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ff6686d2 | 1 | /* Interprocedural scalar replacement of aggregates |
8d9254fc | 2 | Copyright (C) 2008-2020 Free Software Foundation, Inc. |
ff6686d2 MJ |
3 | |
4 | Contributed by Martin Jambor <mjambor@suse.cz> | |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 3, or (at your option) any later | |
11 | version. | |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GCC; see the file COPYING3. If not see | |
20 | <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | /* IPA-SRA is an interprocedural pass that removes unused function return | |
23 | values (turning functions returning a value which is never used into void | |
24 | functions), removes unused function parameters. It can also replace an | |
25 | aggregate parameter by a set of other parameters representing part of the | |
26 | original, turning those passed by reference into new ones which pass the | |
27 | value directly. | |
28 | ||
29 | The pass is a true IPA one, which means that it works in three stages in | |
30 | order to be able to take advantage of LTO. First, summaries about functions | |
31 | and each calls are generated. Function summaries (often called call graph | |
32 | node summaries) contain mainly information about which parameters are | |
33 | potential transformation candidates and which bits of candidates are | |
34 | accessed. We differentiate between accesses done as a part of a call | |
35 | statement (which might be not necessary if the callee is also transformed) | |
36 | and others (which are mandatory). Call summaries (often called call graph | |
37 | edge summaries) contain information about which function formal parameters | |
38 | feed into which actual call arguments so that if two parameters are only | |
39 | used in a sum which is then passed to another function which then however | |
40 | does not use this parameter, all three parameters of the two functions can | |
41 | be eliminated. Edge summaries also have flags whether the return value is | |
42 | used or if it is only returned in the caller too. In LTO mode these | |
43 | summaries are then streamed to the object file in the compilation phase and | |
44 | streamed back in in the WPA analysis stage. | |
45 | ||
46 | The interprocedural analysis phase traverses the graph in topological order | |
47 | in two sweeps, one in each direction. First, from callees to callers for | |
48 | parameter removal and splitting. Each strongly-connected component is | |
49 | processed iteratively until the situation in it stabilizes. The pass from | |
50 | callers to callees is then carried out to remove unused return values in a | |
51 | very similar fashion. | |
52 | ||
53 | Because parameter manipulation has big implications for call redirection | |
54 | which is done only after all call graph nodes materialize, the | |
55 | transformation phase is not part of this patch but is carried out by the | |
56 | clone materialization and edge redirection itself, see comments in | |
57 | ipa-param-manipulation.h for more details. */ | |
58 | ||
59 | ||
60 | ||
61 | #include "config.h" | |
62 | #include "system.h" | |
63 | #include "coretypes.h" | |
64 | #include "backend.h" | |
65 | #include "tree.h" | |
66 | #include "gimple.h" | |
67 | #include "predict.h" | |
68 | #include "tree-pass.h" | |
69 | #include "ssa.h" | |
70 | #include "cgraph.h" | |
71 | #include "gimple-pretty-print.h" | |
72 | #include "alias.h" | |
73 | #include "tree-eh.h" | |
74 | #include "gimple-iterator.h" | |
75 | #include "gimple-walk.h" | |
76 | #include "tree-dfa.h" | |
77 | #include "tree-sra.h" | |
a895e6d7 | 78 | #include "alloc-pool.h" |
ff6686d2 | 79 | #include "symbol-summary.h" |
ff6686d2 MJ |
80 | #include "dbgcnt.h" |
81 | #include "tree-inline.h" | |
82 | #include "ipa-utils.h" | |
83 | #include "builtins.h" | |
84 | #include "cfganal.h" | |
85 | #include "tree-streamer.h" | |
9707b593 | 86 | #include "internal-fn.h" |
ff6686d2 MJ |
87 | |
88 | /* Bits used to track size of an aggregate in bytes interprocedurally. */ | |
89 | #define ISRA_ARG_SIZE_LIMIT_BITS 16 | |
90 | #define ISRA_ARG_SIZE_LIMIT (1 << ISRA_ARG_SIZE_LIMIT_BITS) | |
91 | /* How many parameters can feed into a call actual argument and still be | |
92 | tracked. */ | |
93 | #define IPA_SRA_MAX_PARAM_FLOW_LEN 7 | |
94 | ||
95 | /* Structure describing accesses to a specific portion of an aggregate | |
96 | parameter, as given by the offset and size. Any smaller accesses that occur | |
97 | within a function that fall within another access form a tree. The pass | |
98 | cannot analyze parameters with only partially overlapping accesses. */ | |
99 | ||
100 | struct GTY(()) param_access | |
101 | { | |
102 | /* Type that a potential replacement should have. This field only has | |
103 | meaning in the summary building and transformation phases, when it is | |
dfea3d6f | 104 | reconstructed from the body. Must not be touched in IPA analysis |
ff6686d2 MJ |
105 | stage. */ |
106 | tree type; | |
107 | ||
108 | /* Alias reference type to be used in MEM_REFs when adjusting caller | |
109 | arguments. */ | |
110 | tree alias_ptr_type; | |
111 | ||
112 | /* Values returned by get_ref_base_and_extent but converted to bytes and | |
113 | stored as unsigned ints. */ | |
114 | unsigned unit_offset; | |
115 | unsigned unit_size : ISRA_ARG_SIZE_LIMIT_BITS; | |
116 | ||
117 | /* Set once we are sure that the access will really end up in a potentially | |
118 | transformed function - initially not set for portions of formal parameters | |
119 | that are only used as actual function arguments passed to callees. */ | |
120 | unsigned certain : 1; | |
121 | /* Set if the access has a reversed scalar storage order. */ | |
122 | unsigned reverse : 1; | |
123 | }; | |
124 | ||
dfea3d6f | 125 | /* This structure has the same purpose as the one above and additionally it |
ff6686d2 MJ |
126 | contains some fields that are only necessary in the summary generation |
127 | phase. */ | |
128 | ||
129 | struct gensum_param_access | |
130 | { | |
131 | /* Values returned by get_ref_base_and_extent. */ | |
132 | HOST_WIDE_INT offset; | |
133 | HOST_WIDE_INT size; | |
134 | ||
135 | /* if this access has any children (in terms of the definition above), this | |
136 | points to the first one. */ | |
137 | struct gensum_param_access *first_child; | |
138 | /* In intraprocedural SRA, pointer to the next sibling in the access tree as | |
139 | described above. */ | |
140 | struct gensum_param_access *next_sibling; | |
141 | ||
142 | /* Type that a potential replacement should have. This field only has | |
143 | meaning in the summary building and transformation phases, when it is | |
dfea3d6f | 144 | reconstructed from the body. Must not be touched in IPA analysis |
ff6686d2 MJ |
145 | stage. */ |
146 | tree type; | |
dfea3d6f | 147 | /* Alias reference type to be used in MEM_REFs when adjusting caller |
ff6686d2 MJ |
148 | arguments. */ |
149 | tree alias_ptr_type; | |
150 | ||
151 | /* Have there been writes to or reads from this exact location except for as | |
152 | arguments to a function call that can be tracked. */ | |
153 | bool nonarg; | |
154 | ||
155 | /* Set if the access has a reversed scalar storage order. */ | |
156 | bool reverse; | |
157 | }; | |
158 | ||
159 | /* Summary describing a parameter in the IPA stages. */ | |
160 | ||
161 | struct GTY(()) isra_param_desc | |
162 | { | |
163 | /* List of access representatives to the parameters, sorted according to | |
164 | their offset. */ | |
165 | vec <param_access *, va_gc> *accesses; | |
166 | ||
167 | /* Unit size limit of total size of all replacements. */ | |
168 | unsigned param_size_limit : ISRA_ARG_SIZE_LIMIT_BITS; | |
169 | /* Sum of unit sizes of all certain replacements. */ | |
170 | unsigned size_reached : ISRA_ARG_SIZE_LIMIT_BITS; | |
171 | ||
172 | /* A parameter that is used only in call arguments and can be removed if all | |
173 | concerned actual arguments are removed. */ | |
174 | unsigned locally_unused : 1; | |
175 | /* An aggregate that is a candidate for breaking up or complete removal. */ | |
176 | unsigned split_candidate : 1; | |
177 | /* Is this a parameter passing stuff by reference? */ | |
178 | unsigned by_ref : 1; | |
179 | }; | |
180 | ||
181 | /* Structure used when generating summaries that describes a parameter. */ | |
182 | ||
183 | struct gensum_param_desc | |
184 | { | |
185 | /* Roots of param_accesses. */ | |
186 | gensum_param_access *accesses; | |
187 | /* Number of accesses in the access tree rooted in field accesses. */ | |
188 | unsigned access_count; | |
189 | ||
dfea3d6f | 190 | /* If the below is non-zero, this is the number of uses as actual arguments. */ |
ff6686d2 MJ |
191 | int call_uses; |
192 | /* Number of times this parameter has been directly passed to. */ | |
193 | unsigned ptr_pt_count; | |
194 | ||
195 | /* Size limit of total size of all replacements. */ | |
196 | unsigned param_size_limit; | |
197 | /* Sum of sizes of nonarg accesses. */ | |
198 | unsigned nonarg_acc_size; | |
199 | ||
200 | /* A parameter that is used only in call arguments and can be removed if all | |
201 | concerned actual arguments are removed. */ | |
202 | bool locally_unused; | |
203 | /* An aggregate that is a candidate for breaking up or a pointer passing data | |
204 | by reference that is a candidate for being converted to a set of | |
dfea3d6f | 205 | parameters passing those data by value. */ |
ff6686d2 MJ |
206 | bool split_candidate; |
207 | /* Is this a parameter passing stuff by reference? */ | |
208 | bool by_ref; | |
209 | ||
210 | /* The number of this parameter as they are ordered in function decl. */ | |
211 | int param_number; | |
212 | /* For parameters passing data by reference, this is parameter index to | |
213 | compute indices to bb_dereferences. */ | |
214 | int deref_index; | |
215 | }; | |
216 | ||
dfea3d6f | 217 | /* Properly deallocate accesses of DESC. TODO: Since this data structure is |
ff6686d2 MJ |
218 | not in GC memory, this is not necessary and we can consider removing the |
219 | function. */ | |
220 | ||
221 | static void | |
222 | free_param_decl_accesses (isra_param_desc *desc) | |
223 | { | |
224 | unsigned len = vec_safe_length (desc->accesses); | |
225 | for (unsigned i = 0; i < len; ++i) | |
226 | ggc_free ((*desc->accesses)[i]); | |
227 | vec_free (desc->accesses); | |
228 | } | |
229 | ||
230 | /* Class used to convey information about functions from the | |
dfea3d6f | 231 | intra-procedural analysis stage to inter-procedural one. */ |
ff6686d2 MJ |
232 | |
233 | class GTY((for_user)) isra_func_summary | |
234 | { | |
235 | public: | |
236 | /* initialize the object. */ | |
237 | ||
238 | isra_func_summary () | |
239 | : m_parameters (NULL), m_candidate (false), m_returns_value (false), | |
240 | m_return_ignored (false), m_queued (false) | |
241 | {} | |
242 | ||
243 | /* Destroy m_parameters. */ | |
244 | ||
245 | ~isra_func_summary (); | |
246 | ||
dfea3d6f | 247 | /* Mark the function as not a candidate for any IPA-SRA transformation. |
ff6686d2 MJ |
248 | Return true if it was a candidate until now. */ |
249 | ||
250 | bool zap (); | |
251 | ||
252 | /* Vector of parameter descriptors corresponding to the function being | |
253 | analyzed. */ | |
254 | vec<isra_param_desc, va_gc> *m_parameters; | |
255 | ||
256 | /* Whether the node is even a candidate for any IPA-SRA transformation at | |
257 | all. */ | |
258 | unsigned m_candidate : 1; | |
259 | ||
260 | /* Whether the original function returns any value. */ | |
261 | unsigned m_returns_value : 1; | |
262 | ||
263 | /* Set to true if all call statements do not actually use the returned | |
264 | value. */ | |
265 | ||
266 | unsigned m_return_ignored : 1; | |
267 | ||
268 | /* Whether the node is already queued in IPA SRA stack during processing of | |
269 | call graphs SCCs. */ | |
270 | ||
271 | unsigned m_queued : 1; | |
272 | }; | |
273 | ||
dfea3d6f JJ |
274 | /* Clean up and deallocate isra_func_summary points to. TODO: Since this data |
275 | structure is not in GC memory, this is not necessary and we can consider | |
ff6686d2 MJ |
276 | removing the destructor. */ |
277 | ||
278 | isra_func_summary::~isra_func_summary () | |
279 | { | |
280 | unsigned len = vec_safe_length (m_parameters); | |
281 | for (unsigned i = 0; i < len; ++i) | |
282 | free_param_decl_accesses (&(*m_parameters)[i]); | |
283 | vec_free (m_parameters); | |
284 | } | |
285 | ||
286 | ||
dfea3d6f | 287 | /* Mark the function as not a candidate for any IPA-SRA transformation. Return |
ff6686d2 MJ |
288 | true if it was a candidate until now. */ |
289 | ||
290 | bool | |
291 | isra_func_summary::zap () | |
292 | { | |
293 | bool ret = m_candidate; | |
294 | m_candidate = false; | |
295 | ||
296 | unsigned len = vec_safe_length (m_parameters); | |
297 | for (unsigned i = 0; i < len; ++i) | |
298 | free_param_decl_accesses (&(*m_parameters)[i]); | |
299 | vec_free (m_parameters); | |
300 | ||
301 | return ret; | |
302 | } | |
303 | ||
304 | /* Structure to describe which formal parameters feed into a particular actual | |
305 | arguments. */ | |
306 | ||
307 | struct isra_param_flow | |
308 | { | |
309 | /* Number of elements in array inputs that contain valid data. */ | |
310 | char length; | |
311 | /* Indices of formal parameters that feed into the described actual argument. | |
312 | If aggregate_pass_through or pointer_pass_through below are true, it must | |
313 | contain exactly one element which is passed through from a formal | |
314 | parameter if the given number. Otherwise, the array contains indices of | |
dfea3d6f | 315 | callee's formal parameters which are used to calculate value of this |
ff6686d2 MJ |
316 | actual argument. */ |
317 | unsigned char inputs[IPA_SRA_MAX_PARAM_FLOW_LEN]; | |
318 | ||
319 | /* Offset within the formal parameter. */ | |
320 | unsigned unit_offset; | |
321 | /* Size of the portion of the formal parameter that is being passed. */ | |
322 | unsigned unit_size : ISRA_ARG_SIZE_LIMIT_BITS; | |
323 | ||
324 | /* True when the value of this actual copy is a portion of a formal | |
325 | parameter. */ | |
326 | unsigned aggregate_pass_through : 1; | |
327 | /* True when the value of this actual copy is a verbatim pass through of an | |
328 | obtained pointer. */ | |
329 | unsigned pointer_pass_through : 1; | |
330 | /* True when it is safe to copy access candidates here from the callee, which | |
331 | would mean introducing dereferences into callers of the caller. */ | |
332 | unsigned safe_to_import_accesses : 1; | |
333 | }; | |
334 | ||
dfea3d6f | 335 | /* Structure used to convey information about calls from the intra-procedural |
ff6686d2 MJ |
336 | analysis stage to inter-procedural one. */ |
337 | ||
338 | class isra_call_summary | |
339 | { | |
340 | public: | |
341 | isra_call_summary () | |
342 | : m_arg_flow (), m_return_ignored (false), m_return_returned (false), | |
343 | m_bit_aligned_arg (false) | |
344 | {} | |
345 | ||
346 | void init_inputs (unsigned arg_count); | |
347 | void dump (FILE *f); | |
348 | ||
349 | /* Information about what formal parameters of the caller are used to compute | |
dfea3d6f | 350 | individual actual arguments of this call. */ |
ff6686d2 MJ |
351 | auto_vec <isra_param_flow> m_arg_flow; |
352 | ||
353 | /* Set to true if the call statement does not have a LHS. */ | |
354 | unsigned m_return_ignored : 1; | |
355 | ||
356 | /* Set to true if the LHS of call statement is only used to construct the | |
357 | return value of the caller. */ | |
358 | unsigned m_return_returned : 1; | |
359 | ||
360 | /* Set when any of the call arguments are not byte-aligned. */ | |
361 | unsigned m_bit_aligned_arg : 1; | |
362 | }; | |
363 | ||
364 | /* Class to manage function summaries. */ | |
365 | ||
366 | class GTY((user)) ipa_sra_function_summaries | |
367 | : public function_summary <isra_func_summary *> | |
368 | { | |
369 | public: | |
370 | ipa_sra_function_summaries (symbol_table *table, bool ggc): | |
371 | function_summary<isra_func_summary *> (table, ggc) { } | |
372 | ||
373 | virtual void duplicate (cgraph_node *, cgraph_node *, | |
374 | isra_func_summary *old_sum, | |
375 | isra_func_summary *new_sum); | |
376 | }; | |
377 | ||
378 | /* Hook that is called by summary when a node is duplicated. */ | |
379 | ||
380 | void | |
381 | ipa_sra_function_summaries::duplicate (cgraph_node *, cgraph_node *, | |
382 | isra_func_summary *old_sum, | |
383 | isra_func_summary *new_sum) | |
384 | { | |
385 | /* TODO: Somehow stop copying when ISRA is doing the cloning, it is | |
386 | useless. */ | |
387 | new_sum->m_candidate = old_sum->m_candidate; | |
388 | new_sum->m_returns_value = old_sum->m_returns_value; | |
389 | new_sum->m_return_ignored = old_sum->m_return_ignored; | |
390 | gcc_assert (!old_sum->m_queued); | |
391 | new_sum->m_queued = false; | |
392 | ||
393 | unsigned param_count = vec_safe_length (old_sum->m_parameters); | |
394 | if (!param_count) | |
395 | return; | |
396 | vec_safe_reserve_exact (new_sum->m_parameters, param_count); | |
397 | new_sum->m_parameters->quick_grow_cleared (param_count); | |
398 | for (unsigned i = 0; i < param_count; i++) | |
399 | { | |
400 | isra_param_desc *s = &(*old_sum->m_parameters)[i]; | |
401 | isra_param_desc *d = &(*new_sum->m_parameters)[i]; | |
402 | ||
403 | d->param_size_limit = s->param_size_limit; | |
404 | d->size_reached = s->size_reached; | |
405 | d->locally_unused = s->locally_unused; | |
