290 | isra_verify_access_tree (desc->accesses); | |
2291 | ||
2292 | if (!dereferences_propagated | |
2293 | && desc->by_ref | |
2294 | && desc->accesses) | |
2295 | { | |
2296 | propagate_dereference_distances (fun); | |
2297 | dereferences_propagated = true; | |
2298 | } | |
2299 | ||
2300 | HOST_WIDE_INT nonarg_acc_size = 0; | |
2301 | bool only_calls = true; | |
2302 | bool check_failed = false; | |
2303 | ||
2304 | int entry_bb_index = ENTRY_BLOCK_PTR_FOR_FN (fun)->index; | |
2305 | for (gensum_param_access *acc = desc->accesses; | |
2306 | acc; | |
2307 | acc = acc->next_sibling) | |
2308 | if (check_gensum_access (parm, desc, acc, &nonarg_acc_size, &only_calls, | |
2309 | entry_bb_index)) | |
2310 | { | |
2311 | check_failed = true; | |
2312 | break; | |
2313 | } | |
2314 | if (check_failed) | |
2315 | continue; | |
2316 | ||
2317 | if (only_calls) | |
2318 | desc->locally_unused = true; | |
2319 | ||
2320 | HOST_WIDE_INT cur_param_size | |
2321 | = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (parm))); | |
2322 | HOST_WIDE_INT param_size_limit; | |
2323 | if (!desc->by_ref || optimize_function_for_size_p (fun)) | |
2324 | param_size_limit = cur_param_size; | |
2325 | else | |
2326 | param_size_limit | |
2327 | = opt_for_fn (node->decl, | |
2328 | param_ipa_sra_ptr_growth_factor) * cur_param_size; | |
2329 | if (nonarg_acc_size > param_size_limit | |
2330 | || (!desc->by_ref && nonarg_acc_size == param_size_limit)) | |
2331 | { | |
2332 | disqualify_split_candidate (desc, "Would result into a too big set " | |
2333 | "of replacements."); | |
2334 | } | |
2335 | else | |
2336 | { | |
2337 | /* create_parameter_descriptors makes sure unit sizes of all | |
2338 | candidate parameters fit unsigned integers restricted to | |
2339 | ISRA_ARG_SIZE_LIMIT. */ | |
2340 | desc->param_size_limit = param_size_limit / BITS_PER_UNIT; | |
2341 | desc->nonarg_acc_size = nonarg_acc_size / BITS_PER_UNIT; | |
2342 | if (desc->split_candidate && desc->ptr_pt_count) | |
2343 | { | |
2344 | gcc_assert (desc->by_ref); | |
2345 | check_pass_throughs = true; | |
2346 | } | |
2347 | } | |
2348 | } | |
2349 | ||
2350 | /* When a pointer parameter is passed-through to a callee, in which it is | |
2351 | only used to read only one or a few items, we can attempt to transform it | |
2352 | to obtaining and passing through the items instead of the pointer. But we | |
2353 | must take extra care that 1) we do not introduce any segfault by moving | |
2354 | dereferences above control flow and that 2) the data is not modified | |
2355 | through an alias in this function. The IPA analysis must not introduce | |
2356 | any accesses candidates unless it can prove both. | |
2357 | ||
2358 | The current solution is very crude as it consists of ensuring that the | |
2359 | call postdominates entry BB and that the definition of VUSE of the call is | |
2360 | default definition. TODO: For non-recursive callees in the same | |
2361 | compilation unit we could do better by doing analysis in topological order | |
2362 | an looking into access candidates of callees, using their alias_ptr_types | |
2363 | to attempt real AA. We could also use the maximum known dereferenced | |
2364 | offset in this function at IPA level. | |
2365 | ||
2366 | TODO: Measure the overhead and the effect of just being pessimistic. | |
2367 | Maybe this is only -O3 material? | |
2368 | */ | |
2369 | bool pdoms_calculated = false; | |
2370 | if (check_pass_throughs) | |
2371 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) | |
2372 | { | |
2373 | gcall *call_stmt = cs->call_stmt; | |
2374 | tree vuse = gimple_vuse (call_stmt); | |
2375 | ||
2376 | /* If the callee is a const function, we don't get a VUSE. In such | |
2377 | case there will be no memory accesses in the called function (or the | |
2378 | const attribute is wrong) and then we just don't care. */ | |
2379 | bool uses_memory_as_obtained = vuse && SSA_NAME_IS_DEFAULT_DEF (vuse); | |
2380 | ||
2381 | unsigned count = gimple_call_num_args (call_stmt); | |
2382 | isra_call_summary *csum = call_sums->get_create (cs); | |
2383 | csum->init_inputs (count); | |
2384 | csum->m_before_any_store = uses_memory_as_obtained; | |
2385 | for (unsigned argidx = 0; argidx < count; argidx++) | |
2386 | { | |
2387 | if (!csum->m_arg_flow[argidx].pointer_pass_through) | |
2388 | continue; | |
2389 | unsigned pidx | |
2390 | = get_single_param_flow_source (&csum->m_arg_flow[argidx]); | |
2391 | gensum_param_desc *desc = &(*param_descriptions)[pidx]; | |
2392 | if (!desc->split_candidate) | |
2393 | { | |
2394 | csum->m_arg_flow[argidx].pointer_pass_through = false; | |
2395 | continue; | |
2396 | } | |
2397 | if (!uses_memory_as_obtained) | |
2398 | continue; | |
2399 | ||
2400 | /* Post-dominator check placed last, hoping that it usually won't | |
2401 | be needed. */ | |
2402 | if (!pdoms_calculated) | |
2403 | { | |
2404 | gcc_checking_assert (cfun); | |
2405 | connect_infinite_loops_to_exit (); | |
2406 | calculate_dominance_info (CDI_POST_DOMINATORS); | |
2407 | pdoms_calculated = true; | |
2408 | } | |
2409 | if (dominated_by_p (CDI_POST_DOMINATORS, | |
2410 | gimple_bb (call_stmt), | |
2411 | single_succ (ENTRY_BLOCK_PTR_FOR_FN (fun)))) | |
2412 | csum->m_arg_flow[argidx].safe_to_import_accesses = true; | |
2413 | } | |
2414 | ||
2415 | } | |
2416 | if (pdoms_calculated) | |
2417 | { | |
2418 | free_dominance_info (CDI_POST_DOMINATORS); | |
2419 | remove_fake_exit_edges (); | |
2420 | } | |
2421 | ||
2422 | /* TODO: Add early exit if we disqualified everything. This also requires | |
2423 | that we either relax the restriction that | |
2424 | ipa_param_adjustments.m_always_copy_start must be the number of PARM_DECLs | |
2425 | or store the number of parameters to IPA-SRA function summary and use that | |
2426 | when just removing params. */ | |
2427 | ||
2428 | vec_safe_reserve_exact (ifs->m_parameters, param_count); | |
2429 | ifs->m_parameters->quick_grow_cleared (param_count); | |
2430 | for (unsigned desc_index = 0; desc_index < param_count; desc_index++) | |
2431 | { | |
2432 | gensum_param_desc *s = &(*param_descriptions)[desc_index]; | |
2433 | isra_param_desc *d = &(*ifs->m_parameters)[desc_index]; | |
2434 | ||
2435 | d->param_size_limit = s->param_size_limit; | |
2436 | d->size_reached = s->nonarg_acc_size; | |
2437 | d->locally_unused = s->locally_unused; | |
2438 | d->split_candidate = s->split_candidate; | |
2439 | d->by_ref = s->by_ref; | |
2440 | ||
2441 | for (gensum_param_access *acc = s->accesses; | |
2442 | acc; | |
2443 | acc = acc->next_sibling) | |
2444 | copy_accesses_to_ipa_desc (acc, d); | |
2445 | } | |
2446 | ||
2447 | if (dump_file) | |
2448 | dump_isra_param_descriptors (dump_file, node->decl, ifs); | |
2449 | } | |
2450 | ||
2451 | /* Return true if there are any overlaps among certain accesses of DESC. If | |
2452 | non-NULL, set *CERTAIN_ACCESS_PRESENT_P upon encountering a certain access | |
2453 | too. DESC is assumed to be a split candidate that is not locally | |
2454 | unused. */ | |
2455 | ||
2456 | static bool | |
2457 | overlapping_certain_accesses_p (isra_param_desc *desc, | |
2458 | bool *certain_access_present_p) | |
2459 | { | |
2460 | unsigned pclen = vec_safe_length (desc->accesses); | |
2461 | for (unsigned i = 0; i < pclen; i++) | |
2462 | { | |
2463 | param_access *a1 = (*desc->accesses)[i]; | |
2464 | ||
2465 | if (!a1->certain) | |
2466 | continue; | |
2467 | if (certain_access_present_p) | |
2468 | *certain_access_present_p = true; | |
2469 | for (unsigned j = i + 1; j < pclen; j++) | |
2470 | { | |
2471 | param_access *a2 = (*desc->accesses)[j]; | |
2472 | if (a2->certain | |
2473 | && a1->unit_offset < a2->unit_offset + a2->unit_size | |
2474 | && a1->unit_offset + a1->unit_size > a2->unit_offset) | |
2475 | return true; | |
2476 | } | |
2477 | } | |
2478 | return false; | |
2479 | } | |
2480 | ||
2481 | /* Check for any overlaps of certain param accesses among splitting candidates | |
2482 | and signal an ICE if there are any. If CERTAIN_MUST_EXIST is set, also | |
2483 | check that used splitting candidates have at least one certain access. */ | |
2484 | ||
2485 | static void | |
2486 | verify_splitting_accesses (cgraph_node *node, bool certain_must_exist) | |
2487 | { | |
2488 | isra_func_summary *ifs = func_sums->get (node); | |
2489 | if (!ifs || !ifs->m_candidate) | |
2490 | return; | |
2491 | unsigned param_count = vec_safe_length (ifs->m_parameters); | |
2492 | for (unsigned pidx = 0; pidx < param_count; pidx++) | |
2493 | { | |
2494 | isra_param_desc *desc = &(*ifs->m_parameters)[pidx]; | |
2495 | if (!desc->split_candidate || desc->locally_unused) | |
2496 | continue; | |
2497 | ||
2498 | bool certain_access_present = !certain_must_exist; | |
2499 | if (overlapping_certain_accesses_p (desc, &certain_access_present)) | |
2500 | internal_error ("Function %qs, parameter %u, has IPA-SRA accesses " | |
2501 | "which overlap", node->dump_name (), pidx); | |
2502 | if (!certain_access_present) | |
2503 | internal_error ("Function %s, parameter %u, is used but does not " | |
2504 | "have any certain IPA-SRA access", | |
