1 | /* Interprocedural scalar replacement of aggregates |
2 | Copyright (C) 2019-2024 Free Software Foundation, Inc. |
3 | Contributed by Martin Jambor <mjambor@suse.cz> |
4 | |
5 | This file is part of GCC. |
6 | |
7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free |
9 | Software Foundation; either version 3, or (at your option) any later |
10 | version. |
11 | |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
15 | for more details. |
16 | |
17 | You should have received a copy of the GNU General Public License |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ |
20 | |
21 | /* IPA-SRA is an interprocedural pass that removes unused function return |
22 | values (turning functions returning a value which is never used into void |
23 | functions) and removes unused function parameters. It can also replace an |
24 | aggregate parameter by a set of other parameters representing part of the |
25 | original, turning those passed by reference into new ones which pass the |
26 | value directly. |
27 | |
28 | The pass is a true IPA one, which means that it works in three stages in |
29 | order to be able to take advantage of LTO. First, summaries about functions |
30 | and each calls are generated. Function summaries (often called call graph |
31 | node summaries) contain mainly information about which parameters are |
32 | potential transformation candidates and which bits of candidates are |
33 | accessed. We differentiate between accesses done as a part of a call |
34 | statement (which might be not necessary if the callee is also transformed) |
35 | and others (which are mandatory). Call summaries (often called call graph |
36 | edge summaries) contain information about which function formal parameters |
37 | feed into which actual call arguments so that if two parameters are only |
38 | used in a sum which is then passed to another function which then however |
39 | does not use this parameter, all three parameters of the two functions can |
40 | be eliminated. Edge summaries also have flags whether the return value is |
41 | used or if it is only returned in the caller too. In LTO mode these |
42 | summaries are then streamed to the object file in the compilation phase and |
43 | streamed back in in the WPA analysis stage. |
44 | |
45 | The interprocedural analysis phase traverses the graph in topological order |
46 | in two sweeps, one in each direction. First, from callees to callers for |
47 | parameter removal and splitting. Each strongly-connected component is |
48 | processed iteratively until the situation in it stabilizes. The pass from |
49 | callers to callees is then carried out to remove unused return values in a |
50 | very similar fashion. |
51 | |
52 | Because parameter manipulation has big implications for call redirection |
53 | which is done only after all call graph nodes materialize, the |
54 | transformation phase is not part of this patch but is carried out by the |
55 | clone materialization and edge redirection itself, see comments in |
56 | ipa-param-manipulation.h for more details. */ |
57 | |
58 | |
59 | #include "config.h" |
60 | #include "system.h" |
61 | #include "coretypes.h" |
62 | #include "backend.h" |
63 | #include "tree.h" |
64 | #include "gimple.h" |
65 | #include "predict.h" |
66 | #include "tree-pass.h" |
67 | #include "ssa.h" |
68 | #include "cgraph.h" |
69 | #include "gimple-pretty-print.h" |
70 | #include "alias.h" |
71 | #include "tree-eh.h" |
72 | #include "gimple-iterator.h" |
73 | #include "gimple-walk.h" |
74 | #include "tree-dfa.h" |
75 | #include "tree-sra.h" |
76 | #include "alloc-pool.h" |
77 | #include "symbol-summary.h" |
78 | #include "dbgcnt.h" |
79 | #include "tree-inline.h" |
80 | #include "ipa-utils.h" |
81 | #include "builtins.h" |
82 | #include "cfganal.h" |
83 | #include "tree-streamer.h" |
84 | #include "internal-fn.h" |
85 | #include "symtab-clones.h" |
86 | #include "attribs.h" |
87 | #include "sreal.h" |
88 | #include "ipa-cp.h" |
89 | #include "ipa-prop.h" |
90 | |
91 | static void ipa_sra_summarize_function (cgraph_node *); |
92 | |
93 | /* Bits used to track size of an aggregate in bytes interprocedurally. */ |
94 | #define ISRA_ARG_SIZE_LIMIT_BITS 16 |
95 | #define ISRA_ARG_SIZE_LIMIT (1 << ISRA_ARG_SIZE_LIMIT_BITS) |
96 | /* How many parameters can feed into a call actual argument and still be |
97 | tracked. */ |
98 | #define IPA_SRA_MAX_PARAM_FLOW_LEN 7 |
99 | |
100 | /* Structure describing accesses to a specific portion of an aggregate |
101 | parameter, as given by the offset and size. Any smaller accesses that occur |
102 | within a function that fall within another access form a tree. The pass |
103 | cannot analyze parameters with only partially overlapping accesses. */ |
104 | |
105 | struct GTY(()) param_access |
106 | { |
107 | /* Type that a potential replacement should have. This field only has |
108 | meaning in the summary building and transformation phases, when it is |
109 | reconstructed from the body. Must not be touched in IPA analysis |
110 | stage. */ |
111 | tree type; |
112 | |
113 | /* Alias reference type to be used in MEM_REFs when adjusting caller |
114 | arguments. */ |
115 | tree alias_ptr_type; |
116 | |
117 | /* Values returned by get_ref_base_and_extent but converted to bytes and |
118 | stored as unsigned ints. */ |
119 | unsigned unit_offset; |
120 | unsigned unit_size : ISRA_ARG_SIZE_LIMIT_BITS; |
121 | |
122 | /* Set once we are sure that the access will really end up in a potentially |
123 | transformed function - initially not set for portions of formal parameters |
124 | that are only used as actual function arguments passed to callees. */ |
125 | unsigned certain : 1; |
126 | /* Set if the access has reverse scalar storage order. */ |
127 | unsigned reverse : 1; |
128 | }; |
129 | |
130 | /* This structure has the same purpose as the one above and additionally it |
131 | contains some fields that are only necessary in the summary generation |
132 | phase. */ |
133 | |
134 | struct gensum_param_access |
135 | { |
136 | /* Values returned by get_ref_base_and_extent. */ |
137 | HOST_WIDE_INT offset; |
138 | HOST_WIDE_INT size; |
139 | |
140 | /* if this access has any children (in terms of the definition above), this |
141 | points to the first one. */ |
142 | struct gensum_param_access *first_child; |
143 | /* In intraprocedural SRA, pointer to the next sibling in the access tree as |
144 | described above. */ |
145 | struct gensum_param_access *next_sibling; |
146 | |
147 | /* Type that a potential replacement should have. This field only has |
148 | meaning in the summary building and transformation phases, when it is |
149 | reconstructed from the body. Must not be touched in IPA analysis |
150 | stage. */ |
151 | tree type; |
152 | /* Alias reference type to be used in MEM_REFs when adjusting caller |
153 | arguments. */ |
154 | tree alias_ptr_type; |
155 | |
156 | /* Cumulative count of all loads. */ |
157 | profile_count load_count; |
158 | /* Have there been writes to or reads from this exact location except for as |
159 | arguments to a function call that can be tracked. */ |
160 | bool nonarg; |
161 | |
162 | /* Set if the access has reverse scalar storage order. */ |
163 | bool reverse; |
164 | }; |
165 | |
166 | /* Summary describing a parameter in the IPA stages. */ |
167 | |
168 | struct GTY(()) isra_param_desc |
169 | { |
170 | /* List of access representatives to the parameters, sorted according to |
171 | their offset. */ |
172 | vec <param_access *, va_gc> *accesses; |
173 | |
174 | /* Unit size limit of total size of all replacements. */ |
175 | unsigned param_size_limit : ISRA_ARG_SIZE_LIMIT_BITS; |
176 | /* Sum of unit sizes of all certain replacements. */ |
177 | unsigned size_reached : ISRA_ARG_SIZE_LIMIT_BITS; |
178 | /* Minimum offset that is known to be safe to dereference because of callers |
179 | pass pointers to DECLs of at least this size or because of dereferences in |
180 | callers. */ |
181 | unsigned safe_size : ISRA_ARG_SIZE_LIMIT_BITS; |
182 | |
183 | /* A parameter that is used only in call arguments and can be removed if all |
184 | concerned actual arguments are removed. */ |
185 | unsigned locally_unused : 1; |
186 | /* An aggregate that is a candidate for breaking up or complete removal. */ |
187 | unsigned split_candidate : 1; |
188 | /* Is this a parameter passing stuff by reference? */ |
189 | unsigned by_ref : 1; |
190 | /* If set, this parameter can only be a candidate for removal if the function |
191 | is going to loose its return value. */ |
192 | unsigned remove_only_when_retval_removed : 1; |
193 | /* If set, this parameter can only be a candidate for splitting if the |
194 | function is going to loose its return value. Can only be meaningfully set |
195 | for by_ref parameters. */ |
196 | unsigned split_only_when_retval_removed : 1; |
197 | /* Parameter hint set during IPA analysis when there is a caller which does |
198 | not construct the argument just to pass it to calls. Only meaningful for |
199 | by_ref parameters. */ |
200 | unsigned not_specially_constructed : 1; |
201 | /* Only meaningful for by_ref parameters. If set, this parameter can only be |
202 | a split candidate if all callers pass pointers that are known to point to |
203 | a chunk of memory large enough to contain all accesses. */ |
204 | unsigned conditionally_dereferenceable : 1; |
205 | /* Set when safe_size has been updated from at least one caller. */ |
206 | unsigned safe_size_set : 1; |
207 | }; |
208 | |
209 | /* Structure used when generating summaries that describes a parameter. */ |
210 | |
211 | struct gensum_param_desc |
212 | { |
213 | /* Roots of param_accesses. */ |
214 | gensum_param_access *accesses; |
215 | /* Number of accesses in the access tree rooted in field accesses. */ |
216 | unsigned access_count; |
217 | |
218 | /* If the below is non-zero, this is the number of uses as actual |
219 | arguments. */ |
220 | int call_uses; |
221 | /* Number of times this parameter has been directly passed to. */ |
222 | unsigned ptr_pt_count; |
223 | |
224 | /* Size limit of total size of all replacements. */ |
225 | unsigned param_size_limit; |
226 | /* Sum of sizes of nonarg accesses. */ |
227 | unsigned nonarg_acc_size; |
228 | |
229 | /* A parameter that is used only in call arguments and can be removed if all |
230 | concerned actual arguments are removed. */ |
231 | bool locally_unused; |
232 | /* An aggregate that is a candidate for breaking up or a pointer passing data |
233 | by reference that is a candidate for being converted to a set of |
234 | parameters passing those data by value. */ |
235 | bool split_candidate; |
236 | /* Is this a parameter passing stuff by reference (either a pointer or a |
237 | source language reference type)? */ |
238 | bool by_ref; |
239 | /* If this parameter passes stuff by reference, can it be safely dereferenced |
240 | without performing further checks (for example because it is a |
241 | REFERENCE_TYPE)? */ |
242 | bool safe_ref; |
243 | /* If set, this parameter can only be a candidate for removal if the function |
244 | is going to loose its return value. */ |
245 | bool remove_only_when_retval_removed; |
246 | /* If set, this parameter can only be a candidate for splitting if the |
247 | function is going to loose its return value. Can only be meaningfully set |
248 | for by_ref parameters. */ |
249 | bool split_only_when_retval_removed; |
250 | /* Only meaningful for by_ref parameters. If set, this parameter can only be |
251 | a split candidate if all callers pass pointers that are known to point to |
252 | a chunk of memory large enough to contain all accesses. */ |
253 | bool conditionally_dereferenceable; |
254 | |
255 | /* The number of this parameter as they are ordered in function decl. */ |
256 | int param_number; |
257 | /* For parameters passing data by reference, this is parameter index to |
258 | compute indices to bb_dereferences. */ |
259 | int deref_index; |
260 | }; |
261 | |
262 | /* Properly deallocate accesses of DESC. TODO: Since this data structure is |
263 | allocated in GC memory, this is not necessary and we can consider removing |
264 | the function. */ |
265 | |
266 | static void |
267 | free_param_decl_accesses (isra_param_desc *desc) |
268 | { |
269 | unsigned len = vec_safe_length (v: desc->accesses); |
270 | for (unsigned i = 0; i < len; ++i) |
271 | ggc_free ((*desc->accesses)[i]); |
272 | vec_free (v&: desc->accesses); |
273 | } |
274 | |
275 | /* Class used to convey information about functions from the |
276 | intra-procedural analysis stage to inter-procedural one. */ |
277 | |
278 | class GTY((for_user)) isra_func_summary |
279 | { |
280 | public: |
281 | /* initialize the object. */ |
282 | |
283 | isra_func_summary () |
284 | : m_parameters (NULL), m_candidate (false), m_returns_value (false), |
285 | m_return_ignored (false), m_queued (false) |
286 | {} |
287 | |
288 | /* Destroy m_parameters. */ |
289 | |
290 | ~isra_func_summary (); |
291 | |
292 | /* Mark the function as not a candidate for any IPA-SRA transformation. |
293 | Return true if it was a candidate until now. */ |
294 | |
295 | bool zap (); |
296 | |
297 | /* Vector of parameter descriptors corresponding to the function being |
298 | analyzed. */ |
299 | vec<isra_param_desc, va_gc> *m_parameters; |
300 | |
301 | /* Whether the node is even a candidate for any IPA-SRA transformation at |
302 | all. */ |
303 | unsigned m_candidate : 1; |
304 | |
305 | /* Whether the original function returns any value. */ |
306 | unsigned m_returns_value : 1; |
307 | |
308 | /* Set to true if all call statements do not actually use the returned |
309 | value. */ |
310 | |
311 | unsigned m_return_ignored : 1; |
312 | |
313 | /* Whether the node is already queued in IPA SRA stack during processing of |
314 | call graphs SCCs. */ |
315 | |
316 | unsigned m_queued : 1; |
317 | }; |
318 | |
319 | /* Deallocate the memory pointed to by isra_func_summary. TODO: Since this |
320 | data structure is allocated in GC memory, this is not necessary and we can |
321 | consider removing the destructor. */ |
322 | |
323 | isra_func_summary::~isra_func_summary () |
324 | { |
325 | unsigned len = vec_safe_length (v: m_parameters); |
326 | for (unsigned i = 0; i < len; ++i) |
327 | free_param_decl_accesses (desc: &(*m_parameters)[i]); |
328 | vec_free (v&: m_parameters); |
329 | } |
330 | |
331 | /* Mark the function as not a candidate for any IPA-SRA transformation. Return |
332 | true if it was a candidate until now. */ |
333 | |
334 | bool |
335 | isra_func_summary::zap () |
336 | { |
337 | bool ret = m_candidate; |
338 | m_candidate = false; |
339 | |
340 | /* TODO: see the destructor above. */ |
341 | unsigned len = vec_safe_length (v: m_parameters); |
342 | for (unsigned i = 0; i < len; ++i) |
343 | free_param_decl_accesses (desc: &(*m_parameters)[i]); |
344 | vec_free (v&: m_parameters); |
345 | |
346 | return ret; |
347 | } |
348 | |
349 | /* Structure to describe which formal parameters feed into a particular actual |
350 | argument. */ |
351 | |
352 | struct isra_param_flow |
353 | { |
354 | /* Number of elements in array inputs that contain valid data. */ |
355 | char length; |
356 | /* Indices of formal parameters that feed into the described actual argument. |
357 | If aggregate_pass_through or pointer_pass_through below are true, it must |
358 | contain exactly one element which is passed through from a formal |
359 | parameter if the given number. Otherwise, the array contains indices of |
360 | callee's formal parameters which are used to calculate value of this |
361 | actual argument. */ |
362 | unsigned char inputs[IPA_SRA_MAX_PARAM_FLOW_LEN]; |
363 | |
364 | /* Offset within the formal parameter. */ |
365 | unsigned unit_offset; |
366 | /* When aggregate_pass_through is set, this is the size of the portion of an |
367 | aggregate formal parameter that is being passed. Otherwise, this is size |
368 | of pointed to memory that is known to be valid be dereferenced. */ |
369 | unsigned unit_size : ISRA_ARG_SIZE_LIMIT_BITS; |
370 | |
371 | /* True when the value of this actual argument is a portion of a formal |
372 | parameter. */ |
373 | unsigned aggregate_pass_through : 1; |
374 | /* True when the value of this actual copy is a verbatim pass through of an |
375 | obtained pointer. */ |
376 | unsigned pointer_pass_through : 1; |
377 | /* True when it is safe to copy access candidates here from the callee, which |
378 | would mean introducing dereferences into callers of the caller. */ |
379 | unsigned safe_to_import_accesses : 1; |
380 | /* True when the passed value is an address of a structure that has been |
381 | constructed in the caller just to be passed by reference to functions |
382 | (i.e. is never read). */ |
383 | unsigned constructed_for_calls : 1; |
384 | }; |
385 | |
386 | /* Structure used to convey information about calls from the intra-procedural |
387 | analysis stage to inter-procedural one. */ |
388 | |
389 | class isra_call_summary |
390 | { |
391 | public: |
392 | isra_call_summary () |
393 | : m_arg_flow (), m_return_ignored (false), m_return_returned (false), |
394 | m_bit_aligned_arg (false), m_before_any_store (false) |
395 | {} |
396 | |
397 | void init_inputs (unsigned arg_count); |
398 | void dump (FILE *f); |
399 | |
400 | /* Information about what formal parameters of the caller are used to compute |
401 | individual actual arguments of this call. */ |
402 | auto_vec <isra_param_flow> m_arg_flow; |
403 | |
404 | /* Set to true if the call statement does not have a LHS. */ |
405 | unsigned m_return_ignored : 1; |
406 | |
407 | /* Set to true if the LHS of call statement is only used to construct the |
408 | return value of the caller. */ |
409 | unsigned m_return_returned : 1; |
410 | |
411 | /* Set when any of the call arguments are not byte-aligned. */ |
412 | unsigned m_bit_aligned_arg : 1; |
413 | |
414 | /* Set to true if the call happend before any (other) store to memory in the |
415 | caller. */ |
416 | unsigned m_before_any_store : 1; |
417 | }; |
418 | |
419 | /* Class to manage function summaries. */ |
420 | |
421 | class GTY((user)) ipa_sra_function_summaries |
422 | : public function_summary <isra_func_summary *> |
423 | { |
424 | public: |
425 | ipa_sra_function_summaries (symbol_table *table, bool ggc): |
426 | function_summary<isra_func_summary *> (table, ggc) { } |
427 | |
428 | void duplicate (cgraph_node *, cgraph_node *, |
429 | isra_func_summary *old_sum, |
430 | isra_func_summary *new_sum) final override; |
431 | void insert (cgraph_node *, isra_func_summary *) final override; |
432 | }; |
433 | |
434 | /* Hook that is called by summary when a node is duplicated. */ |
435 | |
436 | void |
437 | ipa_sra_function_summaries::duplicate (cgraph_node *, cgraph_node *, |
438 | isra_func_summary *old_sum, |
439 | isra_func_summary *new_sum) |
440 | { |
441 | /* TODO: Somehow stop copying when ISRA is doing the cloning, it is |
442 | useless. */ |
443 | new_sum->m_candidate = old_sum->m_candidate; |
444 | new_sum->m_returns_value = old_sum->m_returns_value; |
445 | new_sum->m_return_ignored = old_sum->m_return_ignored; |
446 | gcc_assert (!old_sum->m_queued); |
447 | new_sum->m_queued = false; |
448 | |
449 | unsigned param_count = vec_safe_length (v: old_sum->m_parameters); |
450 | if (!param_count) |
451 | return; |
452 | vec_safe_reserve_exact (v&: new_sum->m_parameters, nelems: param_count); |
453 | new_sum->m_parameters->quick_grow_cleared (len: param_count); |
454 | for (unsigned i = 0; i < param_count; i++) |
455 | { |
456 | isra_param_desc *s = &(*old_sum->m_parameters)[i]; |
457 | isra_param_desc *d = &(*new_sum->m_parameters)[i]; |
458 | |
459 | d->param_size_limit = s->param_size_limit; |
460 | d->size_reached = s->size_reached; |
461 | d->safe_size = s->safe_size; |
462 | d->locally_unused = s->locally_unused; |
463 | d->split_candidate = s->split_candidate; |
464 | d->by_ref = s->by_ref; |
465 | d->remove_only_when_retval_removed = s->remove_only_when_retval_removed; |
466 | d->split_only_when_retval_removed = s->split_only_when_retval_removed; |
467 | d->not_specially_constructed = s->not_specially_constructed; |
468 | d->conditionally_dereferenceable = s->conditionally_dereferenceable; |
469 | d->safe_size_set = s->safe_size_set; |
470 | |
471 | unsigned acc_count = vec_safe_length (v: s->accesses); |
472 | vec_safe_reserve_exact (v&: d->accesses, nelems: acc_count); |
473 | for (unsigned j = 0; j < acc_count; j++) |
474 | { |
475 | param_access *from = (*s->accesses)[j]; |
476 | param_access *to = ggc_cleared_alloc<param_access> (); |
477 | to->type = from->type; |
478 | to->alias_ptr_type = from->alias_ptr_type; |
479 | to->unit_offset = from->unit_offset; |
480 | to->unit_size = from->unit_size; |
481 | to->certain = from->certain; |
482 | to->reverse = from->reverse; |
483 | d->accesses->quick_push (obj: to); |
484 | } |
485 | } |
486 | } |
487 | |
488 | /* Pointer to the pass function summary holder. */ |
489 | |
490 | static GTY(()) ipa_sra_function_summaries *func_sums; |
491 | |
492 | /* Hook that is called by summary when new node appears. */ |
493 | |
494 | void |
495 | ipa_sra_function_summaries::insert (cgraph_node *node, isra_func_summary *) |
496 | { |
497 | if (opt_for_fn (node->decl, flag_ipa_sra)) |
498 | { |
499 | push_cfun (DECL_STRUCT_FUNCTION (node->decl)); |
500 | ipa_sra_summarize_function (node); |
501 | pop_cfun (); |
502 | } |
503 | else |
504 | func_sums->remove (node); |
505 | } |
506 | |
507 | /* Class to manage call summaries. */ |
508 | |
509 | class ipa_sra_call_summaries: public call_summary <isra_call_summary *> |
510 | { |
511 | public: |
512 | ipa_sra_call_summaries (symbol_table *table): |
513 | call_summary<isra_call_summary *> (table) { } |
514 | |
515 | /* Duplicate info when an edge is cloned. */ |
516 | void duplicate (cgraph_edge *, cgraph_edge *, |
517 | isra_call_summary *old_sum, |
518 | isra_call_summary *new_sum) final override; |
519 | }; |
520 | |
521 | static ipa_sra_call_summaries *call_sums; |
522 | |
523 | |
524 | /* Initialize m_arg_flow of a particular instance of isra_call_summary. |
525 | ARG_COUNT is the number of actual arguments passed. */ |
526 | |
527 | void |
528 | isra_call_summary::init_inputs (unsigned arg_count) |
529 | { |
530 | if (arg_count == 0) |
531 | { |