406 | d->split_candidate = s->split_candidate; | |
407 | d->by_ref = s->by_ref; | |
408 | ||
409 | unsigned acc_count = vec_safe_length (s->accesses); | |
410 | vec_safe_reserve_exact (d->accesses, acc_count); | |
411 | for (unsigned j = 0; j < acc_count; j++) | |
412 | { | |
413 | param_access *from = (*s->accesses)[j]; | |
414 | param_access *to = ggc_cleared_alloc<param_access> (); | |
415 | to->type = from->type; | |
416 | to->alias_ptr_type = from->alias_ptr_type; | |
417 | to->unit_offset = from->unit_offset; | |
418 | to->unit_size = from->unit_size; | |
419 | to->certain = from->certain; | |
420 | d->accesses->quick_push (to); | |
421 | } | |
422 | } | |
423 | } | |
424 | ||
425 | /* Pointer to the pass function summary holder. */ | |
426 | ||
427 | static GTY(()) ipa_sra_function_summaries *func_sums; | |
428 | ||
429 | /* Class to manage call summaries. */ | |
430 | ||
431 | class ipa_sra_call_summaries: public call_summary <isra_call_summary *> | |
432 | { | |
433 | public: | |
434 | ipa_sra_call_summaries (symbol_table *table): | |
435 | call_summary<isra_call_summary *> (table) { } | |
436 | ||
437 | /* Duplicate info when an edge is cloned. */ | |
438 | virtual void duplicate (cgraph_edge *, cgraph_edge *, | |
439 | isra_call_summary *old_sum, | |
440 | isra_call_summary *new_sum); | |
441 | }; | |
442 | ||
443 | static ipa_sra_call_summaries *call_sums; | |
444 | ||
445 | ||
446 | /* Initialize m_arg_flow of a particular instance of isra_call_summary. | |
447 | ARG_COUNT is the number of actual arguments passed. */ | |
448 | ||
449 | void | |
450 | isra_call_summary::init_inputs (unsigned arg_count) | |
451 | { | |
452 | if (arg_count == 0) | |
453 | { | |
454 | gcc_checking_assert (m_arg_flow.length () == 0); | |
455 | return; | |
456 | } | |
457 | if (m_arg_flow.length () == 0) | |
458 | { | |
459 | m_arg_flow.reserve_exact (arg_count); | |
460 | m_arg_flow.quick_grow_cleared (arg_count); | |
461 | } | |
462 | else | |
463 | gcc_checking_assert (arg_count == m_arg_flow.length ()); | |
464 | } | |
465 | ||
466 | /* Dump all information in call summary to F. */ | |
467 | ||
468 | void | |
469 | isra_call_summary::dump (FILE *f) | |
470 | { | |
471 | if (m_return_ignored) | |
472 | fprintf (f, " return value ignored\n"); | |
473 | if (m_return_returned) | |
474 | fprintf (f, " return value used only to compute caller return value\n"); | |
475 | for (unsigned i = 0; i < m_arg_flow.length (); i++) | |
476 | { | |
477 | fprintf (f, " Parameter %u:\n", i); | |
478 | isra_param_flow *ipf = &m_arg_flow[i]; | |
479 | ||
480 | if (ipf->length) | |
481 | { | |
482 | bool first = true; | |
483 | fprintf (f, " Scalar param sources: "); | |
484 | for (int j = 0; j < ipf->length; j++) | |
485 | { | |
486 | if (!first) | |
487 | fprintf (f, ", "); | |
488 | else | |
489 | first = false; | |
490 | fprintf (f, "%i", (int) ipf->inputs[j]); | |
491 | } | |
492 | fprintf (f, "\n"); | |
493 | } | |
494 | if (ipf->aggregate_pass_through) | |
495 | fprintf (f, " Aggregate pass through from the param given above, " | |
496 | "unit offset: %u , unit size: %u\n", | |
497 | ipf->unit_offset, ipf->unit_size); | |
498 | if (ipf->pointer_pass_through) | |
499 | fprintf (f, " Pointer pass through from the param given above, " | |
500 | "safe_to_import_accesses: %u\n", ipf->safe_to_import_accesses); | |
501 | } | |
502 | } | |
503 | ||
dfea3d6f | 504 | /* Duplicate edge summary when an edge is cloned. */ |
ff6686d2 MJ |
505 | |
506 | void | |
507 | ipa_sra_call_summaries::duplicate (cgraph_edge *, cgraph_edge *, | |
508 | isra_call_summary *old_sum, | |
509 | isra_call_summary *new_sum) | |
510 | { | |
511 | unsigned arg_count = old_sum->m_arg_flow.length (); | |
512 | new_sum->init_inputs (arg_count); | |
513 | for (unsigned i = 0; i < arg_count; i++) | |
514 | new_sum->m_arg_flow[i] = old_sum->m_arg_flow[i]; | |
515 | ||
516 | new_sum->m_return_ignored = old_sum->m_return_ignored; | |
517 | new_sum->m_return_returned = old_sum->m_return_returned; | |
518 | new_sum->m_bit_aligned_arg = old_sum->m_bit_aligned_arg; | |
519 | } | |
520 | ||
521 | ||
522 | /* With all GTY stuff done, we can move to anonymous namespace. */ | |
523 | namespace { | |
524 | /* Quick mapping from a decl to its param descriptor. */ | |
525 | ||
526 | hash_map<tree, gensum_param_desc *> *decl2desc; | |
527 | ||
dfea3d6f | 528 | /* Countdown of allowed Alias analysis steps during summary building. */ |
ff6686d2 MJ |
529 | |
530 | int aa_walking_limit; | |
531 | ||
532 | /* This is a table in which for each basic block and parameter there is a | |
533 | distance (offset + size) in that parameter which is dereferenced and | |
534 | accessed in that BB. */ | |
535 | HOST_WIDE_INT *bb_dereferences = NULL; | |
536 | /* How many by-reference parameters there are in the current function. */ | |
537 | int by_ref_count; | |
538 | ||
539 | /* Bitmap of BBs that can cause the function to "stop" progressing by | |
540 | returning, throwing externally, looping infinitely or calling a function | |
541 | which might abort etc.. */ | |
542 | bitmap final_bbs; | |
543 | ||
544 | /* Obstack to allocate various small structures required only when generating | |
545 | summary for a function. */ | |
546 | struct obstack gensum_obstack; | |
547 | ||
548 | /* Return false the function is apparently unsuitable for IPA-SRA based on it's | |
549 | attributes, return true otherwise. NODE is the cgraph node of the current | |
550 | function. */ | |
551 | ||
552 | static bool | |
553 | ipa_sra_preliminary_function_checks (cgraph_node *node) | |
554 | { | |
87f94429 | 555 | if (!node->can_change_signature) |
ff6686d2 MJ |
556 | { |
557 | if (dump_file) | |
558 | fprintf (dump_file, "Function cannot change signature.\n"); | |
559 | return false; | |
560 | } | |
561 | ||
562 | if (!tree_versionable_function_p (node->decl)) | |
563 | { | |
564 | if (dump_file) | |
565 | fprintf (dump_file, "Function is not versionable.\n"); | |
566 | return false; | |
567 | } | |
568 | ||
569 | if (!opt_for_fn (node->decl, optimize) | |
570 | || !opt_for_fn (node->decl, flag_ipa_sra)) | |
571 | { | |
572 | if (dump_file) | |
573 | fprintf (dump_file, "Not optimizing or IPA-SRA turned off for this " | |
574 | "function.\n"); | |
575 | return false; | |
576 | } | |
577 | ||
578 | if (DECL_VIRTUAL_P (node->decl)) | |
579 | { | |
580 | if (dump_file) | |
581 | fprintf (dump_file, "Function is a virtual method.\n"); | |
582 | return false; | |
583 | } | |
584 | ||
585 | struct function *fun = DECL_STRUCT_FUNCTION (node->decl); | |
586 | if (fun->stdarg) | |
587 | { | |
588 | if (dump_file) | |
589 | fprintf (dump_file, "Function uses stdarg. \n"); | |
590 | return false; | |
591 | } | |
592 | ||
593 | if (TYPE_ATTRIBUTES (TREE_TYPE (node->decl))) | |
594 | { | |
595 | if (dump_file) | |
596 | fprintf (dump_file, "Function type has attributes. \n"); | |
597 | return false; | |
598 | } | |
599 | ||
600 | if (DECL_DISREGARD_INLINE_LIMITS (node->decl)) | |
601 | { | |
602 | if (dump_file) | |
603 | fprintf (dump_file, "Always inline function will be inlined " | |
604 | "anyway. \n"); | |
605 | return false; | |
606 | } | |
607 | ||
608 | return true; | |
609 | } | |
610 | ||
611 | /* Print access tree starting at ACCESS to F. */ | |
612 | ||
613 | static void | |
614 | dump_gensum_access (FILE *f, gensum_param_access *access, unsigned indent) | |
615 | { | |
616 | fprintf (f, " "); | |
617 | for (unsigned i = 0; i < indent; i++) | |
618 | fprintf (f, " "); | |
619 | fprintf (f, " * Access to offset: " HOST_WIDE_INT_PRINT_DEC, | |
620 | access->offset); | |
621 | fprintf (f, ", size: " HOST_WIDE_INT_PRINT_DEC, access->size); | |
622 | fprintf (f, ", type: "); | |
623 | print_generic_expr (f, access->type); | |
624 | fprintf (f, ", alias_ptr_type: "); | |
625 | print_generic_expr (f, access->alias_ptr_type); | |
626 | fprintf (f, ", nonarg: %u, reverse: %u\n", access->nonarg, access->reverse); | |
627 | for (gensum_param_access *ch = access->first_child; | |
628 | ch; | |
629 | ch = ch->next_sibling) | |
630 | dump_gensum_access (f, ch, indent + 2); | |
631 | } | |
632 | ||
633 | ||
634 | /* Print access tree starting at ACCESS to F. */ | |
635 | ||
636 | static void | |
637 | dump_isra_access (FILE *f, param_access *access) | |
638 | { | |
639 | fprintf (f, " * Access to unit offset: %u", access->unit_offset); | |
640 | fprintf (f, ", unit size: %u", access->unit_size); | |
641 | fprintf (f, ", type: "); | |
642 | print_generic_expr (f, access->type); | |
643 | fprintf (f, ", alias_ptr_type: "); | |
644 | print_generic_expr (f, access->alias_ptr_type); | |
645 | if (access->certain) | |
646 | fprintf (f, ", certain"); | |
647 | else | |
648 | fprintf (f, ", not-certain"); | |
649 | if (access->reverse) | |
650 | fprintf (f, ", reverse"); | |
651 | fprintf (f, "\n"); | |
652 | } | |
653 | ||
654 | /* Dump access tree starting at ACCESS to stderr. */ | |
655 | ||
656 | DEBUG_FUNCTION void | |
657 | debug_isra_access (param_access *access) | |
658 | { | |
659 | dump_isra_access (stderr, access); | |
660 | } | |
661 | ||
662 | /* Dump DESC to F. */ | |
663 | ||
664 | static void | |
665 | dump_gensum_param_descriptor (FILE *f, gensum_param_desc *desc) | |
666 | { | |
667 | if (desc->locally_unused) | |
668 | fprintf (f, " unused with %i call_uses\n", desc->call_uses); | |
669 | if (!desc->split_candidate) | |
670 | { | |
671 | fprintf (f, " not a candidate\n"); | |
672 | return; | |
673 | } | |
674 | if (desc->by_ref) | |
675 | fprintf (f, " by_ref with %u pass throughs\n", desc->ptr_pt_count); | |
676 | ||
677 | for (gensum_param_access *acc = desc->accesses; acc; acc = acc->next_sibling) | |
678 | dump_gensum_access (f, acc, 2); | |
679 | } | |
680 | ||
dfea3d6f | 681 | /* Dump all parameter descriptors in IFS, assuming it describes FNDECL, to |
ff6686d2 MJ |
682 | F. */ |
683 | ||
684 | static void | |
685 | dump_gensum_param_descriptors (FILE *f, tree fndecl, | |
686 | vec<gensum_param_desc> *param_descriptions) | |
687 | { | |
688 | tree parm = DECL_ARGUMENTS (fndecl); | |
689 | for (unsigned i = 0; | |
690 | i < param_descriptions->length (); | |
691 | ++i, parm = DECL_CHAIN (parm)) | |
692 | { | |
693 | fprintf (f, " Descriptor for parameter %i ", i); | |
694 | print_generic_expr (f, parm, TDF_UID); | |
695 | fprintf (f, "\n"); | |
696 | dump_gensum_param_descriptor (f, &(*param_descriptions)[i]); | |
697 | } | |
698 | } | |
699 | ||
700 | ||
701 | /* Dump DESC to F. */ | |
702 | ||
703 | static void | |
704 | dump_isra_param_descriptor (FILE *f, isra_param_desc *desc) | |
705 | { | |
706 | if (desc->locally_unused) | |
707 | { | |
708 | fprintf (f, " (locally) unused\n"); | |
709 | } | |
710 | if (!desc->split_candidate) | |
711 | { | |
712 | fprintf (f, " not a candidate for splitting\n"); | |
713 | return; | |
714 | } | |
715 | fprintf (f, " param_size_limit: %u, size_reached: %u%s\n", | |
716 | desc->param_size_limit, desc->size_reached, | |
717 | desc->by_ref ? ", by_ref" : ""); | |
718 | ||
719 | for (unsigned i = 0; i < vec_safe_length (desc->accesses); ++i) | |
720 | { | |
721 | param_access *access = (*desc->accesses)[i]; | |
722 | dump_isra_access (f, access); | |
723 | } | |
724 | } | |
725 | ||
dfea3d6f | 726 | /* Dump all parameter descriptors in IFS, assuming it describes FNDECL, to |
ff6686d2 MJ |
727 | F. */ |
728 | ||
729 | static void | |
730 | dump_isra_param_descriptors (FILE *f, tree fndecl, | |
731 | isra_func_summary *ifs) | |
732 | { | |
733 | tree parm = DECL_ARGUMENTS (fndecl); | |
734 | if (!ifs->m_parameters) | |
735 | { | |
736 | fprintf (f, " parameter descriptors not available\n"); | |
737 | return; | |
738 | } | |
739 | ||
740 | for (unsigned i = 0; | |
741 | i < ifs->m_parameters->length (); | |
742 | ++i, parm = DECL_CHAIN (parm)) | |
743 | { | |
744 | fprintf (f, " Descriptor for parameter %i ", i); | |
745 | print_generic_expr (f, parm, TDF_UID); | |
746 | fprintf (f, "\n"); | |
747 | dump_isra_param_descriptor (f, &(*ifs->m_parameters)[i]); | |
748 | } | |
749 | } | |
750 | ||
751 | /* Add SRC to inputs of PARAM_FLOW, unless it would exceed storage. If the | |
752 | function fails return false, otherwise return true. SRC must fit into an | |
753 | unsigned char. Used for purposes of transitive unused parameter | |
754 | removal. */ | |
755 | ||
756 | static bool | |
757 | add_src_to_param_flow (isra_param_flow *param_flow, int src) | |
758 | { | |
759 | gcc_checking_assert (src >= 0 && src <= UCHAR_MAX); | |
760 | if (param_flow->length == IPA_SRA_MAX_PARAM_FLOW_LEN) | |
761 | return false; | |
762 | ||
763 | param_flow->inputs[(int) param_flow->length] = src; | |
764 | param_flow->length++; | |
765 | return true; | |
766 | } | |
767 | ||
768 | /* Add a SRC to the inputs of PARAM_FLOW unless it is already there and assert | |
769 | it is the only input. Used for purposes of transitive parameter | |
770 | splitting. */ | |
771 | ||
772 | static void | |
773 | set_single_param_flow_source (isra_param_flow *param_flow, int src) | |
774 | { | |
775 | gcc_checking_assert (src >= 0 && src <= UCHAR_MAX); | |
776 | if (param_flow->length == 0) | |
777 | { | |
778 | param_flow->inputs[0] = src; | |
779 | param_flow->length = 1; | |
780 | } | |
781 | else if (param_flow->length == 1) | |
782 | gcc_assert (param_flow->inputs[0] == src); | |
783 | else | |
784 | gcc_unreachable (); | |
785 | } | |
786 | ||
787 | /* Assert that there is only a single value in PARAM_FLOW's inputs and return | |
788 | it. */ | |
789 | ||
790 | static unsigned | |
791 | get_single_param_flow_source (const isra_param_flow *param_flow) | |
792 | { | |
793 | gcc_assert (param_flow->length == 1); | |
794 | return param_flow->inputs[0]; | |
795 | } | |
796 | ||
797 | /* Inspect all uses of NAME and simple arithmetic calculations involving NAME | |
798 | in NODE and return a negative number if any of them is used for something | |
799 | else than either an actual call argument, simple arithmetic operation or | |
800 | debug statement. If there are no such uses, return the number of actual | |
801 | arguments that this parameter eventually feeds to (or zero if there is none). | |
802 | For any such parameter, mark PARM_NUM as one of its sources. ANALYZED is a | |
803 | bitmap that tracks which SSA names we have already started | |
804 | investigating. */ | |
805 | ||
806 | static int | |
807 | isra_track_scalar_value_uses (cgraph_node *node, tree name, int parm_num, | |
808 | bitmap analyzed) | |
809 | { | |
810 | int res = 0; | |
811 | imm_use_iterator imm_iter; | |
812 | gimple *stmt; | |
813 | ||
814 | FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name) | |
815 | { | |
816 | if (is_gimple_debug (stmt)) | |
817 | continue; | |
818 | ||
819 | /* TODO: We could handle at least const builtin functions like arithmetic | |
820 | operations below. */ | |
821 | if (is_gimple_call (stmt)) | |
822 | { | |
823 | int all_uses = 0; | |
824 | use_operand_p use_p; | |
825 | FOR_EACH_IMM_USE_ON_STMT (use_p, imm_iter) | |
826 | all_uses++; | |
827 | ||
828 | gcall *call = as_a <gcall *> (stmt); | |
829 | unsigned arg_count; | |
830 | if (gimple_call_internal_p (call) | |
831 | || (arg_count = gimple_call_num_args (call)) == 0) | |
832 | { | |
833 | res = -1; | |
834 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
835 | } | |
836 | ||
837 | cgraph_edge *cs = node->get_edge (stmt); | |
838 | gcc_checking_assert (cs); | |
839 | isra_call_summary *csum = call_sums->get_create (cs); | |
840 | csum->init_inputs (arg_count); | |
841 | ||
842 | int simple_uses = 0; | |
843 | for (unsigned i = 0; i < arg_count; i++) | |
844 | if (gimple_call_arg (call, i) == name) | |
845 | { | |
846 | if (!add_src_to_param_flow (&csum->m_arg_flow[i], parm_num)) | |
847 | { | |
848 | simple_uses = -1; | |
849 | break; | |
850 | } | |
851 | simple_uses++; | |
852 | } | |
853 | ||
854 | if (simple_uses < 0 | |
855 | || all_uses != simple_uses) | |
856 | { | |
857 | res = -1; | |
858 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
859 | } | |
860 | res += all_uses; | |
861 | } | |
862 | else if ((is_gimple_assign (stmt) && !gimple_has_volatile_ops (stmt)) | |
863 | || gimple_code (stmt) == GIMPLE_PHI) | |
864 | { | |
865 | tree lhs; | |
866 | if (gimple_code (stmt) == GIMPLE_PHI) | |
867 | lhs = gimple_phi_result (stmt); | |
868 | else | |
869 | lhs = gimple_assign_lhs (stmt); | |
870 | ||
871 | if (TREE_CODE (lhs) != SSA_NAME) | |
872 | { | |
873 | res = -1; | |
874 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
875 | } | |
876 | gcc_assert (!gimple_vdef (stmt)); | |
877 | if (bitmap_set_bit (analyzed, SSA_NAME_VERSION (lhs))) | |
878 | { | |
879 | int tmp = isra_track_scalar_value_uses (node, lhs, parm_num, | |
880 | analyzed); | |
881 | if (tmp < 0) | |
882 | { | |
883 | res = tmp; | |
884 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
885 | } | |
886 | res += tmp; | |
887 | } | |
888 | } | |
889 | else | |
890 | { | |
891 | res = -1; | |
892 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
893 | } | |
894 | } | |
895 | return res; | |
896 | } | |
897 | ||
898 | /* Inspect all uses of PARM, which must be a gimple register, in FUN (which is | |
899 | also described by NODE) and simple arithmetic calculations involving PARM | |
900 | and return false if any of them is used for something else than either an | |
901 | actual call argument, simple arithmetic operation or debug statement. If | |
902 | there are no such uses, return true and store the number of actual arguments | |