2505 | node->dump_name (), pidx); | |
2506 | } | |
2507 | } | |
2508 | ||
2509 | /* Intraprocedural part of IPA-SRA analysis. Scan bodies of all functions in | |
2510 | this compilation unit and create summary structures describing IPA-SRA | |
2511 | opportunities and constraints in them. */ | |
2512 | ||
2513 | static void | |
2514 | ipa_sra_generate_summary (void) | |
2515 | { | |
2516 | struct cgraph_node *node; | |
2517 | ||
2518 | gcc_checking_assert (!func_sums); | |
2519 | gcc_checking_assert (!call_sums); | |
2520 | func_sums | |
2521 | = (new (ggc_alloc_no_dtor <ipa_sra_function_summaries> ()) | |
2522 | ipa_sra_function_summaries (symtab, true)); | |
2523 | call_sums = new ipa_sra_call_summaries (symtab); | |
2524 | ||
2525 | FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) | |
2526 | ipa_sra_summarize_function (node); | |
2527 | return; | |
2528 | } | |
2529 | ||
2530 | /* Write intraprocedural analysis information about E and all of its outgoing | |
2531 | edges into a stream for LTO WPA. */ | |
2532 | ||
2533 | static void | |
2534 | isra_write_edge_summary (output_block *ob, cgraph_edge *e) | |
2535 | { | |
2536 | isra_call_summary *csum = call_sums->get (e); | |
2537 | unsigned input_count = csum->m_arg_flow.length (); | |
2538 | streamer_write_uhwi (ob, input_count); | |
2539 | for (unsigned i = 0; i < input_count; i++) | |
2540 | { | |
2541 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
2542 | streamer_write_hwi (ob, ipf->length); | |
2543 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2544 | for (int j = 0; j < ipf->length; j++) | |
2545 | bp_pack_value (&bp, ipf->inputs[j], 8); | |
2546 | bp_pack_value (&bp, ipf->aggregate_pass_through, 1); | |
2547 | bp_pack_value (&bp, ipf->pointer_pass_through, 1); | |
2548 | bp_pack_value (&bp, ipf->safe_to_import_accesses, 1); | |
2549 | streamer_write_bitpack (&bp); | |
2550 | streamer_write_uhwi (ob, ipf->unit_offset); | |
2551 | streamer_write_uhwi (ob, ipf->unit_size); | |
2552 | } | |
2553 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2554 | bp_pack_value (&bp, csum->m_return_ignored, 1); | |
2555 | bp_pack_value (&bp, csum->m_return_returned, 1); | |
2556 | bp_pack_value (&bp, csum->m_bit_aligned_arg, 1); | |
2557 | bp_pack_value (&bp, csum->m_before_any_store, 1); | |
2558 | streamer_write_bitpack (&bp); | |
2559 | } | |
2560 | ||
2561 | /* Write intraprocedural analysis information about NODE and all of its outgoing | |
2562 | edges into a stream for LTO WPA. */ | |
2563 | ||
2564 | static void | |
2565 | isra_write_node_summary (output_block *ob, cgraph_node *node) | |
2566 | { | |
2567 | isra_func_summary *ifs = func_sums->get (node); | |
2568 | lto_symtab_encoder_t encoder = ob->decl_state->symtab_node_encoder; | |
2569 | int node_ref = lto_symtab_encoder_encode (encoder, node); | |
2570 | streamer_write_uhwi (ob, node_ref); | |
2571 | ||
2572 | unsigned param_desc_count = vec_safe_length (ifs->m_parameters); | |
2573 | streamer_write_uhwi (ob, param_desc_count); | |
2574 | for (unsigned i = 0; i < param_desc_count; i++) | |
2575 | { | |
2576 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; | |
2577 | unsigned access_count = vec_safe_length (desc->accesses); | |
2578 | streamer_write_uhwi (ob, access_count); | |
2579 | for (unsigned j = 0; j < access_count; j++) | |
2580 | { | |
2581 | param_access *acc = (*desc->accesses)[j]; | |
2582 | stream_write_tree (ob, acc->type, true); | |
2583 | stream_write_tree (ob, acc->alias_ptr_type, true); | |
2584 | streamer_write_uhwi (ob, acc->unit_offset); | |
2585 | streamer_write_uhwi (ob, acc->unit_size); | |
2586 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2587 | bp_pack_value (&bp, acc->certain, 1); | |
2588 | streamer_write_bitpack (&bp); | |
2589 | } | |
2590 | streamer_write_uhwi (ob, desc->param_size_limit); | |
2591 | streamer_write_uhwi (ob, desc->size_reached); | |
2592 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2593 | bp_pack_value (&bp, desc->locally_unused, 1); | |
2594 | bp_pack_value (&bp, desc->split_candidate, 1); | |
2595 | bp_pack_value (&bp, desc->by_ref, 1); | |
2596 | streamer_write_bitpack (&bp); | |
2597 | } | |
2598 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2599 | bp_pack_value (&bp, ifs->m_candidate, 1); | |
2600 | bp_pack_value (&bp, ifs->m_returns_value, 1); | |
2601 | bp_pack_value (&bp, ifs->m_return_ignored, 1); | |
2602 | gcc_assert (!ifs->m_queued); | |
2603 | streamer_write_bitpack (&bp); | |
2604 | ||
2605 | for (cgraph_edge *e = node->callees; e; e = e->next_callee) | |
2606 | isra_write_edge_summary (ob, e); | |
2607 | for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee) | |
2608 | isra_write_edge_summary (ob, e); | |
2609 | } | |
2610 | ||
2611 | /* Write intraprocedural analysis information into a stream for LTO WPA. */ | |
2612 | ||
2613 | static void | |
2614 | ipa_sra_write_summary (void) | |
2615 | { | |
2616 | if (!func_sums || !call_sums) | |
2617 | return; | |
2618 | ||
2619 | struct output_block *ob = create_output_block (LTO_section_ipa_sra); | |
2620 | lto_symtab_encoder_t encoder = ob->decl_state->symtab_node_encoder; | |
2621 | ob->symbol = NULL; | |
2622 | ||
2623 | unsigned int count = 0; | |
2624 | lto_symtab_encoder_iterator lsei; | |
2625 | for (lsei = lsei_start_function_in_partition (encoder); | |
2626 | !lsei_end_p (lsei); | |
2627 | lsei_next_function_in_partition (&lsei)) | |
2628 | { | |
2629 | cgraph_node *node = lsei_cgraph_node (lsei); | |
2630 | if (node->has_gimple_body_p () | |
2631 | && func_sums->get (node) != NULL) | |
2632 | count++; | |
2633 | } | |
2634 | streamer_write_uhwi (ob, count); | |
2635 | ||
2636 | /* Process all of the functions. */ | |
2637 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); | |
2638 | lsei_next_function_in_partition (&lsei)) | |
2639 | { | |
2640 | cgraph_node *node = lsei_cgraph_node (lsei); | |
2641 | if (node->has_gimple_body_p () | |
2642 | && func_sums->get (node) != NULL) | |
2643 | isra_write_node_summary (ob, node); | |
2644 | } | |
2645 | streamer_write_char_stream (ob->main_stream, 0); | |
2646 | produce_asm (ob, NULL); | |
2647 | destroy_output_block (ob); | |
2648 | } | |
2649 | ||
2650 | /* Read intraprocedural analysis information about E and all of its outgoing | |
2651 | edges into a stream for LTO WPA. */ | |
2652 | ||
2653 | static void | |
2654 | isra_read_edge_summary (struct lto_input_block *ib, cgraph_edge *cs) | |
2655 | { | |
2656 | isra_call_summary *csum = call_sums->get_create (cs); | |
2657 | unsigned input_count = streamer_read_uhwi (ib); | |
2658 | csum->init_inputs (input_count); | |
2659 | for (unsigned i = 0; i < input_count; i++) | |
2660 | { | |
2661 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
2662 | ipf->length = streamer_read_hwi (ib); | |
2663 | bitpack_d bp = streamer_read_bitpack (ib); | |
2664 | for (int j = 0; j < ipf->length; j++) | |
2665 | ipf->inputs[j] = bp_unpack_value (&bp, 8); | |
2666 | ipf->aggregate_pass_through = bp_unpack_value (&bp, 1); | |
2667 | ipf->pointer_pass_through = bp_unpack_value (&bp, 1); | |
2668 | ipf->safe_to_import_accesses = bp_unpack_value (&bp, 1); | |
2669 | ipf->unit_offset = streamer_read_uhwi (ib); | |
2670 | ipf->unit_size = streamer_read_uhwi (ib); | |
2671 | } | |
2672 | bitpack_d bp = streamer_read_bitpack (ib); | |
2673 | csum->m_return_ignored = bp_unpack_value (&bp, 1); | |
2674 | csum->m_return_returned = bp_unpack_value (&bp, 1); | |
2675 | csum->m_bit_aligned_arg = bp_unpack_value (&bp, 1); | |
2676 | csum->m_before_any_store = bp_unpack_value (&bp, 1); | |
2677 | } | |
2678 | ||
2679 | /* Read intraprocedural analysis information about NODE and all of its outgoing | |
2680 | edges into a stream for LTO WPA. */ | |
2681 | ||
2682 | static void | |
2683 | isra_read_node_info (struct lto_input_block *ib, cgraph_node *node, | |
2684 | struct data_in *data_in) | |
2685 | { | |
2686 | isra_func_summary *ifs = func_sums->get_create (node); | |
2687 | unsigned param_desc_count = streamer_read_uhwi (ib); | |
2688 | if (param_desc_count > 0) | |
2689 | { | |
2690 | vec_safe_reserve_exact (ifs->m_parameters, param_desc_count); | |
2691 | ifs->m_parameters->quick_grow_cleared (param_desc_count); | |
2692 | } | |
2693 | for (unsigned i = 0; i < param_desc_count; i++) | |
2694 | { | |
2695 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; | |
2696 | unsigned access_count = streamer_read_uhwi (ib); | |
2697 | for (unsigned j = 0; j < access_count; j++) | |
2698 | { | |
2699 | param_access *acc = ggc_cleared_alloc<param_access> (); | |
2700 | acc->type = stream_read_tree (ib, data_in); | |
2701 | acc->alias_ptr_type = stream_read_tree (ib, data_in); | |
2702 | acc->unit_offset = streamer_read_uhwi (ib); | |
2703 | acc->unit_size = streamer_read_uhwi (ib); | |
2704 | bitpack_d bp = streamer_read_bitpack (ib); | |
2705 | acc->certain = bp_unpack_value (&bp, 1); | |
2706 | vec_safe_push (desc->accesses, acc); | |
2707 | } | |
2708 | desc->param_size_limit = streamer_read_uhwi (ib); | |
2709 | desc->size_reached = streamer_read_uhwi (ib); | |
2710 | bitpack_d bp = streamer_read_bitpack (ib); | |