532 | gcc_checking_assert (m_arg_flow.length () == 0); |
533 | return; |
534 | } |
535 | if (m_arg_flow.length () == 0) |
536 | { |
537 | m_arg_flow.reserve_exact (nelems: arg_count); |
538 | m_arg_flow.quick_grow_cleared (len: arg_count); |
539 | } |
540 | else |
541 | gcc_checking_assert (arg_count == m_arg_flow.length ()); |
542 | } |
543 | |
544 | /* Dump all information in call summary to F. */ |
545 | |
546 | void |
547 | isra_call_summary::dump (FILE *f) |
548 | { |
549 | if (m_return_ignored) |
550 | fprintf (stream: f, format: " return value ignored\n" ); |
551 | if (m_return_returned) |
552 | fprintf (stream: f, format: " return value used only to compute caller return value\n" ); |
553 | if (m_before_any_store) |
554 | fprintf (stream: f, format: " happens before any store to memory\n" ); |
555 | for (unsigned i = 0; i < m_arg_flow.length (); i++) |
556 | { |
557 | fprintf (stream: f, format: " Parameter %u:\n" , i); |
558 | isra_param_flow *ipf = &m_arg_flow[i]; |
559 | |
560 | if (ipf->length) |
561 | { |
562 | bool first = true; |
563 | fprintf (stream: f, format: " Scalar param sources: " ); |
564 | for (int j = 0; j < ipf->length; j++) |
565 | { |
566 | if (!first) |
567 | fprintf (stream: f, format: ", " ); |
568 | else |
569 | first = false; |
570 | fprintf (stream: f, format: "%i" , (int) ipf->inputs[j]); |
571 | } |
572 | fprintf (stream: f, format: "\n" ); |
573 | } |
574 | if (ipf->aggregate_pass_through) |
575 | fprintf (stream: f, format: " Aggregate pass through from the param given above, " |
576 | "unit offset: %u , unit size: %u\n" , |
577 | ipf->unit_offset, ipf->unit_size); |
578 | else if (ipf->unit_size > 0) |
579 | fprintf (stream: f, format: " Known dereferenceable size: %u\n" , ipf->unit_size); |
580 | if (ipf->pointer_pass_through) |
581 | fprintf (stream: f, format: " Pointer pass through from the param given above, " |
582 | "safe_to_import_accesses: %u\n" , ipf->safe_to_import_accesses); |
583 | if (ipf->constructed_for_calls) |
584 | fprintf (stream: f, format: " Variable constructed just to be passed to " |
585 | "calls.\n" ); |
586 | } |
587 | } |
588 | |
589 | /* Duplicate edge summary when an edge is cloned. */ |
590 | |
591 | void |
592 | ipa_sra_call_summaries::duplicate (cgraph_edge *, cgraph_edge *, |
593 | isra_call_summary *old_sum, |
594 | isra_call_summary *new_sum) |
595 | { |
596 | unsigned arg_count = old_sum->m_arg_flow.length (); |
597 | new_sum->init_inputs (arg_count); |
598 | for (unsigned i = 0; i < arg_count; i++) |
599 | new_sum->m_arg_flow[i] = old_sum->m_arg_flow[i]; |
600 | |
601 | new_sum->m_return_ignored = old_sum->m_return_ignored; |
602 | new_sum->m_return_returned = old_sum->m_return_returned; |
603 | new_sum->m_bit_aligned_arg = old_sum->m_bit_aligned_arg; |
604 | new_sum->m_before_any_store = old_sum->m_before_any_store; |
605 | } |
606 | |
607 | |
608 | /* With all GTY stuff done, we can move to anonymous namespace. */ |
609 | namespace { |
610 | /* Quick mapping from a decl to its param descriptor. */ |
611 | |
612 | hash_map<tree, gensum_param_desc *> *decl2desc; |
613 | |
614 | /* All local DECLs ever loaded from of and of those that have their address |
615 | assigned to a variable. */ |
616 | |
617 | hash_set <tree> *loaded_decls; |
618 | |
619 | /* Countdown of allowed Alias Analysis steps during summary building. */ |
620 | |
621 | int aa_walking_limit; |
622 | |
623 | /* This is a table in which for each basic block and parameter there is a |
624 | distance (offset + size) in that parameter which is dereferenced and |
625 | accessed in that BB. */ |
626 | HOST_WIDE_INT *bb_dereferences = NULL; |
627 | /* How many by-reference parameters there are in the current function. */ |
628 | int unsafe_by_ref_count; |
629 | |
630 | /* Bitmap of BBs that can cause the function to "stop" progressing by |
631 | returning, throwing externally, looping infinitely or calling a function |
632 | which might abort etc.. */ |
633 | bitmap final_bbs; |
634 | |
635 | /* Obstack to allocate various small structures required only when generating |
636 | summary for a function. */ |
637 | struct obstack gensum_obstack; |
638 | |
639 | /* Return false the function is apparently unsuitable for IPA-SRA based on it's |
640 | attributes, return true otherwise. NODE is the cgraph node of the current |
641 | function. */ |
642 | |
643 | static bool |
644 | ipa_sra_preliminary_function_checks (cgraph_node *node) |
645 | { |
646 | if (!node->can_change_signature) |
647 | { |
648 | if (dump_file) |
649 | fprintf (stream: dump_file, format: "Function cannot change signature.\n" ); |
650 | return false; |
651 | } |
652 | |
653 | if (!tree_versionable_function_p (node->decl)) |
654 | { |
655 | if (dump_file) |
656 | fprintf (stream: dump_file, format: "Function is not versionable.\n" ); |
657 | return false; |
658 | } |
659 | |
660 | if (!opt_for_fn (node->decl, optimize) |
661 | || !opt_for_fn (node->decl, flag_ipa_sra)) |
662 | { |
663 | if (dump_file) |
664 | fprintf (stream: dump_file, format: "Not optimizing or IPA-SRA turned off for this " |
665 | "function.\n" ); |
666 | return false; |
667 | } |
668 | |
669 | if (DECL_VIRTUAL_P (node->decl)) |
670 | { |
671 | if (dump_file) |
672 | fprintf (stream: dump_file, format: "Function is a virtual method.\n" ); |
673 | return false; |
674 | } |
675 | |
676 | struct function *fun = DECL_STRUCT_FUNCTION (node->decl); |
677 | if (fun->stdarg) |
678 | { |
679 | if (dump_file) |
680 | fprintf (stream: dump_file, format: "Function uses stdarg. \n" ); |
681 | return false; |
682 | } |
683 | |
684 | if (DECL_DISREGARD_INLINE_LIMITS (node->decl)) |
685 | { |
686 | if (dump_file) |
687 | fprintf (stream: dump_file, format: "Always inline function will be inlined " |
688 | "anyway. \n" ); |
689 | return false; |
690 | } |
691 | |
692 | return true; |
693 | } |
694 | |
695 | /* Print access tree starting at ACCESS to F. */ |
696 | |
697 | static void |
698 | dump_gensum_access (FILE *f, gensum_param_access *access, unsigned indent) |
699 | { |
700 | fprintf (stream: f, format: " " ); |
701 | for (unsigned i = 0; i < indent; i++) |
702 | fprintf (stream: f, format: " " ); |
703 | fprintf (stream: f, format: " * Access to offset: " HOST_WIDE_INT_PRINT_DEC, |
704 | access->offset); |
705 | fprintf (stream: f, format: ", size: " HOST_WIDE_INT_PRINT_DEC, access->size); |
706 | fprintf (stream: f, format: ", type: " ); |
707 | print_generic_expr (f, access->type); |
708 | fprintf (stream: f, format: ", alias_ptr_type: " ); |
709 | print_generic_expr (f, access->alias_ptr_type); |
710 | fprintf (stream: f, format: ", load_count: " ); |
711 | access->load_count.dump (f); |
712 | fprintf (stream: f, format: ", nonarg: %u, reverse: %u\n" , access->nonarg, access->reverse); |
713 | for (gensum_param_access *ch = access->first_child; |
714 | ch; |
715 | ch = ch->next_sibling) |
716 | dump_gensum_access (f, access: ch, indent: indent + 2); |
717 | } |
718 | |
719 | |
720 | /* Print access tree starting at ACCESS to F. */ |
721 | |
722 | static void |
723 | dump_isra_access (FILE *f, param_access *access) |
724 | { |
725 | fprintf (stream: f, format: " * Access to unit offset: %u" , access->unit_offset); |
726 | fprintf (stream: f, format: ", unit size: %u" , access->unit_size); |
727 | fprintf (stream: f, format: ", type: " ); |
728 | print_generic_expr (f, access->type); |
729 | fprintf (stream: f, format: ", alias_ptr_type: " ); |
730 | print_generic_expr (f, access->alias_ptr_type); |
731 | if (access->certain) |
732 | fprintf (stream: f, format: ", certain" ); |
733 | else |
734 | fprintf (stream: f, format: ", not certain" ); |
735 | if (access->reverse) |
736 | fprintf (stream: f, format: ", reverse" ); |
737 | fprintf (stream: f, format: "\n" ); |
738 | } |
739 | |
740 | /* Dump access tree starting at ACCESS to stderr. */ |
741 | |
742 | DEBUG_FUNCTION void |
743 | debug_isra_access (param_access *access) |
744 | { |
745 | dump_isra_access (stderr, access); |
746 | } |
747 | |
748 | /* Dump DESC to F. */ |
749 | |
750 | static void |
751 | dump_gensum_param_descriptor (FILE *f, gensum_param_desc *desc) |
752 | { |
753 | if (desc->locally_unused) |
754 | fprintf (stream: f, format: " unused with %i call_uses%s\n" , desc->call_uses, |
755 | desc->remove_only_when_retval_removed ? |
756 | " remove_only_when_retval_removed" : "" ); |
757 | if (!desc->split_candidate) |
758 | { |
759 | fprintf (stream: f, format: " not a candidate\n" ); |
760 | return; |
761 | } |
762 | if (desc->by_ref) |
763 | fprintf (stream: f, format: " %s%s%s by_ref with %u pass throughs\n" , |
764 | desc->safe_ref ? "safe" : "unsafe" , |
765 | desc->conditionally_dereferenceable |
766 | ? " conditionally_dereferenceable" : "" , |
767 | desc->split_only_when_retval_removed |
768 | ? " split_only_when_retval_removed" : "" , |
769 | desc->ptr_pt_count); |
770 | |
771 | for (gensum_param_access *acc = desc->accesses; acc; acc = acc->next_sibling) |
772 | dump_gensum_access (f, access: acc, indent: 2); |
773 | } |
774 | |
775 | /* Dump all parameter descriptors in IFS, assuming it describes FNDECL, to |
776 | F. */ |
777 | |
778 | static void |
779 | dump_gensum_param_descriptors (FILE *f, tree fndecl, |
780 | vec<gensum_param_desc> *param_descriptions) |
781 | { |
782 | tree parm = DECL_ARGUMENTS (fndecl); |
783 | for (unsigned i = 0; |
784 | i < param_descriptions->length (); |
785 | ++i, parm = DECL_CHAIN (parm)) |
786 | { |
787 | fprintf (stream: f, format: " Descriptor for parameter %i " , i); |
788 | print_generic_expr (f, parm, TDF_UID); |
789 | fprintf (stream: f, format: "\n" ); |
790 | dump_gensum_param_descriptor (f, desc: &(*param_descriptions)[i]); |
791 | } |
792 | } |
793 | |
794 | |
795 | /* Dump DESC to F. If HINTS is true, also dump IPA-analysis computed |
796 | hints. */ |
797 | |
798 | static void |
799 | dump_isra_param_descriptor (FILE *f, isra_param_desc *desc, bool hints) |
800 | { |
801 | if (desc->locally_unused) |
802 | { |
803 | fprintf (stream: f, format: " (locally) unused\n" ); |
804 | } |
805 | if (!desc->split_candidate) |
806 | { |
807 | fprintf (stream: f, format: " not a candidate for splitting" ); |
808 | if (hints && desc->by_ref && desc->safe_size_set) |
809 | fprintf (stream: f, format: ", safe_size: %u" , (unsigned) desc->safe_size); |
810 | fprintf (stream: f, format: "\n" ); |
811 | return; |
812 | } |
813 | fprintf (stream: f, format: " param_size_limit: %u, size_reached: %u%s" , |
814 | desc->param_size_limit, desc->size_reached, |
815 | desc->by_ref ? ", by_ref" : "" ); |
816 | if (desc->remove_only_when_retval_removed) |
817 | fprintf (stream: f, format: ", remove_only_when_retval_removed" ); |
818 | if (desc->split_only_when_retval_removed) |
819 | fprintf (stream: f, format: ", split_only_when_retval_removed" ); |
820 | if (desc->by_ref && desc->conditionally_dereferenceable) |
821 | fprintf (stream: f, format: ", conditionally_dereferenceable" ); |
822 | if (hints) |
823 | { |
824 | if (desc->by_ref && !desc->not_specially_constructed) |
825 | fprintf (stream: f, format: ", args_specially_constructed" ); |
826 | if (desc->by_ref && desc->safe_size_set) |
827 | fprintf (stream: f, format: ", safe_size: %u" , (unsigned) desc->safe_size); |
828 | } |
829 | fprintf (stream: f, format: "\n" ); |
830 | |
831 | for (unsigned i = 0; i < vec_safe_length (v: desc->accesses); ++i) |
832 | { |
833 | param_access *access = (*desc->accesses)[i]; |
834 | dump_isra_access (f, access); |
835 | } |
836 | } |
837 | |
838 | /* Dump all parameter descriptors in IFS, assuming it describes FNDECL, to F. |
839 | If HINTS is true, also dump IPA-analysis computed hints. */ |
840 | |
841 | static void |
842 | dump_isra_param_descriptors (FILE *f, tree fndecl, isra_func_summary *ifs, |
843 | bool hints) |
844 | { |
845 | tree parm = DECL_ARGUMENTS (fndecl); |
846 | if (!ifs->m_parameters) |
847 | { |
848 | fprintf (stream: f, format: " parameter descriptors not available\n" ); |
849 | return; |
850 | } |
851 | |
852 | for (unsigned i = 0; |
853 | i < ifs->m_parameters->length (); |
854 | ++i, parm = DECL_CHAIN (parm)) |
855 | { |
856 | fprintf (stream: f, format: " Descriptor for parameter %i " , i); |
857 | print_generic_expr (f, parm, TDF_UID); |
858 | fprintf (stream: f, format: "\n" ); |
859 | dump_isra_param_descriptor (f, desc: &(*ifs->m_parameters)[i], hints); |
860 | } |
861 | } |
862 | |
863 | /* Add SRC to inputs of PARAM_FLOW, unless it would exceed storage. If the |
864 | function fails return false, otherwise return true. SRC must fit into an |
865 | unsigned char. Used for purposes of transitive unused parameter |
866 | removal. */ |
867 | |
868 | static bool |
869 | add_src_to_param_flow (isra_param_flow *param_flow, int src) |
870 | { |
871 | gcc_checking_assert (src >= 0 && src <= UCHAR_MAX); |
872 | if (param_flow->length == IPA_SRA_MAX_PARAM_FLOW_LEN) |
873 | return false; |
874 | |
875 | param_flow->inputs[(int) param_flow->length] = src; |
876 | param_flow->length++; |
877 | return true; |
878 | } |
879 | |
880 | /* Add a SRC to the inputs of PARAM_FLOW unless it is already there and assert |
881 | it is the only input. Used for purposes of transitive parameter |
882 | splitting. */ |
883 | |
884 | static void |
885 | set_single_param_flow_source (isra_param_flow *param_flow, int src) |
886 | { |
887 | gcc_checking_assert (src >= 0 && src <= UCHAR_MAX); |
888 | if (param_flow->length == 0) |
889 | { |
890 | param_flow->inputs[0] = src; |
891 | param_flow->length = 1; |
892 | } |
893 | else if (param_flow->length == 1) |
894 | gcc_assert (param_flow->inputs[0] == src); |
895 | else |
896 | gcc_unreachable (); |
897 | } |
898 | |
899 | /* Assert that there is only a single value in PARAM_FLOW's inputs and return |
900 | it. */ |
901 | |
902 | static unsigned |
903 | get_single_param_flow_source (const isra_param_flow *param_flow) |
904 | { |
905 | gcc_assert (param_flow->length == 1); |
906 | return param_flow->inputs[0]; |
907 | } |
908 | |
909 | /* Inspect all uses of NAME and simple arithmetic calculations involving NAME |
910 | in FUN represented with NODE and return a negative number if any of them is |
911 | used for something else than either an actual call argument, simple return, |
912 | simple arithmetic operation or debug statement. If there are no such uses, |
913 | return the number of actual arguments that this parameter eventually feeds |
914 | to (or zero if there is none). If there are any simple return uses, set |
915 | DESC->remove_only_when_retval_removed. For any such parameter, mark |
916 | PARM_NUM as one of its sources. ANALYZED is a bitmap that tracks which SSA |
917 | names we have already started investigating. */ |
918 | |
919 | static int |
920 | isra_track_scalar_value_uses (function *fun, cgraph_node *node, tree name, |
921 | int parm_num, bitmap analyzed, |
922 | gensum_param_desc *desc) |
923 | { |
924 | int res = 0; |
925 | imm_use_iterator imm_iter; |
926 | gimple *stmt; |
927 | |
928 | FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name) |
929 | { |
930 | if (is_gimple_debug (gs: stmt) |
931 | || gimple_clobber_p (s: stmt)) |
932 | continue; |
933 | |
934 | /* TODO: We could handle at least const builtin functions like arithmetic |
935 | operations below. */ |
936 | if (is_gimple_call (gs: stmt)) |
937 | { |
938 | int all_uses = 0; |
939 | use_operand_p use_p; |
940 | FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) |
941 | all_uses++; |
942 | |
943 | gcall *call = as_a <gcall *> (p: stmt); |
944 | unsigned arg_count; |
945 | if (gimple_call_internal_p (gs: call) |
946 | || (arg_count = gimple_call_num_args (gs: call)) == 0) |
947 | { |
948 | res = -1; |
949 | break; |
950 | } |
951 | |
952 | cgraph_edge *cs = node->get_edge (call_stmt: stmt); |
953 | gcc_checking_assert (cs); |
954 | isra_call_summary *csum = call_sums->get_create (edge: cs); |
955 | csum->init_inputs (arg_count); |
956 | |
957 | int simple_uses = 0; |
958 | for (unsigned i = 0; i < arg_count; i++) |
959 | if (gimple_call_arg (gs: call, index: i) == name) |
960 | { |
961 | if (!add_src_to_param_flow (param_flow: &csum->m_arg_flow[i], src: parm_num)) |
962 | { |
963 | simple_uses = -1; |
964 | break; |
965 | } |
966 | simple_uses++; |
967 | } |
968 | |
969 | if (simple_uses < 0 |
970 | || all_uses != simple_uses) |
971 | { |
972 | res = -1; |
973 | break; |
974 | } |
975 | res += all_uses; |
976 | } |
977 | else if (!stmt_unremovable_because_of_non_call_eh_p (fun, stmt) |
978 | && ((is_gimple_assign (gs: stmt) && !gimple_has_volatile_ops (stmt)) |
979 | || gimple_code (g: stmt) == GIMPLE_PHI)) |
980 | { |
981 | tree lhs; |
982 | if (gimple_code (g: stmt) == GIMPLE_PHI) |
983 | lhs = gimple_phi_result (gs: stmt); |
984 | else |
985 | lhs = gimple_assign_lhs (gs: stmt); |
986 | |
987 | if (TREE_CODE (lhs) != SSA_NAME) |
988 | { |
989 | res = -1; |
990 | break; |
991 | } |
992 | gcc_assert (!gimple_vdef (stmt)); |
993 | if (bitmap_set_bit (analyzed, SSA_NAME_VERSION (lhs))) |
994 | { |
995 | int tmp = isra_track_scalar_value_uses (fun, node, name: lhs, parm_num, |
996 | analyzed, desc); |
997 | if (tmp < 0) |
998 | { |
999 | res = tmp; |
1000 | break; |
1001 | } |
1002 | res += tmp; |
1003 | } |
1004 | } |
1005 | else if (greturn *gr = dyn_cast<greturn *>(p: stmt)) |
1006 | { |
1007 | tree rv = gimple_return_retval (gs: gr); |
1008 | if (rv != name) |
1009 | { |
1010 | res = -1; |
1011 | break; |
1012 | } |
1013 | desc->remove_only_when_retval_removed = true; |
1014 | } |
1015 | else |
1016 | { |
1017 | res = -1; |
1018 | break; |
1019 | } |
1020 | } |
1021 | return res; |
1022 | } |
1023 | |
1024 | /* Inspect all uses of PARM, which must be a gimple register, in FUN (which is |
1025 | also described by NODE) and simple arithmetic calculations involving PARM |
1026 | and return false if any of them is used for something else than either an |
1027 | actual call argument, simple return, simple arithmetic operation or debug |
1028 | statement. If there are no such uses, return true and store the number of |
1029 | actual arguments that this parameter eventually feeds to (or zero if there |
1030 | is none) to DESC->call_uses and set DESC->remove_only_when_retval_removed if |
1031 | there are any uses in return statemens. For any such parameter, mark |
1032 | PARM_NUM as one of its sources. |
1033 | |
1034 | This function is similar to ptr_parm_has_nonarg_uses but its results are |
1035 | meant for unused parameter removal, as opposed to splitting of parameters |
1036 | passed by reference or converting them to passed by value. */ |
1037 | |
1038 | static bool |
1039 | isra_track_scalar_param_local_uses (function *fun, cgraph_node *node, tree parm, |
1040 | int parm_num, gensum_param_desc *desc) |
1041 | { |
1042 | gcc_checking_assert (is_gimple_reg (parm)); |
1043 | |
1044 | tree name = ssa_default_def (fun, parm); |
1045 | if (!name || has_zero_uses (var: name)) |
1046 | { |
1047 | desc->call_uses = 0; |
1048 | return false; |
1049 | } |
1050 | |
1051 | /* Edge summaries can only handle callers with fewer than 256 parameters. */ |
1052 | if (parm_num > UCHAR_MAX) |
1053 | return true; |
1054 | |
1055 | bitmap analyzed = BITMAP_ALLOC (NULL); |
1056 | int call_uses = isra_track_scalar_value_uses (fun, node, name, parm_num, |
1057 | analyzed, desc); |
1058 | BITMAP_FREE (analyzed); |
1059 | if (call_uses < 0) |
1060 | return true; |
1061 | desc->call_uses = call_uses; |
1062 | return false; |
1063 | } |
1064 | |
1065 | /* Scan immediate uses of a default definition SSA name of a parameter PARM and |
1066 | examine whether there are any nonarg uses that are not actual arguments or |
1067 | otherwise infeasible uses. If so, return true, otherwise return false. |
1068 | Create pass-through IPA flow records for any direct uses as argument calls |
1069 | and if returning false, store their number into DESC->ptr_pt_count. If |
1070 | removal of return value would still allow splitting, return true but set |
1071 | DESC->split_only_when_retval_removed. NODE and FUN must represent the |
1072 | function that is currently analyzed, PARM_NUM must be the index of the |
1073 | analyzed parameter. |
1074 | |
1075 | This function is similar to isra_track_scalar_param_local_uses but its |
1076 | results are meant for splitting of parameters passed by reference or turning |
1077 | them into bits passed by value, as opposed to generic unused parameter |
1078 | removal. */ |
1079 | |
1080 | static bool |
1081 | ptr_parm_has_nonarg_uses (cgraph_node *node, function *fun, tree parm, |
1082 | int parm_num, gensum_param_desc *desc) |
1083 | { |
1084 | imm_use_iterator ui; |
1085 | gimple *stmt; |
1086 | tree name = ssa_default_def (fun, parm); |
1087 | bool ret = false; |
1088 | unsigned pt_count = 0; |
1089 | |
1090 | if (!name || has_zero_uses (var: name)) |
1091 | return false; |
1092 | |
1093 | /* Edge summaries can only handle callers with fewer than 256 parameters. */ |
1094 | if (parm_num > UCHAR_MAX) |
1095 | return true; |
1096 | |
1097 | FOR_EACH_IMM_USE_STMT (stmt, ui, name) |
1098 | { |
1099 | unsigned uses_ok = 0; |
1100 | use_operand_p use_p; |
1101 | |
1102 | if (is_gimple_debug (gs: stmt) |
1103 | || gimple_clobber_p (s: stmt)) |
1104 | continue; |
1105 | |
1106 | if (gimple_assign_single_p (gs: stmt)) |
1107 | { |
1108 | tree rhs = gimple_assign_rhs1 (gs: stmt); |
1109 | if (!TREE_THIS_VOLATILE (rhs)) |
1110 | { |
1111 | while (handled_component_p (t: rhs)) |
1112 | rhs = TREE_OPERAND (rhs, 0); |
1113 | if (TREE_CODE (rhs) == MEM_REF |
1114 | && TREE_OPERAND (rhs, 0) == name |
1115 | && integer_zerop (TREE_OPERAND (rhs, 1)) |
1116 | && types_compatible_p (TREE_TYPE (rhs), |
1117 | TREE_TYPE (TREE_TYPE (name)))) |
1118 | uses_ok++; |
1119 | } |
1120 | } |
1121 | else if (is_gimple_call (gs: stmt)) |
1122 | { |
1123 | gcall *call = as_a <gcall *> (p: stmt); |
1124 | unsigned arg_count; |
1125 | if (gimple_call_internal_p (gs: call) |
1126 | || (arg_count = gimple_call_num_args (gs: call)) == 0) |
1127 | { |
1128 | ret = true; |
1129 | break; |
1130 | } |
1131 | |
1132 | cgraph_edge *cs = node->get_edge (call_stmt: stmt); |
1133 | gcc_checking_assert (cs); |
1134 | isra_call_summary *csum = call_sums->get_create (edge: cs); |
1135 | csum->init_inputs (arg_count); |
1136 | |
1137 | for (unsigned i = 0; i < arg_count; ++i) |
1138 | { |
1139 | tree arg = gimple_call_arg (gs: stmt, index: i); |
1140 | |
1141 | if (arg == name) |