903 | that this parameter eventually feeds to (or zero if there is none) to | |
904 | *CALL_USES_P. For any such parameter, mark PARM_NUM as one of its | |
905 | sources. | |
906 | ||
907 | This function is similar to ptr_parm_has_nonarg_uses but its results are | |
908 | meant for unused parameter removal, as opposed to splitting of parameters | |
909 | passed by reference or converting them to passed by value. | |
910 | */ | |
911 | ||
912 | static bool | |
913 | isra_track_scalar_param_local_uses (function *fun, cgraph_node *node, tree parm, | |
914 | int parm_num, int *call_uses_p) | |
915 | { | |
916 | gcc_checking_assert (is_gimple_reg (parm)); | |
917 | ||
918 | tree name = ssa_default_def (fun, parm); | |
919 | if (!name || has_zero_uses (name)) | |
920 | { | |
921 | *call_uses_p = 0; | |
922 | return false; | |
923 | } | |
924 | ||
925 | /* Edge summaries can only handle callers with fewer than 256 parameters. */ | |
926 | if (parm_num > UCHAR_MAX) | |
927 | return true; | |
928 | ||
929 | bitmap analyzed = BITMAP_ALLOC (NULL); | |
930 | int call_uses = isra_track_scalar_value_uses (node, name, parm_num, analyzed); | |
931 | BITMAP_FREE (analyzed); | |
932 | if (call_uses < 0) | |
933 | return true; | |
934 | *call_uses_p = call_uses; | |
935 | return false; | |
936 | } | |
937 | ||
938 | /* Scan immediate uses of a default definition SSA name of a parameter PARM and | |
939 | examine whether there are any nonarg uses that are not actual arguments or | |
940 | otherwise infeasible uses. If so, return true, otherwise return false. | |
941 | Create pass-through IPA flow records for any direct uses as argument calls | |
942 | and if returning false, store their number into *PT_COUNT_P. NODE and FUN | |
943 | must represent the function that is currently analyzed, PARM_NUM must be the | |
944 | index of the analyzed parameter. | |
945 | ||
946 | This function is similar to isra_track_scalar_param_local_uses but its | |
947 | results are meant for splitting of parameters passed by reference or turning | |
948 | them into bits passed by value, as opposed to generic unused parameter | |
949 | removal. | |
950 | */ | |
951 | ||
952 | static bool | |
953 | ptr_parm_has_nonarg_uses (cgraph_node *node, function *fun, tree parm, | |
954 | int parm_num, unsigned *pt_count_p) | |
955 | { | |
956 | imm_use_iterator ui; | |
957 | gimple *stmt; | |
958 | tree name = ssa_default_def (fun, parm); | |
959 | bool ret = false; | |
960 | unsigned pt_count = 0; | |
961 | ||
962 | if (!name || has_zero_uses (name)) | |
963 | return false; | |
964 | ||
965 | /* Edge summaries can only handle callers with fewer than 256 parameters. */ | |
966 | if (parm_num > UCHAR_MAX) | |
967 | return true; | |
968 | ||
969 | FOR_EACH_IMM_USE_STMT (stmt, ui, name) | |
970 | { | |
971 | unsigned uses_ok = 0; | |
972 | use_operand_p use_p; | |
973 | ||
974 | if (is_gimple_debug (stmt)) | |
975 | continue; | |
976 | ||
977 | if (gimple_assign_single_p (stmt)) | |
978 | { | |
979 | tree rhs = gimple_assign_rhs1 (stmt); | |
980 | while (handled_component_p (rhs)) | |
981 | rhs = TREE_OPERAND (rhs, 0); | |
982 | if (TREE_CODE (rhs) == MEM_REF | |
983 | && TREE_OPERAND (rhs, 0) == name | |
984 | && integer_zerop (TREE_OPERAND (rhs, 1)) | |
985 | && types_compatible_p (TREE_TYPE (rhs), | |
986 | TREE_TYPE (TREE_TYPE (name))) | |
987 | && !TREE_THIS_VOLATILE (rhs)) | |
988 | uses_ok++; | |
989 | } | |
990 | else if (is_gimple_call (stmt)) | |
991 | { | |
992 | gcall *call = as_a <gcall *> (stmt); | |
993 | unsigned arg_count; | |
994 | if (gimple_call_internal_p (call) | |
995 | || (arg_count = gimple_call_num_args (call)) == 0) | |
996 | { | |
997 | ret = true; | |
998 | BREAK_FROM_IMM_USE_STMT (ui); | |
999 | } | |
1000 | ||
1001 | cgraph_edge *cs = node->get_edge (stmt); | |
1002 | gcc_checking_assert (cs); | |
1003 | isra_call_summary *csum = call_sums->get_create (cs); | |
1004 | csum->init_inputs (arg_count); | |
1005 | ||
1006 | for (unsigned i = 0; i < arg_count; ++i) | |
1007 | { | |
1008 | tree arg = gimple_call_arg (stmt, i); | |
1009 | ||
1010 | if (arg == name) | |
1011 | { | |
1012 | /* TODO: Allow &MEM_REF[name + offset] here, | |
1013 | ipa_param_body_adjustments::modify_call_stmt has to be | |
1014 | adjusted too. */ | |
1015 | csum->m_arg_flow[i].pointer_pass_through = true; | |
1016 | set_single_param_flow_source (&csum->m_arg_flow[i], parm_num); | |
1017 | pt_count++; | |
1018 | uses_ok++; | |
1019 | continue; | |
1020 | } | |
1021 | ||
1022 | while (handled_component_p (arg)) | |
1023 | arg = TREE_OPERAND (arg, 0); | |
1024 | if (TREE_CODE (arg) == MEM_REF | |
1025 | && TREE_OPERAND (arg, 0) == name | |
1026 | && integer_zerop (TREE_OPERAND (arg, 1)) | |
1027 | && types_compatible_p (TREE_TYPE (arg), | |
1028 | TREE_TYPE (TREE_TYPE (name))) | |
1029 | && !TREE_THIS_VOLATILE (arg)) | |
1030 | uses_ok++; | |
1031 | } | |
1032 | } | |
1033 | ||
1034 | /* If the number of valid uses does not match the number of | |
1035 | uses in this stmt there is an unhandled use. */ | |
1036 | unsigned all_uses = 0; | |
1037 | FOR_EACH_IMM_USE_ON_STMT (use_p, ui) | |
1038 | all_uses++; | |
1039 | ||
1040 | gcc_checking_assert (uses_ok <= all_uses); | |
1041 | if (uses_ok != all_uses) | |
1042 | { | |
1043 | ret = true; | |
1044 | BREAK_FROM_IMM_USE_STMT (ui); | |
1045 | } | |
1046 | } | |
1047 | ||
1048 | *pt_count_p = pt_count; | |
1049 | return ret; | |
1050 | } | |
1051 | ||
1052 | /* Initialize vector of parameter descriptors of NODE. Return true if there | |
1053 | are any candidates for splitting or unused aggregate parameter removal (the | |
1054 | function may return false if there are candidates for removal of register | |
1055 | parameters) and function body must be scanned. */ | |
1056 | ||
1057 | static bool | |
1058 | create_parameter_descriptors (cgraph_node *node, | |
1059 | vec<gensum_param_desc> *param_descriptions) | |
1060 | { | |
1061 | function *fun = DECL_STRUCT_FUNCTION (node->decl); | |
1062 | bool ret = false; | |
1063 | ||
1064 | int num = 0; | |
1065 | for (tree parm = DECL_ARGUMENTS (node->decl); | |
1066 | parm; | |
1067 | parm = DECL_CHAIN (parm), num++) | |
1068 | { | |
1069 | const char *msg; | |
1070 | gensum_param_desc *desc = &(*param_descriptions)[num]; | |
1071 | /* param_descriptions vector is grown cleared in the caller. */ | |
1072 | desc->param_number = num; | |
1073 | decl2desc->put (parm, desc); | |
1074 | ||
1075 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1076 | print_generic_expr (dump_file, parm, TDF_UID); | |
1077 | ||
1078 | int scalar_call_uses; | |
1079 | tree type = TREE_TYPE (parm); | |
1080 | if (TREE_THIS_VOLATILE (parm)) | |
1081 | { | |
1082 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1083 | fprintf (dump_file, " not a candidate, is volatile\n"); | |
1084 | continue; | |
1085 | } | |
1086 | if (!is_gimple_reg_type (type) && is_va_list_type (type)) | |
1087 | { | |
1088 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1089 | fprintf (dump_file, " not a candidate, is a va_list type\n"); | |
1090 | continue; | |
1091 | } | |
1092 | if (TREE_ADDRESSABLE (parm)) | |
1093 | { | |
1094 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1095 | fprintf (dump_file, " not a candidate, is addressable\n"); | |
1096 | continue; | |
1097 | } | |
1098 | if (TREE_ADDRESSABLE (type)) | |
1099 | { | |
1100 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1101 | fprintf (dump_file, " not a candidate, type cannot be split\n"); | |
1102 | continue; | |
1103 | } | |
1104 | ||
1105 | if (is_gimple_reg (parm) | |
1106 | && !isra_track_scalar_param_local_uses (fun, node, parm, num, | |
1107 | &scalar_call_uses)) | |
1108 | { | |
1109 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1110 | fprintf (dump_file, " is a scalar with only %i call uses\n", | |
1111 | scalar_call_uses); | |
1112 | ||
1113 | desc->locally_unused = true; | |
1114 | desc->call_uses = scalar_call_uses; | |
1115 | } | |
1116 | ||
1117 | if (POINTER_TYPE_P (type)) | |
1118 | { | |
1119 | type = TREE_TYPE (type); | |
1120 | ||
1121 | if (TREE_CODE (type) == FUNCTION_TYPE | |
1122 | || TREE_CODE (type) == METHOD_TYPE) | |
1123 | { | |
1124 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1125 | fprintf (dump_file, " not a candidate, reference to " | |
1126 | "a function\n"); | |
1127 | continue; | |
1128 | } | |
1129 | if (TYPE_VOLATILE (type)) | |
1130 | { | |
1131 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1132 | fprintf (dump_file, " not a candidate, reference to " | |
1133 | "a volatile type\n"); | |
1134 | continue; | |
1135 | } | |
1136 | if (TREE_CODE (type) == ARRAY_TYPE | |
1137 | && TYPE_NONALIASED_COMPONENT (type)) | |
1138 | { | |
1139 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
f8cb8bcd JJ |
1140 | fprintf (dump_file, " not a candidate, reference to " |
1141 | "a nonaliased component array\n"); | |
ff6686d2 MJ |
1142 | continue; |
1143 | } | |
1144 | if (!is_gimple_reg (parm)) | |
1145 | { | |
1146 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1147 | fprintf (dump_file, " not a candidate, a reference which is " | |
1148 | "not a gimple register (probably addressable)\n"); | |
1149 | continue; | |
1150 | } | |
1151 | if (is_va_list_type (type)) | |
1152 | { | |
1153 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1154 | fprintf (dump_file, " not a candidate, reference to " | |
1155 | "a va list\n"); | |
1156 | continue; | |
1157 | } | |
1158 | if (ptr_parm_has_nonarg_uses (node, fun, parm, num, | |
1159 | &desc->ptr_pt_count)) | |
1160 | { | |
1161 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1162 | fprintf (dump_file, " not a candidate, reference has " | |
1163 | "nonarg uses\n"); | |
1164 | continue; | |
1165 | } | |
1166 | desc->by_ref = true; | |
1167 | } | |
1168 | else if (!AGGREGATE_TYPE_P (type)) | |
1169 | { | |
1170 | /* This is in an else branch because scalars passed by reference are | |
1171 | still candidates to be passed by value. */ | |
1172 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1173 | fprintf (dump_file, " not a candidate, not an aggregate\n"); | |
1174 | continue; | |
1175 | } | |
1176 | ||
1177 | if (!COMPLETE_TYPE_P (type)) | |
1178 | { | |
1179 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1180 | fprintf (dump_file, " not a candidate, not a complete type\n"); | |
1181 | continue; | |
1182 | } | |
1183 | if (!tree_fits_uhwi_p (TYPE_SIZE (type))) | |
1184 | { | |
1185 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1186 | fprintf (dump_file, " not a candidate, size not representable\n"); | |
1187 | continue; | |
1188 | } | |
1189 | unsigned HOST_WIDE_INT type_size | |
1190 | = tree_to_uhwi (TYPE_SIZE (type)) / BITS_PER_UNIT; | |
1191 | if (type_size == 0 | |
1192 | || type_size >= ISRA_ARG_SIZE_LIMIT) | |
1193 | { | |
1194 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1195 | fprintf (dump_file, " not a candidate, has zero or huge size\n"); | |
1196 | continue; | |
1197 | } | |
1198 | if (type_internals_preclude_sra_p (type, &msg)) | |
1199 | { | |
1200 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1201 | fprintf (dump_file, " not a candidate, %s\n", msg); | |
1202 | continue; | |
1203 | } | |
1204 | ||
1205 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1206 | fprintf (dump_file, " is a candidate\n"); | |
1207 | ||
1208 | ret = true; | |
1209 | desc->split_candidate = true; | |
1210 | if (desc->by_ref) | |
1211 | desc->deref_index = by_ref_count++; | |
1212 | } | |
1213 | return ret; | |
1214 | } | |
1215 | ||
1216 | /* Return pointer to descriptor of parameter DECL or NULL if it cannot be | |
1217 | found, which happens if DECL is for a static chain. */ | |
1218 | ||
1219 | static gensum_param_desc * | |
1220 | get_gensum_param_desc (tree decl) | |
1221 | { | |
1222 | gcc_checking_assert (TREE_CODE (decl) == PARM_DECL); | |
1223 | gensum_param_desc **slot = decl2desc->get (decl); | |
1224 | if (!slot) | |
1225 | /* This can happen for static chains which we cannot handle so far. */ | |
1226 | return NULL; | |
1227 | gcc_checking_assert (*slot); | |
1228 | return *slot; | |
1229 | } | |
1230 | ||
1231 | ||
1232 | /* Remove parameter described by DESC from candidates for IPA-SRA splitting and | |
1233 | write REASON to the dump file if there is one. */ | |
1234 | ||
1235 | static void | |
1236 | disqualify_split_candidate (gensum_param_desc *desc, const char *reason) | |
1237 | { | |
1238 | if (!desc->split_candidate) | |
1239 | return; | |
1240 | ||
1241 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1242 | fprintf (dump_file, "! Disqualifying parameter number %i - %s\n", | |
1243 | desc->param_number, reason); | |
1244 | ||
1245 | desc->split_candidate = false; | |
1246 | } | |
1247 | ||
1248 | /* Remove DECL from candidates for IPA-SRA and write REASON to the dump file if | |
1249 | there is one. */ | |
1250 | ||
1251 | static void | |
1252 | disqualify_split_candidate (tree decl, const char *reason) | |
1253 | { | |
1254 | gensum_param_desc *desc = get_gensum_param_desc (decl); | |
1255 | if (desc) | |
1256 | disqualify_split_candidate (desc, reason); | |
1257 | } | |
1258 | ||
1259 | /* Allocate a new access to DESC and fill it in with OFFSET and SIZE. But | |
1260 | first, check that there are not too many of them already. If so, do not | |
1261 | allocate anything and return NULL. */ | |
1262 | ||
1263 | static gensum_param_access * | |
1264 | allocate_access (gensum_param_desc *desc, | |
1265 | HOST_WIDE_INT offset, HOST_WIDE_INT size) | |
1266 | { | |
1267 | if (desc->access_count | |
028d4092 | 1268 | == (unsigned) param_ipa_sra_max_replacements) |
ff6686d2 MJ |
1269 | { |
1270 | disqualify_split_candidate (desc, "Too many replacement candidates"); | |
1271 | return NULL; | |
1272 | } | |
1273 | ||
1274 | gensum_param_access *access | |
1275 | = (gensum_param_access *) obstack_alloc (&gensum_obstack, | |
1276 | sizeof (gensum_param_access)); | |
1277 | memset (access, 0, sizeof (*access)); | |
1278 | access->offset = offset; | |
1279 | access->size = size; | |
1280 | return access; | |
1281 | } | |
1282 | ||
1283 | /* In what context scan_expr_access has been called, whether it deals with a | |
9707b593 MJ |
1284 | load, a function argument, or a store. Please note that in rare |
1285 | circumstances when it is not clear if the access is a load or store, | |
1286 | ISRA_CTX_STORE is used too. */ | |
ff6686d2 MJ |
1287 | |
1288 | enum isra_scan_context {ISRA_CTX_LOAD, ISRA_CTX_ARG, ISRA_CTX_STORE}; | |
1289 | ||
1290 | /* Return an access describing memory access to the variable described by DESC | |
1291 | at OFFSET with SIZE in context CTX, starting at pointer to the linked list | |
dfea3d6f | 1292 | at a certain tree level FIRST. Attempt to create it and put into the |
ff6686d2 MJ |
1293 | appropriate place in the access tree if does not exist, but fail and return |
1294 | NULL if there are already too many accesses, if it would create a partially | |
dfea3d6f | 1295 | overlapping access or if an access would end up within a pre-existing |
ff6686d2 MJ |
1296 | non-call access. */ |
1297 | ||
1298 | static gensum_param_access * | |
1299 | get_access_1 (gensum_param_desc *desc, gensum_param_access **first, | |
1300 | HOST_WIDE_INT offset, HOST_WIDE_INT size, isra_scan_context ctx) | |
1301 | { | |
1302 | gensum_param_access *access = *first, **ptr = first; | |
1303 | ||
1304 | if (!access) | |
1305 | { | |
1306 | /* No pre-existing access at this level, just create it. */ | |
1307 | gensum_param_access *a = allocate_access (desc, offset, size); | |
1308 | if (!a) | |
1309 | return NULL; | |
1310 | *first = a; | |
1311 | return *first; | |
1312 | } | |
1313 | ||
1314 | if (access->offset >= offset + size) | |
1315 | { | |
1316 | /* We want to squeeze it in front of the very first access, just do | |
1317 | it. */ | |
1318 | gensum_param_access *r = allocate_access (desc, offset, size); | |
1319 | if (!r) | |
1320 | return NULL; | |
1321 | r->next_sibling = access; | |
1322 | *first = r; | |
1323 | return r; | |
1324 | } | |
1325 | ||
1326 | /* Skip all accesses that have to come before us until the next sibling is | |
1327 | already too far. */ | |
1328 | while (offset >= access->offset + access->size | |
1329 | && access->next_sibling | |
1330 | && access->next_sibling->offset < offset + size) | |
1331 | { | |
1332 | ptr = &access->next_sibling; | |
1333 | access = access->next_sibling; | |
1334 | } | |
1335 | ||
1336 | /* At this point we know we do not belong before access. */ | |
1337 | gcc_assert (access->offset < offset + size); | |
1338 | ||
1339 | if (access->offset == offset && access->size == size) | |
1340 | /* We found what we were looking for. */ | |
1341 | return access; | |
1342 | ||
1343 | if (access->offset <= offset | |
1344 | && access->offset + access->size >= offset + size) | |
1345 | { | |
1346 | /* We fit into access which is larger than us. We need to find/create | |
1347 | something below access. But we only allow nesting in call | |
1348 | arguments. */ | |
1349 | if (access->nonarg) | |
1350 | return NULL; | |
1351 | ||
1352 | return get_access_1 (desc, &access->first_child, offset, size, ctx); | |
1353 | } | |
1354 | ||
1355 | if (offset <= access->offset | |
1356 | && offset + size >= access->offset + access->size) | |
1357 | /* We are actually bigger than access, which fully fits into us, take its | |
1358 | place and make all accesses fitting into it its children. */ | |
1359 | { | |
1360 | /* But first, we only allow nesting in call arguments so check if that is | |