2711 | desc->locally_unused = bp_unpack_value (&bp, 1); | |
2712 | desc->split_candidate = bp_unpack_value (&bp, 1); | |
2713 | desc->by_ref = bp_unpack_value (&bp, 1); | |
2714 | } | |
2715 | bitpack_d bp = streamer_read_bitpack (ib); | |
2716 | ifs->m_candidate = bp_unpack_value (&bp, 1); | |
2717 | ifs->m_returns_value = bp_unpack_value (&bp, 1); | |
2718 | ifs->m_return_ignored = bp_unpack_value (&bp, 1); | |
2719 | ifs->m_queued = 0; | |
2720 | ||
2721 | for (cgraph_edge *e = node->callees; e; e = e->next_callee) | |
2722 | isra_read_edge_summary (ib, e); | |
2723 | for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee) | |
2724 | isra_read_edge_summary (ib, e); | |
2725 | } | |
2726 | ||
2727 | /* Read IPA-SRA summaries from a section in file FILE_DATA of length LEN with | |
2728 | data DATA. TODO: This function was copied almost verbatim from ipa-prop.c, | |
2729 | it should be possible to unify them somehow. */ | |
2730 | ||
2731 | static void | |
2732 | isra_read_summary_section (struct lto_file_decl_data *file_data, | |
2733 | const char *data, size_t len) | |
2734 | { | |
2735 | const struct lto_function_header *header = | |
2736 | (const struct lto_function_header *) data; | |
2737 | const int cfg_offset = sizeof (struct lto_function_header); | |
2738 | const int main_offset = cfg_offset + header->cfg_size; | |
2739 | const int string_offset = main_offset + header->main_size; | |
2740 | struct data_in *data_in; | |
2741 | unsigned int i; | |
2742 | unsigned int count; | |
2743 | ||
2744 | lto_input_block ib_main ((const char *) data + main_offset, | |
2745 | header->main_size, file_data->mode_table); | |
2746 | ||
2747 | data_in = | |
2748 | lto_data_in_create (file_data, (const char *) data + string_offset, | |
2749 | header->string_size, vNULL); | |
2750 | count = streamer_read_uhwi (&ib_main); | |
2751 | ||
2752 | for (i = 0; i < count; i++) | |
2753 | { | |
2754 | unsigned int index; | |
2755 | struct cgraph_node *node; | |
2756 | lto_symtab_encoder_t encoder; | |
2757 | ||
2758 | index = streamer_read_uhwi (&ib_main); | |
2759 | encoder = file_data->symtab_node_encoder; | |
2760 | node = dyn_cast<cgraph_node *> (lto_symtab_encoder_deref (encoder, | |
2761 | index)); | |
2762 | gcc_assert (node->definition); | |
2763 | isra_read_node_info (&ib_main, node, data_in); | |
2764 | } | |
2765 | lto_free_section_data (file_data, LTO_section_ipa_sra, NULL, data, | |
2766 | len); | |
2767 | lto_data_in_delete (data_in); | |
2768 | } | |
2769 | ||
2770 | /* Read intraprocedural analysis information into a stream for LTO WPA. */ | |
2771 | ||
2772 | static void | |
2773 | ipa_sra_read_summary (void) | |
2774 | { | |
2775 | struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); | |
2776 | struct lto_file_decl_data *file_data; | |
2777 | unsigned int j = 0; | |
2778 | ||
2779 | gcc_checking_assert (!func_sums); | |
2780 | gcc_checking_assert (!call_sums); | |
2781 | func_sums | |
2782 | = (new (ggc_alloc_no_dtor <ipa_sra_function_summaries> ()) | |
2783 | ipa_sra_function_summaries (symtab, true)); | |
2784 | call_sums = new ipa_sra_call_summaries (symtab); | |
2785 | ||
2786 | while ((file_data = file_data_vec[j++])) | |
2787 | { | |
2788 | size_t len; | |
2789 | const char *data | |
2790 | = lto_get_summary_section_data (file_data, LTO_section_ipa_sra, &len); | |
2791 | if (data) | |
2792 | isra_read_summary_section (file_data, data, len); | |
2793 | } | |
2794 | } | |
2795 | ||
2796 | /* Dump all IPA-SRA summary data for all cgraph nodes and edges to file F. */ | |
2797 | ||
2798 | static void | |
2799 | ipa_sra_dump_all_summaries (FILE *f) | |
2800 | { | |
2801 | cgraph_node *node; | |
2802 | FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) | |
2803 | { | |
2804 | fprintf (f, "\nSummary for node %s:\n", node->dump_name ()); | |
2805 | ||
2806 | isra_func_summary *ifs = func_sums->get (node); | |
2807 | if (!ifs) | |
2808 | fprintf (f, " Function does not have any associated IPA-SRA " | |
2809 | "summary\n"); | |
2810 | else | |
2811 | { | |
2812 | if (!ifs->m_candidate) | |
2813 | { | |
2814 | fprintf (f, " Not a candidate function\n"); | |
2815 | continue; | |
2816 | } | |
2817 | if (ifs->m_returns_value) | |
2818 | fprintf (f, " Returns value\n"); | |
2819 | if (vec_safe_is_empty (ifs->m_parameters)) | |
2820 | fprintf (f, " No parameter information. \n"); | |
2821 | else | |
2822 | for (unsigned i = 0; i < ifs->m_parameters->length (); ++i) | |
2823 | { | |
2824 | fprintf (f, " Descriptor for parameter %i:\n", i); | |
2825 | dump_isra_param_descriptor (f, &(*ifs->m_parameters)[i]); | |
2826 | } | |
2827 | fprintf (f, "\n"); | |
2828 | } | |
2829 | ||
2830 | struct cgraph_edge *cs; | |
2831 | for (cs = node->callees; cs; cs = cs->next_callee) | |
2832 | { | |
2833 | fprintf (f, " Summary for edge %s->%s:\n", cs->caller->dump_name (), | |
2834 | cs->callee->dump_name ()); | |
2835 | isra_call_summary *csum = call_sums->get (cs); | |
2836 | if (csum) | |
2837 | csum->dump (f); | |
2838 | else | |
2839 | fprintf (f, " Call summary is MISSING!\n"); | |
2840 | } | |
2841 | ||
2842 | } | |
2843 | fprintf (f, "\n\n"); | |
2844 | } | |
2845 | ||
2846 | /* Perform function-scope viability tests that can be only made at IPA level | |
2847 | and return false if the function is deemed unsuitable for IPA-SRA. */ | |
2848 | ||
2849 | static bool | |
2850 | ipa_sra_ipa_function_checks (cgraph_node *node) | |
2851 | { | |
2852 | if (!node->can_be_local_p ()) | |
2853 | { | |
2854 | if (dump_file) | |
2855 | fprintf (dump_file, "Function %s disqualified because it cannot be " | |
2856 | "made local.\n", node->dump_name ()); | |
2857 | return false; | |
2858 | } | |
2859 | if (!node->can_change_signature) | |
2860 | { | |
2861 | if (dump_file) | |
2862 | fprintf (dump_file, "Function can not change signature.\n"); | |
2863 | return false; | |
2864 | } | |
2865 | ||
2866 | return true; | |
2867 | } | |
2868 | ||
2869 | /* Issues found out by check_callers_for_issues. */ | |
2870 | ||
2871 | struct caller_issues | |
2872 | { | |
2873 | /* The candidate being considered. */ | |
2874 | cgraph_node *candidate; | |
2875 | /* There is a thunk among callers. */ | |
2876 | bool thunk; | |
2877 | /* Call site with no available information. */ | |
2878 | bool unknown_callsite; | |
2879 | /* Call from outside the the candidate's comdat group. */ | |
2880 | bool call_from_outside_comdat; | |
2881 | /* There is a bit-aligned load into one of non-gimple-typed arguments. */ | |
2882 | bool bit_aligned_aggregate_argument; | |
2883 | }; | |
2884 | ||
2885 | /* Worker for call_for_symbol_and_aliases, set any flags of passed caller_issues | |
2886 | that apply. */ | |
2887 | ||
2888 | static bool | |
2889 | check_for_caller_issues (struct cgraph_node *node, void *data) | |
2890 | { | |
2891 | struct caller_issues *issues = (struct caller_issues *) data; | |
2892 | ||
2893 | for (cgraph_edge *cs = node->callers; cs; cs = cs->next_caller) | |
2894 | { | |
2895 | if (cs->caller->thunk) | |
2896 | { | |
2897 | issues->thunk = true; | |
2898 | /* TODO: We should be able to process at least some types of | |
2899 | thunks. */ | |
2900 | return true; | |
2901 | } | |
2902 | if (issues->candidate->calls_comdat_local | |
2903 | && issues->candidate->same_comdat_group | |
2904 | && !issues->candidate->in_same_comdat_group_p (cs->caller)) | |
2905 | { | |
2906 | issues->call_from_outside_comdat = true; | |
2907 | return true; | |
2908 | } | |
2909 | ||
2910 | isra_call_summary *csum = call_sums->get (cs); | |
2911 | if (!csum) | |
2912 | { | |
2913 | issues->unknown_callsite = true; | |
2914 | return true; | |
2915 | } | |
2916 | ||
2917 | if (csum->m_bit_aligned_arg) | |
2918 | issues->bit_aligned_aggregate_argument = true; | |
2919 | } | |
2920 | return false; | |
2921 | } | |
2922 | ||
2923 | /* Look at all incoming edges to NODE, including aliases and thunks and look | |
2924 | for problems. Return true if NODE type should not be modified at all. */ | |
2925 | ||
2926 | static bool | |
2927 | check_all_callers_for_issues (cgraph_node *node) | |
2928 | { | |
2929 | struct caller_issues issues; | |
2930 | memset (&issues, 0, sizeof (issues)); | |
2931 | issues.candidate = node; | |
2932 | ||
2933 | node->call_for_symbol_and_aliases (check_for_caller_issues, &issues, true); | |
2934 | if (issues.unknown_callsite) | |
2935 | { | |
2936 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2937 | fprintf (dump_file, "A call of %s has not been analyzed. Disabling " | |
2938 | "all modifications.\n", node->dump_name ()); | |
2939 | return true; | |
2940 | } | |
2941 | /* TODO: We should be able to process at least some types of thunks. */ | |
2942 | if (issues.thunk) | |
2943 | { | |
2944 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2945 | fprintf (dump_file, "A call of %s is through thunk, which are not" | |
2946 | " handled yet. Disabling all modifications.\n", | |
2947 | node->dump_name ()); | |
2948 | return true; | |
2949 | } | |
2950 | if (issues.call_from_outside_comdat) | |
2951 | { | |
2952 | if (dump_file) | |