1142 | { |
1143 | /* TODO: Allow &MEM_REF[name + offset] here, |
1144 | ipa_param_body_adjustments::modify_call_stmt has to be |
1145 | adjusted too. */ |
1146 | csum->m_arg_flow[i].pointer_pass_through = true; |
1147 | set_single_param_flow_source (param_flow: &csum->m_arg_flow[i], src: parm_num); |
1148 | pt_count++; |
1149 | uses_ok++; |
1150 | continue; |
1151 | } |
1152 | |
1153 | if (!TREE_THIS_VOLATILE (arg)) |
1154 | { |
1155 | while (handled_component_p (t: arg)) |
1156 | arg = TREE_OPERAND (arg, 0); |
1157 | if (TREE_CODE (arg) == MEM_REF |
1158 | && TREE_OPERAND (arg, 0) == name |
1159 | && integer_zerop (TREE_OPERAND (arg, 1)) |
1160 | && types_compatible_p (TREE_TYPE (arg), |
1161 | TREE_TYPE (TREE_TYPE (name)))) |
1162 | uses_ok++; |
1163 | } |
1164 | } |
1165 | } |
1166 | else if (greturn *gr = dyn_cast<greturn *>(p: stmt)) |
1167 | { |
1168 | tree rv = gimple_return_retval (gs: gr); |
1169 | if (rv == name) |
1170 | { |
1171 | uses_ok++; |
1172 | /* Analysis for feasibility of removal must have already reached |
1173 | the conclusion that the flag must be set if it completed. */ |
1174 | gcc_assert (!desc->locally_unused |
1175 | || desc->remove_only_when_retval_removed); |
1176 | desc->split_only_when_retval_removed = true; |
1177 | } |
1178 | } |
1179 | |
1180 | /* If the number of valid uses does not match the number of |
1181 | uses in this stmt there is an unhandled use. */ |
1182 | unsigned all_uses = 0; |
1183 | FOR_EACH_IMM_USE_ON_STMT (use_p, ui) |
1184 | all_uses++; |
1185 | |
1186 | gcc_checking_assert (uses_ok <= all_uses); |
1187 | if (uses_ok != all_uses) |
1188 | { |
1189 | ret = true; |
1190 | break; |
1191 | } |
1192 | } |
1193 | |
1194 | desc->ptr_pt_count = pt_count; |
1195 | return ret; |
1196 | } |
1197 | |
1198 | /* Initialize vector of parameter descriptors of NODE. Return true if there |
1199 | are any candidates for splitting or unused aggregate parameter removal (the |
1200 | function may return false if there are candidates for removal of register |
1201 | parameters). */ |
1202 | |
1203 | static bool |
1204 | create_parameter_descriptors (cgraph_node *node, |
1205 | vec<gensum_param_desc> *param_descriptions) |
1206 | { |
1207 | function *fun = DECL_STRUCT_FUNCTION (node->decl); |
1208 | bool ret = false; |
1209 | |
1210 | int num = 0; |
1211 | for (tree parm = DECL_ARGUMENTS (node->decl); |
1212 | parm; |
1213 | parm = DECL_CHAIN (parm), num++) |
1214 | { |
1215 | const char *msg; |
1216 | gensum_param_desc *desc = &(*param_descriptions)[num]; |
1217 | /* param_descriptions vector is grown cleared in the caller. */ |
1218 | desc->param_number = num; |
1219 | decl2desc->put (k: parm, v: desc); |
1220 | |
1221 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1222 | print_generic_expr (dump_file, parm, TDF_UID); |
1223 | |
1224 | tree type = TREE_TYPE (parm); |
1225 | if (TREE_THIS_VOLATILE (parm)) |
1226 | { |
1227 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1228 | fprintf (stream: dump_file, format: " not a candidate, is volatile\n" ); |
1229 | continue; |
1230 | } |
1231 | if (!is_gimple_reg_type (type) && is_va_list_type (type)) |
1232 | { |
1233 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1234 | fprintf (stream: dump_file, format: " not a candidate, is a va_list type\n" ); |
1235 | continue; |
1236 | } |
1237 | if (TREE_ADDRESSABLE (parm)) |
1238 | { |
1239 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1240 | fprintf (stream: dump_file, format: " not a candidate, is addressable\n" ); |
1241 | continue; |
1242 | } |
1243 | if (TREE_ADDRESSABLE (type)) |
1244 | { |
1245 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1246 | fprintf (stream: dump_file, format: " not a candidate, type cannot be split\n" ); |
1247 | continue; |
1248 | } |
1249 | |
1250 | if (is_gimple_reg (parm) |
1251 | && !isra_track_scalar_param_local_uses (fun, node, parm, parm_num: num, desc)) |
1252 | { |
1253 | desc->locally_unused = true; |
1254 | |
1255 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1256 | fprintf (stream: dump_file, format: " is a scalar with only %i call uses%s\n" , |
1257 | desc->call_uses, |
1258 | desc->remove_only_when_retval_removed |
1259 | ? " and return uses" : "" ); |
1260 | } |
1261 | |
1262 | if (POINTER_TYPE_P (type)) |
1263 | { |
1264 | desc->by_ref = true; |
1265 | if (TREE_CODE (type) == REFERENCE_TYPE |
1266 | || (num == 0 |
1267 | && TREE_CODE (TREE_TYPE (node->decl)) == METHOD_TYPE)) |
1268 | desc->safe_ref = true; |
1269 | else |
1270 | desc->safe_ref = false; |
1271 | type = TREE_TYPE (type); |
1272 | |
1273 | if (TREE_CODE (type) == FUNCTION_TYPE |
1274 | || TREE_CODE (type) == METHOD_TYPE) |
1275 | { |
1276 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1277 | fprintf (stream: dump_file, format: " not a candidate, reference to " |
1278 | "a function\n" ); |
1279 | continue; |
1280 | } |
1281 | if (TYPE_VOLATILE (type)) |
1282 | { |
1283 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1284 | fprintf (stream: dump_file, format: " not a candidate, reference to " |
1285 | "a volatile type\n" ); |
1286 | continue; |
1287 | } |
1288 | if (TREE_CODE (type) == ARRAY_TYPE |
1289 | && TYPE_NONALIASED_COMPONENT (type)) |
1290 | { |
1291 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1292 | fprintf (stream: dump_file, format: " not a candidate, reference to " |
1293 | "a nonaliased component array\n" ); |
1294 | continue; |
1295 | } |
1296 | if (!is_gimple_reg (parm)) |
1297 | { |
1298 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1299 | fprintf (stream: dump_file, format: " not a candidate, a reference which is " |
1300 | "not a gimple register (probably addressable)\n" ); |
1301 | continue; |
1302 | } |
1303 | if (is_va_list_type (type)) |
1304 | { |
1305 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1306 | fprintf (stream: dump_file, format: " not a candidate, reference to " |
1307 | "a va list\n" ); |
1308 | continue; |
1309 | } |
1310 | if (ptr_parm_has_nonarg_uses (node, fun, parm, parm_num: num, desc)) |
1311 | { |
1312 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1313 | fprintf (stream: dump_file, format: " not a candidate, reference has " |
1314 | "nonarg uses\n" ); |
1315 | continue; |
1316 | } |
1317 | } |
1318 | else if (!AGGREGATE_TYPE_P (type)) |
1319 | { |
1320 | /* This is in an else branch because scalars passed by reference are |
1321 | still candidates to be passed by value. */ |
1322 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1323 | fprintf (stream: dump_file, format: " not a candidate, not an aggregate\n" ); |
1324 | continue; |
1325 | } |
1326 | |
1327 | if (!COMPLETE_TYPE_P (type)) |
1328 | { |
1329 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1330 | fprintf (stream: dump_file, format: " not a candidate, not a complete type\n" ); |
1331 | continue; |
1332 | } |
1333 | if (!tree_fits_uhwi_p (TYPE_SIZE (type))) |
1334 | { |
1335 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1336 | fprintf (stream: dump_file, format: " not a candidate, size not representable\n" ); |
1337 | continue; |
1338 | } |
1339 | unsigned HOST_WIDE_INT type_size |
1340 | = tree_to_uhwi (TYPE_SIZE (type)) / BITS_PER_UNIT; |
1341 | if (type_size == 0 |
1342 | || type_size >= ISRA_ARG_SIZE_LIMIT) |
1343 | { |
1344 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1345 | fprintf (stream: dump_file, format: " not a candidate, has zero or huge size\n" ); |
1346 | continue; |
1347 | } |
1348 | if (type_internals_preclude_sra_p (type, msg: &msg)) |
1349 | { |
1350 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1351 | fprintf (stream: dump_file, format: " not a candidate, %s\n" , msg); |
1352 | continue; |
1353 | } |
1354 | |
1355 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1356 | fprintf (stream: dump_file, format: " is a candidate\n" ); |
1357 | |
1358 | ret = true; |
1359 | desc->split_candidate = true; |
1360 | if (desc->by_ref && !desc->safe_ref) |
1361 | desc->deref_index = unsafe_by_ref_count++; |
1362 | } |
1363 | return ret; |
1364 | } |
1365 | |
1366 | /* Return pointer to descriptor of parameter DECL or NULL if it cannot be |
1367 | found, which happens if DECL is for a static chain. */ |
1368 | |
1369 | static gensum_param_desc * |
1370 | get_gensum_param_desc (tree decl) |
1371 | { |
1372 | if (!decl2desc) |
1373 | return NULL; |
1374 | gcc_checking_assert (TREE_CODE (decl) == PARM_DECL); |
1375 | gensum_param_desc **slot = decl2desc->get (k: decl); |
1376 | if (!slot) |
1377 | /* This can happen for static chains which we cannot handle so far. */ |
1378 | return NULL; |
1379 | gcc_checking_assert (*slot); |
1380 | return *slot; |
1381 | } |
1382 | |
1383 | |
1384 | /* Remove parameter described by DESC from candidates for IPA-SRA splitting and |
1385 | write REASON to the dump file if there is one. */ |
1386 | |
1387 | static void |
1388 | disqualify_split_candidate (gensum_param_desc *desc, const char *reason) |
1389 | { |
1390 | if (!desc->split_candidate) |
1391 | return; |
1392 | |
1393 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1394 | fprintf (stream: dump_file, format: "! Disqualifying parameter number %i - %s\n" , |
1395 | desc->param_number, reason); |
1396 | |
1397 | desc->split_candidate = false; |
1398 | } |
1399 | |
1400 | /* Remove DECL from candidates for IPA-SRA and write REASON to the dump file if |
1401 | there is one. */ |
1402 | |
1403 | static void |
1404 | disqualify_split_candidate (tree decl, const char *reason) |
1405 | { |
1406 | gensum_param_desc *desc = get_gensum_param_desc (decl); |
1407 | if (desc) |
1408 | disqualify_split_candidate (desc, reason); |
1409 | } |
1410 | |
1411 | /* Allocate a new access to DESC and fill it in with OFFSET and SIZE. But |
1412 | first, check that there are not too many of them already. If so, do not |
1413 | allocate anything and return NULL. */ |
1414 | |
1415 | static gensum_param_access * |
1416 | allocate_access (gensum_param_desc *desc, |
1417 | HOST_WIDE_INT offset, HOST_WIDE_INT size) |
1418 | { |
1419 | if (desc->access_count |
1420 | == (unsigned) param_ipa_sra_max_replacements) |
1421 | { |
1422 | disqualify_split_candidate (desc, reason: "Too many replacement candidates" ); |
1423 | return NULL; |
1424 | } |
1425 | |
1426 | gensum_param_access *access |
1427 | = (gensum_param_access *) obstack_alloc (&gensum_obstack, |
1428 | sizeof (gensum_param_access)); |
1429 | memset (s: access, c: 0, n: sizeof (*access)); |
1430 | access->offset = offset; |
1431 | access->size = size; |
1432 | access->load_count = profile_count::zero (); |
1433 | return access; |
1434 | } |
1435 | |
1436 | /* In what context scan_expr_access has been called, whether it deals with a |
1437 | load, a function argument, or a store. Please note that in rare |
1438 | circumstances when it is not clear if the access is a load or store, |
1439 | ISRA_CTX_STORE is used too. */ |
1440 | |
1441 | enum isra_scan_context {ISRA_CTX_LOAD, ISRA_CTX_ARG, ISRA_CTX_STORE}; |
1442 | |
1443 | /* Return an access describing memory access to the variable described by DESC |
1444 | at OFFSET with SIZE in context CTX, starting at pointer to the linked list |
1445 | at a certain tree level FIRST. Attempt to create it and put into the |
1446 | appropriate place in the access tree if does not exist, but fail and return |
1447 | NULL if there are already too many accesses, if it would create a partially |
1448 | overlapping access or if an access would end up within a pre-existing |
1449 | non-call access. */ |
1450 | |
1451 | static gensum_param_access * |
1452 | get_access_1 (gensum_param_desc *desc, gensum_param_access **first, |
1453 | HOST_WIDE_INT offset, HOST_WIDE_INT size, isra_scan_context ctx) |
1454 | { |
1455 | gensum_param_access *access = *first, **ptr = first; |
1456 | |
1457 | if (!access) |
1458 | { |
1459 | /* No pre-existing access at this level, just create it. */ |
1460 | gensum_param_access *a = allocate_access (desc, offset, size); |
1461 | if (!a) |
1462 | return NULL; |
1463 | *first = a; |
1464 | return *first; |
1465 | } |
1466 | |
1467 | if (access->offset >= offset + size) |
1468 | { |
1469 | /* We want to squeeze it in front of the very first access, just do |
1470 | it. */ |
1471 | gensum_param_access *r = allocate_access (desc, offset, size); |
1472 | if (!r) |
1473 | return NULL; |
1474 | r->next_sibling = access; |
1475 | *first = r; |
1476 | return r; |
1477 | } |
1478 | |
1479 | /* Skip all accesses that have to come before us until the next sibling is |
1480 | already too far. */ |
1481 | while (offset >= access->offset + access->size |
1482 | && access->next_sibling |
1483 | && access->next_sibling->offset < offset + size) |
1484 | { |
1485 | ptr = &access->next_sibling; |
1486 | access = access->next_sibling; |
1487 | } |
1488 | |
1489 | /* At this point we know we do not belong before access. */ |
1490 | gcc_assert (access->offset < offset + size); |
1491 | |
1492 | if (access->offset == offset && access->size == size) |
1493 | /* We found what we were looking for. */ |
1494 | return access; |
1495 | |
1496 | if (access->offset <= offset |
1497 | && access->offset + access->size >= offset + size) |
1498 | { |
1499 | /* We fit into access which is larger than us. We need to find/create |
1500 | something below access. But we only allow nesting in call |
1501 | arguments. */ |
1502 | if (access->nonarg) |
1503 | return NULL; |
1504 | |
1505 | return get_access_1 (desc, first: &access->first_child, offset, size, ctx); |
1506 | } |
1507 | |
1508 | if (offset <= access->offset |
1509 | && offset + size >= access->offset + access->size) |
1510 | /* We are actually bigger than access, which fully fits into us, take its |
1511 | place and make all accesses fitting into it its children. */ |
1512 | { |
1513 | /* But first, we only allow nesting in call arguments so check if that is |
1514 | what we are trying to represent. */ |
1515 | if (ctx != ISRA_CTX_ARG) |
1516 | return NULL; |
1517 | |
1518 | gensum_param_access *r = allocate_access (desc, offset, size); |
1519 | if (!r) |
1520 | return NULL; |
1521 | r->first_child = access; |
1522 | |
1523 | while (access->next_sibling |
1524 | && access->next_sibling->offset < offset + size) |
1525 | access = access->next_sibling; |
1526 | if (access->offset + access->size > offset + size) |
1527 | { |
1528 | /* This must be a different access, which are sorted, so the |
1529 | following must be true and this signals a partial overlap. */ |
1530 | gcc_assert (access->offset > offset); |
1531 | return NULL; |
1532 | } |
1533 | |
1534 | r->next_sibling = access->next_sibling; |
1535 | access->next_sibling = NULL; |
1536 | *ptr = r; |
1537 | return r; |
1538 | } |
1539 | |
1540 | if (offset >= access->offset + access->size) |
1541 | { |
1542 | /* We belong after access. */ |
1543 | gensum_param_access *r = allocate_access (desc, offset, size); |
1544 | if (!r) |
1545 | return NULL; |
1546 | r->next_sibling = access->next_sibling; |
1547 | access->next_sibling = r; |
1548 | return r; |
1549 | } |
1550 | |
1551 | if (offset < access->offset) |
1552 | { |
1553 | /* We know the following, otherwise we would have created a |
1554 | super-access. */ |
1555 | gcc_checking_assert (offset + size < access->offset + access->size); |
1556 | return NULL; |
1557 | } |
1558 | |
1559 | if (offset + size > access->offset + access->size) |
1560 | { |
1561 | /* Likewise. */ |
1562 | gcc_checking_assert (offset > access->offset); |
1563 | return NULL; |
1564 | } |
1565 | |
1566 | gcc_unreachable (); |
1567 | } |
1568 | |
1569 | /* Return an access describing memory access to the variable described by DESC |
1570 | at OFFSET with SIZE in context CTX, mark it as used in context CTX. Attempt |
1571 | to create if it does not exist, but fail and return NULL if there are |
1572 | already too many accesses, if it would create a partially overlapping access |
1573 | or if an access would end up in a non-call access. */ |
1574 | |
1575 | static gensum_param_access * |
1576 | get_access (gensum_param_desc *desc, HOST_WIDE_INT offset, HOST_WIDE_INT size, |
1577 | isra_scan_context ctx) |
1578 | { |
1579 | gcc_checking_assert (desc->split_candidate); |
1580 | |
1581 | gensum_param_access *access = get_access_1 (desc, first: &desc->accesses, offset, |
1582 | size, ctx); |
1583 | if (!access) |
1584 | { |
1585 | disqualify_split_candidate (desc, |
1586 | reason: "Bad access overlap or too many accesses" ); |
1587 | return NULL; |
1588 | } |
1589 | |
1590 | switch (ctx) |
1591 | { |
1592 | case ISRA_CTX_STORE: |
1593 | gcc_assert (!desc->by_ref); |
1594 | /* Fall-through */ |
1595 | case ISRA_CTX_LOAD: |
1596 | access->nonarg = true; |
1597 | break; |
1598 | case ISRA_CTX_ARG: |
1599 | break; |
1600 | } |
1601 | |
1602 | return access; |
1603 | } |
1604 | |
1605 | /* Verify that parameter access tree starting with ACCESS is in good shape. |
1606 | PARENT_OFFSET and PARENT_SIZE are the corresponding fields of parent of |
1607 | ACCESS or zero if there is none. */ |
1608 | |
1609 | static bool |
1610 | verify_access_tree_1 (gensum_param_access *access, HOST_WIDE_INT parent_offset, |
1611 | HOST_WIDE_INT parent_size) |
1612 | { |
1613 | while (access) |
1614 | { |
1615 | gcc_assert (access->offset >= 0 && access->size >= 0); |
1616 | |
1617 | if (parent_size != 0) |
1618 | { |
1619 | if (access->offset < parent_offset) |
1620 | { |
1621 | error ("Access offset before parent offset" ); |
1622 | return true; |
1623 | } |
1624 | if (access->size >= parent_size) |
1625 | { |
1626 | error ("Access size greater or equal to its parent size" ); |
1627 | return true; |
1628 | } |
1629 | if (access->offset + access->size > parent_offset + parent_size) |
1630 | { |
1631 | error ("Access terminates outside of its parent" ); |
1632 | return true; |
1633 | } |
1634 | } |
1635 | |
1636 | if (verify_access_tree_1 (access: access->first_child, parent_offset: access->offset, |
1637 | parent_size: access->size)) |
1638 | return true; |
1639 | |
1640 | if (access->next_sibling |
1641 | && (access->next_sibling->offset < access->offset + access->size)) |
1642 | { |
1643 | error ("Access overlaps with its sibling" ); |
1644 | return true; |
1645 | } |
1646 | |
1647 | access = access->next_sibling; |
1648 | } |
1649 | return false; |
1650 | } |
1651 | |
1652 | /* Verify that parameter access tree starting with ACCESS is in good shape, |
1653 | halt compilation and dump the tree to stderr if not. */ |
1654 | |
1655 | DEBUG_FUNCTION void |
1656 | isra_verify_access_tree (gensum_param_access *access) |
1657 | { |
1658 | if (verify_access_tree_1 (access, parent_offset: 0, parent_size: 0)) |
1659 | { |
1660 | for (; access; access = access->next_sibling) |
1661 | dump_gensum_access (stderr, access, indent: 2); |
1662 | internal_error ("IPA-SRA access verification failed" ); |
1663 | } |
1664 | } |
1665 | |
1666 | |
1667 | /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine |
1668 | GIMPLE_ASM operands with memory constrains which cannot be scalarized. */ |
1669 | |
1670 | static bool |
1671 | asm_visit_addr (gimple *, tree op, tree, void *) |
1672 | { |
1673 | op = get_base_address (t: op); |
1674 | if (op |
1675 | && TREE_CODE (op) == PARM_DECL) |
1676 | disqualify_split_candidate (decl: op, reason: "Non-scalarizable GIMPLE_ASM operand." ); |
1677 | |
1678 | return false; |
1679 | } |
1680 | |
1681 | /* Mark a dereference of parameter identified by DESC of distance DIST in a |
1682 | basic block BB, unless the BB has already been marked as a potentially |
1683 | final. */ |
1684 | |
1685 | static void |
1686 | mark_param_dereference (gensum_param_desc *desc, HOST_WIDE_INT dist, |
1687 | basic_block bb) |
1688 | { |
1689 | gcc_assert (desc->by_ref); |
1690 | gcc_checking_assert (desc->split_candidate); |
1691 | |
1692 | if (desc->safe_ref |
1693 | || bitmap_bit_p (final_bbs, bb->index)) |
1694 | return; |
1695 | |
1696 | int idx = bb->index * unsafe_by_ref_count + desc->deref_index; |
1697 | if (bb_dereferences[idx] < dist) |
1698 | bb_dereferences[idx] = dist; |
1699 | } |
1700 | |
1701 | /* Return true, if any potential replacements should use NEW_TYPE as opposed to |
1702 | previously recorded OLD_TYPE. */ |
1703 | |
1704 | static bool |
1705 | type_prevails_p (tree old_type, tree new_type) |
1706 | { |
1707 | if (old_type == new_type) |
1708 | return false; |
1709 | |
1710 | /* Non-aggregates are always better. */ |
1711 | if (!is_gimple_reg_type (type: old_type) |
1712 | && is_gimple_reg_type (type: new_type)) |
1713 | return true; |
1714 | if (is_gimple_reg_type (type: old_type) |
1715 | && !is_gimple_reg_type (type: new_type)) |
1716 | return false; |
1717 | |
1718 | /* Prefer any complex or vector type over any other scalar type. */ |
1719 | if (TREE_CODE (old_type) != COMPLEX_TYPE |
1720 | && TREE_CODE (old_type) != VECTOR_TYPE |
1721 | && (TREE_CODE (new_type) == COMPLEX_TYPE |
1722 | || VECTOR_TYPE_P (new_type))) |
1723 | return true; |
1724 | if ((TREE_CODE (old_type) == COMPLEX_TYPE |
1725 | || VECTOR_TYPE_P (old_type)) |
1726 | && TREE_CODE (new_type) != COMPLEX_TYPE |
1727 | && TREE_CODE (new_type) != VECTOR_TYPE) |
1728 | return false; |
1729 | |
1730 | /* Use the integral type with the bigger precision. */ |
1731 | if (INTEGRAL_TYPE_P (old_type) |
1732 | && INTEGRAL_TYPE_P (new_type)) |
1733 | return (TYPE_PRECISION (new_type) > TYPE_PRECISION (old_type)); |
1734 | |
1735 | /* Attempt to disregard any integral type with non-full precision. */ |
1736 | if (INTEGRAL_TYPE_P (old_type) |
1737 | && (TREE_INT_CST_LOW (TYPE_SIZE (old_type)) |
1738 | != TYPE_PRECISION (old_type))) |
1739 | return true; |
1740 | if (INTEGRAL_TYPE_P (new_type) |
1741 | && (TREE_INT_CST_LOW (TYPE_SIZE (new_type)) |
1742 | != TYPE_PRECISION (new_type))) |
1743 | return false; |
1744 | /* Stabilize the selection. */ |
1745 | return TYPE_UID (old_type) < TYPE_UID (new_type); |
1746 | } |
1747 | |
1748 | /* When scanning an expression which is a call argument, this structure |
1749 | specifies the call and the position of the argument. */ |
1750 | |
1751 | struct scan_call_info |
1752 | { |
1753 | /* Call graph edge representing the call. */ |
1754 | cgraph_edge *cs; |
1755 | /* Total number of arguments in the call. */ |
1756 | unsigned argument_count; |
1757 | /* Number of the actual argument being scanned. */ |
1758 | unsigned arg_idx; |
1759 | }; |
1760 | |
1761 | /* Record use of ACCESS which belongs to a parameter described by DESC in a |