1361 | what we are trying to represent. */ | |
1362 | if (ctx != ISRA_CTX_ARG) | |
1363 | return NULL; | |
1364 | ||
1365 | gensum_param_access *r = allocate_access (desc, offset, size); | |
1366 | if (!r) | |
1367 | return NULL; | |
1368 | r->first_child = access; | |
1369 | ||
1370 | while (access->next_sibling | |
1371 | && access->next_sibling->offset < offset + size) | |
1372 | access = access->next_sibling; | |
1373 | if (access->offset + access->size > offset + size) | |
1374 | { | |
1375 | /* This must be a different access, which are sorted, so the | |
1376 | following must be true and this signals a partial overlap. */ | |
1377 | gcc_assert (access->offset > offset); | |
1378 | return NULL; | |
1379 | } | |
1380 | ||
1381 | r->next_sibling = access->next_sibling; | |
1382 | access->next_sibling = NULL; | |
1383 | *ptr = r; | |
1384 | return r; | |
1385 | } | |
1386 | ||
1387 | if (offset >= access->offset + access->size) | |
1388 | { | |
1389 | /* We belong after access. */ | |
1390 | gensum_param_access *r = allocate_access (desc, offset, size); | |
1391 | if (!r) | |
1392 | return NULL; | |
1393 | r->next_sibling = access->next_sibling; | |
1394 | access->next_sibling = r; | |
1395 | return r; | |
1396 | } | |
1397 | ||
1398 | if (offset < access->offset) | |
1399 | { | |
1400 | /* We know the following, otherwise we would have created a | |
1401 | super-access. */ | |
1402 | gcc_checking_assert (offset + size < access->offset + access->size); | |
1403 | return NULL; | |
1404 | } | |
1405 | ||
1406 | if (offset + size > access->offset + access->size) | |
1407 | { | |
1408 | /* Likewise. */ | |
1409 | gcc_checking_assert (offset > access->offset); | |
1410 | return NULL; | |
1411 | } | |
1412 | ||
1413 | gcc_unreachable (); | |
1414 | } | |
1415 | ||
1416 | /* Return an access describing memory access to the variable described by DESC | |
1417 | at OFFSET with SIZE in context CTX, mark it as used in context CTX. Attempt | |
1418 | to create if it does not exist, but fail and return NULL if there are | |
1419 | already too many accesses, if it would create a partially overlapping access | |
dfea3d6f | 1420 | or if an access would end up in a non-call access. */ |
ff6686d2 MJ |
1421 | |
1422 | static gensum_param_access * | |
1423 | get_access (gensum_param_desc *desc, HOST_WIDE_INT offset, HOST_WIDE_INT size, | |
1424 | isra_scan_context ctx) | |
1425 | { | |
1426 | gcc_checking_assert (desc->split_candidate); | |
1427 | ||
1428 | gensum_param_access *access = get_access_1 (desc, &desc->accesses, offset, | |
1429 | size, ctx); | |
1430 | if (!access) | |
1431 | { | |
1432 | disqualify_split_candidate (desc, | |
1433 | "Bad access overlap or too many accesses"); | |
1434 | return NULL; | |
1435 | } | |
1436 | ||
1437 | switch (ctx) | |
1438 | { | |
1439 | case ISRA_CTX_STORE: | |
1440 | gcc_assert (!desc->by_ref); | |
1441 | /* Fall-through */ | |
1442 | case ISRA_CTX_LOAD: | |
1443 | access->nonarg = true; | |
1444 | break; | |
1445 | case ISRA_CTX_ARG: | |
1446 | break; | |
1447 | } | |
1448 | ||
1449 | return access; | |
1450 | } | |
1451 | ||
1452 | /* Verify that parameter access tree starting with ACCESS is in good shape. | |
dfea3d6f | 1453 | PARENT_OFFSET and PARENT_SIZE are the corresponding fields of parent of |
ff6686d2 MJ |
1454 | ACCESS or zero if there is none. */ |
1455 | ||
1456 | static bool | |
1457 | verify_access_tree_1 (gensum_param_access *access, HOST_WIDE_INT parent_offset, | |
1458 | HOST_WIDE_INT parent_size) | |
1459 | { | |
1460 | while (access) | |
1461 | { | |
1462 | gcc_assert (access->offset >= 0 && access->size > 0); | |
1463 | ||
1464 | if (parent_size != 0) | |
1465 | { | |
1466 | if (access->offset < parent_offset) | |
1467 | { | |
1468 | error ("Access offset before parent offset"); | |
1469 | return true; | |
1470 | } | |
1471 | if (access->size >= parent_size) | |
1472 | { | |
1473 | error ("Access size greater or equal to its parent size"); | |
1474 | return true; | |
1475 | } | |
1476 | if (access->offset + access->size > parent_offset + parent_size) | |
1477 | { | |
1478 | error ("Access terminates outside of its parent"); | |
1479 | return true; | |
1480 | } | |
1481 | } | |
1482 | ||
1483 | if (verify_access_tree_1 (access->first_child, access->offset, | |
1484 | access->size)) | |
1485 | return true; | |
1486 | ||
1487 | if (access->next_sibling | |
1488 | && (access->next_sibling->offset < access->offset + access->size)) | |
1489 | { | |
1490 | error ("Access overlaps with its sibling"); | |
1491 | return true; | |
1492 | } | |
1493 | ||
1494 | access = access->next_sibling; | |
1495 | } | |
1496 | return false; | |
1497 | } | |
1498 | ||
1499 | /* Verify that parameter access tree starting with ACCESS is in good shape, | |
1500 | halt compilation and dump the tree to stderr if not. */ | |
1501 | ||
1502 | DEBUG_FUNCTION void | |
1503 | isra_verify_access_tree (gensum_param_access *access) | |
1504 | { | |
1505 | if (verify_access_tree_1 (access, 0, 0)) | |
1506 | { | |
1507 | for (; access; access = access->next_sibling) | |
1508 | dump_gensum_access (stderr, access, 2); | |
1509 | internal_error ("IPA-SRA access verification failed"); | |
1510 | } | |
1511 | } | |
1512 | ||
1513 | ||
1514 | /* Callback of walk_stmt_load_store_addr_ops visit_addr used to determine | |
1515 | GIMPLE_ASM operands with memory constrains which cannot be scalarized. */ | |
1516 | ||
1517 | static bool | |
1518 | asm_visit_addr (gimple *, tree op, tree, void *) | |
1519 | { | |
1520 | op = get_base_address (op); | |
1521 | if (op | |
1522 | && TREE_CODE (op) == PARM_DECL) | |
1523 | disqualify_split_candidate (op, "Non-scalarizable GIMPLE_ASM operand."); | |
1524 | ||
1525 | return false; | |
1526 | } | |
1527 | ||
1528 | /* Mark a dereference of parameter identified by DESC of distance DIST in a | |
1529 | basic block BB, unless the BB has already been marked as a potentially | |
1530 | final. */ | |
1531 | ||
1532 | static void | |
1533 | mark_param_dereference (gensum_param_desc *desc, HOST_WIDE_INT dist, | |
1534 | basic_block bb) | |
1535 | { | |
1536 | gcc_assert (desc->by_ref); | |
1537 | gcc_checking_assert (desc->split_candidate); | |
1538 | ||
1539 | if (bitmap_bit_p (final_bbs, bb->index)) | |
1540 | return; | |
1541 | ||
1542 | int idx = bb->index * by_ref_count + desc->deref_index; | |
1543 | if (bb_dereferences[idx] < dist) | |
1544 | bb_dereferences[idx] = dist; | |
1545 | } | |
1546 | ||
1547 | /* Return true, if any potential replacements should use NEW_TYPE as opposed to | |
1548 | previously recorded OLD_TYPE. */ | |
1549 | ||
1550 | static bool | |
1551 | type_prevails_p (tree old_type, tree new_type) | |
1552 | { | |
1553 | if (old_type == new_type) | |
1554 | return false; | |
1555 | ||
1556 | /* Non-aggregates are always better. */ | |
1557 | if (!is_gimple_reg_type (old_type) | |
1558 | && is_gimple_reg_type (new_type)) | |
1559 | return true; | |
1560 | if (is_gimple_reg_type (old_type) | |
1561 | && !is_gimple_reg_type (new_type)) | |
1562 | return false; | |
1563 | ||
1564 | /* Prefer any complex or vector type over any other scalar type. */ | |
1565 | if (TREE_CODE (old_type) != COMPLEX_TYPE | |
1566 | && TREE_CODE (old_type) != VECTOR_TYPE | |
1567 | && (TREE_CODE (new_type) == COMPLEX_TYPE | |
1568 | || TREE_CODE (new_type) == VECTOR_TYPE)) | |
1569 | return true; | |
1570 | if ((TREE_CODE (old_type) == COMPLEX_TYPE | |
1571 | || TREE_CODE (old_type) == VECTOR_TYPE) | |
1572 | && TREE_CODE (new_type) != COMPLEX_TYPE | |
1573 | && TREE_CODE (new_type) != VECTOR_TYPE) | |
1574 | return false; | |
1575 | ||
1576 | /* Use the integral type with the bigger precision. */ | |
1577 | if (INTEGRAL_TYPE_P (old_type) | |
1578 | && INTEGRAL_TYPE_P (new_type)) | |
1579 | return (TYPE_PRECISION (new_type) > TYPE_PRECISION (old_type)); | |
1580 | ||
1581 | /* Attempt to disregard any integral type with non-full precision. */ | |
1582 | if (INTEGRAL_TYPE_P (old_type) | |
1583 | && (TREE_INT_CST_LOW (TYPE_SIZE (old_type)) | |
1584 | != TYPE_PRECISION (old_type))) | |
1585 | return true; | |
1586 | if (INTEGRAL_TYPE_P (new_type) | |
1587 | && (TREE_INT_CST_LOW (TYPE_SIZE (new_type)) | |
1588 | != TYPE_PRECISION (new_type))) | |
1589 | return false; | |
1590 | /* Stabilize the selection. */ | |
1591 | return TYPE_UID (old_type) < TYPE_UID (new_type); | |
1592 | } | |
1593 | ||
1594 | /* When scanning an expression which is a call argument, this structure | |
dfea3d6f | 1595 | specifies the call and the position of the argument. */ |
ff6686d2 MJ |
1596 | |
1597 | struct scan_call_info | |
1598 | { | |
1599 | /* Call graph edge representing the call. */ | |
1600 | cgraph_edge *cs; | |
1601 | /* Total number of arguments in the call. */ | |
1602 | unsigned argument_count; | |
1603 | /* Number of the actual argument being scanned. */ | |
1604 | unsigned arg_idx; | |
1605 | }; | |
1606 | ||
1607 | /* Record use of ACCESS which belongs to a parameter described by DESC in a | |
1608 | call argument described by CALL_INFO. */ | |
1609 | ||
1610 | static void | |
1611 | record_nonregister_call_use (gensum_param_desc *desc, | |
1612 | scan_call_info *call_info, | |
1613 | unsigned unit_offset, unsigned unit_size) | |
1614 | { | |
1615 | isra_call_summary *csum = call_sums->get_create (call_info->cs); | |
1616 | csum->init_inputs (call_info->argument_count); | |
1617 | ||
1618 | isra_param_flow *param_flow = &csum->m_arg_flow[call_info->arg_idx]; | |
1619 | param_flow->aggregate_pass_through = true; | |
1620 | set_single_param_flow_source (param_flow, desc->param_number); | |
1621 | param_flow->unit_offset = unit_offset; | |
1622 | param_flow->unit_size = unit_size; | |
1623 | desc->call_uses++; | |
1624 | } | |
1625 | ||
1626 | /* Callback of walk_aliased_vdefs, just mark that there was a possible | |
1627 | modification. */ | |
1628 | ||
1629 | static bool | |
1630 | mark_maybe_modified (ao_ref *, tree, void *data) | |
1631 | { | |
1632 | bool *maybe_modified = (bool *) data; | |
1633 | *maybe_modified = true; | |
1634 | return true; | |
1635 | } | |
1636 | ||
1637 | /* Analyze expression EXPR from GIMPLE for accesses to parameters. CTX | |
1638 | specifies whether EXPR is used in a load, store or as an argument call. BB | |
1639 | must be the basic block in which expr resides. If CTX specifies call | |
dfea3d6f | 1640 | argument context, CALL_INFO must describe that call and argument position, |
ff6686d2 MJ |
1641 | otherwise it is ignored. */ |
1642 | ||
1643 | static void | |
1644 | scan_expr_access (tree expr, gimple *stmt, isra_scan_context ctx, | |
1645 | basic_block bb, scan_call_info *call_info = NULL) | |
1646 | { | |
1647 | poly_int64 poffset, psize, pmax_size; | |
1648 | HOST_WIDE_INT offset, size, max_size; | |
1649 | tree base; | |
1650 | bool deref = false; | |
1651 | bool reverse; | |
1652 | ||
1653 | if (TREE_CODE (expr) == BIT_FIELD_REF | |
1654 | || TREE_CODE (expr) == IMAGPART_EXPR | |
1655 | || TREE_CODE (expr) == REALPART_EXPR) | |
1656 | expr = TREE_OPERAND (expr, 0); | |
1657 | ||
1658 | base = get_ref_base_and_extent (expr, &poffset, &psize, &pmax_size, &reverse); | |
1659 | ||
1660 | if (TREE_CODE (base) == MEM_REF) | |
1661 | { | |
1662 | tree op = TREE_OPERAND (base, 0); | |
1663 | if (TREE_CODE (op) != SSA_NAME | |
1664 | || !SSA_NAME_IS_DEFAULT_DEF (op)) | |
1665 | return; | |
1666 | base = SSA_NAME_VAR (op); | |
1667 | if (!base) | |
1668 | return; | |
1669 | deref = true; | |
1670 | } | |
1671 | if (TREE_CODE (base) != PARM_DECL) | |
1672 | return; | |
1673 | ||
1674 | gensum_param_desc *desc = get_gensum_param_desc (base); | |
1675 | if (!desc || !desc->split_candidate) | |
1676 | return; | |
1677 | ||
1678 | if (!poffset.is_constant (&offset) | |
1679 | || !psize.is_constant (&size) | |
1680 | || !pmax_size.is_constant (&max_size)) | |
1681 | { | |
1682 | disqualify_split_candidate (desc, "Encountered a polynomial-sized " | |
1683 | "access."); | |
1684 | return; | |
1685 | } | |
1686 | if (size < 0 || size != max_size) | |
1687 | { | |
1688 | disqualify_split_candidate (desc, "Encountered a variable sized access."); | |
1689 | return; | |
1690 | } | |
1691 | if (TREE_CODE (expr) == COMPONENT_REF | |
1692 | && DECL_BIT_FIELD (TREE_OPERAND (expr, 1))) | |
1693 | { | |
1694 | disqualify_split_candidate (desc, "Encountered a bit-field access."); | |
1695 | return; | |
1696 | } | |
5a4d0da4 MJ |
1697 | if (offset < 0) |
1698 | { | |
1699 | disqualify_split_candidate (desc, "Encountered an access at a " | |
1700 | "negative offset."); | |
1701 | return; | |
1702 | } | |
ff6686d2 MJ |
1703 | gcc_assert ((offset % BITS_PER_UNIT) == 0); |
1704 | gcc_assert ((size % BITS_PER_UNIT) == 0); | |
1705 | if ((offset / BITS_PER_UNIT) >= (UINT_MAX - ISRA_ARG_SIZE_LIMIT) | |
1706 | || (size / BITS_PER_UNIT) >= ISRA_ARG_SIZE_LIMIT) | |
1707 | { | |
1708 | disqualify_split_candidate (desc, "Encountered an access with too big " | |
1709 | "offset or size"); | |
1710 | return; | |
1711 | } | |
1712 | ||
1713 | tree type = TREE_TYPE (expr); | |
1714 | unsigned int exp_align = get_object_alignment (expr); | |
1715 | ||
1716 | if (exp_align < TYPE_ALIGN (type)) | |
1717 | { | |
1718 | disqualify_split_candidate (desc, "Underaligned access."); | |
1719 | return; | |
1720 | } | |
1721 | ||
1722 | if (deref) | |
1723 | { | |
1724 | if (!desc->by_ref) | |
1725 | { | |
1726 | disqualify_split_candidate (desc, "Dereferencing a non-reference."); | |
1727 | return; | |
1728 | } | |
1729 | else if (ctx == ISRA_CTX_STORE) | |
1730 | { | |
1731 | disqualify_split_candidate (desc, "Storing to data passed by " | |
1732 | "reference."); | |
1733 | return; | |
1734 | } | |
1735 | ||
1736 | if (!aa_walking_limit) | |
1737 | { | |
1738 | disqualify_split_candidate (desc, "Out of alias analysis step " | |
1739 | "limit."); | |
1740 | return; | |
1741 | } | |
1742 | ||
1743 | gcc_checking_assert (gimple_vuse (stmt)); | |
1744 | bool maybe_modified = false; | |
1745 | ao_ref ar; | |
1746 | ||
1747 | ao_ref_init (&ar, expr); | |
1748 | bitmap visited = BITMAP_ALLOC (NULL); | |
1749 | int walked = walk_aliased_vdefs (&ar, gimple_vuse (stmt), | |
1750 | mark_maybe_modified, &maybe_modified, | |
1751 | &visited, NULL, aa_walking_limit); | |
1752 | BITMAP_FREE (visited); | |
1753 | if (walked > 0) | |
1754 | { | |
1755 | gcc_assert (aa_walking_limit > walked); | |
1756 | aa_walking_limit = aa_walking_limit - walked; | |
1757 | } | |
1758 | if (walked < 0) | |
1759 | aa_walking_limit = 0; | |
1760 | if (maybe_modified || walked < 0) | |
1761 | { | |
1762 | disqualify_split_candidate (desc, "Data passed by reference possibly " | |
1763 | "modified through an alias."); | |
1764 | return; | |
1765 | } | |
1766 | else | |
1767 | mark_param_dereference (desc, offset + size, bb); | |
1768 | } | |
1769 | else | |
1770 | /* Pointer parameters with direct uses should have been ruled out by | |
dfea3d6f | 1771 | analyzing SSA default def when looking at the parameters. */ |
ff6686d2 MJ |
1772 | gcc_assert (!desc->by_ref); |
1773 | ||
1774 | gensum_param_access *access = get_access (desc, offset, size, ctx); | |
1775 | if (!access) | |
1776 | return; | |
1777 | ||
1778 | if (ctx == ISRA_CTX_ARG) | |
1779 | { | |
1780 | gcc_checking_assert (call_info); | |
1781 | ||
1782 | if (!deref) | |
1783 | record_nonregister_call_use (desc, call_info, offset / BITS_PER_UNIT, | |
1784 | size / BITS_PER_UNIT); | |
1785 | else | |
1786 | /* This is not a pass-through of a pointer, this is a use like any | |
1787 | other. */ | |
1788 | access->nonarg = true; | |
1789 | } | |
1790 | ||
1791 | if (!access->type) | |
1792 | { | |
1793 | access->type = type; | |
1794 | access->alias_ptr_type = reference_alias_ptr_type (expr); | |
1795 | access->reverse = reverse; | |
1796 | } | |
1797 | else | |
1798 | { | |
1799 | if (exp_align < TYPE_ALIGN (access->type)) | |
1800 | { | |
1801 | disqualify_split_candidate (desc, "Reference has lower alignment " | |
1802 | "than a previous one."); | |
1803 | return; | |
1804 | } | |
1805 | if (access->alias_ptr_type != reference_alias_ptr_type (expr)) | |
1806 | { | |
1807 | disqualify_split_candidate (desc, "Multiple alias pointer types."); | |
1808 | return; | |
1809 | } | |
1810 | if (access->reverse != reverse) | |
1811 | { | |
1812 | disqualify_split_candidate (desc, "Both normal and reverse " | |
1813 | "scalar storage order."); | |
1814 | return; | |
1815 | } | |
1816 | if (!deref | |
1817 | && (AGGREGATE_TYPE_P (type) || AGGREGATE_TYPE_P (access->type)) | |
1818 | && (TYPE_MAIN_VARIANT (access->type) != TYPE_MAIN_VARIANT (type))) | |
1819 | { | |
1820 | /* We need the same aggregate type on all accesses to be able to | |
1821 | distinguish transformation spots from pass-through arguments in | |
dfea3d6f JJ |
1822 | the transformation phase. */ |
1823 | disqualify_split_candidate (desc, "We do not support aggregate " | |
ff6686d2 MJ |
1824 | "type punning."); |
1825 | return; | |
1826 | } | |
1827 | ||
1828 | if (type_prevails_p (access->type, type)) | |
1829 | access->type = type; | |
1830 | } | |
1831 | } | |
1832 | ||
1833 | /* Scan body function described by NODE and FUN and create access trees for | |
1834 | parameters. */ | |
1835 | ||
1836 | static void | |
1837 | scan_function (cgraph_node *node, struct function *fun) | |
1838 | { | |
1839 | basic_block bb; | |
1840 | ||
1841 | FOR_EACH_BB_FN (bb, fun) | |
1842 | { | |
1843 | gimple_stmt_iterator gsi; | |
1844 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
1845 | { | |