2953 | fprintf (dump_file, "Function would become private comdat called " | |
2954 | "outside of its comdat group.\n"); | |
2955 | return true; | |
2956 | } | |
2957 | ||
2958 | if (issues.bit_aligned_aggregate_argument) | |
2959 | { | |
2960 | /* Let's only remove parameters/return values from such functions. | |
2961 | TODO: We could only prevent splitting the problematic parameters if | |
2962 | anybody thinks it is worth it. */ | |
2963 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2964 | fprintf (dump_file, "A call of %s has bit-aligned aggregate argument," | |
2965 | " disabling parameter splitting.\n", node->dump_name ()); | |
2966 | ||
2967 | isra_func_summary *ifs = func_sums->get (node); | |
2968 | gcc_checking_assert (ifs); | |
2969 | unsigned param_count = vec_safe_length (ifs->m_parameters); | |
2970 | for (unsigned i = 0; i < param_count; i++) | |
2971 | (*ifs->m_parameters)[i].split_candidate = false; | |
2972 | } | |
2973 | return false; | |
2974 | } | |
2975 | ||
2976 | /* Find the access with corresponding OFFSET and SIZE among accesses in | |
2977 | PARAM_DESC and return it or NULL if such an access is not there. */ | |
2978 | ||
2979 | static param_access * | |
2980 | find_param_access (isra_param_desc *param_desc, unsigned offset, unsigned size) | |
2981 | { | |
2982 | unsigned pclen = vec_safe_length (param_desc->accesses); | |
2983 | ||
2984 | /* The search is linear but the number of stored accesses is bound by | |
2985 | PARAM_IPA_SRA_MAX_REPLACEMENTS, so most probably 8. */ | |
2986 | ||
2987 | for (unsigned i = 0; i < pclen; i++) | |
2988 | if ((*param_desc->accesses)[i]->unit_offset == offset | |
2989 | && (*param_desc->accesses)[i]->unit_size == size) | |
2990 | return (*param_desc->accesses)[i]; | |
2991 | ||
2992 | return NULL; | |
2993 | } | |
2994 | ||
2995 | /* Return iff the total size of definite replacement SIZE would violate the | |
2996 | limit set for it in PARAM. */ | |
2997 | ||
2998 | static bool | |
2999 | size_would_violate_limit_p (isra_param_desc *desc, unsigned size) | |
3000 | { | |
3001 | unsigned limit = desc->param_size_limit; | |
3002 | if (size > limit | |
3003 | || (!desc->by_ref && size == limit)) | |
3004 | return true; | |
3005 | return false; | |
3006 | } | |
3007 | ||
3008 | /* Increase reached size of DESC by SIZE or disqualify it if it would violate | |
3009 | the set limit. IDX is the parameter number which is dumped when | |
3010 | disqualifying. */ | |
3011 | ||
3012 | static void | |
3013 | bump_reached_size (isra_param_desc *desc, unsigned size, unsigned idx) | |
3014 | { | |
3015 | unsigned after = desc->size_reached + size; | |
3016 | if (size_would_violate_limit_p (desc, after)) | |
3017 | { | |
3018 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3019 | fprintf (dump_file, " ...size limit reached, disqualifying " | |
3020 | "candidate parameter %u\n", idx); | |
3021 | desc->split_candidate = false; | |
3022 | return; | |
3023 | } | |
3024 | desc->size_reached = after; | |
3025 | } | |
3026 | ||
3027 | /* Take all actions required to deal with an edge CS that represents a call to | |
3028 | an unknown or un-analyzed function, for both parameter removal and | |
3029 | splitting. */ | |
3030 | ||
3031 | static void | |
3032 | process_edge_to_unknown_caller (cgraph_edge *cs) | |
3033 | { | |
3034 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3035 | gcc_checking_assert (from_ifs); | |
3036 | isra_call_summary *csum = call_sums->get (cs); | |
3037 | ||
3038 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3039 | fprintf (dump_file, "Processing an edge to an unknown caller from %s:\n", | |
3040 | cs->caller->dump_name ()); | |
3041 | ||
3042 | unsigned args_count = csum->m_arg_flow.length (); | |
3043 | for (unsigned i = 0; i < args_count; i++) | |
3044 | { | |
3045 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3046 | ||
3047 | if (ipf->pointer_pass_through) | |
3048 | { | |
3049 | isra_param_desc *param_desc | |
3050 | = &(*from_ifs->m_parameters)[get_single_param_flow_source (ipf)]; | |
3051 | param_desc->locally_unused = false; | |
3052 | param_desc->split_candidate = false; | |
3053 | continue; | |
3054 | } | |
3055 | if (ipf->aggregate_pass_through) | |
3056 | { | |
3057 | unsigned idx = get_single_param_flow_source (ipf); | |
3058 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; | |
3059 | ||
3060 | param_desc->locally_unused = false; | |
3061 | if (!param_desc->split_candidate) | |
3062 | continue; | |
3063 | gcc_assert (!param_desc->by_ref); | |
3064 | param_access *pacc = find_param_access (param_desc, ipf->unit_offset, | |
3065 | ipf->unit_size); | |
3066 | gcc_checking_assert (pacc); | |
3067 | pacc->certain = true; | |
3068 | if (overlapping_certain_accesses_p (param_desc, NULL)) | |
3069 | { | |
3070 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3071 | fprintf (dump_file, " ...leading to overlap, " | |
3072 | " disqualifying candidate parameter %u\n", | |
3073 | idx); | |
3074 | param_desc->split_candidate = false; | |
3075 | } | |
3076 | else | |
3077 | bump_reached_size (param_desc, pacc->unit_size, idx); | |
3078 | ipf->aggregate_pass_through = false; | |
3079 | continue; | |
3080 | } | |
3081 | ||
3082 | for (int j = 0; j < ipf->length; j++) | |
3083 | { | |
3084 | int input_idx = ipf->inputs[j]; | |
3085 | (*from_ifs->m_parameters)[input_idx].locally_unused = false; | |
3086 | } | |
3087 | } | |
3088 | } | |
3089 | ||
3090 | /* Propagate parameter removal information through cross-SCC edge CS, | |
3091 | i.e. decrease the use count in the caller parameter descriptor for each use | |
3092 | in this call. */ | |
3093 | ||
3094 | static void | |
3095 | param_removal_cross_scc_edge (cgraph_edge *cs) | |
3096 | { | |
3097 | enum availability availability; | |
3098 | cgraph_node *callee = cs->callee->function_symbol (&availability); | |
3099 | isra_func_summary *to_ifs = func_sums->get (callee); | |
3100 | if (!to_ifs || !to_ifs->m_candidate | |
3101 | || (availability < AVAIL_AVAILABLE) | |
3102 | || vec_safe_is_empty (to_ifs->m_parameters)) | |
3103 | { | |
3104 | process_edge_to_unknown_caller (cs); | |
3105 | return; | |
3106 | } | |
3107 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3108 | gcc_checking_assert (from_ifs); | |
3109 | ||
3110 | isra_call_summary *csum = call_sums->get (cs); | |
3111 | unsigned args_count = csum->m_arg_flow.length (); | |
3112 | unsigned param_count = vec_safe_length (to_ifs->m_parameters); | |
3113 | ||
3114 | for (unsigned i = 0; i < args_count; i++) | |
3115 | { | |
3116 | bool unused_in_callee; | |
3117 | if (i < param_count) | |
3118 | unused_in_callee = (*to_ifs->m_parameters)[i].locally_unused; | |
3119 | else | |
3120 | unused_in_callee = false; | |
3121 | ||
3122 | if (!unused_in_callee) | |
3123 | { | |
3124 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3125 | for (int j = 0; j < ipf->length; j++) | |
3126 | { | |
3127 | int input_idx = ipf->inputs[j]; | |
3128 | (*from_ifs->m_parameters)[input_idx].locally_unused = false; | |
3129 | } | |
3130 | } | |
3131 | } | |
3132 | } | |
3133 | ||
3134 | /* Unless it is already there, push NODE which is also described by IFS to | |
3135 | STACK. */ | |
3136 | ||
3137 | static void | |
3138 | isra_push_node_to_stack (cgraph_node *node, isra_func_summary *ifs, | |
3139 | vec<cgraph_node *> *stack) | |
3140 | { | |
3141 | if (!ifs->m_queued) | |
3142 | { | |
3143 | ifs->m_queued = true; | |
3144 | stack->safe_push (node); | |
3145 | } | |
3146 | } | |
3147 | ||
3148 | /* If parameter with index INPUT_IDX is marked as locally unused, mark it as | |
3149 | used and push CALLER on STACK. */ | |
3150 | ||
3151 | static void | |
3152 | isra_mark_caller_param_used (isra_func_summary *from_ifs, int input_idx, | |
3153 | cgraph_node *caller, vec<cgraph_node *> *stack) | |
3154 | { | |
3155 | if ((*from_ifs->m_parameters)[input_idx].locally_unused) | |
3156 | { | |
3157 | (*from_ifs->m_parameters)[input_idx].locally_unused = false; | |
3158 | isra_push_node_to_stack (caller, from_ifs, stack); | |
3159 | } | |
3160 | } | |
3161 | ||
3162 | ||
3163 | /* Propagate information that any parameter is not used only locally within a | |
3164 | SCC across CS to the caller, which must be in the same SCC as the | |
3165 | callee. Push any callers that need to be re-processed to STACK. */ | |
3166 | ||
3167 | static void | |
3168 | propagate_used_across_scc_edge (cgraph_edge *cs, vec<cgraph_node *> *stack) | |
3169 | { | |
3170 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3171 | if (!from_ifs || vec_safe_is_empty (from_ifs->m_parameters)) | |
3172 | return; | |
3173 | ||
3174 | isra_call_summary *csum = call_sums->get (cs); | |
3175 | gcc_checking_assert (csum); | |
3176 | unsigned args_count = csum->m_arg_flow.length (); | |
3177 | enum availability availability; | |
3178 | cgraph_node *callee = cs->callee->function_symbol (&availability); | |
3179 | isra_func_summary *to_ifs = func_sums->get (callee); | |
3180 | ||
3181 | unsigned param_count | |
3182 | = (to_ifs && (availability >= AVAIL_AVAILABLE)) | |
3183 | ? vec_safe_length (to_ifs->m_parameters) : 0; | |
3184 | for (unsigned i = 0; i < args_count; i++) | |