1762 | call argument described by CALL_INFO. */ |
1763 | |
1764 | static void |
1765 | record_nonregister_call_use (gensum_param_desc *desc, |
1766 | scan_call_info *call_info, |
1767 | unsigned unit_offset, unsigned unit_size) |
1768 | { |
1769 | isra_call_summary *csum = call_sums->get_create (edge: call_info->cs); |
1770 | csum->init_inputs (arg_count: call_info->argument_count); |
1771 | |
1772 | isra_param_flow *param_flow = &csum->m_arg_flow[call_info->arg_idx]; |
1773 | param_flow->aggregate_pass_through = true; |
1774 | set_single_param_flow_source (param_flow, src: desc->param_number); |
1775 | param_flow->unit_offset = unit_offset; |
1776 | param_flow->unit_size = unit_size; |
1777 | desc->call_uses++; |
1778 | } |
1779 | |
1780 | /* Callback of walk_aliased_vdefs, just mark that there was a possible |
1781 | modification. */ |
1782 | |
1783 | static bool |
1784 | mark_maybe_modified (ao_ref *, tree, void *data) |
1785 | { |
1786 | bool *maybe_modified = (bool *) data; |
1787 | *maybe_modified = true; |
1788 | return true; |
1789 | } |
1790 | |
1791 | /* Analyze expression EXPR from GIMPLE for accesses to parameters. CTX |
1792 | specifies whether EXPR is used in a load, store or as an argument call. BB |
1793 | must be the basic block in which expr resides. If CTX specifies call |
1794 | argument context, CALL_INFO must describe that call and argument position, |
1795 | otherwise it is ignored. */ |
1796 | |
1797 | static void |
1798 | scan_expr_access (tree expr, gimple *stmt, isra_scan_context ctx, |
1799 | basic_block bb, scan_call_info *call_info = NULL) |
1800 | { |
1801 | poly_int64 poffset, psize, pmax_size; |
1802 | HOST_WIDE_INT offset, size, max_size; |
1803 | tree base; |
1804 | bool deref = false; |
1805 | bool reverse; |
1806 | |
1807 | if (TREE_CODE (expr) == ADDR_EXPR) |
1808 | { |
1809 | if (ctx == ISRA_CTX_ARG) |
1810 | return; |
1811 | tree t = get_base_address (TREE_OPERAND (expr, 0)); |
1812 | if (VAR_P (t) && !TREE_STATIC (t)) |
1813 | loaded_decls->add (k: t); |
1814 | return; |
1815 | } |
1816 | if (TREE_CODE (expr) == SSA_NAME |
1817 | || CONSTANT_CLASS_P (expr)) |
1818 | return; |
1819 | |
1820 | if (TREE_CODE (expr) == BIT_FIELD_REF |
1821 | || TREE_CODE (expr) == IMAGPART_EXPR |
1822 | || TREE_CODE (expr) == REALPART_EXPR) |
1823 | expr = TREE_OPERAND (expr, 0); |
1824 | |
1825 | base = get_ref_base_and_extent (expr, &poffset, &psize, &pmax_size, &reverse); |
1826 | |
1827 | if (TREE_CODE (base) == MEM_REF) |
1828 | { |
1829 | tree op = TREE_OPERAND (base, 0); |
1830 | if (TREE_CODE (op) != SSA_NAME |
1831 | || !SSA_NAME_IS_DEFAULT_DEF (op)) |
1832 | return; |
1833 | base = SSA_NAME_VAR (op); |
1834 | if (!base) |
1835 | return; |
1836 | deref = true; |
1837 | } |
1838 | else if (VAR_P (base) |
1839 | && !TREE_STATIC (base) |
1840 | && (ctx == ISRA_CTX_ARG |
1841 | || ctx == ISRA_CTX_LOAD)) |
1842 | loaded_decls->add (k: base); |
1843 | |
1844 | if (TREE_CODE (base) != PARM_DECL) |
1845 | return; |
1846 | |
1847 | gensum_param_desc *desc = get_gensum_param_desc (decl: base); |
1848 | if (!desc || !desc->split_candidate) |
1849 | return; |
1850 | |
1851 | if (!poffset.is_constant (const_value: &offset) |
1852 | || !psize.is_constant (const_value: &size) |
1853 | || !pmax_size.is_constant (const_value: &max_size)) |
1854 | { |
1855 | disqualify_split_candidate (desc, reason: "Encountered a polynomial-sized " |
1856 | "access." ); |
1857 | return; |
1858 | } |
1859 | if (size < 0 || size != max_size) |
1860 | { |
1861 | disqualify_split_candidate (desc, reason: "Encountered a variable sized access." ); |
1862 | return; |
1863 | } |
1864 | if (TREE_CODE (expr) == COMPONENT_REF |
1865 | && DECL_BIT_FIELD (TREE_OPERAND (expr, 1))) |
1866 | { |
1867 | disqualify_split_candidate (desc, reason: "Encountered a bit-field access." ); |
1868 | return; |
1869 | } |
1870 | if (offset < 0) |
1871 | { |
1872 | disqualify_split_candidate (desc, reason: "Encountered an access at a " |
1873 | "negative offset." ); |
1874 | return; |
1875 | } |
1876 | gcc_assert ((offset % BITS_PER_UNIT) == 0); |
1877 | gcc_assert ((size % BITS_PER_UNIT) == 0); |
1878 | if ((offset / BITS_PER_UNIT) >= (UINT_MAX - ISRA_ARG_SIZE_LIMIT) |
1879 | || (size / BITS_PER_UNIT) >= ISRA_ARG_SIZE_LIMIT) |
1880 | { |
1881 | disqualify_split_candidate (desc, reason: "Encountered an access with too big " |
1882 | "offset or size" ); |
1883 | return; |
1884 | } |
1885 | |
1886 | tree type = TREE_TYPE (expr); |
1887 | unsigned int exp_align = get_object_alignment (expr); |
1888 | |
1889 | if (exp_align < TYPE_ALIGN (type)) |
1890 | { |
1891 | disqualify_split_candidate (desc, reason: "Underaligned access." ); |
1892 | return; |
1893 | } |
1894 | |
1895 | if (deref) |
1896 | { |
1897 | if (!desc->by_ref) |
1898 | { |
1899 | disqualify_split_candidate (desc, reason: "Dereferencing a non-reference." ); |
1900 | return; |
1901 | } |
1902 | else if (ctx == ISRA_CTX_STORE) |
1903 | { |
1904 | disqualify_split_candidate (desc, reason: "Storing to data passed by " |
1905 | "reference." ); |
1906 | return; |
1907 | } |
1908 | |
1909 | if (!aa_walking_limit) |
1910 | { |
1911 | disqualify_split_candidate (desc, reason: "Out of alias analysis step " |
1912 | "limit." ); |
1913 | return; |
1914 | } |
1915 | |
1916 | gcc_checking_assert (gimple_vuse (stmt)); |
1917 | bool maybe_modified = false; |
1918 | ao_ref ar; |
1919 | |
1920 | ao_ref_init (&ar, expr); |
1921 | bitmap visited = BITMAP_ALLOC (NULL); |
1922 | int walked = walk_aliased_vdefs (&ar, gimple_vuse (g: stmt), |
1923 | mark_maybe_modified, &maybe_modified, |
1924 | &visited, NULL, limit: aa_walking_limit); |
1925 | BITMAP_FREE (visited); |
1926 | if (walked > 0) |
1927 | { |
1928 | gcc_assert (aa_walking_limit > walked); |
1929 | aa_walking_limit = aa_walking_limit - walked; |
1930 | } |
1931 | if (walked < 0) |
1932 | aa_walking_limit = 0; |
1933 | if (maybe_modified || walked < 0) |
1934 | { |
1935 | disqualify_split_candidate (desc, reason: "Data passed by reference possibly " |
1936 | "modified through an alias." ); |
1937 | return; |
1938 | } |
1939 | else |
1940 | mark_param_dereference (desc, dist: offset + size, bb); |
1941 | } |
1942 | else |
1943 | /* Pointer parameters with direct uses should have been ruled out by |
1944 | analyzing SSA default def when looking at the parameters. */ |
1945 | gcc_assert (!desc->by_ref); |
1946 | |
1947 | gensum_param_access *access = get_access (desc, offset, size, ctx); |
1948 | if (!access) |
1949 | return; |
1950 | |
1951 | if (ctx == ISRA_CTX_ARG) |
1952 | { |
1953 | gcc_checking_assert (call_info); |
1954 | |
1955 | if (!deref) |
1956 | record_nonregister_call_use (desc, call_info, unit_offset: offset / BITS_PER_UNIT, |
1957 | unit_size: size / BITS_PER_UNIT); |
1958 | else |
1959 | /* This is not a pass-through of a pointer, this is a use like any |
1960 | other. */ |
1961 | access->nonarg = true; |
1962 | } |
1963 | else if (ctx == ISRA_CTX_LOAD && bb->count.initialized_p ()) |
1964 | access->load_count += bb->count; |
1965 | |
1966 | if (!access->type) |
1967 | { |
1968 | access->type = type; |
1969 | access->alias_ptr_type = reference_alias_ptr_type (expr); |
1970 | access->reverse = reverse; |
1971 | } |
1972 | else |
1973 | { |
1974 | if (exp_align < TYPE_ALIGN (access->type)) |
1975 | { |
1976 | disqualify_split_candidate (desc, reason: "Reference has lower alignment " |
1977 | "than a previous one." ); |
1978 | return; |
1979 | } |
1980 | if (access->alias_ptr_type != reference_alias_ptr_type (expr)) |
1981 | { |
1982 | disqualify_split_candidate (desc, reason: "Multiple alias pointer types." ); |
1983 | return; |
1984 | } |
1985 | if (access->reverse != reverse) |
1986 | { |
1987 | disqualify_split_candidate (desc, reason: "Both normal and reverse " |
1988 | "scalar storage order." ); |
1989 | return; |
1990 | } |
1991 | if (!deref |
1992 | && (AGGREGATE_TYPE_P (type) || AGGREGATE_TYPE_P (access->type)) |
1993 | && (TYPE_MAIN_VARIANT (access->type) != TYPE_MAIN_VARIANT (type))) |
1994 | { |
1995 | /* We need the same aggregate type on all accesses to be able to |
1996 | distinguish transformation spots from pass-through arguments in |
1997 | the transformation phase. */ |
1998 | disqualify_split_candidate (desc, reason: "We do not support aggregate " |
1999 | "type punning." ); |
2000 | return; |
2001 | } |
2002 | |
2003 | if (type_prevails_p (old_type: access->type, new_type: type)) |
2004 | access->type = type; |
2005 | } |
2006 | } |
2007 | |
2008 | /* Scan body function described by NODE and FUN and create access trees for |
2009 | parameters. */ |
2010 | |
2011 | static void |
2012 | scan_function (cgraph_node *node, struct function *fun) |
2013 | { |
2014 | basic_block bb; |
2015 | |
2016 | FOR_EACH_BB_FN (bb, fun) |
2017 | { |
2018 | gimple_stmt_iterator gsi; |
2019 | for (gsi = gsi_start_bb (bb); !gsi_end_p (i: gsi); gsi_next (i: &gsi)) |
2020 | { |
2021 | gimple *stmt = gsi_stmt (i: gsi); |
2022 | |
2023 | if (final_bbs && stmt_can_throw_external (fun, stmt)) |
2024 | bitmap_set_bit (final_bbs, bb->index); |
2025 | switch (gimple_code (g: stmt)) |
2026 | { |
2027 | case GIMPLE_RETURN: |
2028 | { |
2029 | tree t = gimple_return_retval (gs: as_a <greturn *> (p: stmt)); |
2030 | if (t != NULL_TREE) |
2031 | scan_expr_access (expr: t, stmt, ctx: ISRA_CTX_LOAD, bb); |
2032 | if (final_bbs) |
2033 | bitmap_set_bit (final_bbs, bb->index); |
2034 | } |
2035 | break; |
2036 | |
2037 | case GIMPLE_ASSIGN: |
2038 | if (gimple_assign_single_p (gs: stmt) |
2039 | && !gimple_clobber_p (s: stmt)) |
2040 | { |
2041 | tree rhs = gimple_assign_rhs1 (gs: stmt); |
2042 | scan_expr_access (expr: rhs, stmt, ctx: ISRA_CTX_LOAD, bb); |
2043 | tree lhs = gimple_assign_lhs (gs: stmt); |
2044 | scan_expr_access (expr: lhs, stmt, ctx: ISRA_CTX_STORE, bb); |
2045 | } |
2046 | break; |
2047 | |
2048 | case GIMPLE_CALL: |
2049 | { |
2050 | unsigned argument_count = gimple_call_num_args (gs: stmt); |
2051 | isra_scan_context ctx = ISRA_CTX_ARG; |
2052 | scan_call_info call_info, *call_info_p = &call_info; |
2053 | if (gimple_call_internal_p (gs: stmt)) |
2054 | { |
2055 | call_info_p = NULL; |
2056 | ctx = ISRA_CTX_LOAD; |
2057 | internal_fn ifn = gimple_call_internal_fn (gs: stmt); |
2058 | if (internal_store_fn_p (ifn)) |
2059 | ctx = ISRA_CTX_STORE; |
2060 | } |
2061 | else |
2062 | { |
2063 | call_info.cs = node->get_edge (call_stmt: stmt); |
2064 | call_info.argument_count = argument_count; |
2065 | } |
2066 | |
2067 | for (unsigned i = 0; i < argument_count; i++) |
2068 | { |
2069 | call_info.arg_idx = i; |
2070 | scan_expr_access (expr: gimple_call_arg (gs: stmt, index: i), stmt, |
2071 | ctx, bb, call_info: call_info_p); |
2072 | } |
2073 | |
2074 | tree lhs = gimple_call_lhs (gs: stmt); |
2075 | if (lhs) |
2076 | scan_expr_access (expr: lhs, stmt, ctx: ISRA_CTX_STORE, bb); |
2077 | int flags = gimple_call_flags (stmt); |
2078 | if (final_bbs |
2079 | && (((flags & (ECF_CONST | ECF_PURE)) == 0) |
2080 | || (flags & ECF_LOOPING_CONST_OR_PURE))) |
2081 | bitmap_set_bit (final_bbs, bb->index); |
2082 | } |
2083 | break; |
2084 | |
2085 | case GIMPLE_ASM: |
2086 | { |
2087 | gasm *asm_stmt = as_a <gasm *> (p: stmt); |
2088 | walk_stmt_load_store_addr_ops (asm_stmt, NULL, NULL, NULL, |
2089 | asm_visit_addr); |
2090 | if (final_bbs) |
2091 | bitmap_set_bit (final_bbs, bb->index); |
2092 | |
2093 | for (unsigned i = 0; i < gimple_asm_ninputs (asm_stmt); i++) |
2094 | { |
2095 | tree t = TREE_VALUE (gimple_asm_input_op (asm_stmt, i)); |
2096 | scan_expr_access (expr: t, stmt, ctx: ISRA_CTX_LOAD, bb); |
2097 | } |
2098 | for (unsigned i = 0; i < gimple_asm_noutputs (asm_stmt); i++) |
2099 | { |
2100 | tree t = TREE_VALUE (gimple_asm_output_op (asm_stmt, i)); |
2101 | scan_expr_access (expr: t, stmt, ctx: ISRA_CTX_STORE, bb); |
2102 | } |
2103 | } |
2104 | break; |
2105 | |
2106 | default: |
2107 | break; |
2108 | } |
2109 | } |
2110 | } |
2111 | } |
2112 | |
2113 | /* Return true if SSA_NAME NAME of function described by FUN is only used in |
2114 | return statements, or if results of any operations it is involved in are |
2115 | only used in return statements. ANALYZED is a bitmap that tracks which SSA |
2116 | names we have already started investigating. */ |
2117 | |
2118 | static bool |
2119 | ssa_name_only_returned_p (function *fun, tree name, bitmap analyzed) |
2120 | { |
2121 | bool res = true; |
2122 | imm_use_iterator imm_iter; |
2123 | gimple *stmt; |
2124 | |
2125 | FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name) |
2126 | { |
2127 | if (is_gimple_debug (gs: stmt)) |
2128 | continue; |
2129 | |
2130 | if (gimple_code (g: stmt) == GIMPLE_RETURN) |
2131 | { |
2132 | tree t = gimple_return_retval (gs: as_a <greturn *> (p: stmt)); |
2133 | if (t != name) |
2134 | { |
2135 | res = false; |
2136 | break; |
2137 | } |
2138 | } |
2139 | else if (!stmt_unremovable_because_of_non_call_eh_p (fun, stmt) |
2140 | && ((is_gimple_assign (gs: stmt) && !gimple_has_volatile_ops (stmt)) |
2141 | || gimple_code (g: stmt) == GIMPLE_PHI)) |
2142 | { |
2143 | /* TODO: And perhaps for const function calls too? */ |
2144 | tree lhs; |
2145 | if (gimple_code (g: stmt) == GIMPLE_PHI) |
2146 | lhs = gimple_phi_result (gs: stmt); |
2147 | else |
2148 | lhs = gimple_assign_lhs (gs: stmt); |
2149 | |
2150 | if (TREE_CODE (lhs) != SSA_NAME) |
2151 | { |
2152 | res = false; |
2153 | break; |
2154 | } |
2155 | gcc_assert (!gimple_vdef (stmt)); |
2156 | if (bitmap_set_bit (analyzed, SSA_NAME_VERSION (lhs)) |
2157 | && !ssa_name_only_returned_p (fun, name: lhs, analyzed)) |
2158 | { |
2159 | res = false; |
2160 | break; |
2161 | } |
2162 | } |
2163 | else |
2164 | { |
2165 | res = false; |
2166 | break; |
2167 | } |
2168 | } |
2169 | return res; |
2170 | } |
2171 | |
2172 | /* Inspect the uses of the return value of the call associated with CS, and if |
2173 | it is not used or if it is only used to construct the return value of the |
2174 | caller, mark it as such in call or caller summary. Also check for |
2175 | misaligned arguments. */ |
2176 | |
2177 | static void |
2178 | isra_analyze_call (cgraph_edge *cs) |
2179 | { |
2180 | gcall *call_stmt = cs->call_stmt; |
2181 | unsigned count = gimple_call_num_args (gs: call_stmt); |
2182 | isra_call_summary *csum = call_sums->get_create (edge: cs); |
2183 | |
2184 | for (unsigned i = 0; i < count; i++) |
2185 | { |
2186 | tree arg = gimple_call_arg (gs: call_stmt, index: i); |
2187 | if (TREE_CODE (arg) == ADDR_EXPR) |
2188 | { |
2189 | poly_int64 poffset, psize, pmax_size; |
2190 | bool reverse; |
2191 | tree base = get_ref_base_and_extent (TREE_OPERAND (arg, 0), &poffset, |
2192 | &psize, &pmax_size, &reverse); |
2193 | HOST_WIDE_INT offset; |
2194 | unsigned HOST_WIDE_INT ds; |
2195 | if (DECL_P (base) |
2196 | && (poffset.is_constant (const_value: &offset)) |
2197 | && tree_fits_uhwi_p (DECL_SIZE (base)) |
2198 | && ((ds = tree_to_uhwi (DECL_SIZE (base)) - offset) |
2199 | < ISRA_ARG_SIZE_LIMIT * BITS_PER_UNIT)) |
2200 | { |
2201 | csum->init_inputs (arg_count: count); |
2202 | gcc_assert (!csum->m_arg_flow[i].aggregate_pass_through); |
2203 | csum->m_arg_flow[i].unit_size = ds / BITS_PER_UNIT; |
2204 | } |
2205 | |
2206 | if (TREE_CODE (base) == VAR_DECL |
2207 | && !TREE_STATIC (base) |
2208 | && !loaded_decls->contains (k: base)) |
2209 | { |
2210 | csum->init_inputs (arg_count: count); |
2211 | csum->m_arg_flow[i].constructed_for_calls = true; |
2212 | } |
2213 | } |
2214 | |
2215 | if (is_gimple_reg (arg)) |
2216 | continue; |
2217 | |
2218 | tree offset; |
2219 | poly_int64 bitsize, bitpos; |
2220 | machine_mode mode; |
2221 | int unsignedp, reversep, volatilep = 0; |
2222 | get_inner_reference (arg, &bitsize, &bitpos, &offset, &mode, |
2223 | &unsignedp, &reversep, &volatilep); |
2224 | if (!multiple_p (a: bitpos, BITS_PER_UNIT)) |
2225 | { |
2226 | csum->m_bit_aligned_arg = true; |
2227 | break; |
2228 | } |
2229 | } |
2230 | |
2231 | tree lhs = gimple_call_lhs (gs: call_stmt); |
2232 | if (lhs) |
2233 | { |
2234 | /* TODO: Also detect aggregates on a LHS of a call that are only returned |
2235 | from this function (without being read anywhere). */ |
2236 | if (TREE_CODE (lhs) == SSA_NAME) |
2237 | { |
2238 | bitmap analyzed = BITMAP_ALLOC (NULL); |
2239 | if (ssa_name_only_returned_p (DECL_STRUCT_FUNCTION (cs->caller->decl), |
2240 | name: lhs, analyzed)) |
2241 | csum->m_return_returned = true; |
2242 | BITMAP_FREE (analyzed); |
2243 | } |
2244 | } |
2245 | else |
2246 | csum->m_return_ignored = true; |
2247 | } |
2248 | |
2249 | /* Look at all calls going out of NODE, described also by IFS and perform all |
2250 | analyses necessary for IPA-SRA that are not done at body scan time or done |
2251 | even when body is not scanned because the function is not a candidate. */ |
2252 | |
2253 | static void |
2254 | isra_analyze_all_outgoing_calls (cgraph_node *node) |
2255 | { |
2256 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) |
2257 | isra_analyze_call (cs); |
2258 | for (cgraph_edge *cs = node->indirect_calls; cs; cs = cs->next_callee) |
2259 | isra_analyze_call (cs); |
2260 | } |
2261 | |
2262 | /* Dump a dereferences table with heading STR to file F. */ |
2263 | |
2264 | static void |
2265 | dump_dereferences_table (FILE *f, struct function *fun, const char *str) |
2266 | { |
2267 | basic_block bb; |
2268 | |
2269 | fprintf (stream: dump_file, format: "%s" , str); |
2270 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (fun), |
2271 | EXIT_BLOCK_PTR_FOR_FN (fun), next_bb) |
2272 | { |
2273 | fprintf (stream: f, format: "%4i %i " , bb->index, bitmap_bit_p (final_bbs, bb->index)); |
2274 | if (bb != EXIT_BLOCK_PTR_FOR_FN (fun)) |
2275 | { |
2276 | int i; |
2277 | for (i = 0; i < unsafe_by_ref_count; i++) |
2278 | { |
2279 | int idx = bb->index * unsafe_by_ref_count + i; |
2280 | fprintf (stream: f, format: " %4" HOST_WIDE_INT_PRINT "d" , bb_dereferences[idx]); |
2281 | } |
2282 | } |
2283 | fprintf (stream: f, format: "\n" ); |
2284 | } |
2285 | fprintf (stream: dump_file, format: "\n" ); |
2286 | } |
2287 | |
2288 | /* Propagate distances in bb_dereferences in the opposite direction than the |
2289 | control flow edges, in each step storing the maximum of the current value |
2290 | and the minimum of all successors. These steps are repeated until the table |
2291 | stabilizes. Note that BBs which might terminate the functions (according to |
2292 | final_bbs bitmap) never updated in this way. */ |
2293 | |
2294 | static void |
2295 | propagate_dereference_distances (struct function *fun) |
2296 | { |
2297 | basic_block bb; |
2298 | |
2299 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2300 | dump_dereferences_table (f: dump_file, fun, |
2301 | str: "Dereference table before propagation:\n" ); |
2302 | |
2303 | auto_vec<basic_block> queue (last_basic_block_for_fn (fun)); |
2304 | queue.quick_push (ENTRY_BLOCK_PTR_FOR_FN (fun)); |
2305 | FOR_EACH_BB_FN (bb, fun) |
2306 | { |
2307 | queue.quick_push (obj: bb); |
2308 | bb->aux = bb; |
2309 | } |
2310 | |
2311 | while (!queue.is_empty ()) |
2312 | { |
2313 | edge_iterator ei; |
2314 | edge e; |
2315 | bool change = false; |
2316 | int i; |
2317 | |
2318 | bb = queue.pop (); |
2319 | bb->aux = NULL; |
2320 | |
2321 | if (bitmap_bit_p (final_bbs, bb->index)) |
2322 | continue; |
2323 | |
2324 | for (i = 0; i < unsafe_by_ref_count; i++) |
2325 | { |
2326 | int idx = bb->index * unsafe_by_ref_count + i; |
2327 | bool first = true; |
2328 | HOST_WIDE_INT inh = 0; |
2329 | |
2330 | FOR_EACH_EDGE (e, ei, bb->succs) |
2331 | { |
2332 | int succ_idx = e->dest->index * unsafe_by_ref_count + i; |
2333 | |
2334 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (fun)) |
2335 | continue; |
2336 | |
2337 | if (first) |
2338 | { |
2339 | first = false; |
2340 | inh = bb_dereferences [succ_idx]; |
2341 | } |
2342 | else if (bb_dereferences [succ_idx] < inh) |
2343 | inh = bb_dereferences [succ_idx]; |
2344 | } |
2345 | |
2346 | if (!first && bb_dereferences[idx] < inh) |
2347 | { |
2348 | bb_dereferences[idx] = inh; |
2349 | change = true; |
2350 | } |
2351 | } |
2352 | |
2353 | if (change) |
2354 | FOR_EACH_EDGE (e, ei, bb->preds) |
2355 | { |
2356 | if (e->src->aux) |
2357 | continue; |
2358 | |
2359 | e->src->aux = e->src; |
2360 | queue.quick_push (obj: e->src); |
2361 | } |
2362 | } |
2363 | |
2364 | if (dump_file && (dump_flags & TDF_DETAILS)) |
2365 | dump_dereferences_table (f: dump_file, fun, |
2366 | str: "Dereference table after propagation:\n" ); |
2367 | } |
2368 | |
2369 | /* Return true if the ACCESS loads happen frequently enough in FUN to risk |
2370 | moving them to the caller and only pass the result. */ |
2371 | |
2372 | static bool |
2373 | dereference_probable_p (struct function *fun, gensum_param_access *access) |
2374 | { |
2375 | int threshold = opt_for_fn (fun->decl, param_ipa_sra_deref_prob_threshold); |
2376 | return access->load_count |
2377 | >= ENTRY_BLOCK_PTR_FOR_FN (fun)->count.apply_scale (num: threshold, den: 100); |
2378 | } |
2379 | |
2380 | /* Perform basic checks on ACCESS to PARM (of FUN) described by DESC and all |
2381 | its children, return true if the parameter cannot be split, otherwise return |
2382 | false and update *NONARG_ACC_SIZE and *ONLY_CALLS. ENTRY_BB_INDEX must be |
2383 | the index of the entry BB in the function of PARM. */ |
2384 | |
2385 | static bool |
2386 | check_gensum_access (struct function *fun, tree parm, gensum_param_desc *desc, |
2387 | gensum_param_access *access, |
2388 | HOST_WIDE_INT *nonarg_acc_size, bool *only_calls, |
2389 | int entry_bb_index) |
2390 | { |
2391 | if (access->nonarg) |
2392 | { |
2393 | *only_calls = false; |
2394 | *nonarg_acc_size += access->size; |
2395 | |
2396 | if (access->first_child) |
2397 | { |
2398 | disqualify_split_candidate (desc, reason: "Overlapping non-call uses." ); |
2399 | return true; |
2400 | } |
2401 | } |
2402 | /* Do not decompose a non-BLKmode param in a way that would create |
2403 | BLKmode params. Especially for by-reference passing (thus, |
2404 | pointer-type param) this is hardly worthwhile. */ |
2405 | if (DECL_MODE (parm) != BLKmode |
2406 | && TYPE_MODE (access->type) == BLKmode) |
2407 | { |
2408 | disqualify_split_candidate (desc, reason: "Would convert a non-BLK to a BLK." ); |
2409 | return true; |
2410 | } |
2411 | |
2412 | if (desc->by_ref) |
2413 | { |