1846 | gimple *stmt = gsi_stmt (gsi); | |
1847 | ||
1848 | if (stmt_can_throw_external (fun, stmt)) | |
1849 | bitmap_set_bit (final_bbs, bb->index); | |
1850 | switch (gimple_code (stmt)) | |
1851 | { | |
1852 | case GIMPLE_RETURN: | |
1853 | { | |
1854 | tree t = gimple_return_retval (as_a <greturn *> (stmt)); | |
1855 | if (t != NULL_TREE) | |
1856 | scan_expr_access (t, stmt, ISRA_CTX_LOAD, bb); | |
1857 | bitmap_set_bit (final_bbs, bb->index); | |
1858 | } | |
1859 | break; | |
1860 | ||
1861 | case GIMPLE_ASSIGN: | |
1862 | if (gimple_assign_single_p (stmt) | |
1863 | && !gimple_clobber_p (stmt)) | |
1864 | { | |
1865 | tree rhs = gimple_assign_rhs1 (stmt); | |
1866 | scan_expr_access (rhs, stmt, ISRA_CTX_LOAD, bb); | |
1867 | tree lhs = gimple_assign_lhs (stmt); | |
1868 | scan_expr_access (lhs, stmt, ISRA_CTX_STORE, bb); | |
1869 | } | |
1870 | break; | |
1871 | ||
1872 | case GIMPLE_CALL: | |
1873 | { | |
1874 | unsigned argument_count = gimple_call_num_args (stmt); | |
9707b593 MJ |
1875 | isra_scan_context ctx = ISRA_CTX_ARG; |
1876 | scan_call_info call_info, *call_info_p = &call_info; | |
1877 | if (gimple_call_internal_p (stmt)) | |
1878 | { | |
1879 | call_info_p = NULL; | |
1880 | ctx = ISRA_CTX_LOAD; | |
1881 | internal_fn ifn = gimple_call_internal_fn (stmt); | |
1882 | if (internal_store_fn_p (ifn)) | |
1883 | ctx = ISRA_CTX_STORE; | |
1884 | } | |
1885 | else | |
1886 | { | |
1887 | call_info.cs = node->get_edge (stmt); | |
1888 | call_info.argument_count = argument_count; | |
1889 | } | |
ff6686d2 MJ |
1890 | |
1891 | for (unsigned i = 0; i < argument_count; i++) | |
1892 | { | |
1893 | call_info.arg_idx = i; | |
1894 | scan_expr_access (gimple_call_arg (stmt, i), stmt, | |
9707b593 | 1895 | ctx, bb, call_info_p); |
ff6686d2 MJ |
1896 | } |
1897 | ||
1898 | tree lhs = gimple_call_lhs (stmt); | |
1899 | if (lhs) | |
1900 | scan_expr_access (lhs, stmt, ISRA_CTX_STORE, bb); | |
1901 | int flags = gimple_call_flags (stmt); | |
1902 | if ((flags & (ECF_CONST | ECF_PURE)) == 0) | |
1903 | bitmap_set_bit (final_bbs, bb->index); | |
1904 | } | |
1905 | break; | |
1906 | ||
1907 | case GIMPLE_ASM: | |
1908 | { | |
1909 | gasm *asm_stmt = as_a <gasm *> (stmt); | |
1910 | walk_stmt_load_store_addr_ops (asm_stmt, NULL, NULL, NULL, | |
1911 | asm_visit_addr); | |
1912 | bitmap_set_bit (final_bbs, bb->index); | |
1913 | ||
1914 | for (unsigned i = 0; i < gimple_asm_ninputs (asm_stmt); i++) | |
1915 | { | |
1916 | tree t = TREE_VALUE (gimple_asm_input_op (asm_stmt, i)); | |
1917 | scan_expr_access (t, stmt, ISRA_CTX_LOAD, bb); | |
1918 | } | |
1919 | for (unsigned i = 0; i < gimple_asm_noutputs (asm_stmt); i++) | |
1920 | { | |
1921 | tree t = TREE_VALUE (gimple_asm_output_op (asm_stmt, i)); | |
1922 | scan_expr_access (t, stmt, ISRA_CTX_STORE, bb); | |
1923 | } | |
1924 | } | |
1925 | break; | |
1926 | ||
1927 | default: | |
1928 | break; | |
1929 | } | |
1930 | } | |
1931 | } | |
1932 | } | |
1933 | ||
1934 | /* Return true if SSA_NAME NAME is only used in return statements, or if | |
1935 | results of any operations it is involved in are only used in return | |
1936 | statements. ANALYZED is a bitmap that tracks which SSA names we have | |
1937 | already started investigating. */ | |
1938 | ||
1939 | static bool | |
1940 | ssa_name_only_returned_p (tree name, bitmap analyzed) | |
1941 | { | |
1942 | bool res = true; | |
1943 | imm_use_iterator imm_iter; | |
1944 | gimple *stmt; | |
1945 | ||
1946 | FOR_EACH_IMM_USE_STMT (stmt, imm_iter, name) | |
1947 | { | |
1948 | if (is_gimple_debug (stmt)) | |
1949 | continue; | |
1950 | ||
1951 | if (gimple_code (stmt) == GIMPLE_RETURN) | |
1952 | { | |
1953 | tree t = gimple_return_retval (as_a <greturn *> (stmt)); | |
1954 | if (t != name) | |
1955 | { | |
1956 | res = false; | |
1957 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
1958 | } | |
1959 | } | |
1960 | else if ((is_gimple_assign (stmt) && !gimple_has_volatile_ops (stmt)) | |
1961 | || gimple_code (stmt) == GIMPLE_PHI) | |
1962 | { | |
1963 | /* TODO: And perhaps for const function calls too? */ | |
1964 | tree lhs; | |
1965 | if (gimple_code (stmt) == GIMPLE_PHI) | |
1966 | lhs = gimple_phi_result (stmt); | |
1967 | else | |
1968 | lhs = gimple_assign_lhs (stmt); | |
1969 | ||
1970 | if (TREE_CODE (lhs) != SSA_NAME) | |
1971 | { | |
1972 | res = false; | |
1973 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
1974 | } | |
1975 | gcc_assert (!gimple_vdef (stmt)); | |
1976 | if (bitmap_set_bit (analyzed, SSA_NAME_VERSION (lhs)) | |
1977 | && !ssa_name_only_returned_p (lhs, analyzed)) | |
1978 | { | |
1979 | res = false; | |
1980 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
1981 | } | |
1982 | } | |
1983 | else | |
1984 | { | |
1985 | res = false; | |
1986 | BREAK_FROM_IMM_USE_STMT (imm_iter); | |
1987 | } | |
1988 | } | |
1989 | return res; | |
1990 | } | |
1991 | ||
1992 | /* Inspect the uses of the return value of the call associated with CS, and if | |
1993 | it is not used or if it is only used to construct the return value of the | |
1994 | caller, mark it as such in call or caller summary. Also check for | |
1995 | misaligned arguments. */ | |
1996 | ||
1997 | static void | |
1998 | isra_analyze_call (cgraph_edge *cs) | |
1999 | { | |
2000 | gcall *call_stmt = cs->call_stmt; | |
2001 | unsigned count = gimple_call_num_args (call_stmt); | |
2002 | isra_call_summary *csum = call_sums->get_create (cs); | |
2003 | ||
2004 | for (unsigned i = 0; i < count; i++) | |
2005 | { | |
2006 | tree arg = gimple_call_arg (call_stmt, i); | |
2007 | if (is_gimple_reg (arg)) | |
2008 | continue; | |
2009 | ||
2010 | tree offset; | |
2011 | poly_int64 bitsize, bitpos; | |
2012 | machine_mode mode; | |
2013 | int unsignedp, reversep, volatilep = 0; | |
2014 | get_inner_reference (arg, &bitsize, &bitpos, &offset, &mode, | |
2015 | &unsignedp, &reversep, &volatilep); | |
2016 | if (!multiple_p (bitpos, BITS_PER_UNIT)) | |
2017 | { | |
2018 | csum->m_bit_aligned_arg = true; | |
2019 | break; | |
2020 | } | |
2021 | } | |
2022 | ||
2023 | tree lhs = gimple_call_lhs (call_stmt); | |
2024 | if (lhs) | |
2025 | { | |
2026 | /* TODO: Also detect aggregates on a LHS of a call that are only returned | |
2027 | from this function (without being read anywhere). */ | |
2028 | if (TREE_CODE (lhs) == SSA_NAME) | |
2029 | { | |
2030 | bitmap analyzed = BITMAP_ALLOC (NULL); | |
2031 | if (ssa_name_only_returned_p (lhs, analyzed)) | |
2032 | csum->m_return_returned = true; | |
2033 | BITMAP_FREE (analyzed); | |
2034 | } | |
2035 | } | |
2036 | else | |
2037 | csum->m_return_ignored = true; | |
2038 | } | |
2039 | ||
2040 | /* Look at all calls going out of NODE, described also by IFS and perform all | |
2041 | analyses necessary for IPA-SRA that are not done at body scan time or done | |
2042 | even when body is not scanned because the function is not a candidate. */ | |
2043 | ||
2044 | static void | |
2045 | isra_analyze_all_outgoing_calls (cgraph_node *node) | |
2046 | { | |
2047 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) | |
2048 | isra_analyze_call (cs); | |
2049 | for (cgraph_edge *cs = node->indirect_calls; cs; cs = cs->next_callee) | |
2050 | isra_analyze_call (cs); | |
2051 | } | |
2052 | ||
2053 | /* Dump a dereferences table with heading STR to file F. */ | |
2054 | ||
2055 | static void | |
2056 | dump_dereferences_table (FILE *f, struct function *fun, const char *str) | |
2057 | { | |
2058 | basic_block bb; | |
2059 | ||
2060 | fprintf (dump_file, "%s", str); | |
2061 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (fun), | |
2062 | EXIT_BLOCK_PTR_FOR_FN (fun), next_bb) | |
2063 | { | |
2064 | fprintf (f, "%4i %i ", bb->index, bitmap_bit_p (final_bbs, bb->index)); | |
2065 | if (bb != EXIT_BLOCK_PTR_FOR_FN (fun)) | |
2066 | { | |
2067 | int i; | |
2068 | for (i = 0; i < by_ref_count; i++) | |
2069 | { | |
2070 | int idx = bb->index * by_ref_count + i; | |
2071 | fprintf (f, " %4" HOST_WIDE_INT_PRINT "d", bb_dereferences[idx]); | |
2072 | } | |
2073 | } | |
2074 | fprintf (f, "\n"); | |
2075 | } | |
2076 | fprintf (dump_file, "\n"); | |
2077 | } | |
2078 | ||
2079 | /* Propagate distances in bb_dereferences in the opposite direction than the | |
2080 | control flow edges, in each step storing the maximum of the current value | |
2081 | and the minimum of all successors. These steps are repeated until the table | |
2082 | stabilizes. Note that BBs which might terminate the functions (according to | |
2083 | final_bbs bitmap) never updated in this way. */ | |
2084 | ||
2085 | static void | |
2086 | propagate_dereference_distances (struct function *fun) | |
2087 | { | |
2088 | basic_block bb; | |
2089 | ||
2090 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2091 | dump_dereferences_table (dump_file, fun, | |
2092 | "Dereference table before propagation:\n"); | |
2093 | ||
2094 | auto_vec<basic_block> queue (last_basic_block_for_fn (fun)); | |
2095 | queue.quick_push (ENTRY_BLOCK_PTR_FOR_FN (fun)); | |
2096 | FOR_EACH_BB_FN (bb, fun) | |
2097 | { | |
2098 | queue.quick_push (bb); | |
2099 | bb->aux = bb; | |
2100 | } | |
2101 | ||
2102 | while (!queue.is_empty ()) | |
2103 | { | |
2104 | edge_iterator ei; | |
2105 | edge e; | |
2106 | bool change = false; | |
2107 | int i; | |
2108 | ||
2109 | bb = queue.pop (); | |
2110 | bb->aux = NULL; | |
2111 | ||
2112 | if (bitmap_bit_p (final_bbs, bb->index)) | |
2113 | continue; | |
2114 | ||
2115 | for (i = 0; i < by_ref_count; i++) | |
2116 | { | |
2117 | int idx = bb->index * by_ref_count + i; | |
2118 | bool first = true; | |
2119 | HOST_WIDE_INT inh = 0; | |
2120 | ||
2121 | FOR_EACH_EDGE (e, ei, bb->succs) | |
2122 | { | |
2123 | int succ_idx = e->dest->index * by_ref_count + i; | |
2124 | ||
2125 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (fun)) | |
2126 | continue; | |
2127 | ||
2128 | if (first) | |
2129 | { | |
2130 | first = false; | |
2131 | inh = bb_dereferences [succ_idx]; | |
2132 | } | |
2133 | else if (bb_dereferences [succ_idx] < inh) | |
2134 | inh = bb_dereferences [succ_idx]; | |
2135 | } | |
2136 | ||
2137 | if (!first && bb_dereferences[idx] < inh) | |
2138 | { | |
2139 | bb_dereferences[idx] = inh; | |
2140 | change = true; | |
2141 | } | |
2142 | } | |
2143 | ||
2144 | if (change) | |
2145 | FOR_EACH_EDGE (e, ei, bb->preds) | |
2146 | { | |
2147 | if (e->src->aux) | |
2148 | continue; | |
2149 | ||
2150 | e->src->aux = e->src; | |
2151 | queue.quick_push (e->src); | |
2152 | } | |
2153 | } | |
2154 | ||
2155 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2156 | dump_dereferences_table (dump_file, fun, | |
2157 | "Dereference table after propagation:\n"); | |
2158 | } | |
2159 | ||
2160 | /* Perform basic checks on ACCESS to PARM described by DESC and all its | |
2161 | children, return true if the parameter cannot be split, otherwise return | |
2162 | true and update *TOTAL_SIZE and *ONLY_CALLS. ENTRY_BB_INDEX must be the | |
2163 | index of the entry BB in the function of PARM. */ | |
2164 | ||
2165 | static bool | |
2166 | check_gensum_access (tree parm, gensum_param_desc *desc, | |
2167 | gensum_param_access *access, | |
2168 | HOST_WIDE_INT *nonarg_acc_size, bool *only_calls, | |
2169 | int entry_bb_index) | |
2170 | { | |
2171 | if (access->nonarg) | |
2172 | { | |
2173 | *only_calls = false; | |
2174 | *nonarg_acc_size += access->size; | |
2175 | ||
2176 | if (access->first_child) | |
2177 | { | |
2178 | disqualify_split_candidate (desc, "Overlapping non-call uses."); | |
2179 | return true; | |
2180 | } | |
2181 | } | |
2182 | /* Do not decompose a non-BLKmode param in a way that would create | |
2183 | BLKmode params. Especially for by-reference passing (thus, | |
2184 | pointer-type param) this is hardly worthwhile. */ | |
2185 | if (DECL_MODE (parm) != BLKmode | |
2186 | && TYPE_MODE (access->type) == BLKmode) | |
2187 | { | |
2188 | disqualify_split_candidate (desc, "Would convert a non-BLK to a BLK."); | |
2189 | return true; | |
2190 | } | |
2191 | ||
2192 | if (desc->by_ref) | |
2193 | { | |
2194 | int idx = (entry_bb_index * by_ref_count + desc->deref_index); | |
2195 | if ((access->offset + access->size) > bb_dereferences[idx]) | |
2196 | { | |
2197 | disqualify_split_candidate (desc, "Would create a possibly " | |
2198 | "illegal dereference in a caller."); | |
2199 | return true; | |
2200 | } | |
2201 | } | |
2202 | ||
2203 | for (gensum_param_access *ch = access->first_child; | |
2204 | ch; | |
2205 | ch = ch->next_sibling) | |
2206 | if (check_gensum_access (parm, desc, ch, nonarg_acc_size, only_calls, | |
2207 | entry_bb_index)) | |
2208 | return true; | |
2209 | ||
2210 | return false; | |
2211 | } | |
2212 | ||
2213 | /* Copy data from FROM and all of its children to a vector of accesses in IPA | |
2214 | descriptor DESC. */ | |
2215 | ||
2216 | static void | |
2217 | copy_accesses_to_ipa_desc (gensum_param_access *from, isra_param_desc *desc) | |
2218 | { | |
2219 | param_access *to = ggc_cleared_alloc<param_access> (); | |
2220 | gcc_checking_assert ((from->offset % BITS_PER_UNIT) == 0); | |
2221 | gcc_checking_assert ((from->size % BITS_PER_UNIT) == 0); | |
2222 | to->unit_offset = from->offset / BITS_PER_UNIT; | |
2223 | to->unit_size = from->size / BITS_PER_UNIT; | |
2224 | to->type = from->type; | |
2225 | to->alias_ptr_type = from->alias_ptr_type; | |
2226 | to->certain = from->nonarg; | |
2227 | to->reverse = from->reverse; | |
2228 | vec_safe_push (desc->accesses, to); | |
2229 | ||
2230 | for (gensum_param_access *ch = from->first_child; | |
2231 | ch; | |
2232 | ch = ch->next_sibling) | |
2233 | copy_accesses_to_ipa_desc (ch, desc); | |
2234 | } | |
2235 | ||
2236 | /* Analyze function body scan results stored in param_accesses and | |
2237 | param_accesses, detect possible transformations and store information of | |
2238 | those in function summary. NODE, FUN and IFS are all various structures | |
2239 | describing the currently analyzed function. */ | |
2240 | ||
2241 | static void | |
2242 | process_scan_results (cgraph_node *node, struct function *fun, | |
2243 | isra_func_summary *ifs, | |
2244 | vec<gensum_param_desc> *param_descriptions) | |
2245 | { | |
2246 | bool check_pass_throughs = false; | |
2247 | bool dereferences_propagated = false; | |
2248 | tree parm = DECL_ARGUMENTS (node->decl); | |
2249 | unsigned param_count = param_descriptions->length(); | |
2250 | ||
2251 | for (unsigned desc_index = 0; | |
2252 | desc_index < param_count; | |
2253 | desc_index++, parm = DECL_CHAIN (parm)) | |
2254 | { | |
2255 | gensum_param_desc *desc = &(*param_descriptions)[desc_index]; | |
581b519f | 2256 | if (!desc->split_candidate) |
ff6686d2 MJ |
2257 | continue; |
2258 | ||
2259 | if (flag_checking) | |
2260 | isra_verify_access_tree (desc->accesses); | |
2261 | ||
2262 | if (!dereferences_propagated | |
2263 | && desc->by_ref | |
2264 | && desc->accesses) | |
2265 | { | |
2266 | propagate_dereference_distances (fun); | |
2267 | dereferences_propagated = true; | |
2268 | } | |
2269 | ||
2270 | HOST_WIDE_INT nonarg_acc_size = 0; | |
2271 | bool only_calls = true; | |
2272 | bool check_failed = false; | |
2273 | ||
2274 | int entry_bb_index = ENTRY_BLOCK_PTR_FOR_FN (fun)->index; | |
2275 | for (gensum_param_access *acc = desc->accesses; | |
2276 | acc; | |
2277 | acc = acc->next_sibling) | |
2278 | if (check_gensum_access (parm, desc, acc, &nonarg_acc_size, &only_calls, | |
2279 | entry_bb_index)) | |
2280 | { | |
2281 | check_failed = true; | |
2282 | break; | |
2283 | } | |
2284 | if (check_failed) | |
2285 | continue; | |
2286 | ||
2287 | if (only_calls) | |
2288 | desc->locally_unused = true; | |
2289 | ||
2290 | HOST_WIDE_INT cur_param_size | |
2291 | = tree_to_uhwi (TYPE_SIZE (TREE_TYPE (parm))); | |
2292 | HOST_WIDE_INT param_size_limit; | |
2293 | if (!desc->by_ref || optimize_function_for_size_p (fun)) | |
2294 | param_size_limit = cur_param_size; | |
2295 | else | |
fdfd7f53 ML |
2296 | param_size_limit |
2297 | = opt_for_fn (node->decl, | |
2298 | param_ipa_sra_ptr_growth_factor) * cur_param_size; | |
ff6686d2 MJ |
2299 | if (nonarg_acc_size > param_size_limit |
2300 | || (!desc->by_ref && nonarg_acc_size == param_size_limit)) | |
2301 | { | |
f8cb8bcd JJ |
2302 | disqualify_split_candidate (desc, "Would result into a too big set " |
2303 | "of replacements."); | |
ff6686d2 MJ |
2304 | } |
2305 | else | |
2306 | { | |
2307 | /* create_parameter_descriptors makes sure unit sizes of all | |
2308 | candidate parameters fit unsigned integers restricted to | |
2309 | ISRA_ARG_SIZE_LIMIT. */ | |
2310 | desc->param_size_limit = param_size_limit / BITS_PER_UNIT; | |
2311 | desc->nonarg_acc_size = nonarg_acc_size / BITS_PER_UNIT; | |
2312 | if (desc->split_candidate && desc->ptr_pt_count) | |
2313 | { | |
2314 | gcc_assert (desc->by_ref); | |
2315 | check_pass_throughs = true; | |
2316 | } | |
2317 | } | |
2318 | } | |
2319 | ||
2320 | /* When a pointer parameter is passed-through to a callee, in which it is | |
2321 | only used to read only one or a few items, we can attempt to transform it | |
2322 | to obtaining and passing through the items instead of the pointer. But we | |
2323 | must take extra care that 1) we do not introduce any segfault by moving | |
2324 | dereferences above control flow and that 2) the data is not modified | |
2325 | through an alias in this function. The IPA analysis must not introduce | |
2326 | any accesses candidates unless it can prove both. | |
2327 | ||
2328 | The current solution is very crude as it consists of ensuring that the | |