3185 | { | |
3186 | if (i < param_count | |
3187 | && (*to_ifs->m_parameters)[i].locally_unused) | |
3188 | continue; | |
3189 | ||
3190 | /* The argument is needed in the callee it, we must mark the parameter as | |
3191 | used also in the caller and its callers within this SCC. */ | |
3192 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3193 | for (int j = 0; j < ipf->length; j++) | |
3194 | { | |
3195 | int input_idx = ipf->inputs[j]; | |
3196 | isra_mark_caller_param_used (from_ifs, input_idx, cs->caller, stack); | |
3197 | } | |
3198 | } | |
3199 | } | |
3200 | ||
3201 | /* Propagate information that any parameter is not used only locally within a | |
3202 | SCC (i.e. is used also elsewhere) to all callers of NODE that are in the | |
3203 | same SCC. Push any callers that need to be re-processed to STACK. */ | |
3204 | ||
3205 | static bool | |
3206 | propagate_used_to_scc_callers (cgraph_node *node, void *data) | |
3207 | { | |
3208 | vec<cgraph_node *> *stack = (vec<cgraph_node *> *) data; | |
3209 | cgraph_edge *cs; | |
3210 | for (cs = node->callers; cs; cs = cs->next_caller) | |
3211 | if (ipa_edge_within_scc (cs)) | |
3212 | propagate_used_across_scc_edge (cs, stack); | |
3213 | return false; | |
3214 | } | |
3215 | ||
3216 | /* Return true iff all certain accesses in ARG_DESC are also present as | |
3217 | certain accesses in PARAM_DESC. */ | |
3218 | ||
3219 | static bool | |
3220 | all_callee_accesses_present_p (isra_param_desc *param_desc, | |
3221 | isra_param_desc *arg_desc) | |
3222 | { | |
3223 | unsigned aclen = vec_safe_length (arg_desc->accesses); | |
3224 | for (unsigned j = 0; j < aclen; j++) | |
3225 | { | |
3226 | param_access *argacc = (*arg_desc->accesses)[j]; | |
3227 | if (!argacc->certain) | |
3228 | continue; | |
3229 | param_access *pacc = find_param_access (param_desc, argacc->unit_offset, | |
3230 | argacc->unit_size); | |
3231 | if (!pacc | |
3232 | || !pacc->certain | |
3233 | || !types_compatible_p (argacc->type, pacc->type)) | |
3234 | return false; | |
3235 | } | |
3236 | return true; | |
3237 | } | |
3238 | ||
3239 | /* Type internal to function pull_accesses_from_callee. Unfortunately gcc 4.8 | |
3240 | does not allow instantiating an auto_vec with a type defined within a | |
3241 | function so it is a global type. */ | |
3242 | enum acc_prop_kind {ACC_PROP_DONT, ACC_PROP_COPY, ACC_PROP_CERTAIN}; | |
3243 | ||
3244 | ||
3245 | /* Attempt to propagate all definite accesses from ARG_DESC to PARAM_DESC, | |
3246 | (which belongs to CALLER) if they would not violate some constraint there. | |
3247 | If successful, return NULL, otherwise return the string reason for failure | |
3248 | (which can be written to the dump file). DELTA_OFFSET is the known offset | |
3249 | of the actual argument withing the formal parameter (so of ARG_DESCS within | |
3250 | PARAM_DESCS), ARG_SIZE is the size of the actual argument or zero, if not | |
3251 | known. In case of success, set *CHANGE_P to true if propagation actually | |
3252 | changed anything. */ | |
3253 | ||
3254 | static const char * | |
3255 | pull_accesses_from_callee (cgraph_node *caller, isra_param_desc *param_desc, | |
3256 | isra_param_desc *arg_desc, | |
3257 | unsigned delta_offset, unsigned arg_size, | |
3258 | bool *change_p) | |
3259 | { | |
3260 | unsigned pclen = vec_safe_length (param_desc->accesses); | |
3261 | unsigned aclen = vec_safe_length (arg_desc->accesses); | |
3262 | unsigned prop_count = 0; | |
3263 | unsigned prop_size = 0; | |
3264 | bool change = false; | |
3265 | ||
3266 | auto_vec <enum acc_prop_kind, 8> prop_kinds (aclen); | |
3267 | for (unsigned j = 0; j < aclen; j++) | |
3268 | { | |
3269 | param_access *argacc = (*arg_desc->accesses)[j]; | |
3270 | prop_kinds.safe_push (ACC_PROP_DONT); | |
3271 | ||
3272 | if (arg_size > 0 | |
3273 | && argacc->unit_offset + argacc->unit_size > arg_size) | |
3274 | return "callee access outsize size boundary"; | |
3275 | ||
3276 | if (!argacc->certain) | |
3277 | continue; | |
3278 | ||
3279 | unsigned offset = argacc->unit_offset + delta_offset; | |
3280 | /* Given that accesses are initially stored according to increasing | |
3281 | offset and decreasing size in case of equal offsets, the following | |
3282 | searches could be written more efficiently if we kept the ordering | |
3283 | when copying. But the number of accesses is capped at | |
3284 | PARAM_IPA_SRA_MAX_REPLACEMENTS (so most likely 8) and the code gets | |
3285 | messy quickly, so let's improve on that only if necessary. */ | |
3286 | ||
3287 | bool exact_match = false; | |
3288 | for (unsigned i = 0; i < pclen; i++) | |
3289 | { | |
3290 | /* Check for overlaps. */ | |
3291 | param_access *pacc = (*param_desc->accesses)[i]; | |
3292 | if (pacc->unit_offset == offset | |
3293 | && pacc->unit_size == argacc->unit_size) | |
3294 | { | |
3295 | if (argacc->alias_ptr_type != pacc->alias_ptr_type | |
3296 | || !types_compatible_p (argacc->type, pacc->type)) | |
3297 | return "propagated access types would not match existing ones"; | |
3298 | ||
3299 | exact_match = true; | |
3300 | if (!pacc->certain) | |
3301 | { | |
3302 | prop_kinds[j] = ACC_PROP_CERTAIN; | |
3303 | prop_size += argacc->unit_size; | |
3304 | change = true; | |
3305 | } | |
3306 | continue; | |
3307 | } | |
3308 | ||
3309 | if (offset < pacc->unit_offset + pacc->unit_size | |
3310 | && offset + argacc->unit_size > pacc->unit_offset) | |
3311 | { | |
3312 | /* None permissible with load accesses, possible to fit into | |
3313 | argument ones. */ | |
3314 | if (pacc->certain | |
3315 | || offset < pacc->unit_offset | |
3316 | || (offset + argacc->unit_size | |
3317 | > pacc->unit_offset + pacc->unit_size)) | |
3318 | return "a propagated access would conflict in caller"; | |
3319 | } | |
3320 | } | |
3321 | ||
3322 | if (!exact_match) | |
3323 | { | |
3324 | prop_kinds[j] = ACC_PROP_COPY; | |
3325 | prop_count++; | |
3326 | prop_size += argacc->unit_size; | |
3327 | change = true; | |
3328 | } | |
3329 | } | |
3330 | ||
3331 | if (!change) | |
3332 | return NULL; | |
3333 | ||
3334 | if ((prop_count + pclen | |
3335 | > (unsigned) opt_for_fn (caller->decl, param_ipa_sra_max_replacements)) | |
3336 | || size_would_violate_limit_p (param_desc, | |
3337 | param_desc->size_reached + prop_size)) | |
3338 | return "propagating accesses would violate the count or size limit"; | |
3339 | ||
3340 | *change_p = true; | |
3341 | for (unsigned j = 0; j < aclen; j++) | |
3342 | { | |
3343 | if (prop_kinds[j] == ACC_PROP_COPY) | |
3344 | { | |
3345 | param_access *argacc = (*arg_desc->accesses)[j]; | |
3346 | ||
3347 | param_access *copy = ggc_cleared_alloc<param_access> (); | |
3348 | copy->unit_offset = argacc->unit_offset + delta_offset; | |
3349 | copy->unit_size = argacc->unit_size; | |
3350 | copy->type = argacc->type; | |
3351 | copy->alias_ptr_type = argacc->alias_ptr_type; | |
3352 | copy->certain = true; | |
3353 | vec_safe_push (param_desc->accesses, copy); | |
3354 | } | |
3355 | else if (prop_kinds[j] == ACC_PROP_CERTAIN) | |
3356 | { | |
3357 | param_access *argacc = (*arg_desc->accesses)[j]; | |
3358 | param_access *csp | |
3359 | = find_param_access (param_desc, argacc->unit_offset + delta_offset, | |
3360 | argacc->unit_size); | |
3361 | csp->certain = true; | |
3362 | } | |
3363 | } | |
3364 | ||
3365 | param_desc->size_reached += prop_size; | |
3366 | ||
3367 | return NULL; | |
3368 | } | |
3369 | ||
3370 | /* Propagate parameter splitting information through call graph edge CS. | |
3371 | Return true if any changes that might need to be propagated within SCCs have | |
3372 | been made. The function also clears the aggregate_pass_through and | |
3373 | pointer_pass_through in call summaries which do not need to be processed | |
3374 | again if this CS is revisited when iterating while changes are propagated | |
3375 | within an SCC. */ | |
3376 | ||
3377 | static bool | |
3378 | param_splitting_across_edge (cgraph_edge *cs) | |
3379 | { | |
3380 | bool res = false; | |
3381 | bool cross_scc = !ipa_edge_within_scc (cs); | |
3382 | enum availability availability; | |
3383 | cgraph_node *callee = cs->callee->function_symbol (&availability); | |
3384 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3385 | gcc_checking_assert (from_ifs && from_ifs->m_parameters); | |
3386 | ||
3387 | isra_call_summary *csum = call_sums->get (cs); | |
3388 | gcc_checking_assert (csum); | |
3389 | unsigned args_count = csum->m_arg_flow.length (); | |
3390 | isra_func_summary *to_ifs = func_sums->get (callee); | |
3391 | unsigned param_count | |
3392 | = ((to_ifs && to_ifs->m_candidate && (availability >= AVAIL_AVAILABLE)) | |
3393 | ? vec_safe_length (to_ifs->m_parameters) | |
3394 | : 0); | |
3395 | ||
3396 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3397 | fprintf (dump_file, "Splitting across %s->%s:\n", | |
3398 | cs->caller->dump_name (), callee->dump_name ()); | |
3399 | ||
3400 | unsigned i; | |
3401 | for (i = 0; (i < args_count) && (i < param_count); i++) | |
3402 | { | |
3403 | isra_param_desc *arg_desc = &(*to_ifs->m_parameters)[i]; | |