2414 | if (desc->safe_ref) |
2415 | { |
2416 | if (!dereference_probable_p (fun, access)) |
2417 | { |
2418 | disqualify_split_candidate (desc, reason: "Dereferences in callers " |
2419 | "would happen much more frequently." ); |
2420 | return true; |
2421 | } |
2422 | } |
2423 | else |
2424 | { |
2425 | int idx = (entry_bb_index * unsafe_by_ref_count + desc->deref_index); |
2426 | if ((access->offset + access->size) > bb_dereferences[idx]) |
2427 | { |
2428 | if (!dereference_probable_p (fun, access)) |
2429 | { |
2430 | disqualify_split_candidate (desc, reason: "Would create a possibly " |
2431 | "illegal dereference in a " |
2432 | "caller." ); |
2433 | return true; |
2434 | } |
2435 | desc->conditionally_dereferenceable = true; |
2436 | } |
2437 | } |
2438 | } |
2439 | |
2440 | for (gensum_param_access *ch = access->first_child; |
2441 | ch; |
2442 | ch = ch->next_sibling) |
2443 | if (check_gensum_access (fun, parm, desc, access: ch, nonarg_acc_size, only_calls, |
2444 | entry_bb_index)) |
2445 | return true; |
2446 | |
2447 | return false; |
2448 | } |
2449 | |
2450 | /* Copy data from FROM and all of its children to a vector of accesses in IPA |
2451 | descriptor DESC. */ |
2452 | |
2453 | static void |
2454 | copy_accesses_to_ipa_desc (gensum_param_access *from, isra_param_desc *desc) |
2455 | { |
2456 | param_access *to = ggc_cleared_alloc<param_access> (); |
2457 | gcc_checking_assert ((from->offset % BITS_PER_UNIT) == 0); |
2458 | gcc_checking_assert ((from->size % BITS_PER_UNIT) == 0); |
2459 | to->unit_offset = from->offset / BITS_PER_UNIT; |
2460 | to->unit_size = from->size / BITS_PER_UNIT; |
2461 | to->type = from->type; |
2462 | to->alias_ptr_type = from->alias_ptr_type; |
2463 | to->certain = from->nonarg; |
2464 | to->reverse = from->reverse; |
2465 | vec_safe_push (v&: desc->accesses, obj: to); |
2466 | |
2467 | for (gensum_param_access *ch = from->first_child; |
2468 | ch; |
2469 | ch = ch->next_sibling) |
2470 | copy_accesses_to_ipa_desc (from: ch, desc); |
2471 | } |
2472 | |
2473 | /* Analyze function body scan results stored in param_accesses and |
2474 | param_accesses, detect possible transformations and store information of |
2475 | those in function summary. NODE, FUN and IFS are all various structures |
2476 | describing the currently analyzed function. */ |
2477 | |
2478 | static void |
2479 | process_scan_results (cgraph_node *node, struct function *fun, |
2480 | isra_func_summary *ifs, |
2481 | vec<gensum_param_desc> *param_descriptions) |
2482 | { |
2483 | bool check_pass_throughs = false; |
2484 | bool dereferences_propagated = false; |
2485 | tree parm = DECL_ARGUMENTS (node->decl); |
2486 | unsigned param_count = param_descriptions->length(); |
2487 | |
2488 | for (unsigned desc_index = 0; |
2489 | desc_index < param_count; |
2490 | desc_index++, parm = DECL_CHAIN (parm)) |
2491 | { |
2492 | gensum_param_desc *desc = &(*param_descriptions)[desc_index]; |
2493 | if (!desc->split_candidate) |
2494 | continue; |
2495 | |
2496 | if (flag_checking) |
2497 | isra_verify_access_tree (access: desc->accesses); |
2498 | |
2499 | if (!dereferences_propagated |
2500 | && desc->by_ref |
2501 | && !desc->safe_ref |
2502 | && desc->accesses) |
2503 | { |
2504 | propagate_dereference_distances (fun); |
2505 | dereferences_propagated = true; |
2506 | } |
2507 | |
2508 | HOST_WIDE_INT nonarg_acc_size = 0; |
2509 | bool only_calls = true; |
2510 | bool check_failed = false; |
2511 | |
2512 | int entry_bb_index = ENTRY_BLOCK_PTR_FOR_FN (fun)->index; |
2513 | for (gensum_param_access *acc = desc->accesses; |
2514 | acc; |
2515 | acc = acc->next_sibling) |
2516 | if (check_gensum_access (fun, parm, desc, access: acc, nonarg_acc_size: &nonarg_acc_size, |
2517 | only_calls: &only_calls, entry_bb_index)) |
2518 | { |
2519 | check_failed = true; |
2520 | break; |
2521 | } |
2522 | if (check_failed) |
2523 | continue; |
2524 | |
2525 | if (only_calls) |
2526 | desc->locally_unused = true; |
2527 | |
2528 | HOST_WIDE_INT cur_param_size |
2529 | = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (parm))); |
2530 | HOST_WIDE_INT param_size_limit, optimistic_limit; |
2531 | if (!desc->by_ref || optimize_function_for_size_p (fun)) |
2532 | { |
2533 | param_size_limit = cur_param_size; |
2534 | optimistic_limit = cur_param_size; |
2535 | } |
2536 | else |
2537 | { |
2538 | param_size_limit |
2539 | = opt_for_fn (node->decl, |
2540 | param_ipa_sra_ptr_growth_factor) * cur_param_size; |
2541 | optimistic_limit |
2542 | = (opt_for_fn (node->decl, param_ipa_sra_ptrwrap_growth_factor) |
2543 | * param_size_limit); |
2544 | } |
2545 | |
2546 | if (nonarg_acc_size > optimistic_limit |
2547 | || (!desc->by_ref && nonarg_acc_size == param_size_limit)) |
2548 | { |
2549 | disqualify_split_candidate (desc, reason: "Would result into a too big set " |
2550 | "of replacements even in best " |
2551 | "scenarios." ); |
2552 | } |
2553 | else |
2554 | { |
2555 | /* create_parameter_descriptors makes sure unit sizes of all |
2556 | candidate parameters fit unsigned integers restricted to |
2557 | ISRA_ARG_SIZE_LIMIT. */ |
2558 | desc->param_size_limit = param_size_limit / BITS_PER_UNIT; |
2559 | desc->nonarg_acc_size = nonarg_acc_size / BITS_PER_UNIT; |
2560 | if (desc->split_candidate && desc->ptr_pt_count) |
2561 | { |
2562 | gcc_assert (desc->by_ref); |
2563 | check_pass_throughs = true; |
2564 | } |
2565 | } |
2566 | } |
2567 | |
2568 | /* When a pointer parameter is passed-through to a callee, in which it is |
2569 | only used to read only one or a few items, we can attempt to transform it |
2570 | to obtaining and passing through the items instead of the pointer. But we |
2571 | must take extra care that 1) we do not introduce any segfault by moving |
2572 | dereferences above control flow and that 2) the data is not modified |
2573 | through an alias in this function. The IPA analysis must not introduce |
2574 | any accesses candidates unless it can prove both. |
2575 | |
2576 | The current solution is very crude as it consists of ensuring that the |
2577 | call postdominates entry BB and that the definition of VUSE of the call is |
2578 | default definition. TODO: For non-recursive callees in the same |
2579 | compilation unit we could do better by doing analysis in topological order |
2580 | an looking into access candidates of callees, using their alias_ptr_types |
2581 | to attempt real AA. We could also use the maximum known dereferenced |
2582 | offset in this function at IPA level. |
2583 | |
2584 | TODO: Measure the overhead and the effect of just being pessimistic. |
2585 | Maybe this is only -O3 material? */ |
2586 | |
2587 | hash_map<gimple *, bool> analyzed_stmts; |
2588 | bitmap always_executed_bbs = NULL; |
2589 | if (check_pass_throughs) |
2590 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) |
2591 | { |
2592 | gcall *call_stmt = cs->call_stmt; |
2593 | tree vuse = gimple_vuse (g: call_stmt); |
2594 | |
2595 | /* If the callee is a const function, we don't get a VUSE. In such |
2596 | case there will be no memory accesses in the called function (or the |
2597 | const attribute is wrong) and then we just don't care. */ |
2598 | bool uses_memory_as_obtained = vuse && SSA_NAME_IS_DEFAULT_DEF (vuse); |
2599 | |
2600 | unsigned count = gimple_call_num_args (gs: call_stmt); |
2601 | isra_call_summary *csum = call_sums->get_create (edge: cs); |
2602 | csum->init_inputs (arg_count: count); |
2603 | csum->m_before_any_store = uses_memory_as_obtained; |
2604 | for (unsigned argidx = 0; argidx < count; argidx++) |
2605 | { |
2606 | if (!csum->m_arg_flow[argidx].pointer_pass_through) |
2607 | continue; |
2608 | unsigned pidx |
2609 | = get_single_param_flow_source (param_flow: &csum->m_arg_flow[argidx]); |
2610 | gensum_param_desc *desc = &(*param_descriptions)[pidx]; |
2611 | if (!desc->split_candidate) |
2612 | { |
2613 | csum->m_arg_flow[argidx].pointer_pass_through = false; |
2614 | continue; |
2615 | } |
2616 | if (!uses_memory_as_obtained) |
2617 | continue; |
2618 | |
2619 | if (desc->safe_ref) |
2620 | { |
2621 | csum->m_arg_flow[argidx].safe_to_import_accesses = true; |
2622 | continue; |
2623 | } |
2624 | |
2625 | /* Walk basic block and see if its execution can terminate earlier. |
2626 | Keep the info for later re-use to avoid quadratic behavoiur here. */ |
2627 | gimple_stmt_iterator gsi = gsi_for_stmt (call_stmt); |
2628 | bool safe = true; |
2629 | int n = 0; |
2630 | for (gsi_prev (i: &gsi); !gsi_end_p (i: gsi); gsi_prev (i: &gsi)) |
2631 | { |
2632 | bool *b = analyzed_stmts.get (k: gsi_stmt (i: gsi)); |
2633 | if (b) |
2634 | { |
2635 | safe = *b; |
2636 | gsi_next (i: &gsi); |
2637 | break; |
2638 | } |
2639 | n++; |
2640 | if (stmt_may_terminate_function_p (fun, stmt: gsi_stmt (i: gsi), assume_return_or_eh: false)) |
2641 | { |
2642 | safe = false; |
2643 | break; |
2644 | } |
2645 | } |
2646 | if (n) |
2647 | { |
2648 | if (gsi_end_p (i: gsi)) |
2649 | gsi = gsi_start_bb (bb: gimple_bb (g: call_stmt)); |
2650 | for (; gsi_stmt (i: gsi) != call_stmt; gsi_next (i: &gsi)) |
2651 | analyzed_stmts.get_or_insert (k: gsi_stmt (i: gsi)) = safe; |
2652 | } |
2653 | |
2654 | if (safe && !always_executed_bbs) |
2655 | { |
2656 | mark_dfs_back_edges (); |
2657 | always_executed_bbs = find_always_executed_bbs (fun, assume_return_or_eh: false); |
2658 | } |
2659 | if (safe && bitmap_bit_p (always_executed_bbs, gimple_bb (g: call_stmt)->index)) |
2660 | csum->m_arg_flow[argidx].safe_to_import_accesses = true; |
2661 | } |
2662 | |
2663 | } |
2664 | BITMAP_FREE (always_executed_bbs); |
2665 | |
2666 | /* TODO: Add early exit if we disqualified everything. This also requires |
2667 | that we either relax the restriction that |
2668 | ipa_param_adjustments.m_always_copy_start must be the number of PARM_DECLs |
2669 | or store the number of parameters to IPA-SRA function summary and use that |
2670 | when just removing params. */ |
2671 | |
2672 | vec_safe_reserve_exact (v&: ifs->m_parameters, nelems: param_count); |
2673 | ifs->m_parameters->quick_grow_cleared (len: param_count); |
2674 | for (unsigned desc_index = 0; desc_index < param_count; desc_index++) |
2675 | { |
2676 | gensum_param_desc *s = &(*param_descriptions)[desc_index]; |
2677 | isra_param_desc *d = &(*ifs->m_parameters)[desc_index]; |
2678 | |
2679 | d->param_size_limit = s->param_size_limit; |
2680 | d->size_reached = s->nonarg_acc_size; |
2681 | d->locally_unused = s->locally_unused; |
2682 | d->split_candidate = s->split_candidate; |
2683 | d->by_ref = s->by_ref; |
2684 | d->remove_only_when_retval_removed = s->remove_only_when_retval_removed; |
2685 | d->split_only_when_retval_removed = s->split_only_when_retval_removed; |
2686 | d->conditionally_dereferenceable = s->conditionally_dereferenceable; |
2687 | |
2688 | for (gensum_param_access *acc = s->accesses; |
2689 | acc; |
2690 | acc = acc->next_sibling) |
2691 | copy_accesses_to_ipa_desc (from: acc, desc: d); |
2692 | } |
2693 | |
2694 | if (dump_file) |
2695 | dump_isra_param_descriptors (f: dump_file, fndecl: node->decl, ifs, hints: false); |
2696 | } |
2697 | |
2698 | /* Return true if there are any overlaps among certain accesses of DESC. If |
2699 | non-NULL, set *CERTAIN_ACCESS_PRESENT_P upon encountering a certain access |
2700 | too. DESC is assumed to be a split candidate that is not locally |
2701 | unused. */ |
2702 | |
2703 | static bool |
2704 | overlapping_certain_accesses_p (isra_param_desc *desc, |
2705 | bool *certain_access_present_p) |
2706 | { |
2707 | unsigned pclen = vec_safe_length (v: desc->accesses); |
2708 | for (unsigned i = 0; i < pclen; i++) |
2709 | { |
2710 | param_access *a1 = (*desc->accesses)[i]; |
2711 | |
2712 | if (!a1->certain) |
2713 | continue; |
2714 | if (certain_access_present_p) |
2715 | *certain_access_present_p = true; |
2716 | for (unsigned j = i + 1; j < pclen; j++) |
2717 | { |
2718 | param_access *a2 = (*desc->accesses)[j]; |
2719 | if (a2->certain |
2720 | && a1->unit_offset < a2->unit_offset + a2->unit_size |
2721 | && a1->unit_offset + a1->unit_size > a2->unit_offset) |
2722 | return true; |
2723 | } |
2724 | } |
2725 | return false; |
2726 | } |
2727 | |
2728 | /* Check for any overlaps of certain param accesses among splitting candidates |
2729 | and signal an ICE if there are any. If CERTAIN_MUST_EXIST is set, also |
2730 | check that used splitting candidates have at least one certain access. */ |
2731 | |
2732 | static void |
2733 | verify_splitting_accesses (cgraph_node *node, bool certain_must_exist) |
2734 | { |
2735 | isra_func_summary *ifs = func_sums->get (node); |
2736 | if (!ifs || !ifs->m_candidate) |
2737 | return; |
2738 | unsigned param_count = vec_safe_length (v: ifs->m_parameters); |
2739 | for (unsigned pidx = 0; pidx < param_count; pidx++) |
2740 | { |
2741 | isra_param_desc *desc = &(*ifs->m_parameters)[pidx]; |
2742 | if (!desc->split_candidate || desc->locally_unused) |
2743 | continue; |
2744 | |
2745 | bool certain_access_present = !certain_must_exist; |
2746 | if (overlapping_certain_accesses_p (desc, certain_access_present_p: &certain_access_present)) |
2747 | internal_error ("function %qs, parameter %u, has IPA-SRA accesses " |
2748 | "which overlap" , node->dump_name (), pidx); |
2749 | if (!certain_access_present) |
2750 | internal_error ("function %qs, parameter %u, is used but does not " |
2751 | "have any certain IPA-SRA access" , |
2752 | node->dump_name (), pidx); |
2753 | } |
2754 | } |
2755 | |
2756 | /* Intraprocedural part of IPA-SRA analysis. Scan bodies of all functions in |
2757 | this compilation unit and create summary structures describing IPA-SRA |
2758 | opportunities and constraints in them. */ |
2759 | |
2760 | static void |
2761 | ipa_sra_generate_summary (void) |
2762 | { |
2763 | struct cgraph_node *node; |
2764 | |
2765 | gcc_checking_assert (!func_sums); |
2766 | gcc_checking_assert (!call_sums); |
2767 | func_sums |
2768 | = (new (ggc_alloc_no_dtor <ipa_sra_function_summaries> ()) |
2769 | ipa_sra_function_summaries (symtab, true)); |
2770 | call_sums = new ipa_sra_call_summaries (symtab); |
2771 | |
2772 | FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) |
2773 | ipa_sra_summarize_function (node); |
2774 | return; |
2775 | } |
2776 | |
2777 | /* Write intraprocedural analysis information about E and all of its outgoing |
2778 | edges into a stream for LTO WPA. */ |
2779 | |
2780 | static void |
2781 | isra_write_edge_summary (output_block *ob, cgraph_edge *e) |
2782 | { |
2783 | isra_call_summary *csum = call_sums->get (edge: e); |
2784 | unsigned input_count = csum->m_arg_flow.length (); |
2785 | streamer_write_uhwi (ob, input_count); |
2786 | for (unsigned i = 0; i < input_count; i++) |
2787 | { |
2788 | isra_param_flow *ipf = &csum->m_arg_flow[i]; |
2789 | streamer_write_hwi (ob, ipf->length); |
2790 | bitpack_d bp = bitpack_create (s: ob->main_stream); |
2791 | for (int j = 0; j < ipf->length; j++) |
2792 | bp_pack_value (bp: &bp, val: ipf->inputs[j], nbits: 8); |
2793 | bp_pack_value (bp: &bp, val: ipf->aggregate_pass_through, nbits: 1); |
2794 | bp_pack_value (bp: &bp, val: ipf->pointer_pass_through, nbits: 1); |
2795 | bp_pack_value (bp: &bp, val: ipf->safe_to_import_accesses, nbits: 1); |
2796 | bp_pack_value (bp: &bp, val: ipf->constructed_for_calls, nbits: 1); |
2797 | streamer_write_bitpack (bp: &bp); |
2798 | streamer_write_uhwi (ob, ipf->unit_offset); |
2799 | streamer_write_uhwi (ob, ipf->unit_size); |
2800 | } |
2801 | bitpack_d bp = bitpack_create (s: ob->main_stream); |
2802 | bp_pack_value (bp: &bp, val: csum->m_return_ignored, nbits: 1); |
2803 | bp_pack_value (bp: &bp, val: csum->m_return_returned, nbits: 1); |
2804 | bp_pack_value (bp: &bp, val: csum->m_bit_aligned_arg, nbits: 1); |
2805 | bp_pack_value (bp: &bp, val: csum->m_before_any_store, nbits: 1); |
2806 | streamer_write_bitpack (bp: &bp); |
2807 | } |
2808 | |
2809 | /* Write intraprocedural analysis information about NODE and all of its outgoing |
2810 | edges into a stream for LTO WPA. */ |
2811 | |
2812 | static void |
2813 | isra_write_node_summary (output_block *ob, cgraph_node *node) |
2814 | { |
2815 | isra_func_summary *ifs = func_sums->get (node); |
2816 | lto_symtab_encoder_t encoder = ob->decl_state->symtab_node_encoder; |
2817 | int node_ref = lto_symtab_encoder_encode (encoder, node); |
2818 | streamer_write_uhwi (ob, node_ref); |
2819 | |
2820 | unsigned param_desc_count = vec_safe_length (v: ifs->m_parameters); |
2821 | streamer_write_uhwi (ob, param_desc_count); |
2822 | for (unsigned i = 0; i < param_desc_count; i++) |
2823 | { |
2824 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; |
2825 | unsigned access_count = vec_safe_length (v: desc->accesses); |
2826 | streamer_write_uhwi (ob, access_count); |
2827 | for (unsigned j = 0; j < access_count; j++) |
2828 | { |
2829 | param_access *acc = (*desc->accesses)[j]; |
2830 | stream_write_tree (ob, acc->type, true); |
2831 | stream_write_tree (ob, acc->alias_ptr_type, true); |
2832 | streamer_write_uhwi (ob, acc->unit_offset); |
2833 | streamer_write_uhwi (ob, acc->unit_size); |
2834 | bitpack_d bp = bitpack_create (s: ob->main_stream); |
2835 | bp_pack_value (bp: &bp, val: acc->certain, nbits: 1); |
2836 | bp_pack_value (bp: &bp, val: acc->reverse, nbits: 1); |
2837 | streamer_write_bitpack (bp: &bp); |
2838 | } |
2839 | streamer_write_uhwi (ob, desc->param_size_limit); |
2840 | streamer_write_uhwi (ob, desc->size_reached); |
2841 | gcc_assert (desc->safe_size == 0); |
2842 | bitpack_d bp = bitpack_create (s: ob->main_stream); |
2843 | bp_pack_value (bp: &bp, val: desc->locally_unused, nbits: 1); |
2844 | bp_pack_value (bp: &bp, val: desc->split_candidate, nbits: 1); |
2845 | bp_pack_value (bp: &bp, val: desc->by_ref, nbits: 1); |
2846 | gcc_assert (!desc->not_specially_constructed); |
2847 | bp_pack_value (bp: &bp, val: desc->remove_only_when_retval_removed, nbits: 1); |
2848 | bp_pack_value (bp: &bp, val: desc->split_only_when_retval_removed, nbits: 1); |
2849 | bp_pack_value (bp: &bp, val: desc->conditionally_dereferenceable, nbits: 1); |
2850 | gcc_assert (!desc->safe_size_set); |
2851 | streamer_write_bitpack (bp: &bp); |
2852 | } |
2853 | bitpack_d bp = bitpack_create (s: ob->main_stream); |
2854 | bp_pack_value (bp: &bp, val: ifs->m_candidate, nbits: 1); |
2855 | bp_pack_value (bp: &bp, val: ifs->m_returns_value, nbits: 1); |
2856 | bp_pack_value (bp: &bp, val: ifs->m_return_ignored, nbits: 1); |
2857 | gcc_assert (!ifs->m_queued); |
2858 | streamer_write_bitpack (bp: &bp); |
2859 | |
2860 | for (cgraph_edge *e = node->callees; e; e = e->next_callee) |
2861 | isra_write_edge_summary (ob, e); |
2862 | for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee) |
2863 | isra_write_edge_summary (ob, e); |
2864 | } |
2865 | |
2866 | /* Write intraprocedural analysis information into a stream for LTO WPA. */ |
2867 | |
2868 | static void |
2869 | ipa_sra_write_summary (void) |
2870 | { |
2871 | if (!func_sums || !call_sums) |
2872 | return; |
2873 | |
2874 | struct output_block *ob = create_output_block (LTO_section_ipa_sra); |
2875 | lto_symtab_encoder_t encoder = ob->decl_state->symtab_node_encoder; |
2876 | ob->symbol = NULL; |
2877 | |
2878 | unsigned int count = 0; |
2879 | lto_symtab_encoder_iterator lsei; |
2880 | for (lsei = lsei_start_function_in_partition (encoder); |
2881 | !lsei_end_p (lsei); |
2882 | lsei_next_function_in_partition (lsei: &lsei)) |
2883 | { |
2884 | cgraph_node *node = lsei_cgraph_node (lsei); |
2885 | if (node->has_gimple_body_p () |
2886 | && func_sums->get (node) != NULL) |
2887 | count++; |
2888 | } |
2889 | streamer_write_uhwi (ob, count); |
2890 | |
2891 | /* Process all of the functions. */ |
2892 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); |
2893 | lsei_next_function_in_partition (lsei: &lsei)) |
2894 | { |
2895 | cgraph_node *node = lsei_cgraph_node (lsei); |
2896 | if (node->has_gimple_body_p () |
2897 | && func_sums->get (node) != NULL) |
2898 | isra_write_node_summary (ob, node); |
2899 | } |
2900 | streamer_write_char_stream (obs: ob->main_stream, c: 0); |
2901 | produce_asm (ob, NULL); |
2902 | destroy_output_block (ob); |
2903 | } |
2904 | |
2905 | /* Read intraprocedural analysis information about E and all of its outgoing |
2906 | edges into a stream for LTO WPA. */ |
2907 | |
2908 | static void |
2909 | isra_read_edge_summary (struct lto_input_block *ib, cgraph_edge *cs) |
2910 | { |
2911 | isra_call_summary *csum = call_sums->get_create (edge: cs); |
2912 | unsigned input_count = streamer_read_uhwi (ib); |
2913 | csum->init_inputs (arg_count: input_count); |
2914 | for (unsigned i = 0; i < input_count; i++) |
2915 | { |
2916 | isra_param_flow *ipf = &csum->m_arg_flow[i]; |
2917 | ipf->length = streamer_read_hwi (ib); |
2918 | bitpack_d bp = streamer_read_bitpack (ib); |
2919 | for (int j = 0; j < ipf->length; j++) |
2920 | ipf->inputs[j] = bp_unpack_value (bp: &bp, nbits: 8); |
2921 | ipf->aggregate_pass_through = bp_unpack_value (bp: &bp, nbits: 1); |
2922 | ipf->pointer_pass_through = bp_unpack_value (bp: &bp, nbits: 1); |
2923 | ipf->safe_to_import_accesses = bp_unpack_value (bp: &bp, nbits: 1); |
2924 | ipf->constructed_for_calls = bp_unpack_value (bp: &bp, nbits: 1); |
2925 | ipf->unit_offset = streamer_read_uhwi (ib); |
2926 | ipf->unit_size = streamer_read_uhwi (ib); |
2927 | } |
2928 | bitpack_d bp = streamer_read_bitpack (ib); |
2929 | csum->m_return_ignored = bp_unpack_value (bp: &bp, nbits: 1); |
2930 | csum->m_return_returned = bp_unpack_value (bp: &bp, nbits: 1); |
2931 | csum->m_bit_aligned_arg = bp_unpack_value (bp: &bp, nbits: 1); |
2932 | csum->m_before_any_store = bp_unpack_value (bp: &bp, nbits: 1); |
2933 | } |
2934 | |
2935 | /* Read intraprocedural analysis information about NODE and all of its outgoing |
2936 | edges into a stream for LTO WPA. */ |
2937 | |
2938 | static void |
2939 | isra_read_node_info (struct lto_input_block *ib, cgraph_node *node, |
2940 | struct data_in *data_in) |
2941 | { |
2942 | isra_func_summary *ifs = func_sums->get_create (node); |
2943 | unsigned param_desc_count = streamer_read_uhwi (ib); |
2944 | if (param_desc_count > 0) |
2945 | { |
2946 | vec_safe_reserve_exact (v&: ifs->m_parameters, nelems: param_desc_count); |
2947 | ifs->m_parameters->quick_grow_cleared (len: param_desc_count); |
2948 | } |
2949 | for (unsigned i = 0; i < param_desc_count; i++) |
2950 | { |