2329 | call postdominates entry BB and that the definition of VUSE of the call is | |
2330 | default definition. TODO: For non-recursive callees in the same | |
2331 | compilation unit we could do better by doing analysis in topological order | |
2332 | an looking into access candidates of callees, using their alias_ptr_types | |
2333 | to attempt real AA. We could also use the maximum known dereferenced | |
2334 | offset in this function at IPA level. | |
2335 | ||
2336 | TODO: Measure the overhead and the effect of just being pessimistic. | |
dfea3d6f | 2337 | Maybe this is only -O3 material? |
ff6686d2 MJ |
2338 | */ |
2339 | bool pdoms_calculated = false; | |
2340 | if (check_pass_throughs) | |
2341 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) | |
2342 | { | |
2343 | gcall *call_stmt = cs->call_stmt; | |
2344 | tree vuse = gimple_vuse (call_stmt); | |
2345 | ||
2346 | /* If the callee is a const function, we don't get a VUSE. In such | |
2347 | case there will be no memory accesses in the called function (or the | |
2348 | const attribute is wrong) and then we just don't care. */ | |
2349 | bool uses_memory_as_obtained = vuse && SSA_NAME_IS_DEFAULT_DEF (vuse); | |
2350 | ||
2351 | unsigned count = gimple_call_num_args (call_stmt); | |
2352 | isra_call_summary *csum = call_sums->get_create (cs); | |
2353 | csum->init_inputs (count); | |
2354 | for (unsigned argidx = 0; argidx < count; argidx++) | |
2355 | { | |
2356 | if (!csum->m_arg_flow[argidx].pointer_pass_through) | |
2357 | continue; | |
2358 | unsigned pidx | |
2359 | = get_single_param_flow_source (&csum->m_arg_flow[argidx]); | |
2360 | gensum_param_desc *desc = &(*param_descriptions)[pidx]; | |
2361 | if (!desc->split_candidate) | |
2362 | { | |
2363 | csum->m_arg_flow[argidx].pointer_pass_through = false; | |
2364 | continue; | |
2365 | } | |
2366 | if (!uses_memory_as_obtained) | |
2367 | continue; | |
2368 | ||
2369 | /* Post-dominator check placed last, hoping that it usually won't | |
2370 | be needed. */ | |
2371 | if (!pdoms_calculated) | |
2372 | { | |
2373 | gcc_checking_assert (cfun); | |
2374 | add_noreturn_fake_exit_edges (); | |
2375 | connect_infinite_loops_to_exit (); | |
2376 | calculate_dominance_info (CDI_POST_DOMINATORS); | |
2377 | pdoms_calculated = true; | |
2378 | } | |
2379 | if (dominated_by_p (CDI_POST_DOMINATORS, | |
2380 | gimple_bb (call_stmt), | |
2381 | single_succ (ENTRY_BLOCK_PTR_FOR_FN (fun)))) | |
2382 | csum->m_arg_flow[argidx].safe_to_import_accesses = true; | |
2383 | } | |
2384 | ||
2385 | } | |
2386 | if (pdoms_calculated) | |
2387 | { | |
2388 | free_dominance_info (CDI_POST_DOMINATORS); | |
2389 | remove_fake_exit_edges (); | |
2390 | } | |
2391 | ||
2392 | /* TODO: Add early exit if we disqualified everything. This also requires | |
2393 | that we either relax the restriction that | |
dfea3d6f | 2394 | ipa_param_adjustments.m_always_copy_start must be the number of PARM_DECLs |
ff6686d2 MJ |
2395 | or store the number of parameters to IPA-SRA function summary and use that |
2396 | when just removing params. */ | |
2397 | ||
2398 | vec_safe_reserve_exact (ifs->m_parameters, param_count); | |
2399 | ifs->m_parameters->quick_grow_cleared (param_count); | |
2400 | for (unsigned desc_index = 0; desc_index < param_count; desc_index++) | |
2401 | { | |
2402 | gensum_param_desc *s = &(*param_descriptions)[desc_index]; | |
2403 | isra_param_desc *d = &(*ifs->m_parameters)[desc_index]; | |
2404 | ||
2405 | d->param_size_limit = s->param_size_limit; | |
2406 | d->size_reached = s->nonarg_acc_size; | |
2407 | d->locally_unused = s->locally_unused; | |
2408 | d->split_candidate = s->split_candidate; | |
2409 | d->by_ref = s->by_ref; | |
2410 | ||
2411 | for (gensum_param_access *acc = s->accesses; | |
2412 | acc; | |
2413 | acc = acc->next_sibling) | |
2414 | copy_accesses_to_ipa_desc (acc, d); | |
2415 | } | |
2416 | ||
2417 | if (dump_file) | |
2418 | dump_isra_param_descriptors (dump_file, node->decl, ifs); | |
2419 | } | |
2420 | ||
2421 | /* Return true if there are any overlaps among certain accesses of DESC. If | |
dfea3d6f | 2422 | non-NULL, set *CERTAIN_ACCESS_PRESENT_P upon encountering a certain access |
ff6686d2 MJ |
2423 | too. DESC is assumed to be a split candidate that is not locally |
2424 | unused. */ | |
2425 | ||
2426 | static bool | |
2427 | overlapping_certain_accesses_p (isra_param_desc *desc, | |
2428 | bool *certain_access_present_p) | |
2429 | { | |
2430 | unsigned pclen = vec_safe_length (desc->accesses); | |
2431 | for (unsigned i = 0; i < pclen; i++) | |
2432 | { | |
2433 | param_access *a1 = (*desc->accesses)[i]; | |
2434 | ||
2435 | if (!a1->certain) | |
2436 | continue; | |
2437 | if (certain_access_present_p) | |
2438 | *certain_access_present_p = true; | |
2439 | for (unsigned j = i + 1; j < pclen; j++) | |
2440 | { | |
2441 | param_access *a2 = (*desc->accesses)[j]; | |
2442 | if (a2->certain | |
2443 | && a1->unit_offset < a2->unit_offset + a2->unit_size | |
2444 | && a1->unit_offset + a1->unit_size > a2->unit_offset) | |
2445 | return true; | |
2446 | } | |
2447 | } | |
2448 | return false; | |
2449 | } | |
2450 | ||
2451 | /* Check for any overlaps of certain param accesses among splitting candidates | |
2452 | and signal an ICE if there are any. If CERTAIN_MUST_EXIST is set, also | |
2453 | check that used splitting candidates have at least one certain access. */ | |
2454 | ||
2455 | static void | |
2456 | verify_splitting_accesses (cgraph_node *node, bool certain_must_exist) | |
2457 | { | |
2458 | isra_func_summary *ifs = func_sums->get (node); | |
2459 | if (!ifs || !ifs->m_candidate) | |
2460 | return; | |
2461 | unsigned param_count = vec_safe_length (ifs->m_parameters); | |
2462 | for (unsigned pidx = 0; pidx < param_count; pidx++) | |
2463 | { | |
2464 | isra_param_desc *desc = &(*ifs->m_parameters)[pidx]; | |
2465 | if (!desc->split_candidate || desc->locally_unused) | |
2466 | continue; | |
2467 | ||
2468 | bool certain_access_present = !certain_must_exist; | |
2469 | if (overlapping_certain_accesses_p (desc, &certain_access_present)) | |
e2b1923b | 2470 | internal_error ("Function %qs, parameter %u, has IPA-SRA accesses " |
ff6686d2 MJ |
2471 | "which overlap", node->dump_name (), pidx); |
2472 | if (!certain_access_present) | |
2473 | internal_error ("Function %s, parameter %u, is used but does not " | |
2474 | "have any certain IPA-SRA access", | |
2475 | node->dump_name (), pidx); | |
2476 | } | |
2477 | } | |
2478 | ||
2479 | /* Intraprocedural part of IPA-SRA analysis. Scan function body of NODE and | |
2480 | create a summary structure describing IPA-SRA opportunities and constraints | |
2481 | in it. */ | |
2482 | ||
2483 | static void | |
2484 | ipa_sra_summarize_function (cgraph_node *node) | |
2485 | { | |
2486 | if (dump_file) | |
2487 | fprintf (dump_file, "Creating summary for %s/%i:\n", node->name (), | |
2488 | node->order); | |
2489 | if (!ipa_sra_preliminary_function_checks (node)) | |
2490 | return; | |
2491 | gcc_obstack_init (&gensum_obstack); | |
2492 | isra_func_summary *ifs = func_sums->get_create (node); | |
2493 | ifs->m_candidate = true; | |
2494 | tree ret = TREE_TYPE (TREE_TYPE (node->decl)); | |
2495 | ifs->m_returns_value = (TREE_CODE (ret) != VOID_TYPE); | |
2496 | ||
2497 | decl2desc = new hash_map<tree, gensum_param_desc *>; | |
2498 | unsigned count = 0; | |
2499 | for (tree parm = DECL_ARGUMENTS (node->decl); parm; parm = DECL_CHAIN (parm)) | |
2500 | count++; | |
2501 | ||
2502 | if (count > 0) | |
2503 | { | |
2504 | auto_vec<gensum_param_desc, 16> param_descriptions (count); | |
2505 | param_descriptions.reserve_exact (count); | |
2506 | param_descriptions.quick_grow_cleared (count); | |
2507 | ||
2508 | bool cfun_pushed = false; | |
2509 | struct function *fun = DECL_STRUCT_FUNCTION (node->decl); | |
2510 | if (create_parameter_descriptors (node, ¶m_descriptions)) | |
2511 | { | |
2512 | push_cfun (fun); | |
2513 | cfun_pushed = true; | |
2514 | final_bbs = BITMAP_ALLOC (NULL); | |
2515 | bb_dereferences = XCNEWVEC (HOST_WIDE_INT, | |
2516 | by_ref_count | |
2517 | * last_basic_block_for_fn (fun)); | |
fdfd7f53 | 2518 | aa_walking_limit = opt_for_fn (node->decl, param_ipa_max_aa_steps); |
ff6686d2 MJ |
2519 | scan_function (node, fun); |
2520 | ||
2521 | if (dump_file) | |
2522 | { | |
2523 | dump_gensum_param_descriptors (dump_file, node->decl, | |
2524 | ¶m_descriptions); | |
2525 | fprintf (dump_file, "----------------------------------------\n"); | |
2526 | } | |
2527 | } | |
2528 | process_scan_results (node, fun, ifs, ¶m_descriptions); | |
2529 | ||
2530 | if (cfun_pushed) | |
2531 | pop_cfun (); | |
2532 | if (bb_dereferences) | |
2533 | { | |
2534 | free (bb_dereferences); | |
2535 | bb_dereferences = NULL; | |
2536 | BITMAP_FREE (final_bbs); | |
2537 | final_bbs = NULL; | |
2538 | } | |
2539 | } | |
2540 | isra_analyze_all_outgoing_calls (node); | |
2541 | ||
2542 | delete decl2desc; | |
2543 | decl2desc = NULL; | |
2544 | obstack_free (&gensum_obstack, NULL); | |
2545 | if (dump_file) | |
2546 | fprintf (dump_file, "\n\n"); | |
2547 | if (flag_checking) | |
2548 | verify_splitting_accesses (node, false); | |
2549 | return; | |
2550 | } | |
2551 | ||
2552 | /* Intraprocedural part of IPA-SRA analysis. Scan bodies of all functions in | |
2553 | this compilation unit and create summary structures describing IPA-SRA | |
2554 | opportunities and constraints in them. */ | |
2555 | ||
2556 | static void | |
2557 | ipa_sra_generate_summary (void) | |
2558 | { | |
2559 | struct cgraph_node *node; | |
2560 | ||
2561 | gcc_checking_assert (!func_sums); | |
2562 | gcc_checking_assert (!call_sums); | |
2563 | func_sums | |
78cd68c0 | 2564 | = (new (ggc_alloc_no_dtor <ipa_sra_function_summaries> ()) |
ff6686d2 MJ |
2565 | ipa_sra_function_summaries (symtab, true)); |
2566 | call_sums = new ipa_sra_call_summaries (symtab); | |
2567 | ||
2568 | FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) | |
2569 | ipa_sra_summarize_function (node); | |
2570 | return; | |
2571 | } | |
2572 | ||
dfea3d6f | 2573 | /* Write intraprocedural analysis information about E and all of its outgoing |
ff6686d2 MJ |
2574 | edges into a stream for LTO WPA. */ |
2575 | ||
2576 | static void | |
2577 | isra_write_edge_summary (output_block *ob, cgraph_edge *e) | |
2578 | { | |
2579 | isra_call_summary *csum = call_sums->get (e); | |
2580 | unsigned input_count = csum->m_arg_flow.length (); | |
2581 | streamer_write_uhwi (ob, input_count); | |
2582 | for (unsigned i = 0; i < input_count; i++) | |
2583 | { | |
2584 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
2585 | streamer_write_hwi (ob, ipf->length); | |
2586 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2587 | for (int j = 0; j < ipf->length; j++) | |
2588 | bp_pack_value (&bp, ipf->inputs[j], 8); | |
2589 | bp_pack_value (&bp, ipf->aggregate_pass_through, 1); | |
2590 | bp_pack_value (&bp, ipf->pointer_pass_through, 1); | |
2591 | bp_pack_value (&bp, ipf->safe_to_import_accesses, 1); | |
2592 | streamer_write_bitpack (&bp); | |
2593 | streamer_write_uhwi (ob, ipf->unit_offset); | |
2594 | streamer_write_uhwi (ob, ipf->unit_size); | |
2595 | } | |
2596 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2597 | bp_pack_value (&bp, csum->m_return_ignored, 1); | |
2598 | bp_pack_value (&bp, csum->m_return_returned, 1); | |
2599 | bp_pack_value (&bp, csum->m_bit_aligned_arg, 1); | |
2600 | streamer_write_bitpack (&bp); | |
2601 | } | |
2602 | ||
dfea3d6f | 2603 | /* Write intraprocedural analysis information about NODE and all of its outgoing |
ff6686d2 MJ |
2604 | edges into a stream for LTO WPA. */ |
2605 | ||
2606 | static void | |
2607 | isra_write_node_summary (output_block *ob, cgraph_node *node) | |
2608 | { | |
2609 | isra_func_summary *ifs = func_sums->get (node); | |
2610 | lto_symtab_encoder_t encoder = ob->decl_state->symtab_node_encoder; | |
2611 | int node_ref = lto_symtab_encoder_encode (encoder, node); | |
2612 | streamer_write_uhwi (ob, node_ref); | |
2613 | ||
2614 | unsigned param_desc_count = vec_safe_length (ifs->m_parameters); | |
2615 | streamer_write_uhwi (ob, param_desc_count); | |
2616 | for (unsigned i = 0; i < param_desc_count; i++) | |
2617 | { | |
2618 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; | |
2619 | unsigned access_count = vec_safe_length (desc->accesses); | |
2620 | streamer_write_uhwi (ob, access_count); | |
2621 | for (unsigned j = 0; j < access_count; j++) | |
2622 | { | |
2623 | param_access *acc = (*desc->accesses)[j]; | |
2624 | stream_write_tree (ob, acc->type, true); | |
2625 | stream_write_tree (ob, acc->alias_ptr_type, true); | |
2626 | streamer_write_uhwi (ob, acc->unit_offset); | |
2627 | streamer_write_uhwi (ob, acc->unit_size); | |
2628 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2629 | bp_pack_value (&bp, acc->certain, 1); | |
2630 | streamer_write_bitpack (&bp); | |
2631 | } | |
2632 | streamer_write_uhwi (ob, desc->param_size_limit); | |
2633 | streamer_write_uhwi (ob, desc->size_reached); | |
2634 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2635 | bp_pack_value (&bp, desc->locally_unused, 1); | |
2636 | bp_pack_value (&bp, desc->split_candidate, 1); | |
2637 | bp_pack_value (&bp, desc->by_ref, 1); | |
2638 | streamer_write_bitpack (&bp); | |
2639 | } | |
2640 | bitpack_d bp = bitpack_create (ob->main_stream); | |
2641 | bp_pack_value (&bp, ifs->m_candidate, 1); | |
2642 | bp_pack_value (&bp, ifs->m_returns_value, 1); | |
2643 | bp_pack_value (&bp, ifs->m_return_ignored, 1); | |
2644 | gcc_assert (!ifs->m_queued); | |
2645 | streamer_write_bitpack (&bp); | |
2646 | ||
2647 | for (cgraph_edge *e = node->callees; e; e = e->next_callee) | |
2648 | isra_write_edge_summary (ob, e); | |
2649 | for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee) | |
2650 | isra_write_edge_summary (ob, e); | |
2651 | } | |
2652 | ||
dfea3d6f | 2653 | /* Write intraprocedural analysis information into a stream for LTO WPA. */ |
ff6686d2 MJ |
2654 | |
2655 | static void | |
2656 | ipa_sra_write_summary (void) | |
2657 | { | |
2658 | if (!func_sums || !call_sums) | |
2659 | return; | |
2660 | ||
2661 | struct output_block *ob = create_output_block (LTO_section_ipa_sra); | |
2662 | lto_symtab_encoder_t encoder = ob->decl_state->symtab_node_encoder; | |
2663 | ob->symbol = NULL; | |
2664 | ||
2665 | unsigned int count = 0; | |
2666 | lto_symtab_encoder_iterator lsei; | |
2667 | for (lsei = lsei_start_function_in_partition (encoder); | |
2668 | !lsei_end_p (lsei); | |
2669 | lsei_next_function_in_partition (&lsei)) | |
2670 | { | |
2671 | cgraph_node *node = lsei_cgraph_node (lsei); | |
2672 | if (node->has_gimple_body_p () | |
2673 | && func_sums->get (node) != NULL) | |
2674 | count++; | |
2675 | } | |
2676 | streamer_write_uhwi (ob, count); | |
2677 | ||
2678 | /* Process all of the functions. */ | |
2679 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); | |
2680 | lsei_next_function_in_partition (&lsei)) | |
2681 | { | |
2682 | cgraph_node *node = lsei_cgraph_node (lsei); | |
2683 | if (node->has_gimple_body_p () | |
2684 | && func_sums->get (node) != NULL) | |
2685 | isra_write_node_summary (ob, node); | |
2686 | } | |
2687 | streamer_write_char_stream (ob->main_stream, 0); | |
2688 | produce_asm (ob, NULL); | |
2689 | destroy_output_block (ob); | |
2690 | } | |
2691 | ||
dfea3d6f | 2692 | /* Read intraprocedural analysis information about E and all of its outgoing |
ff6686d2 MJ |
2693 | edges into a stream for LTO WPA. */ |
2694 | ||
2695 | static void | |
2696 | isra_read_edge_summary (struct lto_input_block *ib, cgraph_edge *cs) | |
2697 | { | |
2698 | isra_call_summary *csum = call_sums->get_create (cs); | |
2699 | unsigned input_count = streamer_read_uhwi (ib); | |
2700 | csum->init_inputs (input_count); | |
2701 | for (unsigned i = 0; i < input_count; i++) | |
2702 | { | |
2703 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
2704 | ipf->length = streamer_read_hwi (ib); | |
2705 | bitpack_d bp = streamer_read_bitpack (ib); | |
2706 | for (int j = 0; j < ipf->length; j++) | |
2707 | ipf->inputs[j] = bp_unpack_value (&bp, 8); | |
2708 | ipf->aggregate_pass_through = bp_unpack_value (&bp, 1); | |
2709 | ipf->pointer_pass_through = bp_unpack_value (&bp, 1); | |
2710 | ipf->safe_to_import_accesses = bp_unpack_value (&bp, 1); | |
2711 | ipf->unit_offset = streamer_read_uhwi (ib); | |
2712 | ipf->unit_size = streamer_read_uhwi (ib); | |
2713 | } | |
2714 | bitpack_d bp = streamer_read_bitpack (ib); | |
2715 | csum->m_return_ignored = bp_unpack_value (&bp, 1); | |
2716 | csum->m_return_returned = bp_unpack_value (&bp, 1); | |
2717 | csum->m_bit_aligned_arg = bp_unpack_value (&bp, 1); | |
2718 | } | |
2719 | ||
dfea3d6f | 2720 | /* Read intraprocedural analysis information about NODE and all of its outgoing |
ff6686d2 MJ |
2721 | edges into a stream for LTO WPA. */ |
2722 | ||
2723 | static void | |
2724 | isra_read_node_info (struct lto_input_block *ib, cgraph_node *node, | |
2725 | struct data_in *data_in) | |
2726 | { | |
2727 | isra_func_summary *ifs = func_sums->get_create (node); | |
2728 | unsigned param_desc_count = streamer_read_uhwi (ib); | |
2729 | if (param_desc_count > 0) | |
2730 | { | |
2731 | vec_safe_reserve_exact (ifs->m_parameters, param_desc_count); | |
2732 | ifs->m_parameters->quick_grow_cleared (param_desc_count); | |
2733 | } | |
2734 | for (unsigned i = 0; i < param_desc_count; i++) | |
2735 | { | |
2736 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; | |