3404 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3405 | ||
3406 | if (arg_desc->locally_unused) | |
3407 | { | |
3408 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3409 | fprintf (dump_file, " ->%u: unused in callee\n", i); | |
3410 | ipf->pointer_pass_through = false; | |
3411 | continue; | |
3412 | } | |
3413 | ||
3414 | if (ipf->pointer_pass_through) | |
3415 | { | |
3416 | int idx = get_single_param_flow_source (ipf); | |
3417 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; | |
3418 | if (!param_desc->split_candidate) | |
3419 | continue; | |
3420 | gcc_assert (param_desc->by_ref); | |
3421 | ||
3422 | if (!arg_desc->split_candidate || !arg_desc->by_ref) | |
3423 | { | |
3424 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3425 | fprintf (dump_file, " %u->%u: not candidate or not by " | |
3426 | "reference in callee\n", idx, i); | |
3427 | param_desc->split_candidate = false; | |
3428 | ipf->pointer_pass_through = false; | |
3429 | res = true; | |
3430 | } | |
3431 | else if (!ipf->safe_to_import_accesses) | |
3432 | { | |
3433 | if (!csum->m_before_any_store | |
3434 | || !all_callee_accesses_present_p (param_desc, arg_desc)) | |
3435 | { | |
3436 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3437 | fprintf (dump_file, " %u->%u: cannot import accesses.\n", | |
3438 | idx, i); | |
3439 | param_desc->split_candidate = false; | |
3440 | ipf->pointer_pass_through = false; | |
3441 | res = true; | |
3442 | ||
3443 | } | |
3444 | else | |
3445 | { | |
3446 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3447 | fprintf (dump_file, " %u->%u: verified callee accesses " | |
3448 | "present.\n", idx, i); | |
3449 | if (cross_scc) | |
3450 | ipf->pointer_pass_through = false; | |
3451 | } | |
3452 | } | |
3453 | else | |
3454 | { | |
3455 | const char *pull_failure | |
3456 | = pull_accesses_from_callee (cs->caller, param_desc, arg_desc, | |
3457 | 0, 0, &res); | |
3458 | if (pull_failure) | |
3459 | { | |
3460 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3461 | fprintf (dump_file, " %u->%u: by_ref access pull " | |
3462 | "failed: %s.\n", idx, i, pull_failure); | |
3463 | param_desc->split_candidate = false; | |
3464 | ipf->pointer_pass_through = false; | |
3465 | res = true; | |
3466 | } | |
3467 | else | |
3468 | { | |
3469 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3470 | fprintf (dump_file, " %u->%u: by_ref access pull " | |
3471 | "succeeded.\n", idx, i); | |
3472 | if (cross_scc) | |
3473 | ipf->pointer_pass_through = false; | |
3474 | } | |
3475 | } | |
3476 | } | |
3477 | else if (ipf->aggregate_pass_through) | |
3478 | { | |
3479 | int idx = get_single_param_flow_source (ipf); | |
3480 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; | |
3481 | if (!param_desc->split_candidate) | |
3482 | continue; | |
3483 | gcc_assert (!param_desc->by_ref); | |
3484 | param_access *pacc = find_param_access (param_desc, ipf->unit_offset, | |
3485 | ipf->unit_size); | |
3486 | gcc_checking_assert (pacc); | |
3487 | ||
3488 | if (pacc->certain) | |
3489 | { | |
3490 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3491 | fprintf (dump_file, " %u->%u: already certain\n", idx, i); | |
3492 | ipf->aggregate_pass_through = false; | |
3493 | } | |
3494 | else if (!arg_desc->split_candidate || arg_desc->by_ref) | |
3495 | { | |
3496 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3497 | fprintf (dump_file, " %u->%u: not candidate or by " | |
3498 | "reference in callee\n", idx, i); | |
3499 | ||
3500 | pacc->certain = true; | |
3501 | if (overlapping_certain_accesses_p (param_desc, NULL)) | |
3502 | { | |
3503 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3504 | fprintf (dump_file, " ...leading to overlap, " | |
3505 | " disqualifying candidate parameter %u\n", | |
3506 | idx); | |
3507 | param_desc->split_candidate = false; | |
3508 | } | |
3509 | else | |
3510 | bump_reached_size (param_desc, pacc->unit_size, idx); | |
3511 | ||
3512 | ipf->aggregate_pass_through = false; | |
3513 | res = true; | |
3514 | } | |
3515 | else | |
3516 | { | |
3517 | const char *pull_failure | |
3518 | = pull_accesses_from_callee (cs->caller, param_desc, arg_desc, | |
3519 | ipf->unit_offset, | |
3520 | ipf->unit_size, &res); | |
3521 | if (pull_failure) | |
3522 | { | |
3523 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3524 | fprintf (dump_file, " %u->%u: arg access pull " | |
3525 | "failed: %s.\n", idx, i, pull_failure); | |
3526 | ||
3527 | ipf->aggregate_pass_through = false; | |
3528 | pacc->certain = true; | |
3529 | ||
3530 | if (overlapping_certain_accesses_p (param_desc, NULL)) | |
3531 | { | |
3532 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3533 | fprintf (dump_file, " ...leading to overlap, " | |
3534 | " disqualifying candidate parameter %u\n", | |
3535 | idx); | |
3536 | param_desc->split_candidate = false; | |
3537 | } | |
3538 | else | |
3539 | bump_reached_size (param_desc, pacc->unit_size, idx); | |
3540 | ||
3541 | res = true; | |
3542 | } | |
3543 | else | |
3544 | { | |
3545 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3546 | fprintf (dump_file, " %u->%u: arg access pull " | |
3547 | "succeeded.\n", idx, i); | |
3548 | if (cross_scc) | |
3549 | ipf->aggregate_pass_through = false; | |
3550 | } | |
3551 | } | |
3552 | } | |
3553 | } | |
3554 | ||
3555 | /* Handle argument-parameter count mismatches. */ | |
3556 | for (; (i < args_count); i++) | |
3557 | { | |
3558 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3559 | ||
3560 | if (ipf->pointer_pass_through || ipf->aggregate_pass_through) | |
3561 | { | |
3562 | int idx = get_single_param_flow_source (ipf); | |
3563 | ipf->pointer_pass_through = false; | |
3564 | ipf->aggregate_pass_through = false; | |
3565 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; | |
3566 | if (!param_desc->split_candidate) | |
3567 | continue; | |
3568 | ||
3569 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3570 | fprintf (dump_file, " %u->%u: no corresponding formal parameter\n", | |
3571 | idx, i); | |
3572 | param_desc->split_candidate = false; | |
3573 | res = true; | |
3574 | } | |
3575 | } | |
3576 | return res; | |
3577 | } | |
3578 | ||
3579 | /* Worker for call_for_symbol_and_aliases, look at all callers and if all their | |
3580 | callers ignore the return value, or come from the same SCC and use the | |
3581 | return value only to compute their return value, return false, otherwise | |
3582 | return true. */ | |
3583 | ||
3584 | static bool | |
3585 | retval_used_p (cgraph_node *node, void *) | |
3586 | { | |
3587 | for (cgraph_edge *cs = node->callers; cs; cs = cs->next_caller) | |
3588 | { | |
3589 | isra_call_summary *csum = call_sums->get (cs); | |
3590 | gcc_checking_assert (csum); | |
3591 | if (csum->m_return_ignored) | |
3592 | continue; | |
3593 | if (!csum->m_return_returned) | |
3594 | return true; | |
3595 | ||
3596 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3597 | if (!from_ifs || !from_ifs->m_candidate) | |
3598 | return true; | |
3599 | ||
3600 | if (!ipa_edge_within_scc (cs) | |
3601 | && !from_ifs->m_return_ignored) | |
3602 | return true; | |
3603 | } | |
3604 | ||
3605 | return false; | |
3606 | } | |
3607 | ||
3608 | /* Push into NEW_PARAMS all required parameter adjustment entries to copy or | |
3609 | modify parameter which originally had index BASE_INDEX, in the adjustment | |
3610 | vector of parent clone (if any) had PREV_CLONE_INDEX and was described by | |
3611 | PREV_ADJUSTMENT. If the parent clone is the original function, | |
3612 | PREV_ADJUSTMENT is NULL and PREV_CLONE_INDEX is equal to BASE_INDEX. */ | |
3613 | ||
3614 | ||
3615 | static void | |
3616 | push_param_adjustments_for_index (isra_func_summary *ifs, unsigned base_index, | |
3617 | unsigned prev_clone_index, | |
3618 | ipa_adjusted_param *prev_adjustment, | |
3619 | vec<ipa_adjusted_param, va_gc> **new_params) | |
3620 | { | |
3621 | isra_param_desc *desc = &(*ifs->m_parameters)[base_index]; | |
3622 | if (desc->locally_unused) | |
3623 | { | |
3624 | if (dump_file) | |
3625 | fprintf (dump_file, " Will remove parameter %u\n", base_index); | |
3626 | return; | |
3627 | } | |
3628 | ||
3629 | if (!desc->split_candidate) | |
3630 | { | |
3631 | ipa_adjusted_param adj; | |
3632 | if (prev_adjustment) | |
3633 | { | |
3634 | adj = *prev_adjustment; | |
3635 | adj.prev_clone_adjustment = true; | |
3636 | adj.prev_clone_index = prev_clone_index; | |
3637 | } | |
3638 | else | |
3639 | { | |
3640 | memset (&adj, 0, sizeof (adj)); | |
3641 | adj.op = IPA_PARAM_OP_COPY; | |
3642 | adj.base_index = base_index; | |
3643 | adj.prev_clone_index = prev_clone_index; | |
3644 | } | |
3645 | vec_safe_push ((*new_params), adj); | |
3646 | return; | |
3647 | } | |
3648 | ||
3649 | if (dump_file) | |
3650 | fprintf (dump_file, " Will split parameter %u\n", base_index); | |
3651 | ||
3652 | gcc_assert (!prev_adjustment || prev_adjustment->op == IPA_PARAM_OP_COPY); | |
3653 | unsigned aclen = vec_safe_length (desc->accesses); | |
3654 | for (unsigned j = 0; j < aclen; j++) | |
3655 | { | |
3656 | param_access *pa = (*desc->accesses)[j]; | |