2951 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; |
2952 | unsigned access_count = streamer_read_uhwi (ib); |
2953 | for (unsigned j = 0; j < access_count; j++) |
2954 | { |
2955 | param_access *acc = ggc_cleared_alloc<param_access> (); |
2956 | acc->type = stream_read_tree (ib, data_in); |
2957 | acc->alias_ptr_type = stream_read_tree (ib, data_in); |
2958 | acc->unit_offset = streamer_read_uhwi (ib); |
2959 | acc->unit_size = streamer_read_uhwi (ib); |
2960 | bitpack_d bp = streamer_read_bitpack (ib); |
2961 | acc->certain = bp_unpack_value (bp: &bp, nbits: 1); |
2962 | acc->reverse = bp_unpack_value (bp: &bp, nbits: 1); |
2963 | vec_safe_push (v&: desc->accesses, obj: acc); |
2964 | } |
2965 | desc->param_size_limit = streamer_read_uhwi (ib); |
2966 | desc->size_reached = streamer_read_uhwi (ib); |
2967 | desc->safe_size = 0; |
2968 | bitpack_d bp = streamer_read_bitpack (ib); |
2969 | desc->locally_unused = bp_unpack_value (bp: &bp, nbits: 1); |
2970 | desc->split_candidate = bp_unpack_value (bp: &bp, nbits: 1); |
2971 | desc->by_ref = bp_unpack_value (bp: &bp, nbits: 1); |
2972 | desc->not_specially_constructed = 0; |
2973 | desc->remove_only_when_retval_removed = bp_unpack_value (bp: &bp, nbits: 1); |
2974 | desc->split_only_when_retval_removed = bp_unpack_value (bp: &bp, nbits: 1); |
2975 | desc->conditionally_dereferenceable = bp_unpack_value (bp: &bp, nbits: 1); |
2976 | desc->safe_size_set = 0; |
2977 | } |
2978 | bitpack_d bp = streamer_read_bitpack (ib); |
2979 | ifs->m_candidate = bp_unpack_value (bp: &bp, nbits: 1); |
2980 | ifs->m_returns_value = bp_unpack_value (bp: &bp, nbits: 1); |
2981 | ifs->m_return_ignored = bp_unpack_value (bp: &bp, nbits: 1); |
2982 | ifs->m_queued = 0; |
2983 | |
2984 | for (cgraph_edge *e = node->callees; e; e = e->next_callee) |
2985 | isra_read_edge_summary (ib, cs: e); |
2986 | for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee) |
2987 | isra_read_edge_summary (ib, cs: e); |
2988 | } |
2989 | |
2990 | /* Read IPA-SRA summaries from a section in file FILE_DATA of length LEN with |
2991 | data DATA. TODO: This function was copied almost verbatim from ipa-prop.cc, |
2992 | it should be possible to unify them somehow. */ |
2993 | |
2994 | static void |
2995 | isra_read_summary_section (struct lto_file_decl_data *file_data, |
2996 | const char *data, size_t len) |
2997 | { |
2998 | const struct lto_function_header * = |
2999 | (const struct lto_function_header *) data; |
3000 | const int cfg_offset = sizeof (struct lto_function_header); |
3001 | const int main_offset = cfg_offset + header->cfg_size; |
3002 | const int string_offset = main_offset + header->main_size; |
3003 | struct data_in *data_in; |
3004 | unsigned int i; |
3005 | unsigned int count; |
3006 | |
3007 | lto_input_block ib_main ((const char *) data + main_offset, |
3008 | header->main_size, file_data); |
3009 | |
3010 | data_in = |
3011 | lto_data_in_create (file_data, (const char *) data + string_offset, |
3012 | header->string_size, vNULL); |
3013 | count = streamer_read_uhwi (&ib_main); |
3014 | |
3015 | for (i = 0; i < count; i++) |
3016 | { |
3017 | unsigned int index; |
3018 | struct cgraph_node *node; |
3019 | lto_symtab_encoder_t encoder; |
3020 | |
3021 | index = streamer_read_uhwi (&ib_main); |
3022 | encoder = file_data->symtab_node_encoder; |
3023 | node = dyn_cast<cgraph_node *> (p: lto_symtab_encoder_deref (encoder, |
3024 | ref: index)); |
3025 | gcc_assert (node->definition); |
3026 | isra_read_node_info (ib: &ib_main, node, data_in); |
3027 | } |
3028 | lto_free_section_data (file_data, LTO_section_ipa_sra, NULL, data, |
3029 | len); |
3030 | lto_data_in_delete (data_in); |
3031 | } |
3032 | |
3033 | /* Read intraprocedural analysis information into a stream for LTO WPA. */ |
3034 | |
3035 | static void |
3036 | ipa_sra_read_summary (void) |
3037 | { |
3038 | struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); |
3039 | struct lto_file_decl_data *file_data; |
3040 | unsigned int j = 0; |
3041 | |
3042 | gcc_checking_assert (!func_sums); |
3043 | gcc_checking_assert (!call_sums); |
3044 | func_sums |
3045 | = (new (ggc_alloc_no_dtor <ipa_sra_function_summaries> ()) |
3046 | ipa_sra_function_summaries (symtab, true)); |
3047 | call_sums = new ipa_sra_call_summaries (symtab); |
3048 | |
3049 | while ((file_data = file_data_vec[j++])) |
3050 | { |
3051 | size_t len; |
3052 | const char *data |
3053 | = lto_get_summary_section_data (file_data, LTO_section_ipa_sra, &len); |
3054 | if (data) |
3055 | isra_read_summary_section (file_data, data, len); |
3056 | } |
3057 | } |
3058 | |
3059 | /* Dump all IPA-SRA summary data for all cgraph nodes and edges to file F. If |
3060 | HINTS is true, also dump IPA-analysis computed hints. */ |
3061 | |
3062 | static void |
3063 | ipa_sra_dump_all_summaries (FILE *f, bool hints) |
3064 | { |
3065 | cgraph_node *node; |
3066 | FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) |
3067 | { |
3068 | fprintf (stream: f, format: "\nSummary for node %s:\n" , node->dump_name ()); |
3069 | |
3070 | isra_func_summary *ifs = func_sums->get (node); |
3071 | if (!ifs) |
3072 | fprintf (stream: f, format: " Function does not have any associated IPA-SRA " |
3073 | "summary\n" ); |
3074 | else if (!ifs->m_candidate) |
3075 | fprintf (stream: f, format: " Not a candidate function\n" ); |
3076 | else |
3077 | { |
3078 | if (ifs->m_returns_value) |
3079 | fprintf (stream: f, format: " Returns value\n" ); |
3080 | if (vec_safe_is_empty (v: ifs->m_parameters)) |
3081 | fprintf (stream: f, format: " No parameter information. \n" ); |
3082 | else |
3083 | for (unsigned i = 0; i < ifs->m_parameters->length (); ++i) |
3084 | { |
3085 | fprintf (stream: f, format: " Descriptor for parameter %i:\n" , i); |
3086 | dump_isra_param_descriptor (f, desc: &(*ifs->m_parameters)[i], hints); |
3087 | } |
3088 | fprintf (stream: f, format: "\n" ); |
3089 | } |
3090 | |
3091 | struct cgraph_edge *cs; |
3092 | for (cs = node->callees; cs; cs = cs->next_callee) |
3093 | { |
3094 | fprintf (stream: f, format: " Summary for edge %s->%s:\n" , cs->caller->dump_name (), |
3095 | cs->callee->dump_name ()); |
3096 | isra_call_summary *csum = call_sums->get (edge: cs); |
3097 | if (csum) |
3098 | csum->dump (f); |
3099 | else |
3100 | fprintf (stream: f, format: " Call summary is MISSING!\n" ); |
3101 | } |
3102 | |
3103 | } |
3104 | fprintf (stream: f, format: "\n\n" ); |
3105 | } |
3106 | |
3107 | /* Perform function-scope viability tests that can be only made at IPA level |
3108 | and return false if the function is deemed unsuitable for IPA-SRA. */ |
3109 | |
3110 | static bool |
3111 | ipa_sra_ipa_function_checks (cgraph_node *node) |
3112 | { |
3113 | if (!node->can_be_local_p ()) |
3114 | { |
3115 | if (dump_file) |
3116 | fprintf (stream: dump_file, format: "Function %s disqualified because it cannot be " |
3117 | "made local.\n" , node->dump_name ()); |
3118 | return false; |
3119 | } |
3120 | if (!node->can_change_signature) |
3121 | { |
3122 | if (dump_file) |
3123 | fprintf (stream: dump_file, format: "Function can not change signature.\n" ); |
3124 | return false; |
3125 | } |
3126 | |
3127 | return true; |
3128 | } |
3129 | |
3130 | /* Issues found out by check_callers_for_issues. */ |
3131 | |
3132 | struct caller_issues |
3133 | { |
3134 | /* The candidate being considered. */ |
3135 | cgraph_node *candidate; |
3136 | /* There is a thunk among callers. */ |
3137 | bool thunk; |
3138 | /* Set if there is at least one caller that is OK. */ |
3139 | bool there_is_one; |
3140 | /* Call site with no available information. */ |
3141 | bool unknown_callsite; |
3142 | /* Call from outside the candidate's comdat group. */ |
3143 | bool call_from_outside_comdat; |
3144 | /* There is a bit-aligned load into one of non-gimple-typed arguments. */ |
3145 | bool bit_aligned_aggregate_argument; |
3146 | }; |
3147 | |
3148 | /* Worker for call_for_symbol_and_aliases, set any flags of passed caller_issues |
3149 | that apply. */ |
3150 | |
3151 | static bool |
3152 | check_for_caller_issues (struct cgraph_node *node, void *data) |
3153 | { |
3154 | struct caller_issues *issues = (struct caller_issues *) data; |
3155 | |
3156 | for (cgraph_edge *cs = node->callers; cs; cs = cs->next_caller) |
3157 | { |
3158 | if (cs->caller->thunk) |
3159 | { |
3160 | issues->thunk = true; |
3161 | /* TODO: We should be able to process at least some types of |
3162 | thunks. */ |
3163 | return true; |
3164 | } |
3165 | if (issues->candidate->calls_comdat_local |
3166 | && issues->candidate->same_comdat_group |
3167 | && !issues->candidate->in_same_comdat_group_p (target: cs->caller)) |
3168 | { |
3169 | issues->call_from_outside_comdat = true; |
3170 | return true; |
3171 | } |
3172 | |
3173 | isra_call_summary *csum = call_sums->get (edge: cs); |
3174 | if (!csum) |
3175 | { |
3176 | issues->unknown_callsite = true; |
3177 | return true; |
3178 | } |
3179 | |
3180 | if (csum->m_bit_aligned_arg) |
3181 | issues->bit_aligned_aggregate_argument = true; |
3182 | |
3183 | issues->there_is_one = true; |
3184 | } |
3185 | return false; |
3186 | } |
3187 | |
3188 | /* Look at all incoming edges to NODE, including aliases and thunks and look |
3189 | for problems. Return true if NODE type should not be modified at all. */ |
3190 | |
3191 | static bool |
3192 | check_all_callers_for_issues (cgraph_node *node) |
3193 | { |
3194 | struct caller_issues issues; |
3195 | memset (s: &issues, c: 0, n: sizeof (issues)); |
3196 | issues.candidate = node; |
3197 | |
3198 | node->call_for_symbol_and_aliases (callback: check_for_caller_issues, data: &issues, include_overwritable: true); |
3199 | if (issues.unknown_callsite) |
3200 | { |
3201 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3202 | fprintf (stream: dump_file, format: "A call of %s has not been analyzed. Disabling " |
3203 | "all modifications.\n" , node->dump_name ()); |
3204 | return true; |
3205 | } |
3206 | /* TODO: We should be able to process at least some types of thunks. */ |
3207 | if (issues.thunk) |
3208 | { |
3209 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3210 | fprintf (stream: dump_file, format: "A call of %s is through thunk, which are not" |
3211 | " handled yet. Disabling all modifications.\n" , |
3212 | node->dump_name ()); |
3213 | return true; |
3214 | } |
3215 | if (issues.call_from_outside_comdat) |
3216 | { |
3217 | if (dump_file) |
3218 | fprintf (stream: dump_file, format: "Function would become private comdat called " |
3219 | "outside of its comdat group.\n" ); |
3220 | return true; |
3221 | } |
3222 | |
3223 | if (issues.bit_aligned_aggregate_argument) |
3224 | { |
3225 | /* Let's only remove parameters/return values from such functions. |
3226 | TODO: We could only prevent splitting the problematic parameters if |
3227 | anybody thinks it is worth it. */ |
3228 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3229 | fprintf (stream: dump_file, format: "A call of %s has bit-aligned aggregate argument," |
3230 | " disabling parameter splitting.\n" , node->dump_name ()); |
3231 | |
3232 | isra_func_summary *ifs = func_sums->get (node); |
3233 | gcc_checking_assert (ifs); |
3234 | unsigned param_count = vec_safe_length (v: ifs->m_parameters); |
3235 | for (unsigned i = 0; i < param_count; i++) |
3236 | (*ifs->m_parameters)[i].split_candidate = false; |
3237 | } |
3238 | if (!issues.there_is_one) |
3239 | { |
3240 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3241 | fprintf (stream: dump_file, format: "There is no call to %s that we can modify. " |
3242 | "Disabling all modifications.\n" , node->dump_name ()); |
3243 | return true; |
3244 | } |
3245 | return false; |
3246 | } |
3247 | |
3248 | /* Find the access with corresponding OFFSET and SIZE among accesses in |
3249 | PARAM_DESC and return it or NULL if such an access is not there. */ |
3250 | |
3251 | static param_access * |
3252 | find_param_access (isra_param_desc *param_desc, unsigned offset, unsigned size) |
3253 | { |
3254 | unsigned pclen = vec_safe_length (v: param_desc->accesses); |
3255 | |
3256 | /* The search is linear but the number of stored accesses is bound by |
3257 | PARAM_IPA_SRA_MAX_REPLACEMENTS, so most probably 8. */ |
3258 | |
3259 | for (unsigned i = 0; i < pclen; i++) |
3260 | if ((*param_desc->accesses)[i]->unit_offset == offset |
3261 | && (*param_desc->accesses)[i]->unit_size == size) |
3262 | return (*param_desc->accesses)[i]; |
3263 | |
3264 | return NULL; |
3265 | } |
3266 | |
3267 | /* Return iff the total size of definite replacement SIZE would violate the |
3268 | limit set for it in PARAM. */ |
3269 | |
3270 | static bool |
3271 | size_would_violate_limit_p (isra_param_desc *desc, unsigned size) |
3272 | { |
3273 | unsigned limit = desc->param_size_limit; |
3274 | if (size > limit |
3275 | || (!desc->by_ref && size == limit)) |
3276 | return true; |
3277 | return false; |
3278 | } |
3279 | |
3280 | /* Increase reached size of DESC by SIZE or disqualify it if it would violate |
3281 | the set limit. IDX is the parameter number which is dumped when |
3282 | disqualifying. */ |
3283 | |
3284 | static void |
3285 | bump_reached_size (isra_param_desc *desc, unsigned size, unsigned idx) |
3286 | { |
3287 | unsigned after = desc->size_reached + size; |
3288 | if (size_would_violate_limit_p (desc, size: after)) |
3289 | { |
3290 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3291 | fprintf (stream: dump_file, format: " ...size limit reached, disqualifying " |
3292 | "candidate parameter %u\n" , idx); |
3293 | desc->split_candidate = false; |
3294 | return; |
3295 | } |
3296 | desc->size_reached = after; |
3297 | } |
3298 | |
3299 | /* Take all actions required to deal with an edge CS that represents a call to |
3300 | an unknown or un-analyzed function, for both parameter removal and |
3301 | splitting. */ |
3302 | |
3303 | static void |
3304 | process_edge_to_unknown_caller (cgraph_edge *cs) |
3305 | { |
3306 | isra_func_summary *from_ifs = func_sums->get (node: cs->caller); |
3307 | gcc_checking_assert (from_ifs); |
3308 | isra_call_summary *csum = call_sums->get (edge: cs); |
3309 | |
3310 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3311 | fprintf (stream: dump_file, format: "Processing an edge to an unknown caller from %s:\n" , |
3312 | cs->caller->dump_name ()); |
3313 | |
3314 | unsigned args_count = csum->m_arg_flow.length (); |
3315 | for (unsigned i = 0; i < args_count; i++) |
3316 | { |
3317 | isra_param_flow *ipf = &csum->m_arg_flow[i]; |
3318 | |
3319 | if (ipf->pointer_pass_through) |
3320 | { |
3321 | isra_param_desc *param_desc |
3322 | = &(*from_ifs->m_parameters)[get_single_param_flow_source (param_flow: ipf)]; |
3323 | param_desc->locally_unused = false; |
3324 | param_desc->split_candidate = false; |
3325 | continue; |
3326 | } |
3327 | if (ipf->aggregate_pass_through) |
3328 | { |
3329 | unsigned idx = get_single_param_flow_source (param_flow: ipf); |
3330 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; |
3331 | |
3332 | param_desc->locally_unused = false; |
3333 | if (!param_desc->split_candidate) |
3334 | continue; |
3335 | gcc_assert (!param_desc->by_ref); |
3336 | param_access *pacc = find_param_access (param_desc, offset: ipf->unit_offset, |
3337 | size: ipf->unit_size); |
3338 | gcc_checking_assert (pacc); |
3339 | pacc->certain = true; |
3340 | if (overlapping_certain_accesses_p (desc: param_desc, NULL)) |
3341 | { |
3342 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3343 | fprintf (stream: dump_file, format: " ...leading to overlap, " |
3344 | " disqualifying candidate parameter %u\n" , |
3345 | idx); |
3346 | param_desc->split_candidate = false; |
3347 | } |
3348 | else |
3349 | bump_reached_size (desc: param_desc, size: pacc->unit_size, idx); |
3350 | ipf->aggregate_pass_through = false; |
3351 | continue; |
3352 | } |
3353 | |
3354 | for (int j = 0; j < ipf->length; j++) |
3355 | { |
3356 | int input_idx = ipf->inputs[j]; |
3357 | (*from_ifs->m_parameters)[input_idx].locally_unused = false; |
3358 | } |
3359 | } |
3360 | } |
3361 | |
3362 | /* Propagate parameter removal information through cross-SCC edge CS, |
3363 | i.e. decrease the use count in the caller parameter descriptor for each use |
3364 | in this call. */ |
3365 | |
3366 | static void |
3367 | param_removal_cross_scc_edge (cgraph_edge *cs) |
3368 | { |
3369 | enum availability availability; |
3370 | cgraph_node *callee = cs->callee->function_symbol (avail: &availability); |
3371 | isra_func_summary *to_ifs = func_sums->get (node: callee); |
3372 | if (!to_ifs || !to_ifs->m_candidate |
3373 | || (availability < AVAIL_AVAILABLE) |
3374 | || vec_safe_is_empty (v: to_ifs->m_parameters)) |
3375 | { |
3376 | process_edge_to_unknown_caller (cs); |
3377 | return; |
3378 | } |
3379 | isra_func_summary *from_ifs = func_sums->get (node: cs->caller); |
3380 | gcc_checking_assert (from_ifs); |
3381 | |
3382 | isra_call_summary *csum = call_sums->get (edge: cs); |
3383 | unsigned args_count = csum->m_arg_flow.length (); |
3384 | unsigned param_count = vec_safe_length (v: to_ifs->m_parameters); |
3385 | |
3386 | for (unsigned i = 0; i < args_count; i++) |
3387 | { |
3388 | bool unused_in_callee; |
3389 | if (i < param_count) |
3390 | unused_in_callee = (*to_ifs->m_parameters)[i].locally_unused; |
3391 | else |
3392 | unused_in_callee = false; |
3393 | |
3394 | if (!unused_in_callee) |
3395 | { |
3396 | isra_param_flow *ipf = &csum->m_arg_flow[i]; |
3397 | for (int j = 0; j < ipf->length; j++) |
3398 | { |
3399 | int input_idx = ipf->inputs[j]; |
3400 | (*from_ifs->m_parameters)[input_idx].locally_unused = false; |
3401 | } |
3402 | } |
3403 | } |
3404 | } |
3405 | |
3406 | /* Unless it is already there, push NODE which is also described by IFS to |
3407 | STACK. */ |
3408 | |
3409 | static void |
3410 | isra_push_node_to_stack (cgraph_node *node, isra_func_summary *ifs, |
3411 | vec<cgraph_node *> *stack) |
3412 | { |
3413 | if (!ifs->m_queued) |
3414 | { |
3415 | ifs->m_queued = true; |
3416 | stack->safe_push (obj: node); |
3417 | } |
3418 | } |
3419 | |
3420 | /* If parameter with index INPUT_IDX is marked as locally unused, mark it as |
3421 | used and push CALLER on STACK. */ |
3422 | |
3423 | static void |
3424 | isra_mark_caller_param_used (isra_func_summary *from_ifs, int input_idx, |
3425 | cgraph_node *caller, vec<cgraph_node *> *stack) |
3426 | { |
3427 | if ((*from_ifs->m_parameters)[input_idx].locally_unused) |
3428 | { |
3429 | (*from_ifs->m_parameters)[input_idx].locally_unused = false; |
3430 | isra_push_node_to_stack (node: caller, ifs: from_ifs, stack); |
3431 | } |
3432 | } |
3433 | |
3434 | /* Combine safe_size of DESC with SIZE and return true if it has changed. */ |
3435 | |
3436 | static bool |
3437 | update_safe_size (isra_param_desc *desc, unsigned size) |
3438 | { |
3439 | if (!desc->safe_size_set) |
3440 | { |
3441 | desc->safe_size_set = 1; |
3442 | desc->safe_size = size; |
3443 | return true; |
3444 | } |
3445 | if (desc->safe_size <= size) |
3446 | return false; |
3447 | desc->safe_size = size; |
3448 | return true; |
3449 | } |
3450 | |
3451 | /* Set all param hints in DESC to the pessimistic values. Return true if any |
3452 | hints that need to potentially trigger further propagation have changed. */ |
3453 | |
3454 | static bool |
3455 | flip_all_hints_pessimistic (isra_param_desc *desc) |
3456 | { |
3457 | desc->not_specially_constructed = true; |
3458 | return update_safe_size (desc, size: 0); |
3459 | } |
3460 | |
3461 | /* Because we have not analyzed or otherwise problematic caller, go over all |
3462 | parameter int flags of IFS describing a call graph node of a calllee and |
3463 | turn them pessimistic. Return true if any hints that need to potentially |
3464 | trigger further propagation have changed. */ |
3465 | |
3466 | static bool |
3467 | flip_all_param_hints_pessimistic (isra_func_summary *ifs) |
3468 | { |
3469 | if (!ifs || !ifs->m_candidate) |
3470 | return false; |
3471 | |
3472 | bool ret = false; |
3473 | unsigned param_count = vec_safe_length (v: ifs->m_parameters); |
3474 | |
3475 | for (unsigned i = 0; i < param_count; i++) |
3476 | ret |= flip_all_hints_pessimistic (desc: &(*ifs->m_parameters)[i]); |
3477 | |
3478 | return ret; |
3479 | } |
3480 | |
3481 | /* Propagate hints accross edge CS which ultimately leads to a node described |
3482 | by TO_IFS. Return true if any hints of the callee which should potentially |
3483 | trigger further propagation have changed. */ |
3484 | |
3485 | static bool |
3486 | propagate_param_hints_accross_call (cgraph_edge *cs, isra_func_summary *to_ifs) |
3487 | { |
3488 | if (!to_ifs || !to_ifs->m_candidate) |
3489 | return false; |
3490 | |
3491 | isra_call_summary *csum = call_sums->get (edge: cs); |
3492 | bool ret = false; |
3493 | unsigned args_count = csum->m_arg_flow.length (); |
3494 | unsigned param_count = vec_safe_length (v: to_ifs->m_parameters); |
3495 | |
3496 | for (unsigned i = 0; i < param_count; i++) |
3497 | { |
3498 | isra_param_desc *desc = &(*to_ifs->m_parameters)[i]; |
3499 | if (i >= args_count) |
3500 | { |
3501 | ret |= flip_all_hints_pessimistic (desc); |
3502 | continue; |
3503 | } |
3504 | |
3505 | if (desc->by_ref) |
3506 | { |
3507 | isra_param_flow *ipf = &csum->m_arg_flow[i]; |
3508 | |
3509 | if (!ipf->constructed_for_calls) |
3510 | desc->not_specially_constructed = true; |
3511 | |
3512 | if (ipf->pointer_pass_through) |
3513 | { |
3514 | isra_func_summary *from_ifs = func_sums->get (node: cs->caller); |
3515 | int srcidx = get_single_param_flow_source (param_flow: ipf); |
3516 | if (vec_safe_length (v: from_ifs->m_parameters) > (unsigned) srcidx) |
3517 | { |
3518 | isra_param_desc *src_d = &(*from_ifs->m_parameters)[srcidx]; |
3519 | if (src_d->safe_size_set) |
3520 | ret |= update_safe_size (desc, size: src_d->safe_size); |
3521 | } |
3522 | else |
3523 | ret |= update_safe_size (desc, size: 0); |
3524 | } |
3525 | else if (!ipf->aggregate_pass_through) |
3526 | ret |= update_safe_size (desc, size: ipf->unit_size); |
3527 | else |
3528 | /* LTOing type-mismatched programs can end up here. */ |
3529 | ret |= update_safe_size (desc, size: 0); |
3530 | } |
3531 | } |
3532 | return ret; |
3533 | } |
3534 | |
3535 | /* Propagate hints from NODE described by FROM_IFS to all its (dorect) callees, |
3536 | push those that may need re-visiting onto STACK. */ |
3537 | |
3538 | static void |