2737 | unsigned access_count = streamer_read_uhwi (ib); | |
2738 | for (unsigned j = 0; j < access_count; j++) | |
2739 | { | |
2740 | param_access *acc = ggc_cleared_alloc<param_access> (); | |
2741 | acc->type = stream_read_tree (ib, data_in); | |
2742 | acc->alias_ptr_type = stream_read_tree (ib, data_in); | |
2743 | acc->unit_offset = streamer_read_uhwi (ib); | |
2744 | acc->unit_size = streamer_read_uhwi (ib); | |
2745 | bitpack_d bp = streamer_read_bitpack (ib); | |
2746 | acc->certain = bp_unpack_value (&bp, 1); | |
2747 | vec_safe_push (desc->accesses, acc); | |
2748 | } | |
2749 | desc->param_size_limit = streamer_read_uhwi (ib); | |
2750 | desc->size_reached = streamer_read_uhwi (ib); | |
2751 | bitpack_d bp = streamer_read_bitpack (ib); | |
2752 | desc->locally_unused = bp_unpack_value (&bp, 1); | |
2753 | desc->split_candidate = bp_unpack_value (&bp, 1); | |
2754 | desc->by_ref = bp_unpack_value (&bp, 1); | |
2755 | } | |
2756 | bitpack_d bp = streamer_read_bitpack (ib); | |
2757 | ifs->m_candidate = bp_unpack_value (&bp, 1); | |
2758 | ifs->m_returns_value = bp_unpack_value (&bp, 1); | |
2759 | ifs->m_return_ignored = bp_unpack_value (&bp, 1); | |
2760 | ifs->m_queued = 0; | |
2761 | ||
2762 | for (cgraph_edge *e = node->callees; e; e = e->next_callee) | |
2763 | isra_read_edge_summary (ib, e); | |
2764 | for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee) | |
2765 | isra_read_edge_summary (ib, e); | |
2766 | } | |
2767 | ||
2768 | /* Read IPA-SRA summaries from a section in file FILE_DATA of length LEN with | |
2769 | data DATA. TODO: This function was copied almost verbatim from ipa-prop.c, | |
2770 | it should be possible to unify them somehow. */ | |
2771 | ||
2772 | static void | |
2773 | isra_read_summary_section (struct lto_file_decl_data *file_data, | |
2774 | const char *data, size_t len) | |
2775 | { | |
2776 | const struct lto_function_header *header = | |
2777 | (const struct lto_function_header *) data; | |
2778 | const int cfg_offset = sizeof (struct lto_function_header); | |
2779 | const int main_offset = cfg_offset + header->cfg_size; | |
2780 | const int string_offset = main_offset + header->main_size; | |
2781 | struct data_in *data_in; | |
2782 | unsigned int i; | |
2783 | unsigned int count; | |
2784 | ||
2785 | lto_input_block ib_main ((const char *) data + main_offset, | |
2786 | header->main_size, file_data->mode_table); | |
2787 | ||
2788 | data_in = | |
2789 | lto_data_in_create (file_data, (const char *) data + string_offset, | |
2790 | header->string_size, vNULL); | |
2791 | count = streamer_read_uhwi (&ib_main); | |
2792 | ||
2793 | for (i = 0; i < count; i++) | |
2794 | { | |
2795 | unsigned int index; | |
2796 | struct cgraph_node *node; | |
2797 | lto_symtab_encoder_t encoder; | |
2798 | ||
2799 | index = streamer_read_uhwi (&ib_main); | |
2800 | encoder = file_data->symtab_node_encoder; | |
2801 | node = dyn_cast<cgraph_node *> (lto_symtab_encoder_deref (encoder, | |
2802 | index)); | |
2803 | gcc_assert (node->definition); | |
2804 | isra_read_node_info (&ib_main, node, data_in); | |
2805 | } | |
2806 | lto_free_section_data (file_data, LTO_section_ipa_sra, NULL, data, | |
2807 | len); | |
2808 | lto_data_in_delete (data_in); | |
2809 | } | |
2810 | ||
dfea3d6f | 2811 | /* Read intraprocedural analysis information into a stream for LTO WPA. */ |
ff6686d2 MJ |
2812 | |
2813 | static void | |
2814 | ipa_sra_read_summary (void) | |
2815 | { | |
2816 | struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); | |
2817 | struct lto_file_decl_data *file_data; | |
2818 | unsigned int j = 0; | |
2819 | ||
2820 | gcc_checking_assert (!func_sums); | |
2821 | gcc_checking_assert (!call_sums); | |
2822 | func_sums | |
78cd68c0 | 2823 | = (new (ggc_alloc_no_dtor <ipa_sra_function_summaries> ()) |
ff6686d2 MJ |
2824 | ipa_sra_function_summaries (symtab, true)); |
2825 | call_sums = new ipa_sra_call_summaries (symtab); | |
2826 | ||
2827 | while ((file_data = file_data_vec[j++])) | |
2828 | { | |
2829 | size_t len; | |
3c56d8d8 ML |
2830 | const char *data |
2831 | = lto_get_summary_section_data (file_data, LTO_section_ipa_sra, &len); | |
ff6686d2 MJ |
2832 | if (data) |
2833 | isra_read_summary_section (file_data, data, len); | |
2834 | } | |
2835 | } | |
2836 | ||
2837 | /* Dump all IPA-SRA summary data for all cgraph nodes and edges to file F. */ | |
2838 | ||
2839 | static void | |
2840 | ipa_sra_dump_all_summaries (FILE *f) | |
2841 | { | |
2842 | cgraph_node *node; | |
2843 | FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) | |
2844 | { | |
2845 | fprintf (f, "\nSummary for node %s:\n", node->dump_name ()); | |
2846 | ||
2847 | isra_func_summary *ifs = func_sums->get (node); | |
2848 | if (!ifs) | |
2849 | { | |
2850 | fprintf (f, " Function does not have any associated IPA-SRA " | |
2851 | "summary\n"); | |
2852 | continue; | |
2853 | } | |
2854 | if (!ifs->m_candidate) | |
2855 | { | |
2856 | fprintf (f, " Not a candidate function\n"); | |
2857 | continue; | |
2858 | } | |
2859 | if (ifs->m_returns_value) | |
2860 | fprintf (f, " Returns value\n"); | |
2861 | if (vec_safe_is_empty (ifs->m_parameters)) | |
2862 | fprintf (f, " No parameter information. \n"); | |
2863 | else | |
2864 | for (unsigned i = 0; i < ifs->m_parameters->length (); ++i) | |
2865 | { | |
2866 | fprintf (f, " Descriptor for parameter %i:\n", i); | |
2867 | dump_isra_param_descriptor (f, &(*ifs->m_parameters)[i]); | |
2868 | } | |
2869 | fprintf (f, "\n"); | |
2870 | ||
2871 | struct cgraph_edge *cs; | |
2872 | for (cs = node->callees; cs; cs = cs->next_callee) | |
2873 | { | |
2874 | fprintf (f, " Summary for edge %s->%s:\n", cs->caller->dump_name (), | |
2875 | cs->callee->dump_name ()); | |
2876 | isra_call_summary *csum = call_sums->get (cs); | |
2877 | if (csum) | |
2878 | csum->dump (f); | |
2879 | else | |
2880 | fprintf (f, " Call summary is MISSING!\n"); | |
2881 | } | |
2882 | ||
2883 | } | |
2884 | fprintf (f, "\n\n"); | |
2885 | } | |
2886 | ||
2887 | /* Perform function-scope viability tests that can be only made at IPA level | |
2888 | and return false if the function is deemed unsuitable for IPA-SRA. */ | |
2889 | ||
2890 | static bool | |
2891 | ipa_sra_ipa_function_checks (cgraph_node *node) | |
2892 | { | |
2893 | if (!node->can_be_local_p ()) | |
2894 | { | |
2895 | if (dump_file) | |
2896 | fprintf (dump_file, "Function %s disqualified because it cannot be " | |
2897 | "made local.\n", node->dump_name ()); | |
2898 | return false; | |
2899 | } | |
87f94429 | 2900 | if (!node->can_change_signature) |
ff6686d2 MJ |
2901 | { |
2902 | if (dump_file) | |
2903 | fprintf (dump_file, "Function can not change signature.\n"); | |
2904 | return false; | |
2905 | } | |
2906 | ||
2907 | return true; | |
2908 | } | |
2909 | ||
2910 | /* Issues found out by check_callers_for_issues. */ | |
2911 | ||
2912 | struct caller_issues | |
2913 | { | |
b90061c6 MJ |
2914 | /* The candidate being considered. */ |
2915 | cgraph_node *candidate; | |
ff6686d2 MJ |
2916 | /* There is a thunk among callers. */ |
2917 | bool thunk; | |
2918 | /* Call site with no available information. */ | |
2919 | bool unknown_callsite; | |
b90061c6 MJ |
2920 | /* Call from outside the the candidate's comdat group. */ |
2921 | bool call_from_outside_comdat; | |
ff6686d2 MJ |
2922 | /* There is a bit-aligned load into one of non-gimple-typed arguments. */ |
2923 | bool bit_aligned_aggregate_argument; | |
2924 | }; | |
2925 | ||
2926 | /* Worker for call_for_symbol_and_aliases, set any flags of passed caller_issues | |
2927 | that apply. */ | |
2928 | ||
2929 | static bool | |
2930 | check_for_caller_issues (struct cgraph_node *node, void *data) | |
2931 | { | |
2932 | struct caller_issues *issues = (struct caller_issues *) data; | |
2933 | ||
2934 | for (cgraph_edge *cs = node->callers; cs; cs = cs->next_caller) | |
2935 | { | |
2936 | if (cs->caller->thunk.thunk_p) | |
2937 | { | |
2938 | issues->thunk = true; | |
2939 | /* TODO: We should be able to process at least some types of | |
2940 | thunks. */ | |
2941 | return true; | |
2942 | } | |
b90061c6 MJ |
2943 | if (issues->candidate->calls_comdat_local |
2944 | && issues->candidate->same_comdat_group | |
2945 | && !issues->candidate->in_same_comdat_group_p (cs->caller)) | |
2946 | { | |
2947 | issues->call_from_outside_comdat = true; | |
2948 | return true; | |
2949 | } | |
ff6686d2 MJ |
2950 | |
2951 | isra_call_summary *csum = call_sums->get (cs); | |
2952 | if (!csum) | |
2953 | { | |
2954 | issues->unknown_callsite = true; | |
2955 | return true; | |
2956 | } | |
2957 | ||
2958 | if (csum->m_bit_aligned_arg) | |
2959 | issues->bit_aligned_aggregate_argument = true; | |
2960 | } | |
2961 | return false; | |
2962 | } | |
2963 | ||
2964 | /* Look at all incoming edges to NODE, including aliases and thunks and look | |
2965 | for problems. Return true if NODE type should not be modified at all. */ | |
2966 | ||
2967 | static bool | |
2968 | check_all_callers_for_issues (cgraph_node *node) | |
2969 | { | |
2970 | struct caller_issues issues; | |
2971 | memset (&issues, 0, sizeof (issues)); | |
b90061c6 | 2972 | issues.candidate = node; |
ff6686d2 MJ |
2973 | |
2974 | node->call_for_symbol_and_aliases (check_for_caller_issues, &issues, true); | |
2975 | if (issues.unknown_callsite) | |
2976 | { | |
2977 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2978 | fprintf (dump_file, "A call of %s has not been analyzed. Disabling " | |
2979 | "all modifications.\n", node->dump_name ()); | |
2980 | return true; | |
2981 | } | |
2982 | /* TODO: We should be able to process at least some types of thunks. */ | |
2983 | if (issues.thunk) | |
2984 | { | |
2985 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
2986 | fprintf (dump_file, "A call of %s is through thunk, which are not" | |
2987 | " handled yet. Disabling all modifications.\n", | |
2988 | node->dump_name ()); | |
2989 | return true; | |
2990 | } | |
b90061c6 MJ |
2991 | if (issues.call_from_outside_comdat) |
2992 | { | |
2993 | if (dump_file) | |
2994 | fprintf (dump_file, "Function would become private comdat called " | |
2995 | "outside of its comdat group.\n"); | |
2996 | return true; | |
2997 | } | |
ff6686d2 MJ |
2998 | |
2999 | if (issues.bit_aligned_aggregate_argument) | |
3000 | { | |
3001 | /* Let's only remove parameters/return values from such functions. | |
3002 | TODO: We could only prevent splitting the problematic parameters if | |
3003 | anybody thinks it is worth it. */ | |
3004 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
dfea3d6f | 3005 | fprintf (dump_file, "A call of %s has bit-aligned aggregate argument," |
ff6686d2 MJ |
3006 | " disabling parameter splitting.\n", node->dump_name ()); |
3007 | ||
3008 | isra_func_summary *ifs = func_sums->get (node); | |
3009 | gcc_checking_assert (ifs); | |
3010 | unsigned param_count = vec_safe_length (ifs->m_parameters); | |
3011 | for (unsigned i = 0; i < param_count; i++) | |
3012 | (*ifs->m_parameters)[i].split_candidate = false; | |
3013 | } | |
3014 | return false; | |
3015 | } | |
3016 | ||
3017 | /* Find the access with corresponding OFFSET and SIZE among accesses in | |
3018 | PARAM_DESC and return it or NULL if such an access is not there. */ | |
3019 | ||
3020 | static param_access * | |
3021 | find_param_access (isra_param_desc *param_desc, unsigned offset, unsigned size) | |
3022 | { | |
3023 | unsigned pclen = vec_safe_length (param_desc->accesses); | |
3024 | ||
3025 | /* The search is linear but the number of stored accesses is bound by | |
3026 | PARAM_IPA_SRA_MAX_REPLACEMENTS, so most probably 8. */ | |
3027 | ||
3028 | for (unsigned i = 0; i < pclen; i++) | |
3029 | if ((*param_desc->accesses)[i]->unit_offset == offset | |
3030 | && (*param_desc->accesses)[i]->unit_size == size) | |
3031 | return (*param_desc->accesses)[i]; | |
3032 | ||
3033 | return NULL; | |
3034 | } | |
3035 | ||
3036 | /* Return iff the total size of definite replacement SIZE would violate the | |
3037 | limit set for it in PARAM. */ | |
3038 | ||
3039 | static bool | |
3040 | size_would_violate_limit_p (isra_param_desc *desc, unsigned size) | |
3041 | { | |
3042 | unsigned limit = desc->param_size_limit; | |
3043 | if (size > limit | |
3044 | || (!desc->by_ref && size == limit)) | |
3045 | return true; | |
3046 | return false; | |
3047 | } | |
3048 | ||
3049 | /* Increase reached size of DESC by SIZE or disqualify it if it would violate | |
3050 | the set limit. IDX is the parameter number which is dumped when | |
3051 | disqualifying. */ | |
3052 | ||
3053 | static void | |
3054 | bump_reached_size (isra_param_desc *desc, unsigned size, unsigned idx) | |
3055 | { | |
3056 | unsigned after = desc->size_reached + size; | |
3057 | if (size_would_violate_limit_p (desc, after)) | |
3058 | { | |
3059 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3060 | fprintf (dump_file, " ...size limit reached, disqualifying " | |
3061 | "candidate parameter %u\n", idx); | |
3062 | desc->split_candidate = false; | |
3063 | return; | |
3064 | } | |
3065 | desc->size_reached = after; | |
3066 | } | |
3067 | ||
3068 | /* Take all actions required to deal with an edge CS that represents a call to | |
3069 | an unknown or un-analyzed function, for both parameter removal and | |
3070 | splitting. */ | |
3071 | ||
3072 | static void | |
3073 | process_edge_to_unknown_caller (cgraph_edge *cs) | |
3074 | { | |
3075 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3076 | gcc_checking_assert (from_ifs); | |
3077 | isra_call_summary *csum = call_sums->get (cs); | |
3078 | ||
3079 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3080 | fprintf (dump_file, "Processing an edge to an unknown caller from %s:\n", | |
3081 | cs->caller->dump_name ()); | |
3082 | ||
3083 | unsigned args_count = csum->m_arg_flow.length (); | |
3084 | for (unsigned i = 0; i < args_count; i++) | |
3085 | { | |
3086 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3087 | ||
3088 | if (ipf->pointer_pass_through) | |
3089 | { | |
3090 | isra_param_desc *param_desc | |
3091 | = &(*from_ifs->m_parameters)[get_single_param_flow_source (ipf)]; | |
3092 | param_desc->locally_unused = false; | |
3093 | param_desc->split_candidate = false; | |
3094 | continue; | |
3095 | } | |
3096 | if (ipf->aggregate_pass_through) | |
3097 | { | |
3098 | unsigned idx = get_single_param_flow_source (ipf); | |
3099 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; | |
3100 | ||
3101 | param_desc->locally_unused = false; | |
3102 | if (!param_desc->split_candidate) | |
3103 | continue; | |
3104 | gcc_assert (!param_desc->by_ref); | |
3105 | param_access *pacc = find_param_access (param_desc, ipf->unit_offset, | |
3106 | ipf->unit_size); | |
3107 | gcc_checking_assert (pacc); | |
3108 | pacc->certain = true; | |
3109 | if (overlapping_certain_accesses_p (param_desc, NULL)) | |
3110 | { | |
3111 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3112 | fprintf (dump_file, " ...leading to overlap, " | |
3113 | " disqualifying candidate parameter %u\n", | |
3114 | idx); | |
3115 | param_desc->split_candidate = false; | |
3116 | } | |
3117 | else | |
3118 | bump_reached_size (param_desc, pacc->unit_size, idx); | |
3119 | ipf->aggregate_pass_through = false; | |
3120 | continue; | |
3121 | } | |
3122 | ||
3123 | for (int j = 0; j < ipf->length; j++) | |
3124 | { | |
3125 | int input_idx = ipf->inputs[j]; | |
3126 | (*from_ifs->m_parameters)[input_idx].locally_unused = false; | |
3127 | } | |
3128 | } | |
3129 | } | |
3130 | ||
3131 | /* Propagate parameter removal information through cross-SCC edge CS, | |
3132 | i.e. decrease the use count in the caller parameter descriptor for each use | |
3133 | in this call. */ | |
3134 | ||
3135 | static void | |
3136 | param_removal_cross_scc_edge (cgraph_edge *cs) | |
3137 | { | |
3138 | enum availability availability; | |
3139 | cgraph_node *callee = cs->callee->function_symbol (&availability); | |
3140 | isra_func_summary *to_ifs = func_sums->get (callee); | |
3141 | if (!to_ifs || !to_ifs->m_candidate | |
3142 | || (availability < AVAIL_AVAILABLE) | |
3143 | || vec_safe_is_empty (to_ifs->m_parameters)) | |
3144 | { | |
3145 | process_edge_to_unknown_caller (cs); | |
3146 | return; | |
3147 | } | |
3148 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3149 | gcc_checking_assert (from_ifs); | |
3150 | ||
3151 | isra_call_summary *csum = call_sums->get (cs); | |
3152 | unsigned args_count = csum->m_arg_flow.length (); | |
3153 | unsigned param_count = vec_safe_length (to_ifs->m_parameters); | |
3154 | ||
3155 | for (unsigned i = 0; i < args_count; i++) | |
3156 | { | |
3157 | bool unused_in_callee; | |
3158 | if (i < param_count) | |
3159 | unused_in_callee = (*to_ifs->m_parameters)[i].locally_unused; | |
3160 | else | |
3161 | unused_in_callee = false; | |
3162 | ||
3163 | if (!unused_in_callee) | |
3164 | { | |
3165 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3166 | for (int j = 0; j < ipf->length; j++) | |
3167 | { | |
3168 | int input_idx = ipf->inputs[j]; | |
3169 | (*from_ifs->m_parameters)[input_idx].locally_unused = false; | |
3170 | } | |
3171 | } | |
3172 | } | |
3173 | } | |
3174 | ||
3175 | /* Unless it is already there, push NODE which is also described by IFS to | |
3176 | STACK. */ | |
3177 | ||
3178 | static void | |
3179 | isra_push_node_to_stack (cgraph_node *node, isra_func_summary *ifs, | |
3180 | vec<cgraph_node *> *stack) | |
3181 | { | |
3182 | if (!ifs->m_queued) | |
3183 | { | |
3184 | ifs->m_queued = true; | |