3657 | if (!pa->certain) | |
3658 | continue; | |
3659 | if (dump_file) | |
3660 | fprintf (dump_file, " - component at byte offset %u, " | |
3661 | "size %u\n", pa->unit_offset, pa->unit_size); | |
3662 | ||
3663 | ipa_adjusted_param adj; | |
3664 | memset (&adj, 0, sizeof (adj)); | |
3665 | adj.op = IPA_PARAM_OP_SPLIT; | |
3666 | adj.base_index = base_index; | |
3667 | adj.prev_clone_index = prev_clone_index; | |
3668 | adj.param_prefix_index = IPA_PARAM_PREFIX_ISRA; | |
3669 | adj.reverse = pa->reverse; | |
3670 | adj.type = pa->type; | |
3671 | adj.alias_ptr_type = pa->alias_ptr_type; | |
3672 | adj.unit_offset = pa->unit_offset; | |
3673 | vec_safe_push ((*new_params), adj); | |
3674 | } | |
3675 | } | |
3676 | ||
3677 | /* Worker for all call_for_symbol_thunks_and_aliases. Set calls_comdat_local | |
3678 | flag of all callers of NODE. */ | |
3679 | ||
3680 | static bool | |
3681 | mark_callers_calls_comdat_local (struct cgraph_node *node, void *) | |
3682 | { | |
3683 | for (cgraph_edge *cs = node->callers; cs; cs = cs->next_caller) | |
3684 | cs->caller->calls_comdat_local = true; | |
3685 | return false; | |
3686 | } | |
3687 | ||
3688 | ||
3689 | /* Do final processing of results of IPA propagation regarding NODE, clone it | |
3690 | if appropriate. */ | |
3691 | ||
3692 | static void | |
3693 | process_isra_node_results (cgraph_node *node, | |
3694 | hash_map<const char *, unsigned> *clone_num_suffixes) | |
3695 | { | |
3696 | isra_func_summary *ifs = func_sums->get (node); | |
3697 | if (!ifs || !ifs->m_candidate) | |
3698 | return; | |
3699 | ||
3700 | auto_vec<bool, 16> surviving_params; | |
3701 | bool check_surviving = false; | |
3702 | clone_info *cinfo = clone_info::get (node); | |
3703 | if (cinfo && cinfo->param_adjustments) | |
3704 | { | |
3705 | check_surviving = true; | |
3706 | cinfo->param_adjustments->get_surviving_params (&surviving_params); | |
3707 | } | |
3708 | ||
3709 | unsigned param_count = vec_safe_length (ifs->m_parameters); | |
3710 | bool will_change_function = false; | |
3711 | if (ifs->m_returns_value && ifs->m_return_ignored) | |
3712 | will_change_function = true; | |
3713 | else | |
3714 | for (unsigned i = 0; i < param_count; i++) | |
3715 | { | |
3716 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; | |
3717 | if ((desc->locally_unused || desc->split_candidate) | |
3718 | /* Make sure we do not clone just to attempt to remove an already | |
3719 | removed unused argument. */ | |
3720 | && (!check_surviving | |
3721 | || (i < surviving_params.length () | |
3722 | && surviving_params[i]))) | |
3723 | { | |
3724 | will_change_function = true; | |
3725 | break; | |
3726 | } | |
3727 | } | |
3728 | if (!will_change_function) | |
3729 | return; | |
3730 | ||
3731 | if (dump_file) | |
3732 | { | |
3733 | fprintf (dump_file, "\nEvaluating analysis results for %s\n", | |
3734 | node->dump_name ()); | |
3735 | if (ifs->m_returns_value && ifs->m_return_ignored) | |
3736 | fprintf (dump_file, " Will remove return value.\n"); | |
3737 | } | |
3738 | ||
3739 | vec<ipa_adjusted_param, va_gc> *new_params = NULL; | |
3740 | if (ipa_param_adjustments *old_adjustments | |
3741 | = cinfo ? cinfo->param_adjustments : NULL) | |
3742 | { | |
3743 | unsigned old_adj_len = vec_safe_length (old_adjustments->m_adj_params); | |
3744 | for (unsigned i = 0; i < old_adj_len; i++) | |
3745 | { | |
3746 | ipa_adjusted_param *old_adj = &(*old_adjustments->m_adj_params)[i]; | |
3747 | push_param_adjustments_for_index (ifs, old_adj->base_index, i, | |
3748 | old_adj, &new_params); | |
3749 | } | |
3750 | } | |
3751 | else | |
3752 | for (unsigned i = 0; i < param_count; i++) | |
3753 | push_param_adjustments_for_index (ifs, i, i, NULL, &new_params); | |
3754 | ||
3755 | ipa_param_adjustments *new_adjustments | |
3756 | = (new (ggc_alloc <ipa_param_adjustments> ()) | |
3757 | ipa_param_adjustments (new_params, param_count, | |
3758 | ifs->m_returns_value && ifs->m_return_ignored)); | |
3759 | ||
3760 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3761 | { | |
3762 | fprintf (dump_file, "\n Created adjustments:\n"); | |
3763 | new_adjustments->dump (dump_file); | |
3764 | } | |
3765 | ||
3766 | unsigned &suffix_counter = clone_num_suffixes->get_or_insert ( | |
3767 | IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME ( | |
3768 | node->decl))); | |
3769 | auto_vec<cgraph_edge *> callers = node->collect_callers (); | |
3770 | cgraph_node *new_node | |
3771 | = node->create_virtual_clone (callers, NULL, new_adjustments, "isra", | |
3772 | suffix_counter); | |
3773 | suffix_counter++; | |
3774 | if (node->calls_comdat_local && node->same_comdat_group) | |
3775 | { | |
3776 | new_node->add_to_same_comdat_group (node); | |
3777 | new_node->call_for_symbol_and_aliases (mark_callers_calls_comdat_local, | |
3778 | NULL, true); | |
3779 | } | |
3780 | new_node->calls_comdat_local = node->calls_comdat_local; | |
3781 | ||
3782 | if (dump_file) | |
3783 | fprintf (dump_file, " Created new node %s\n", new_node->dump_name ()); | |
3784 | callers.release (); | |
3785 | } | |
3786 | ||
3787 | /* Check which parameters of NODE described by IFS have survived until IPA-SRA | |
3788 | and disable transformations for those which have not or which should not | |
3789 | transformed because the associated debug counter reached its limit. Return | |
3790 | true if none survived or if there were no candidates to begin with. */ | |
3791 | ||
3792 | static bool | |
3793 | disable_unavailable_parameters (cgraph_node *node, isra_func_summary *ifs) | |
3794 | { | |
3795 | bool ret = true; | |
3796 | unsigned len = vec_safe_length (ifs->m_parameters); | |
3797 | if (!len) | |
3798 | return true; | |
3799 | ||
3800 | auto_vec<bool, 16> surviving_params; | |
3801 | bool check_surviving = false; | |
3802 | clone_info *cinfo = clone_info::get (node); | |
3803 | if (cinfo && cinfo->param_adjustments) | |
3804 | { | |
3805 | check_surviving = true; | |
3806 | cinfo->param_adjustments->get_surviving_params (&surviving_params); | |
3807 | } | |
3808 | bool dumped_first = false; | |
3809 | for (unsigned i = 0; i < len; i++) | |
3810 | { | |
3811 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; | |
3812 | if (!dbg_cnt (ipa_sra_params)) | |
3813 | { | |
3814 | desc->locally_unused = false; | |
3815 | desc->split_candidate = false; | |
3816 | } | |
3817 | else if (check_surviving | |
3818 | && (i >= surviving_params.length () | |
3819 | || !surviving_params[i])) | |
3820 | { | |
3821 | /* Even if the parameter was removed by a previous IPA pass, we do | |
3822 | not clear locally_unused because if it really is unused, this | |
3823 | information might be useful in callers. */ | |
3824 | desc->split_candidate = false; | |
3825 | ||
3826 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3827 | { | |
3828 | if (!dumped_first) | |
3829 | { | |
3830 | fprintf (dump_file, | |
3831 | "The following parameters of %s are dead on " | |
3832 | "arrival:", node->dump_name ()); | |
3833 | dumped_first = true; | |
3834 | } | |
3835 | fprintf (dump_file, " %u", i); | |
3836 | } | |
3837 | } | |
3838 | else if (desc->locally_unused || desc->split_candidate) | |
3839 | ret = false; | |
3840 | } | |
3841 | ||
3842 | if (dumped_first) | |
3843 | fprintf (dump_file, "\n"); | |
3844 | ||
3845 | return ret; | |
3846 | } | |
3847 | ||
3848 | ||
3849 | /* Run the interprocedural part of IPA-SRA. */ | |
3850 | ||
3851 | static unsigned int | |
3852 | ipa_sra_analysis (void) | |
3853 | { | |
3854 | if (dump_file) | |
3855 | { | |
3856 | fprintf (dump_file, "\n========== IPA-SRA IPA stage ==========\n"); | |
3857 | ipa_sra_dump_all_summaries (dump_file); | |
3858 | } | |
3859 | ||
3860 | gcc_checking_assert (func_sums); | |
3861 | gcc_checking_assert (call_sums); | |
3862 | cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count); | |
3863 | auto_vec <cgraph_node *, 16> stack; | |
3864 | int node_scc_count = ipa_reduced_postorder (order, true, NULL); | |
3865 | ||
3866 | /* One sweep from callees to callers for parameter removal and splitting. */ | |
3867 | for (int i = 0; i < node_scc_count; i++) | |
3868 | { | |
3869 | cgraph_node *scc_rep = order[i]; | |
3870 | vec<cgraph_node *> cycle_nodes = ipa_get_nodes_in_cycle (scc_rep); | |
3871 | unsigned j; | |
3872 | ||
3873 | /* Preliminary IPA function level checks and first step of parameter | |
3874 | removal. */ | |
3875 | cgraph_node *v; | |
3876 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) | |
3877 | { | |
3878 | isra_func_summary *ifs = func_sums->get (v); | |
3879 | if (!ifs || !ifs->m_candidate) | |
3880 | continue; | |
3881 | if (!ipa_sra_ipa_function_checks (v) | |
3882 | || check_all_callers_for_issues (v)) | |
3883 | { | |
3884 | ifs->zap (); | |
3885 | continue; | |
3886 | } | |
3887 | if (disable_unavailable_parameters (v, ifs)) | |
3888 | continue; | |
3889 | for (cgraph_edge *cs = v->indirect_calls; cs; cs = cs->next_callee) | |
3890 | process_edge_to_unknown_caller (cs); | |
3891 | for (cgraph_edge *cs = v->callees; cs; cs = cs->next_callee) | |
3892 | if (!ipa_edge_within_scc (cs)) | |
3893 | param_removal_cross_scc_edge (cs); | |