3539 | propagate_hints_to_all_callees (cgraph_node *node, isra_func_summary *from_ifs, |
3540 | vec<cgraph_node *> *stack) |
3541 | { |
3542 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) |
3543 | { |
3544 | enum availability availability; |
3545 | cgraph_node *callee = cs->callee->function_symbol (avail: &availability); |
3546 | isra_func_summary *to_ifs = func_sums->get (node: callee); |
3547 | if (!from_ifs) |
3548 | { |
3549 | if (flip_all_param_hints_pessimistic (ifs: to_ifs) |
3550 | && ipa_edge_within_scc (cs)) |
3551 | isra_push_node_to_stack (node: callee, ifs: to_ifs, stack); |
3552 | } |
3553 | else if (propagate_param_hints_accross_call (cs, to_ifs) |
3554 | && ipa_edge_within_scc (cs)) |
3555 | isra_push_node_to_stack (node: callee, ifs: to_ifs, stack); |
3556 | } |
3557 | } |
3558 | |
3559 | /* Propagate information that any parameter is not used only locally within a |
3560 | SCC across CS to the caller, which must be in the same SCC as the |
3561 | callee. Push any callers that need to be re-processed to STACK. */ |
3562 | |
3563 | static void |
3564 | propagate_used_across_scc_edge (cgraph_edge *cs, vec<cgraph_node *> *stack) |
3565 | { |
3566 | isra_func_summary *from_ifs = func_sums->get (node: cs->caller); |
3567 | if (!from_ifs || vec_safe_is_empty (v: from_ifs->m_parameters)) |
3568 | return; |
3569 | |
3570 | isra_call_summary *csum = call_sums->get (edge: cs); |
3571 | gcc_checking_assert (csum); |
3572 | unsigned args_count = csum->m_arg_flow.length (); |
3573 | enum availability availability; |
3574 | cgraph_node *callee = cs->callee->function_symbol (avail: &availability); |
3575 | isra_func_summary *to_ifs = func_sums->get (node: callee); |
3576 | |
3577 | unsigned param_count |
3578 | = (to_ifs && (availability >= AVAIL_AVAILABLE)) |
3579 | ? vec_safe_length (v: to_ifs->m_parameters) : 0; |
3580 | for (unsigned i = 0; i < args_count; i++) |
3581 | { |
3582 | if (i < param_count |
3583 | && (*to_ifs->m_parameters)[i].locally_unused) |
3584 | continue; |
3585 | |
3586 | /* The argument is needed in the callee it, we must mark the parameter as |
3587 | used also in the caller and its callers within this SCC. */ |
3588 | isra_param_flow *ipf = &csum->m_arg_flow[i]; |
3589 | for (int j = 0; j < ipf->length; j++) |
3590 | { |
3591 | int input_idx = ipf->inputs[j]; |
3592 | isra_mark_caller_param_used (from_ifs, input_idx, caller: cs->caller, stack); |
3593 | } |
3594 | } |
3595 | } |
3596 | |
3597 | /* Propagate information that any parameter is not used only locally within a |
3598 | SCC (i.e. is used also elsewhere) to all callers of NODE that are in the |
3599 | same SCC. Push any callers that need to be re-processed to STACK. */ |
3600 | |
3601 | static bool |
3602 | propagate_used_to_scc_callers (cgraph_node *node, void *data) |
3603 | { |
3604 | vec<cgraph_node *> *stack = (vec<cgraph_node *> *) data; |
3605 | cgraph_edge *cs; |
3606 | for (cs = node->callers; cs; cs = cs->next_caller) |
3607 | if (ipa_edge_within_scc (cs)) |
3608 | propagate_used_across_scc_edge (cs, stack); |
3609 | return false; |
3610 | } |
3611 | |
3612 | /* Return true iff all certain accesses in ARG_DESC are also present as |
3613 | certain accesses in PARAM_DESC. */ |
3614 | |
3615 | static bool |
3616 | all_callee_accesses_present_p (isra_param_desc *param_desc, |
3617 | isra_param_desc *arg_desc) |
3618 | { |
3619 | unsigned aclen = vec_safe_length (v: arg_desc->accesses); |
3620 | for (unsigned j = 0; j < aclen; j++) |
3621 | { |
3622 | param_access *argacc = (*arg_desc->accesses)[j]; |
3623 | if (!argacc->certain) |
3624 | continue; |
3625 | param_access *pacc = find_param_access (param_desc, offset: argacc->unit_offset, |
3626 | size: argacc->unit_size); |
3627 | if (!pacc |
3628 | || !pacc->certain |
3629 | || !types_compatible_p (type1: argacc->type, type2: pacc->type)) |
3630 | return false; |
3631 | } |
3632 | return true; |
3633 | } |
3634 | |
3635 | /* Type internal to function pull_accesses_from_callee. Unfortunately gcc 4.8 |
3636 | does not allow instantiating an auto_vec with a type defined within a |
3637 | function so it is a global type. */ |
3638 | enum acc_prop_kind {ACC_PROP_DONT, ACC_PROP_COPY, ACC_PROP_CERTAIN}; |
3639 | |
3640 | |
3641 | /* Attempt to propagate all definite accesses from ARG_DESC to PARAM_DESC, |
3642 | (which belongs to CALLER) if they would not violate some constraint there. |
3643 | If successful, return NULL, otherwise return the string reason for failure |
3644 | (which can be written to the dump file). DELTA_OFFSET is the known offset |
3645 | of the actual argument withing the formal parameter (so of ARG_DESCS within |
3646 | PARAM_DESCS), ARG_SIZE is the size of the actual argument or zero, if not |
3647 | known. In case of success, set *CHANGE_P to true if propagation actually |
3648 | changed anything. */ |
3649 | |
3650 | static const char * |
3651 | pull_accesses_from_callee (cgraph_node *caller, isra_param_desc *param_desc, |
3652 | isra_param_desc *arg_desc, |
3653 | unsigned delta_offset, unsigned arg_size, |
3654 | bool *change_p) |
3655 | { |
3656 | unsigned pclen = vec_safe_length (v: param_desc->accesses); |
3657 | unsigned aclen = vec_safe_length (v: arg_desc->accesses); |
3658 | unsigned prop_count = 0; |
3659 | unsigned prop_size = 0; |
3660 | bool change = false; |
3661 | |
3662 | auto_vec <enum acc_prop_kind, 8> prop_kinds (aclen); |
3663 | for (unsigned j = 0; j < aclen; j++) |
3664 | { |
3665 | param_access *argacc = (*arg_desc->accesses)[j]; |
3666 | prop_kinds.safe_push (obj: ACC_PROP_DONT); |
3667 | |
3668 | if (arg_size > 0 |
3669 | && argacc->unit_offset + argacc->unit_size > arg_size) |
3670 | return "callee access outsize size boundary" ; |
3671 | |
3672 | if (!argacc->certain) |
3673 | continue; |
3674 | |
3675 | unsigned offset = argacc->unit_offset + delta_offset; |
3676 | /* Given that accesses are initially stored according to increasing |
3677 | offset and decreasing size in case of equal offsets, the following |
3678 | searches could be written more efficiently if we kept the ordering |
3679 | when copying. But the number of accesses is capped at |
3680 | PARAM_IPA_SRA_MAX_REPLACEMENTS (so most likely 8) and the code gets |
3681 | messy quickly, so let's improve on that only if necessary. */ |
3682 | |
3683 | bool exact_match = false; |
3684 | for (unsigned i = 0; i < pclen; i++) |
3685 | { |
3686 | /* Check for overlaps. */ |
3687 | param_access *pacc = (*param_desc->accesses)[i]; |
3688 | if (pacc->unit_offset == offset |
3689 | && pacc->unit_size == argacc->unit_size) |
3690 | { |
3691 | if (argacc->alias_ptr_type != pacc->alias_ptr_type |
3692 | || !types_compatible_p (type1: argacc->type, type2: pacc->type) |
3693 | || argacc->reverse != pacc->reverse) |
3694 | return "propagated access types would not match existing ones" ; |
3695 | |
3696 | exact_match = true; |
3697 | if (!pacc->certain) |
3698 | { |
3699 | prop_kinds[j] = ACC_PROP_CERTAIN; |
3700 | prop_size += argacc->unit_size; |
3701 | change = true; |
3702 | } |
3703 | continue; |
3704 | } |
3705 | |
3706 | if (offset < pacc->unit_offset + pacc->unit_size |
3707 | && offset + argacc->unit_size > pacc->unit_offset) |
3708 | { |
3709 | /* None permissible with load accesses, possible to fit into |
3710 | argument ones. */ |
3711 | if (pacc->certain |
3712 | || offset < pacc->unit_offset |
3713 | || (offset + argacc->unit_size |
3714 | > pacc->unit_offset + pacc->unit_size)) |
3715 | return "a propagated access would conflict in caller" ; |
3716 | } |
3717 | } |
3718 | |
3719 | if (!exact_match) |
3720 | { |
3721 | prop_kinds[j] = ACC_PROP_COPY; |
3722 | prop_count++; |
3723 | prop_size += argacc->unit_size; |
3724 | change = true; |
3725 | } |
3726 | } |
3727 | |
3728 | if (!change) |
3729 | return NULL; |
3730 | |
3731 | if ((prop_count + pclen |
3732 | > (unsigned) opt_for_fn (caller->decl, param_ipa_sra_max_replacements)) |
3733 | || size_would_violate_limit_p (desc: param_desc, |
3734 | size: param_desc->size_reached + prop_size)) |
3735 | return "propagating accesses would violate the count or size limit" ; |
3736 | |
3737 | *change_p = true; |
3738 | for (unsigned j = 0; j < aclen; j++) |
3739 | { |
3740 | if (prop_kinds[j] == ACC_PROP_COPY) |
3741 | { |
3742 | param_access *argacc = (*arg_desc->accesses)[j]; |
3743 | |
3744 | param_access *copy = ggc_cleared_alloc<param_access> (); |
3745 | copy->unit_offset = argacc->unit_offset + delta_offset; |
3746 | copy->unit_size = argacc->unit_size; |
3747 | copy->type = argacc->type; |
3748 | copy->alias_ptr_type = argacc->alias_ptr_type; |
3749 | copy->certain = true; |
3750 | copy->reverse = argacc->reverse; |
3751 | vec_safe_push (v&: param_desc->accesses, obj: copy); |
3752 | } |
3753 | else if (prop_kinds[j] == ACC_PROP_CERTAIN) |
3754 | { |
3755 | param_access *argacc = (*arg_desc->accesses)[j]; |
3756 | param_access *csp |
3757 | = find_param_access (param_desc, offset: argacc->unit_offset + delta_offset, |
3758 | size: argacc->unit_size); |
3759 | csp->certain = true; |
3760 | } |
3761 | } |
3762 | |
3763 | param_desc->size_reached += prop_size; |
3764 | |
3765 | return NULL; |
3766 | } |
3767 | |
3768 | /* Propagate parameter splitting information through call graph edge CS. |
3769 | Return true if any changes that might need to be propagated within SCCs have |
3770 | been made. The function also clears the aggregate_pass_through and |
3771 | pointer_pass_through in call summaries which do not need to be processed |
3772 | again if this CS is revisited when iterating while changes are propagated |
3773 | within an SCC. */ |
3774 | |
3775 | static bool |
3776 | param_splitting_across_edge (cgraph_edge *cs) |
3777 | { |
3778 | bool res = false; |
3779 | bool cross_scc = !ipa_edge_within_scc (cs); |
3780 | enum availability availability; |
3781 | cgraph_node *callee = cs->callee->function_symbol (avail: &availability); |
3782 | isra_func_summary *from_ifs = func_sums->get (node: cs->caller); |
3783 | gcc_checking_assert (from_ifs && from_ifs->m_parameters); |
3784 | |
3785 | isra_call_summary *csum = call_sums->get (edge: cs); |
3786 | gcc_checking_assert (csum); |
3787 | unsigned args_count = csum->m_arg_flow.length (); |
3788 | isra_func_summary *to_ifs = func_sums->get (node: callee); |
3789 | unsigned param_count |
3790 | = ((to_ifs && to_ifs->m_candidate && (availability >= AVAIL_AVAILABLE)) |
3791 | ? vec_safe_length (v: to_ifs->m_parameters) |
3792 | : 0); |
3793 | |
3794 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3795 | fprintf (stream: dump_file, format: "Splitting across %s->%s:\n" , |
3796 | cs->caller->dump_name (), callee->dump_name ()); |
3797 | |
3798 | unsigned i; |
3799 | for (i = 0; (i < args_count) && (i < param_count); i++) |
3800 | { |
3801 | isra_param_desc *arg_desc = &(*to_ifs->m_parameters)[i]; |
3802 | isra_param_flow *ipf = &csum->m_arg_flow[i]; |
3803 | |
3804 | if (arg_desc->locally_unused) |
3805 | { |
3806 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3807 | fprintf (stream: dump_file, format: " ->%u: unused in callee\n" , i); |
3808 | ipf->pointer_pass_through = false; |
3809 | continue; |
3810 | } |
3811 | |
3812 | if (ipf->pointer_pass_through) |
3813 | { |
3814 | int idx = get_single_param_flow_source (param_flow: ipf); |
3815 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; |
3816 | if (!param_desc->split_candidate) |
3817 | continue; |
3818 | gcc_assert (param_desc->by_ref); |
3819 | |
3820 | if (!arg_desc->split_candidate || !arg_desc->by_ref) |
3821 | { |
3822 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3823 | fprintf (stream: dump_file, format: " %u->%u: not candidate or not by " |
3824 | "reference in callee\n" , idx, i); |
3825 | param_desc->split_candidate = false; |
3826 | ipf->pointer_pass_through = false; |
3827 | res = true; |
3828 | } |
3829 | else if (!ipf->safe_to_import_accesses) |
3830 | { |
3831 | if (!csum->m_before_any_store |
3832 | || !all_callee_accesses_present_p (param_desc, arg_desc)) |
3833 | { |
3834 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3835 | fprintf (stream: dump_file, format: " %u->%u: cannot import accesses.\n" , |
3836 | idx, i); |
3837 | param_desc->split_candidate = false; |
3838 | ipf->pointer_pass_through = false; |
3839 | res = true; |
3840 | |
3841 | } |
3842 | else |
3843 | { |
3844 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3845 | fprintf (stream: dump_file, format: " %u->%u: verified callee accesses " |
3846 | "present.\n" , idx, i); |
3847 | if (cross_scc) |
3848 | ipf->pointer_pass_through = false; |
3849 | } |
3850 | } |
3851 | else |
3852 | { |
3853 | const char *pull_failure |
3854 | = pull_accesses_from_callee (caller: cs->caller, param_desc, arg_desc, |
3855 | delta_offset: 0, arg_size: 0, change_p: &res); |
3856 | if (pull_failure) |
3857 | { |
3858 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3859 | fprintf (stream: dump_file, format: " %u->%u: by_ref access pull " |
3860 | "failed: %s.\n" , idx, i, pull_failure); |
3861 | param_desc->split_candidate = false; |
3862 | ipf->pointer_pass_through = false; |
3863 | res = true; |
3864 | } |
3865 | else |
3866 | { |
3867 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3868 | fprintf (stream: dump_file, format: " %u->%u: by_ref access pull " |
3869 | "succeeded.\n" , idx, i); |
3870 | if (cross_scc) |
3871 | ipf->pointer_pass_through = false; |
3872 | } |
3873 | } |
3874 | } |
3875 | else if (ipf->aggregate_pass_through) |
3876 | { |
3877 | int idx = get_single_param_flow_source (param_flow: ipf); |
3878 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; |
3879 | if (!param_desc->split_candidate) |
3880 | continue; |
3881 | gcc_assert (!param_desc->by_ref); |
3882 | param_access *pacc = find_param_access (param_desc, offset: ipf->unit_offset, |
3883 | size: ipf->unit_size); |
3884 | gcc_checking_assert (pacc); |
3885 | |
3886 | if (pacc->certain) |
3887 | { |
3888 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3889 | fprintf (stream: dump_file, format: " %u->%u: already certain\n" , idx, i); |
3890 | ipf->aggregate_pass_through = false; |
3891 | } |
3892 | else if (!arg_desc->split_candidate || arg_desc->by_ref) |
3893 | { |
3894 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3895 | fprintf (stream: dump_file, format: " %u->%u: not candidate or by " |
3896 | "reference in callee\n" , idx, i); |
3897 | |
3898 | pacc->certain = true; |
3899 | if (overlapping_certain_accesses_p (desc: param_desc, NULL)) |
3900 | { |
3901 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3902 | fprintf (stream: dump_file, format: " ...leading to overlap, " |
3903 | " disqualifying candidate parameter %u\n" , |
3904 | idx); |
3905 | param_desc->split_candidate = false; |
3906 | } |
3907 | else |
3908 | bump_reached_size (desc: param_desc, size: pacc->unit_size, idx); |
3909 | |
3910 | ipf->aggregate_pass_through = false; |
3911 | res = true; |
3912 | } |
3913 | else |
3914 | { |
3915 | const char *pull_failure |
3916 | = pull_accesses_from_callee (caller: cs->caller, param_desc, arg_desc, |
3917 | delta_offset: ipf->unit_offset, |
3918 | arg_size: ipf->unit_size, change_p: &res); |
3919 | if (pull_failure) |
3920 | { |
3921 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3922 | fprintf (stream: dump_file, format: " %u->%u: arg access pull " |
3923 | "failed: %s.\n" , idx, i, pull_failure); |
3924 | |
3925 | ipf->aggregate_pass_through = false; |
3926 | pacc->certain = true; |
3927 | |
3928 | if (overlapping_certain_accesses_p (desc: param_desc, NULL)) |
3929 | { |
3930 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3931 | fprintf (stream: dump_file, format: " ...leading to overlap, " |
3932 | " disqualifying candidate parameter %u\n" , |
3933 | idx); |
3934 | param_desc->split_candidate = false; |
3935 | } |
3936 | else |
3937 | bump_reached_size (desc: param_desc, size: pacc->unit_size, idx); |
3938 | |
3939 | res = true; |
3940 | } |
3941 | else |
3942 | { |
3943 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3944 | fprintf (stream: dump_file, format: " %u->%u: arg access pull " |
3945 | "succeeded.\n" , idx, i); |
3946 | if (cross_scc) |
3947 | ipf->aggregate_pass_through = false; |
3948 | } |
3949 | } |
3950 | } |
3951 | } |
3952 | |
3953 | /* Handle argument-parameter count mismatches. */ |
3954 | for (; (i < args_count); i++) |
3955 | { |
3956 | isra_param_flow *ipf = &csum->m_arg_flow[i]; |
3957 | |
3958 | if (ipf->pointer_pass_through || ipf->aggregate_pass_through) |
3959 | { |
3960 | int idx = get_single_param_flow_source (param_flow: ipf); |
3961 | ipf->pointer_pass_through = false; |
3962 | ipf->aggregate_pass_through = false; |
3963 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; |
3964 | if (!param_desc->split_candidate) |
3965 | continue; |
3966 | |
3967 | if (dump_file && (dump_flags & TDF_DETAILS)) |
3968 | fprintf (stream: dump_file, format: " %u->%u: no corresponding formal parameter\n" , |
3969 | idx, i); |
3970 | param_desc->split_candidate = false; |
3971 | res = true; |
3972 | } |
3973 | } |
3974 | return res; |
3975 | } |
3976 | |
3977 | /* Worker for call_for_symbol_and_aliases, look at all callers and if all their |
3978 | callers ignore the return value, or come from the same SCC and use the |
3979 | return value only to compute their return value, return false, otherwise |
3980 | return true. */ |
3981 | |
3982 | static bool |
3983 | retval_used_p (cgraph_node *node, void *) |
3984 | { |
3985 | for (cgraph_edge *cs = node->callers; cs; cs = cs->next_caller) |
3986 | { |
3987 | isra_call_summary *csum = call_sums->get (edge: cs); |
3988 | gcc_checking_assert (csum); |
3989 | if (csum->m_return_ignored) |
3990 | continue; |
3991 | if (!csum->m_return_returned) |
3992 | return true; |
3993 | |
3994 | isra_func_summary *from_ifs = func_sums->get (node: cs->caller); |
3995 | if (!from_ifs || !from_ifs->m_candidate) |
3996 | return true; |
3997 | |
3998 | if (!ipa_edge_within_scc (cs) |
3999 | && !from_ifs->m_return_ignored) |
4000 | return true; |
4001 | } |
4002 | |
4003 | return false; |
4004 | } |
4005 | |
4006 | /* Push into NEW_PARAMS all required parameter adjustment entries to copy or |
4007 | modify parameter which originally had index BASE_INDEX, in the adjustment |
4008 | vector of parent clone (if any) had PREV_CLONE_INDEX and was described by |
4009 | PREV_ADJUSTMENT. If IPA-CP has created a transformation summary for the |
4010 | original node, it needs to be passed in IPCP_TS, otherwise it should be |
4011 | NULL. If the parent clone is the original function, PREV_ADJUSTMENT is NULL |
4012 | and PREV_CLONE_INDEX is equal to BASE_INDEX. */ |
4013 | |
4014 | static void |
4015 | push_param_adjustments_for_index (isra_func_summary *ifs, unsigned base_index, |
4016 | unsigned prev_clone_index, |
4017 | ipa_adjusted_param *prev_adjustment, |
4018 | ipcp_transformation *ipcp_ts, |
4019 | vec<ipa_adjusted_param, va_gc> **new_params) |
4020 | { |
4021 | isra_param_desc *desc = &(*ifs->m_parameters)[base_index]; |
4022 | if (desc->locally_unused) |
4023 | { |
4024 | if (dump_file) |
4025 | fprintf (stream: dump_file, format: " Will remove parameter %u\n" , base_index); |
4026 | return; |
4027 | } |
4028 | |
4029 | if (!desc->split_candidate) |
4030 | { |
4031 | ipa_adjusted_param adj; |
4032 | if (prev_adjustment) |
4033 | { |
4034 | adj = *prev_adjustment; |
4035 | adj.prev_clone_adjustment = true; |
4036 | adj.prev_clone_index = prev_clone_index; |
4037 | } |
4038 | else |
4039 | { |
4040 | memset (s: &adj, c: 0, n: sizeof (adj)); |
4041 | adj.op = IPA_PARAM_OP_COPY; |
4042 | adj.base_index = base_index; |
4043 | adj.prev_clone_index = prev_clone_index; |
4044 | } |
4045 | vec_safe_push (v&: (*new_params), obj: adj); |
4046 | return; |
4047 | } |
4048 | |
4049 | if (dump_file) |
4050 | fprintf (stream: dump_file, format: " Will split parameter %u\n" , base_index); |
4051 | |
4052 | gcc_assert (!prev_adjustment || prev_adjustment->op == IPA_PARAM_OP_COPY); |
4053 | unsigned aclen = vec_safe_length (v: desc->accesses); |
4054 | for (unsigned j = 0; j < aclen; j++) |
4055 | { |
4056 | param_access *pa = (*desc->accesses)[j]; |
4057 | if (!pa->certain) |
4058 | continue; |
4059 | |
4060 | if (ipcp_ts) |
4061 | { |
4062 | ipa_argagg_value_list avl (ipcp_ts); |
4063 | tree value = avl.get_value (index: base_index, unit_offset: pa->unit_offset); |
4064 | if (value && !AGGREGATE_TYPE_P (pa->type)) |
4065 | { |
4066 | if (dump_file) |
4067 | fprintf (stream: dump_file, format: " - omitting component at byte " |
4068 | "offset %u which is known to have a constant value\n " , |
4069 | pa->unit_offset); |
4070 | continue; |
4071 | } |
4072 | } |
4073 | |
4074 | if (dump_file) |
4075 | fprintf (stream: dump_file, format: " - component at byte offset %u, " |
4076 | "size %u\n" , pa->unit_offset, pa->unit_size); |
4077 | |
4078 | ipa_adjusted_param adj; |
4079 | memset (s: &adj, c: 0, n: sizeof (adj)); |
4080 | adj.op = IPA_PARAM_OP_SPLIT; |
4081 | adj.base_index = base_index; |
4082 | adj.prev_clone_index = prev_clone_index; |
4083 | adj.param_prefix_index = IPA_PARAM_PREFIX_ISRA; |
4084 | adj.reverse = pa->reverse; |
4085 | adj.type = pa->type; |
4086 | adj.alias_ptr_type = pa->alias_ptr_type; |
4087 | adj.unit_offset = pa->unit_offset; |
4088 | vec_safe_push (v&: (*new_params), obj: adj); |
4089 | } |
4090 | } |
4091 | |
4092 | /* Worker for all call_for_symbol_thunks_and_aliases. Set calls_comdat_local |
4093 | flag of all callers of NODE. */ |
4094 | |
4095 | static bool |
4096 | mark_callers_calls_comdat_local (struct cgraph_node *node, void *) |
4097 | { |
4098 | for (cgraph_edge *cs = node->callers; cs; cs = cs->next_caller) |
4099 | cs->caller->calls_comdat_local = true; |
4100 | return false; |
4101 | } |
4102 | |
4103 | /* Remove any IPA-CP results stored in TS that are associated with removed |
4104 | parameters as marked in IFS. */ |
4105 | |
4106 | static void |
4107 | zap_useless_ipcp_results (const isra_func_summary *ifs, ipcp_transformation *ts) |
4108 | { |
4109 | ts->remove_argaggs_if (predicate: [ifs](const ipa_argagg_value &v) |
4110 | { |
4111 | return (*ifs->m_parameters)[v.index].locally_unused; |
4112 | }); |
4113 | |
4114 | bool useful_vr = false; |
4115 | unsigned count = vec_safe_length (v: ts->m_vr); |
4116 | for (unsigned i = 0; i < count; i++) |
4117 | if ((*ts->m_vr)[i].known_p ()) |
4118 | { |
4119 | const isra_param_desc *desc = &(*ifs->m_parameters)[i]; |
4120 | if (desc->locally_unused) |
4121 | (*ts->m_vr)[i].set_unknown (); |
4122 | else |
4123 | useful_vr = true; |
4124 | } |
4125 | if (!useful_vr) |
4126 | ts->m_vr = NULL; |
4127 | } |
4128 | |
4129 | /* Do final processing of results of IPA propagation regarding NODE, clone it |
4130 | if appropriate. */ |
4131 | |
4132 | static void |
4133 | process_isra_node_results (cgraph_node *node, |
4134 | hash_map<const char *, unsigned> *clone_num_suffixes) |
4135 | { |
4136 | isra_func_summary *ifs = func_sums->get (node); |
4137 | if (!ifs || !ifs->m_candidate) |
4138 | return; |
4139 | |
4140 | auto_vec<bool, 16> surviving_params; |
4141 | bool check_surviving = false; |
4142 | clone_info *cinfo = clone_info::get (node); |
4143 | if (cinfo && cinfo->param_adjustments) |
4144 | { |
4145 | check_surviving = true; |
4146 | cinfo->param_adjustments->get_surviving_params (surviving_params: &surviving_params); |
4147 | } |
4148 | |
4149 | unsigned param_count = vec_safe_length (v: ifs->m_parameters); |
4150 | bool will_change_function = false; |
4151 | if (ifs->m_returns_value && ifs->m_return_ignored) |
4152 | will_change_function = true; |
4153 | else |
4154 | for (unsigned i = 0; i < param_count; i++) |
4155 | { |
4156 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; |
4157 | if ((desc->locally_unused || desc->split_candidate) |
4158 | /* Make sure we do not clone just to attempt to remove an already |
4159 | removed unused argument. */ |
4160 | && (!check_surviving |
4161 | || (i < surviving_params.length () |
4162 | && surviving_params[i]))) |
4163 | { |
4164 | will_change_function = true; |
4165 | break; |
4166 | } |
4167 | } |
4168 | if (!will_change_function) |
4169 | return; |
4170 | |
4171 | if (dump_file) |
4172 | { |
4173 | fprintf (stream: dump_file, format: "\nEvaluating analysis results for %s\n" , |
4174 | node->dump_name ()); |
4175 | if (ifs->m_returns_value && ifs->m_return_ignored) |
4176 | fprintf (stream: dump_file, format: " Will remove return value.\n" ); |
4177 | } |
4178 | |
4179 | ipcp_transformation *ipcp_ts = ipcp_get_transformation_summary (node); |
4180 | if (ipcp_ts) |
4181 | zap_useless_ipcp_results (ifs, ts: ipcp_ts); |
4182 | vec<ipa_adjusted_param, va_gc> *new_params = NULL; |
4183 | if (ipa_param_adjustments *old_adjustments |
4184 | = cinfo ? cinfo->param_adjustments : NULL) |
4185 | { |
4186 | unsigned old_adj_len = vec_safe_length (v: old_adjustments->m_adj_params); |
4187 | for (unsigned i = 0; i < old_adj_len; i++) |
4188 | { |
4189 | ipa_adjusted_param *old_adj = &(*old_adjustments->m_adj_params)[i]; |
4190 | push_param_adjustments_for_index (ifs, base_index: old_adj->base_index, prev_clone_index: i, |
4191 | prev_adjustment: old_adj, ipcp_ts, new_params: &new_params); |
4192 | } |
4193 | } |
4194 | else |
4195 | for (unsigned i = 0; i < param_count; i++) |
4196 | push_param_adjustments_for_index (ifs, base_index: i, prev_clone_index: i, NULL, ipcp_ts, new_params: &new_params); |
4197 | |
4198 | ipa_param_adjustments *new_adjustments |
4199 | = (new (ggc_alloc <ipa_param_adjustments> ()) |
4200 | ipa_param_adjustments (new_params, param_count, |
4201 | ifs->m_returns_value && ifs->m_return_ignored)); |
4202 | |
4203 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4204 | { |
4205 | fprintf (stream: dump_file, format: "\n Created adjustments:\n" ); |
4206 | new_adjustments->dump (f: dump_file); |
4207 | } |
4208 | |
4209 | unsigned &suffix_counter = clone_num_suffixes->get_or_insert ( |
4210 | IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME ( |
4211 | node->decl))); |
4212 | auto_vec<cgraph_edge *> callers = node->collect_callers (); |
4213 | cgraph_node *new_node |
4214 | = node->create_virtual_clone (redirect_callers: callers, NULL, param_adjustments: new_adjustments, suffix: "isra" , |
4215 | num_suffix: suffix_counter); |
4216 | suffix_counter++; |
4217 | if (node->calls_comdat_local && node->same_comdat_group) |
4218 | { |
4219 | new_node->add_to_same_comdat_group (old_node: node); |
4220 | new_node->call_for_symbol_and_aliases (callback: mark_callers_calls_comdat_local, |
4221 | NULL, include_overwritable: true); |
4222 | } |
4223 | new_node->calls_comdat_local = node->calls_comdat_local; |
4224 | |
4225 | if (dump_file) |
4226 | fprintf (stream: dump_file, format: " Created new node %s\n" , new_node->dump_name ()); |
4227 | callers.release (); |
4228 | } |
4229 | |
4230 | /* If INDICES is not empty, dump a combination of NODE's dump_name and MSG |
4231 | followed by the list of numbers in INDICES. */ |
4232 | |
4233 | static void |
4234 | dump_list_of_param_indices (const cgraph_node *node, const char* msg, |
4235 | const vec<unsigned> &indices) |
4236 | { |
4237 | if (indices.is_empty ()) |
4238 | return; |
4239 | fprintf (stream: dump_file, format: "The following parameters of %s %s:" , node->dump_name (), |
4240 | msg); |
4241 | for (unsigned i : indices) |
4242 | fprintf (stream: dump_file, format: " %u" , i); |
4243 | fprintf (stream: dump_file, format: "\n" ); |
4244 | } |
4245 | |
4246 | /* Check which parameters of NODE described by IFS have survived until IPA-SRA |
4247 | and disable transformations for those which have not or which should not |
4248 | transformed because the associated debug counter reached its limit. Return |
4249 | true if none survived or if there were no candidates to begin with. |
4250 | Additionally, also adjust parameter descriptions based on debug counters and |
4251 | hints propagated earlier. */ |
4252 | |
4253 | static bool |
4254 | adjust_parameter_descriptions (cgraph_node *node, isra_func_summary *ifs) |
4255 | { |
4256 | bool ret = true; |
4257 | unsigned len = vec_safe_length (v: ifs->m_parameters); |
4258 | if (!len) |
4259 | return true; |
4260 | |
4261 | auto_vec<bool, 16> surviving_params; |
4262 | bool check_surviving = false; |
4263 | clone_info *cinfo = clone_info::get (node); |
4264 | if (cinfo && cinfo->param_adjustments) |
4265 | { |
4266 | check_surviving = true; |
4267 | cinfo->param_adjustments->get_surviving_params (surviving_params: &surviving_params); |
4268 | } |
4269 | ipcp_transformation *ipcp_ts = ipcp_get_transformation_summary (node); |
4270 | auto_vec <unsigned> dump_dead_indices; |
4271 | auto_vec <unsigned> dump_bad_cond_indices; |
4272 | for (unsigned i = 0; i < len; i++) |
4273 | { |
4274 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; |
4275 | if (!dbg_cnt (index: ipa_sra_params)) |
4276 | { |
4277 | desc->locally_unused = false; |
4278 | desc->split_candidate = false; |
4279 | continue; |
4280 | } |
4281 | |
4282 | if (desc->split_only_when_retval_removed |
4283 | && !ifs->m_return_ignored) |
4284 | { |
4285 | if (dump_file && (dump_flags & TDF_DETAILS) |
4286 | && (desc->locally_unused || desc->split_candidate)) |
4287 | dump_bad_cond_indices.safe_push (obj: i); |
4288 | |
4289 | gcc_checking_assert (!desc->locally_unused |
4290 | || desc->remove_only_when_retval_removed); |
4291 | desc->locally_unused = false; |
4292 | desc->split_candidate = false; |
4293 | continue; |
4294 | } |
4295 | if (desc->remove_only_when_retval_removed |
4296 | && !ifs->m_return_ignored) |
4297 | { |
4298 | if (dump_file && (dump_flags & TDF_DETAILS) |
4299 | && (desc->locally_unused || desc->split_candidate)) |
4300 | dump_bad_cond_indices.safe_push (obj: i); |
4301 | |
4302 | desc->locally_unused = false; |
4303 | } |
4304 | if (check_surviving |
4305 | && (i >= surviving_params.length () |
4306 | || !surviving_params[i])) |
4307 | { |
4308 | /* Even if the parameter was removed by a previous IPA pass, we do |
4309 | not clear locally_unused because if it really is unused, this |
4310 | information might be useful in callers. */ |
4311 | desc->split_candidate = false; |
4312 | |
4313 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4314 | dump_dead_indices.safe_push (obj: i); |
4315 | } |
4316 | |
4317 | if (desc->split_candidate && desc->conditionally_dereferenceable) |
4318 | { |
4319 | gcc_assert (desc->safe_size_set); |
4320 | for (param_access *pa : *desc->accesses) |
4321 | if ((pa->unit_offset + pa->unit_size) > desc->safe_size) |
4322 | { |
4323 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4324 | dump_bad_cond_indices.safe_push (obj: i); |
4325 | desc->split_candidate = false; |
4326 | break; |
4327 | } |
4328 | } |
4329 | |
4330 | if (desc->split_candidate) |
4331 | { |
4332 | if (desc->by_ref && !desc->not_specially_constructed) |
4333 | { |
4334 | int |
4335 | = opt_for_fn (node->decl, |
4336 | param_ipa_sra_ptrwrap_growth_factor); |
4337 | desc->param_size_limit = extra_factor * desc->param_size_limit; |
4338 | } |
4339 | if (size_would_violate_limit_p (desc, size: desc->size_reached)) |
4340 | desc->split_candidate = false; |
4341 | } |
4342 | |
4343 | /* Avoid ICEs on size-mismatched VIEW_CONVERT_EXPRs when callers and |
4344 | callees don't agree on types in aggregates and we try to do both |
4345 | IPA-CP and IPA-SRA. */ |
4346 | if (ipcp_ts && desc->split_candidate) |
4347 | { |
4348 | ipa_argagg_value_list avl (ipcp_ts); |
4349 | for (const param_access *pa : desc->accesses) |
4350 | { |
4351 | if (!pa->certain) |
4352 | continue; |
4353 | tree value = avl.get_value (index: i, unit_offset: pa->unit_offset); |
4354 | if (value |
4355 | && ((tree_to_uhwi (TYPE_SIZE (TREE_TYPE (value))) |
4356 | / BITS_PER_UNIT) |
4357 | != pa->unit_size)) |
4358 | { |
4359 | desc->split_candidate = false; |
4360 | if (dump_file && (dump_flags & TDF_DETAILS)) |
4361 | dump_dead_indices.safe_push (obj: i); |
4362 | break; |
4363 | } |
4364 | } |
4365 | } |
4366 | |
4367 | if (desc->locally_unused || desc->split_candidate) |
4368 | ret = false; |
4369 | } |
4370 | |
4371 | dump_list_of_param_indices (node, msg: "are dead on arrival or have a type " |
4372 | "mismatch with IPA-CP" , indices: dump_dead_indices); |
4373 | dump_list_of_param_indices (node, msg: "fail additional requirements " , |
4374 | indices: dump_bad_cond_indices); |
4375 | |
4376 | return ret; |
4377 | } |
4378 | |
4379 | |
4380 | /* Run the interprocedural part of IPA-SRA. */ |
4381 | |
4382 | static unsigned int |
4383 | ipa_sra_analysis (void) |
4384 | { |
4385 | if (dump_file) |
4386 | { |
4387 | fprintf (stream: dump_file, format: "\n========== IPA-SRA IPA stage ==========\n" ); |
4388 | ipa_sra_dump_all_summaries (f: dump_file, hints: false); |
4389 | } |
4390 | |
4391 | gcc_checking_assert (func_sums); |
4392 | gcc_checking_assert (call_sums); |
4393 | cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count); |
4394 | auto_vec <cgraph_node *, 16> stack; |
4395 | int node_scc_count = ipa_reduced_postorder (order, true, NULL); |
4396 | |
4397 | /* One sweep from callers to callees for return value removal. */ |
4398 | for (int i = node_scc_count - 1; i >= 0 ; i--) |
4399 | { |
4400 | cgraph_node *scc_rep = order[i]; |
4401 | vec<cgraph_node *> cycle_nodes = ipa_get_nodes_in_cycle (scc_rep); |
4402 | |
4403 | /* Preliminary IPA function level checks. */ |
4404 | for (cgraph_node *v : cycle_nodes) |
4405 | { |
4406 | isra_func_summary *ifs = func_sums->get (node: v); |
4407 | if (!ifs || !ifs->m_candidate) |
4408 | continue; |
4409 | if (!ipa_sra_ipa_function_checks (node: v) |
4410 | || check_all_callers_for_issues (node: v)) |
4411 | ifs->zap (); |
4412 | } |
4413 | |
4414 | for (cgraph_node *v : cycle_nodes) |
4415 | { |
4416 | isra_func_summary *ifs = func_sums->get (node: v); |
4417 | if (!ifs || !ifs->m_candidate) |
4418 | continue; |
4419 | bool return_needed |
4420 | = (ifs->m_returns_value |
4421 | && (!dbg_cnt (index: ipa_sra_retvalues) |
4422 | || v->call_for_symbol_and_aliases (callback: retval_used_p, |
4423 | NULL, include_overwritable: true))); |
4424 | ifs->m_return_ignored = !return_needed; |
4425 | if (return_needed) |
4426 | isra_push_node_to_stack (node: v, ifs, stack: &stack); |
4427 | } |
4428 | |
4429 | while (!stack.is_empty ()) |
4430 | { |
4431 | cgraph_node *node = stack.pop (); |
4432 | isra_func_summary *ifs = func_sums->get (node); |
4433 | gcc_checking_assert (ifs && ifs->m_queued); |
4434 | ifs->m_queued = false; |
4435 | |
4436 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) |
4437 | if (ipa_edge_within_scc (cs) |
4438 | && call_sums->get (edge: cs)->m_return_returned) |
4439 | { |
4440 | enum availability av; |
4441 | cgraph_node *callee = cs->callee->function_symbol (avail: &av); |
4442 | isra_func_summary *to_ifs = func_sums->get (node: callee); |
4443 | if (to_ifs && to_ifs->m_return_ignored) |
4444 | { |
4445 | to_ifs->m_return_ignored = false; |
4446 | isra_push_node_to_stack (node: callee, ifs: to_ifs, stack: &stack); |
4447 | } |
4448 | } |
4449 | } |
4450 | |
4451 | /* Parameter hint propagation. */ |
4452 | for (cgraph_node *v : cycle_nodes) |
4453 | { |
4454 | isra_func_summary *ifs = func_sums->get (node: v); |
4455 | propagate_hints_to_all_callees (node: v, from_ifs: ifs, stack: &stack); |
4456 | } |
4457 | |
4458 | while (!stack.is_empty ()) |
4459 | { |
4460 | cgraph_node *node = stack.pop (); |
4461 | isra_func_summary *ifs = func_sums->get (node); |
4462 | gcc_checking_assert (ifs && ifs->m_queued); |
4463 | ifs->m_queued = false; |
4464 | propagate_hints_to_all_callees (node, from_ifs: ifs, stack: &stack); |
4465 | } |
4466 | |
4467 | cycle_nodes.release (); |
4468 | } |
4469 | |
4470 | /* One sweep from callees to callers for parameter removal and splitting. */ |
4471 | for (int i = 0; i < node_scc_count; i++) |
4472 | { |
4473 | cgraph_node *scc_rep = order[i]; |
4474 | vec<cgraph_node *> cycle_nodes = ipa_get_nodes_in_cycle (scc_rep); |
4475 | |
4476 | /* First step of parameter removal. */ |
4477 | for (cgraph_node *v : cycle_nodes) |
4478 | { |
4479 | isra_func_summary *ifs = func_sums->get (node: v); |
4480 | if (!ifs || !ifs->m_candidate) |
4481 | continue; |
4482 | if (adjust_parameter_descriptions (node: v, ifs)) |
4483 | continue; |
4484 | for (cgraph_edge *cs = v->indirect_calls; cs; cs = cs->next_callee) |
4485 | process_edge_to_unknown_caller (cs); |
4486 | for (cgraph_edge *cs = v->callees; cs; cs = cs->next_callee) |
4487 | if (!ipa_edge_within_scc (cs)) |
4488 | param_removal_cross_scc_edge (cs); |
4489 | } |
4490 | |
4491 | /* Look at edges within the current SCC and propagate used-ness across |
4492 | them, pushing onto the stack all notes which might need to be |
4493 | revisited. */ |
4494 | for (cgraph_node *v : cycle_nodes) |
4495 | v->call_for_symbol_thunks_and_aliases (callback: propagate_used_to_scc_callers, |
4496 | data: &stack, include_overwritable: true); |
4497 | |
4498 | /* Keep revisiting and pushing until nothing changes. */ |
4499 | while (!stack.is_empty ()) |
4500 | { |
4501 | cgraph_node *v = stack.pop (); |
4502 | isra_func_summary *ifs = func_sums->get (node: v); |
4503 | gcc_checking_assert (ifs && ifs->m_queued); |
4504 | ifs->m_queued = false; |
4505 | |
4506 | v->call_for_symbol_thunks_and_aliases (callback: propagate_used_to_scc_callers, |
4507 | data: &stack, include_overwritable: true); |
4508 | } |
4509 | |
4510 | /* Parameter splitting. */ |
4511 | bool repeat_scc_access_propagation; |
4512 | do |
4513 | { |
4514 | repeat_scc_access_propagation = false; |
4515 | for (cgraph_node *v : cycle_nodes) |
4516 | { |
4517 | isra_func_summary *ifs = func_sums->get (node: v); |
4518 | if (!ifs |
4519 | || !ifs->m_candidate |
4520 | || vec_safe_is_empty (v: ifs->m_parameters)) |
4521 | continue; |
4522 | for (cgraph_edge *cs = v->callees; cs; cs = cs->next_callee) |
4523 | if (param_splitting_across_edge (cs)) |
4524 | repeat_scc_access_propagation = true; |
4525 | } |
4526 | } |
4527 | while (repeat_scc_access_propagation); |
4528 | |
4529 | if (flag_checking) |
4530 | for (cgraph_node *v : cycle_nodes) |
4531 | verify_splitting_accesses (node: v, certain_must_exist: true); |
4532 | |
4533 | cycle_nodes.release (); |
4534 | } |
4535 | |
4536 | ipa_free_postorder_info (); |
4537 | free (ptr: order); |
4538 | |
4539 | if (dump_file) |
4540 | { |
4541 | if (dump_flags & TDF_DETAILS) |
4542 | { |
4543 | fprintf (stream: dump_file, format: "\n========== IPA-SRA propagation final state " |
4544 | " ==========\n" ); |
4545 | ipa_sra_dump_all_summaries (f: dump_file, hints: true); |
4546 | } |
4547 | fprintf (stream: dump_file, format: "\n========== IPA-SRA decisions ==========\n" ); |
4548 | } |
4549 | |
4550 | hash_map<const char *, unsigned> *clone_num_suffixes |
4551 | = new hash_map<const char *, unsigned>; |
4552 | |
4553 | cgraph_node *node; |
4554 | FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) |
4555 | process_isra_node_results (node, clone_num_suffixes); |
4556 | |
4557 | delete clone_num_suffixes; |
4558 | ggc_delete (ptr: func_sums); |
4559 | func_sums = NULL; |
4560 | delete call_sums; |
4561 | call_sums = NULL; |
4562 | |
4563 | if (dump_file) |
4564 | fprintf (stream: dump_file, format: "\n========== IPA SRA IPA analysis done " |
4565 | "==========\n\n" ); |
4566 | return 0; |
4567 | } |
4568 | |
4569 | |
4570 | const pass_data pass_data_ipa_sra = |
4571 | { |
4572 | .type: IPA_PASS, /* type */ |
4573 | .name: "sra" , /* name */ |
4574 | .optinfo_flags: OPTGROUP_NONE, /* optinfo_flags */ |
4575 | .tv_id: TV_IPA_SRA, /* tv_id */ |
4576 | .properties_required: 0, /* properties_required */ |
4577 | .properties_provided: 0, /* properties_provided */ |
4578 | .properties_destroyed: 0, /* properties_destroyed */ |
4579 | .todo_flags_start: 0, /* todo_flags_start */ |
4580 | .todo_flags_finish: ( TODO_dump_symtab | TODO_remove_functions ), /* todo_flags_finish */ |
4581 | }; |
4582 | |
4583 | class pass_ipa_sra : public ipa_opt_pass_d |
4584 | { |
4585 | public: |
4586 | pass_ipa_sra (gcc::context *ctxt) |
4587 | : ipa_opt_pass_d (pass_data_ipa_sra, ctxt, |
4588 | ipa_sra_generate_summary, /* generate_summary */ |
4589 | ipa_sra_write_summary, /* write_summary */ |
4590 | ipa_sra_read_summary, /* read_summary */ |
4591 | NULL , /* write_optimization_summary */ |
4592 | NULL, /* read_optimization_summary */ |
4593 | NULL, /* stmt_fixup */ |
4594 | 0, /* function_transform_todo_flags_start */ |
4595 | NULL, /* function_transform */ |
4596 | NULL) /* variable_transform */ |
4597 | {} |
4598 | |
4599 | /* opt_pass methods: */ |
4600 | bool gate (function *) final override |
4601 | { |
4602 | /* TODO: We should remove the optimize check after we ensure we never run |
4603 | IPA passes when not optimizing. */ |
4604 | return (flag_ipa_sra && optimize); |
4605 | } |
4606 | |
4607 | unsigned int execute (function *) final override |
4608 | { |
4609 | return ipa_sra_analysis (); |
4610 | } |
4611 | |
4612 | }; // class pass_ipa_sra |
4613 | |
4614 | } // anon namespace |
4615 | |
4616 | /* Intraprocedural part of IPA-SRA analysis. Scan function body of NODE and |
4617 | create a summary structure describing IPA-SRA opportunities and constraints |
4618 | in it. */ |
4619 | |
4620 | static void |
4621 | ipa_sra_summarize_function (cgraph_node *node) |
4622 | { |
4623 | if (dump_file) |
4624 | fprintf (stream: dump_file, format: "Creating summary for %s/%i:\n" , node->name (), |
4625 | node->order); |
4626 | gcc_obstack_init (&gensum_obstack); |
4627 | loaded_decls = new hash_set<tree>; |
4628 | |
4629 | isra_func_summary *ifs = NULL; |
4630 | unsigned count = 0; |
4631 | if (ipa_sra_preliminary_function_checks (node)) |
4632 | { |
4633 | ifs = func_sums->get_create (node); |
4634 | ifs->m_candidate = true; |
4635 | tree ret = TREE_TYPE (TREE_TYPE (node->decl)); |
4636 | ifs->m_returns_value = (TREE_CODE (ret) != VOID_TYPE); |
4637 | for (tree parm = DECL_ARGUMENTS (node->decl); |
4638 | parm; |
4639 | parm = DECL_CHAIN (parm)) |
4640 | count++; |
4641 | } |
4642 | auto_vec<gensum_param_desc, 16> param_descriptions (count); |
4643 | |
4644 | struct function *fun = DECL_STRUCT_FUNCTION (node->decl); |
4645 | bool cfun_pushed = false; |
4646 | if (count > 0) |
4647 | { |
4648 | decl2desc = new hash_map<tree, gensum_param_desc *>; |
4649 | param_descriptions.reserve_exact (nelems: count); |
4650 | param_descriptions.quick_grow_cleared (len: count); |
4651 | |
4652 | if (create_parameter_descriptors (node, param_descriptions: ¶m_descriptions)) |
4653 | { |
4654 | push_cfun (new_cfun: fun); |
4655 | cfun_pushed = true; |
4656 | final_bbs = BITMAP_ALLOC (NULL); |
4657 | bb_dereferences = XCNEWVEC (HOST_WIDE_INT, |
4658 | unsafe_by_ref_count |
4659 | * last_basic_block_for_fn (fun)); |
4660 | aa_walking_limit = opt_for_fn (node->decl, param_ipa_max_aa_steps); |
4661 | } |
4662 | } |
4663 | /* Scan function is run even when there are no removal or splitting |
4664 | candidates so that we can calculate hints on call edges which can be |
4665 | useful in callees. */ |
4666 | scan_function (node, fun); |
4667 | |
4668 | if (count > 0) |
4669 | { |
4670 | if (dump_file) |
4671 | { |
4672 | dump_gensum_param_descriptors (f: dump_file, fndecl: node->decl, |
4673 | param_descriptions: ¶m_descriptions); |
4674 | fprintf (stream: dump_file, format: "----------------------------------------\n" ); |
4675 | } |
4676 | |
4677 | process_scan_results (node, fun, ifs, param_descriptions: ¶m_descriptions); |
4678 | |
4679 | if (cfun_pushed) |
4680 | pop_cfun (); |
4681 | if (bb_dereferences) |
4682 | { |
4683 | free (ptr: bb_dereferences); |
4684 | bb_dereferences = NULL; |
4685 | BITMAP_FREE (final_bbs); |
4686 | final_bbs = NULL; |
4687 | } |
4688 | } |
4689 | isra_analyze_all_outgoing_calls (node); |
4690 | |
4691 | delete loaded_decls; |
4692 | loaded_decls = NULL; |
4693 | if (decl2desc) |
4694 | { |
4695 | delete decl2desc; |
4696 | decl2desc = NULL; |
4697 | } |
4698 | obstack_free (&gensum_obstack, NULL); |
4699 | if (dump_file) |
4700 | fprintf (stream: dump_file, format: "\n\n" ); |
4701 | if (flag_checking) |
4702 | verify_splitting_accesses (node, certain_must_exist: false); |
4703 | return; |
4704 | } |
4705 | |
4706 | ipa_opt_pass_d * |
4707 | make_pass_ipa_sra (gcc::context *ctxt) |
4708 | { |
4709 | return new pass_ipa_sra (ctxt); |
4710 | } |
4711 | |
4712 | /* Reset all state within ipa-sra.cc so that we can rerun the compiler |
4713 | within the same process. For use by toplev::finalize. */ |
4714 | |
4715 | void |
4716 | ipa_sra_cc_finalize (void) |
4717 | { |
4718 | if (func_sums) |
4719 | ggc_delete (ptr: func_sums); |
4720 | func_sums = NULL; |
4721 | delete call_sums; |
4722 | call_sums = NULL; |
4723 | } |
4724 | |
4725 | #include "gt-ipa-sra.h" |
4726 | |