3894 | } | |
3895 | ||
3896 | /* Look at edges within the current SCC and propagate used-ness across | |
3897 | them, pushing onto the stack all notes which might need to be | |
3898 | revisited. */ | |
3899 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) | |
3900 | v->call_for_symbol_thunks_and_aliases (propagate_used_to_scc_callers, | |
3901 | &stack, true); | |
3902 | ||
3903 | /* Keep revisiting and pushing until nothing changes. */ | |
3904 | while (!stack.is_empty ()) | |
3905 | { | |
3906 | cgraph_node *v = stack.pop (); | |
3907 | isra_func_summary *ifs = func_sums->get (v); | |
3908 | gcc_checking_assert (ifs && ifs->m_queued); | |
3909 | ifs->m_queued = false; | |
3910 | ||
3911 | v->call_for_symbol_thunks_and_aliases (propagate_used_to_scc_callers, | |
3912 | &stack, true); | |
3913 | } | |
3914 | ||
3915 | /* Parameter splitting. */ | |
3916 | bool repeat_scc_access_propagation; | |
3917 | do | |
3918 | { | |
3919 | repeat_scc_access_propagation = false; | |
3920 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) | |
3921 | { | |
3922 | isra_func_summary *ifs = func_sums->get (v); | |
3923 | if (!ifs | |
3924 | || !ifs->m_candidate | |
3925 | || vec_safe_is_empty (ifs->m_parameters)) | |
3926 | continue; | |
3927 | for (cgraph_edge *cs = v->callees; cs; cs = cs->next_callee) | |
3928 | if (param_splitting_across_edge (cs)) | |
3929 | repeat_scc_access_propagation = true; | |
3930 | } | |
3931 | } | |
3932 | while (repeat_scc_access_propagation); | |
3933 | ||
3934 | if (flag_checking) | |
3935 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) | |
3936 | verify_splitting_accesses (v, true); | |
3937 | ||
3938 | cycle_nodes.release (); | |
3939 | } | |
3940 | ||
3941 | /* One sweep from caller to callees for result removal. */ | |
3942 | for (int i = node_scc_count - 1; i >= 0 ; i--) | |
3943 | { | |
3944 | cgraph_node *scc_rep = order[i]; | |
3945 | vec<cgraph_node *> cycle_nodes = ipa_get_nodes_in_cycle (scc_rep); | |
3946 | unsigned j; | |
3947 | ||
3948 | cgraph_node *v; | |
3949 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) | |
3950 | { | |
3951 | isra_func_summary *ifs = func_sums->get (v); | |
3952 | if (!ifs || !ifs->m_candidate) | |
3953 | continue; | |
3954 | ||
3955 | bool return_needed | |
3956 | = (ifs->m_returns_value | |
3957 | && (!dbg_cnt (ipa_sra_retvalues) | |
3958 | || v->call_for_symbol_and_aliases (retval_used_p, | |
3959 | NULL, true))); | |
3960 | ifs->m_return_ignored = !return_needed; | |
3961 | if (return_needed) | |
3962 | isra_push_node_to_stack (v, ifs, &stack); | |
3963 | } | |
3964 | ||
3965 | while (!stack.is_empty ()) | |
3966 | { | |
3967 | cgraph_node *node = stack.pop (); | |
3968 | isra_func_summary *ifs = func_sums->get (node); | |
3969 | gcc_checking_assert (ifs && ifs->m_queued); | |
3970 | ifs->m_queued = false; | |
3971 | ||
3972 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) | |
3973 | if (ipa_edge_within_scc (cs) | |
3974 | && call_sums->get (cs)->m_return_returned) | |
3975 | { | |
3976 | enum availability av; | |
3977 | cgraph_node *callee = cs->callee->function_symbol (&av); | |
3978 | isra_func_summary *to_ifs = func_sums->get (callee); | |
3979 | if (to_ifs && to_ifs->m_return_ignored) | |
3980 | { | |
3981 | to_ifs->m_return_ignored = false; | |
3982 | isra_push_node_to_stack (callee, to_ifs, &stack); | |
3983 | } | |
3984 | } | |
3985 | } | |
3986 | cycle_nodes.release (); | |
3987 | } | |
3988 | ||
3989 | ipa_free_postorder_info (); | |
3990 | free (order); | |
3991 | ||
3992 | if (dump_file) | |
3993 | { | |
3994 | if (dump_flags & TDF_DETAILS) | |
3995 | { | |
3996 | fprintf (dump_file, "\n========== IPA-SRA propagation final state " | |
3997 | " ==========\n"); | |
3998 | ipa_sra_dump_all_summaries (dump_file); | |
3999 | } | |
4000 | fprintf (dump_file, "\n========== IPA-SRA decisions ==========\n"); | |
4001 | } | |
4002 | ||
4003 | hash_map<const char *, unsigned> *clone_num_suffixes | |
4004 | = new hash_map<const char *, unsigned>; | |
4005 | ||
4006 | cgraph_node *node; | |
4007 | FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) | |
4008 | process_isra_node_results (node, clone_num_suffixes); | |
4009 | ||
4010 | delete clone_num_suffixes; | |
4011 | ggc_delete (func_sums); | |
4012 | func_sums = NULL; | |
4013 | delete call_sums; | |
4014 | call_sums = NULL; | |
4015 | ||
4016 | if (dump_file) | |
4017 | fprintf (dump_file, "\n========== IPA SRA IPA analysis done " | |
4018 | "==========\n\n"); | |
4019 | return 0; | |
4020 | } | |
4021 | ||
4022 | ||
4023 | const pass_data pass_data_ipa_sra = | |
4024 | { | |
4025 | IPA_PASS, /* type */ | |
4026 | "sra", /* name */ | |
4027 | OPTGROUP_NONE, /* optinfo_flags */ | |
4028 | TV_IPA_SRA, /* tv_id */ | |
4029 | 0, /* properties_required */ | |
4030 | 0, /* properties_provided */ | |
4031 | 0, /* properties_destroyed */ | |
4032 | 0, /* todo_flags_start */ | |
4033 | ( TODO_dump_symtab | TODO_remove_functions ), /* todo_flags_finish */ | |
4034 | }; | |
4035 | ||
4036 | class pass_ipa_sra : public ipa_opt_pass_d | |
4037 | { | |
4038 | public: | |
4039 | pass_ipa_sra (gcc::context *ctxt) | |
4040 | : ipa_opt_pass_d (pass_data_ipa_sra, ctxt, | |
4041 | ipa_sra_generate_summary, /* generate_summary */ | |
4042 | ipa_sra_write_summary, /* write_summary */ | |
4043 | ipa_sra_read_summary, /* read_summary */ | |
4044 | NULL , /* write_optimization_summary */ | |
4045 | NULL, /* read_optimization_summary */ | |
4046 | NULL, /* stmt_fixup */ | |
4047 | 0, /* function_transform_todo_flags_start */ | |
4048 | NULL, /* function_transform */ | |
4049 | NULL) /* variable_transform */ | |
4050 | {} | |
4051 | ||
4052 | /* opt_pass methods: */ | |
4053 | virtual bool gate (function *) | |
4054 | { | |
4055 | /* TODO: We should remove the optimize check after we ensure we never run | |
4056 | IPA passes when not optimizing. */ | |
4057 | return (flag_ipa_sra && optimize); | |
4058 | } | |
4059 | ||
4060 | virtual unsigned int execute (function *) { return ipa_sra_analysis (); } | |
4061 | ||
4062 | }; // class pass_ipa_sra | |
4063 | ||
4064 | } // anon namespace | |
4065 | ||
4066 | /* Intraprocedural part of IPA-SRA analysis. Scan function body of NODE and | |
4067 | create a summary structure describing IPA-SRA opportunities and constraints | |
4068 | in it. */ | |
4069 | ||
4070 | static void | |
4071 | ipa_sra_summarize_function (cgraph_node *node) | |
4072 | { | |
4073 | if (dump_file) | |
4074 | fprintf (dump_file, "Creating summary for %s/%i:\n", node->name (), | |
4075 | node->order); | |
4076 | if (!ipa_sra_preliminary_function_checks (node)) | |
4077 | { | |
4078 | isra_analyze_all_outgoing_calls (node); | |
4079 | return; | |
4080 | } | |
4081 | gcc_obstack_init (&gensum_obstack); | |
4082 | isra_func_summary *ifs = func_sums->get_create (node); | |
4083 | ifs->m_candidate = true; | |
4084 | tree ret = TREE_TYPE (TREE_TYPE (node->decl)); | |
4085 | ifs->m_returns_value = (TREE_CODE (ret) != VOID_TYPE); | |
4086 | ||
4087 | decl2desc = new hash_map<tree, gensum_param_desc *>; | |
4088 | unsigned count = 0; | |
4089 | for (tree parm = DECL_ARGUMENTS (node->decl); parm; parm = DECL_CHAIN (parm)) | |
4090 | count++; | |
4091 | ||
4092 | if (count > 0) | |
4093 | { | |
4094 | auto_vec<gensum_param_desc, 16> param_descriptions (count); | |
4095 | param_descriptions.reserve_exact (count); | |
4096 | param_descriptions.quick_grow_cleared (count); | |
4097 | ||
4098 | bool cfun_pushed = false; | |
4099 | struct function *fun = DECL_STRUCT_FUNCTION (node->decl); | |
4100 | if (create_parameter_descriptors (node, ¶m_descriptions)) | |
4101 | { | |
4102 | push_cfun (fun); | |
4103 | cfun_pushed = true; | |
4104 | final_bbs = BITMAP_ALLOC (NULL); | |
4105 | bb_dereferences = XCNEWVEC (HOST_WIDE_INT, | |
4106 | by_ref_count | |
4107 | * last_basic_block_for_fn (fun)); | |
4108 | aa_walking_limit = opt_for_fn (node->decl, param_ipa_max_aa_steps); | |
4109 | scan_function (node, fun); | |
4110 | ||
4111 | if (dump_file) | |
4112 | { | |
4113 | dump_gensum_param_descriptors (dump_file, node->decl, | |
4114 | ¶m_descriptions); | |
4115 | fprintf (dump_file, "----------------------------------------\n"); | |
4116 | } | |
4117 | } | |
4118 | process_scan_results (node, fun, ifs, ¶m_descriptions); | |
4119 | ||
4120 | if (cfun_pushed) | |
4121 | pop_cfun (); | |
4122 | if (bb_dereferences) | |
4123 | { | |
4124 | free (bb_dereferences); | |
4125 | bb_dereferences = NULL; | |
4126 | BITMAP_FREE (final_bbs); | |
4127 | final_bbs = NULL; | |
4128 | } | |
4129 | } | |
4130 | isra_analyze_all_outgoing_calls (node); | |
4131 | ||
4132 | delete decl2desc; | |
4133 | decl2desc = NULL; | |
4134 | obstack_free (&gensum_obstack, NULL); | |
4135 | if (dump_file) | |
4136 | fprintf (dump_file, "\n\n"); | |
4137 | if (flag_checking) | |
4138 | verify_splitting_accesses (node, false); | |
4139 | return; | |
4140 | } | |
4141 | ||
4142 | ipa_opt_pass_d * | |
4143 | make_pass_ipa_sra (gcc::context *ctxt) | |
4144 | { | |
4145 | return new pass_ipa_sra (ctxt); | |
4146 | } | |
4147 | ||
4148 | ||
4149 | #include "gt-ipa-sra.h" |