3185 | stack->safe_push (node); | |
3186 | } | |
3187 | } | |
3188 | ||
3189 | /* If parameter with index INPUT_IDX is marked as locally unused, mark it as | |
3190 | used and push CALLER on STACK. */ | |
3191 | ||
3192 | static void | |
3193 | isra_mark_caller_param_used (isra_func_summary *from_ifs, int input_idx, | |
3194 | cgraph_node *caller, vec<cgraph_node *> *stack) | |
3195 | { | |
3196 | if ((*from_ifs->m_parameters)[input_idx].locally_unused) | |
3197 | { | |
3198 | (*from_ifs->m_parameters)[input_idx].locally_unused = false; | |
3199 | isra_push_node_to_stack (caller, from_ifs, stack); | |
3200 | } | |
3201 | } | |
3202 | ||
3203 | ||
3204 | /* Propagate information that any parameter is not used only locally within a | |
6b6a8065 | 3205 | SCC across CS to the caller, which must be in the same SCC as the |
ff6686d2 MJ |
3206 | callee. Push any callers that need to be re-processed to STACK. */ |
3207 | ||
3208 | static void | |
3209 | propagate_used_across_scc_edge (cgraph_edge *cs, vec<cgraph_node *> *stack) | |
3210 | { | |
3211 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3212 | if (!from_ifs || vec_safe_is_empty (from_ifs->m_parameters)) | |
3213 | return; | |
3214 | ||
3215 | isra_call_summary *csum = call_sums->get (cs); | |
3216 | gcc_checking_assert (csum); | |
3217 | unsigned args_count = csum->m_arg_flow.length (); | |
3218 | enum availability availability; | |
3219 | cgraph_node *callee = cs->callee->function_symbol (&availability); | |
3220 | isra_func_summary *to_ifs = func_sums->get (callee); | |
3221 | ||
3222 | unsigned param_count | |
3223 | = (to_ifs && (availability >= AVAIL_AVAILABLE)) | |
3224 | ? vec_safe_length (to_ifs->m_parameters) : 0; | |
3225 | for (unsigned i = 0; i < args_count; i++) | |
3226 | { | |
3227 | if (i < param_count | |
3228 | && (*to_ifs->m_parameters)[i].locally_unused) | |
3229 | continue; | |
3230 | ||
3231 | /* The argument is needed in the callee it, we must mark the parameter as | |
3232 | used also in the caller and its callers within this SCC. */ | |
3233 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3234 | for (int j = 0; j < ipf->length; j++) | |
3235 | { | |
3236 | int input_idx = ipf->inputs[j]; | |
3237 | isra_mark_caller_param_used (from_ifs, input_idx, cs->caller, stack); | |
3238 | } | |
3239 | } | |
3240 | } | |
3241 | ||
3242 | /* Propagate information that any parameter is not used only locally within a | |
3243 | SCC (i.e. is used also elsewhere) to all callers of NODE that are in the | |
3244 | same SCC. Push any callers that need to be re-processed to STACK. */ | |
3245 | ||
3246 | static bool | |
3247 | propagate_used_to_scc_callers (cgraph_node *node, void *data) | |
3248 | { | |
3249 | vec<cgraph_node *> *stack = (vec<cgraph_node *> *) data; | |
3250 | cgraph_edge *cs; | |
3251 | for (cs = node->callers; cs; cs = cs->next_caller) | |
3252 | if (ipa_edge_within_scc (cs)) | |
3253 | propagate_used_across_scc_edge (cs, stack); | |
3254 | return false; | |
3255 | } | |
3256 | ||
3257 | /* Return true iff all certain accesses in ARG_DESC are also present as | |
3258 | certain accesses in PARAM_DESC. */ | |
3259 | ||
3260 | static bool | |
3261 | all_callee_accesses_present_p (isra_param_desc *param_desc, | |
3262 | isra_param_desc *arg_desc) | |
3263 | { | |
3264 | unsigned aclen = vec_safe_length (arg_desc->accesses); | |
3265 | for (unsigned j = 0; j < aclen; j++) | |
3266 | { | |
3267 | param_access *argacc = (*arg_desc->accesses)[j]; | |
3268 | if (!argacc->certain) | |
3269 | continue; | |
3270 | param_access *pacc = find_param_access (param_desc, argacc->unit_offset, | |
3271 | argacc->unit_size); | |
3272 | if (!pacc || !pacc->certain) | |
3273 | return false; | |
3274 | } | |
3275 | return true; | |
3276 | } | |
3277 | ||
3278 | /* Type internal to function pull_accesses_from_callee. Unfortunately gcc 4.8 | |
3279 | does not allow instantiating an auto_vec with a type defined within a | |
3280 | function so it is a global type. */ | |
3281 | enum acc_prop_kind {ACC_PROP_DONT, ACC_PROP_COPY, ACC_PROP_CERTAIN}; | |
3282 | ||
3283 | ||
1a315435 MJ |
3284 | /* Attempt to propagate all definite accesses from ARG_DESC to PARAM_DESC, |
3285 | (which belongs to CALLER) if they would not violate some constraint there. | |
3286 | If successful, return NULL, otherwise return the string reason for failure | |
3287 | (which can be written to the dump file). DELTA_OFFSET is the known offset | |
3288 | of the actual argument withing the formal parameter (so of ARG_DESCS within | |
3289 | PARAM_DESCS), ARG_SIZE is the size of the actual argument or zero, if not | |
3290 | known. In case of success, set *CHANGE_P to true if propagation actually | |
3291 | changed anything. */ | |
ff6686d2 MJ |
3292 | |
3293 | static const char * | |
1a315435 | 3294 | pull_accesses_from_callee (cgraph_node *caller, isra_param_desc *param_desc, |
ff6686d2 MJ |
3295 | isra_param_desc *arg_desc, |
3296 | unsigned delta_offset, unsigned arg_size, | |
3297 | bool *change_p) | |
3298 | { | |
3299 | unsigned pclen = vec_safe_length (param_desc->accesses); | |
3300 | unsigned aclen = vec_safe_length (arg_desc->accesses); | |
3301 | unsigned prop_count = 0; | |
3302 | unsigned prop_size = 0; | |
3303 | bool change = false; | |
3304 | ||
3305 | auto_vec <enum acc_prop_kind, 8> prop_kinds (aclen); | |
3306 | for (unsigned j = 0; j < aclen; j++) | |
3307 | { | |
3308 | param_access *argacc = (*arg_desc->accesses)[j]; | |
3309 | prop_kinds.safe_push (ACC_PROP_DONT); | |
3310 | ||
3311 | if (arg_size > 0 | |
3312 | && argacc->unit_offset + argacc->unit_size > arg_size) | |
3313 | return "callee access outsize size boundary"; | |
3314 | ||
3315 | if (!argacc->certain) | |
3316 | continue; | |
3317 | ||
3318 | unsigned offset = argacc->unit_offset + delta_offset; | |
3319 | /* Given that accesses are initially stored according to increasing | |
3320 | offset and decreasing size in case of equal offsets, the following | |
3321 | searches could be written more efficiently if we kept the ordering | |
3322 | when copying. But the number of accesses is capped at | |
3323 | PARAM_IPA_SRA_MAX_REPLACEMENTS (so most likely 8) and the code gets | |
3324 | messy quickly, so let's improve on that only if necessary. */ | |
3325 | ||
3326 | bool exact_match = false; | |
3327 | for (unsigned i = 0; i < pclen; i++) | |
3328 | { | |
3329 | /* Check for overlaps. */ | |
3330 | param_access *pacc = (*param_desc->accesses)[i]; | |
3331 | if (pacc->unit_offset == offset | |
3332 | && pacc->unit_size == argacc->unit_size) | |
3333 | { | |
3334 | if (argacc->alias_ptr_type != pacc->alias_ptr_type | |
3335 | || !types_compatible_p (argacc->type, pacc->type)) | |
3336 | return "propagated access types would not match existing ones"; | |
3337 | ||
3338 | exact_match = true; | |
3339 | if (!pacc->certain) | |
3340 | { | |
3341 | prop_kinds[j] = ACC_PROP_CERTAIN; | |
3342 | prop_size += argacc->unit_size; | |
3343 | change = true; | |
3344 | } | |
3345 | continue; | |
3346 | } | |
3347 | ||
3348 | if (offset < pacc->unit_offset + pacc->unit_size | |
3349 | && offset + argacc->unit_size > pacc->unit_offset) | |
3350 | { | |
3351 | /* None permissible with load accesses, possible to fit into | |
3352 | argument ones. */ | |
3353 | if (pacc->certain | |
3354 | || offset < pacc->unit_offset | |
3355 | || (offset + argacc->unit_size | |
3356 | > pacc->unit_offset + pacc->unit_size)) | |
3357 | return "a propagated access would conflict in caller"; | |
3358 | } | |
3359 | } | |
3360 | ||
3361 | if (!exact_match) | |
3362 | { | |
3363 | prop_kinds[j] = ACC_PROP_COPY; | |
3364 | prop_count++; | |
3365 | prop_size += argacc->unit_size; | |
3366 | change = true; | |
3367 | } | |
3368 | } | |
3369 | ||
3370 | if (!change) | |
3371 | return NULL; | |
3372 | ||
3373 | if ((prop_count + pclen | |
1a315435 | 3374 | > (unsigned) opt_for_fn (caller->decl, param_ipa_sra_max_replacements)) |
ff6686d2 MJ |
3375 | || size_would_violate_limit_p (param_desc, |
3376 | param_desc->size_reached + prop_size)) | |
3377 | return "propagating accesses would violate the count or size limit"; | |
3378 | ||
3379 | *change_p = true; | |
3380 | for (unsigned j = 0; j < aclen; j++) | |
3381 | { | |
3382 | if (prop_kinds[j] == ACC_PROP_COPY) | |
3383 | { | |
3384 | param_access *argacc = (*arg_desc->accesses)[j]; | |
3385 | ||
3386 | param_access *copy = ggc_cleared_alloc<param_access> (); | |
3387 | copy->unit_offset = argacc->unit_offset + delta_offset; | |
3388 | copy->unit_size = argacc->unit_size; | |
3389 | copy->type = argacc->type; | |
3390 | copy->alias_ptr_type = argacc->alias_ptr_type; | |
3391 | copy->certain = true; | |
3392 | vec_safe_push (param_desc->accesses, copy); | |
3393 | } | |
3394 | else if (prop_kinds[j] == ACC_PROP_CERTAIN) | |
3395 | { | |
3396 | param_access *argacc = (*arg_desc->accesses)[j]; | |
3397 | param_access *csp | |
3398 | = find_param_access (param_desc, argacc->unit_offset + delta_offset, | |
3399 | argacc->unit_size); | |
3400 | csp->certain = true; | |
3401 | } | |
3402 | } | |
3403 | ||
3404 | param_desc->size_reached += prop_size; | |
3405 | ||
3406 | return NULL; | |
3407 | } | |
3408 | ||
3409 | /* Propagate parameter splitting information through call graph edge CS. | |
3410 | Return true if any changes that might need to be propagated within SCCs have | |
3411 | been made. The function also clears the aggregate_pass_through and | |
dfea3d6f | 3412 | pointer_pass_through in call summaries which do not need to be processed |
ff6686d2 MJ |
3413 | again if this CS is revisited when iterating while changes are propagated |
3414 | within an SCC. */ | |
3415 | ||
3416 | static bool | |
3417 | param_splitting_across_edge (cgraph_edge *cs) | |
3418 | { | |
3419 | bool res = false; | |
3420 | bool cross_scc = !ipa_edge_within_scc (cs); | |
3421 | enum availability availability; | |
3422 | cgraph_node *callee = cs->callee->function_symbol (&availability); | |
3423 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3424 | gcc_checking_assert (from_ifs && from_ifs->m_parameters); | |
3425 | ||
3426 | isra_call_summary *csum = call_sums->get (cs); | |
3427 | gcc_checking_assert (csum); | |
3428 | unsigned args_count = csum->m_arg_flow.length (); | |
3429 | isra_func_summary *to_ifs = func_sums->get (callee); | |
3430 | unsigned param_count | |
3431 | = ((to_ifs && to_ifs->m_candidate && (availability >= AVAIL_AVAILABLE)) | |
3432 | ? vec_safe_length (to_ifs->m_parameters) | |
3433 | : 0); | |
3434 | ||
3435 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
6b6a8065 | 3436 | fprintf (dump_file, "Splitting across %s->%s:\n", |
ff6686d2 MJ |
3437 | cs->caller->dump_name (), callee->dump_name ()); |
3438 | ||
3439 | unsigned i; | |
3440 | for (i = 0; (i < args_count) && (i < param_count); i++) | |
3441 | { | |
3442 | isra_param_desc *arg_desc = &(*to_ifs->m_parameters)[i]; | |
3443 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3444 | ||
3445 | if (arg_desc->locally_unused) | |
3446 | { | |
3447 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3448 | fprintf (dump_file, " ->%u: unused in callee\n", i); | |
3449 | ipf->pointer_pass_through = false; | |
3450 | continue; | |
3451 | } | |
3452 | ||
3453 | if (ipf->pointer_pass_through) | |
3454 | { | |
3455 | int idx = get_single_param_flow_source (ipf); | |
3456 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; | |
3457 | if (!param_desc->split_candidate) | |
3458 | continue; | |
3459 | gcc_assert (param_desc->by_ref); | |
3460 | ||
3461 | if (!arg_desc->split_candidate || !arg_desc->by_ref) | |
3462 | { | |
3463 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3464 | fprintf (dump_file, " %u->%u: not candidate or not by " | |
3465 | "reference in callee\n", idx, i); | |
3466 | param_desc->split_candidate = false; | |
3467 | ipf->pointer_pass_through = false; | |
3468 | res = true; | |
3469 | } | |
3470 | else if (!ipf->safe_to_import_accesses) | |
3471 | { | |
3472 | if (!all_callee_accesses_present_p (param_desc, arg_desc)) | |
3473 | { | |
3474 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3475 | fprintf (dump_file, " %u->%u: cannot import accesses.\n", | |
3476 | idx, i); | |
3477 | param_desc->split_candidate = false; | |
3478 | ipf->pointer_pass_through = false; | |
3479 | res = true; | |
3480 | ||
3481 | } | |
3482 | else | |
3483 | { | |
3484 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3485 | fprintf (dump_file, " %u->%u: verified callee accesses " | |
3486 | "present.\n", idx, i); | |
3487 | if (cross_scc) | |
3488 | ipf->pointer_pass_through = false; | |
3489 | } | |
3490 | } | |
3491 | else | |
3492 | { | |
3493 | const char *pull_failure | |
1a315435 MJ |
3494 | = pull_accesses_from_callee (cs->caller, param_desc, arg_desc, |
3495 | 0, 0, &res); | |
ff6686d2 MJ |
3496 | if (pull_failure) |
3497 | { | |
3498 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3499 | fprintf (dump_file, " %u->%u: by_ref access pull " | |
3500 | "failed: %s.\n", idx, i, pull_failure); | |
3501 | param_desc->split_candidate = false; | |
3502 | ipf->pointer_pass_through = false; | |
3503 | res = true; | |
3504 | } | |
3505 | else | |
3506 | { | |
3507 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3508 | fprintf (dump_file, " %u->%u: by_ref access pull " | |
3509 | "succeeded.\n", idx, i); | |
3510 | if (cross_scc) | |
3511 | ipf->pointer_pass_through = false; | |
3512 | } | |
3513 | } | |
3514 | } | |
3515 | else if (ipf->aggregate_pass_through) | |
3516 | { | |
3517 | int idx = get_single_param_flow_source (ipf); | |
3518 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; | |
3519 | if (!param_desc->split_candidate) | |
3520 | continue; | |
3521 | gcc_assert (!param_desc->by_ref); | |
3522 | param_access *pacc = find_param_access (param_desc, ipf->unit_offset, | |
3523 | ipf->unit_size); | |
3524 | gcc_checking_assert (pacc); | |
3525 | ||
3526 | if (pacc->certain) | |
3527 | { | |
3528 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3529 | fprintf (dump_file, " %u->%u: already certain\n", idx, i); | |
3530 | ipf->aggregate_pass_through = false; | |
3531 | } | |
3532 | else if (!arg_desc->split_candidate || arg_desc->by_ref) | |
3533 | { | |
3534 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3535 | fprintf (dump_file, " %u->%u: not candidate or by " | |
3536 | "reference in callee\n", idx, i); | |
3537 | ||
3538 | pacc->certain = true; | |
3539 | if (overlapping_certain_accesses_p (param_desc, NULL)) | |
3540 | { | |
3541 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3542 | fprintf (dump_file, " ...leading to overlap, " | |
3543 | " disqualifying candidate parameter %u\n", | |
3544 | idx); | |
3545 | param_desc->split_candidate = false; | |
3546 | } | |
3547 | else | |
3548 | bump_reached_size (param_desc, pacc->unit_size, idx); | |
3549 | ||
3550 | ipf->aggregate_pass_through = false; | |
3551 | res = true; | |
3552 | } | |
3553 | else | |
3554 | { | |
3555 | const char *pull_failure | |
1a315435 | 3556 | = pull_accesses_from_callee (cs->caller, param_desc, arg_desc, |
ff6686d2 MJ |
3557 | ipf->unit_offset, |
3558 | ipf->unit_size, &res); | |
3559 | if (pull_failure) | |
3560 | { | |
3561 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3562 | fprintf (dump_file, " %u->%u: arg access pull " | |
3563 | "failed: %s.\n", idx, i, pull_failure); | |
3564 | ||
3565 | ipf->aggregate_pass_through = false; | |
3566 | pacc->certain = true; | |
3567 | ||
3568 | if (overlapping_certain_accesses_p (param_desc, NULL)) | |
3569 | { | |
3570 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3571 | fprintf (dump_file, " ...leading to overlap, " | |
3572 | " disqualifying candidate parameter %u\n", | |
3573 | idx); | |
3574 | param_desc->split_candidate = false; | |
3575 | } | |
3576 | else | |
3577 | bump_reached_size (param_desc, pacc->unit_size, idx); | |
3578 | ||
3579 | res = true; | |
3580 | } | |
3581 | else | |
3582 | { | |
3583 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3584 | fprintf (dump_file, " %u->%u: arg access pull " | |
3585 | "succeeded.\n", idx, i); | |
3586 | if (cross_scc) | |
3587 | ipf->aggregate_pass_through = false; | |
3588 | } | |
3589 | } | |
3590 | } | |
3591 | } | |
3592 | ||
3593 | /* Handle argument-parameter count mismatches. */ | |
3594 | for (; (i < args_count); i++) | |
3595 | { | |
3596 | isra_param_flow *ipf = &csum->m_arg_flow[i]; | |
3597 | ||
3598 | if (ipf->pointer_pass_through || ipf->aggregate_pass_through) | |
3599 | { | |
3600 | int idx = get_single_param_flow_source (ipf); | |
3601 | ipf->pointer_pass_through = false; | |
3602 | ipf->aggregate_pass_through = false; | |
3603 | isra_param_desc *param_desc = &(*from_ifs->m_parameters)[idx]; | |
3604 | if (!param_desc->split_candidate) | |
3605 | continue; | |
3606 | ||
3607 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3608 | fprintf (dump_file, " %u->%u: no corresponding formal parameter\n", | |
3609 | idx, i); | |
3610 | param_desc->split_candidate = false; | |
3611 | res = true; | |
3612 | } | |
3613 | } | |
3614 | return res; | |
3615 | } | |
3616 | ||
3617 | /* Worker for call_for_symbol_and_aliases, look at all callers and if all their | |
3618 | callers ignore the return value, or come from the same SCC and use the | |
3619 | return value only to compute their return value, return false, otherwise | |
3620 | return true. */ | |
3621 | ||
3622 | static bool | |
3623 | retval_used_p (cgraph_node *node, void *) | |
3624 | { | |
3625 | for (cgraph_edge *cs = node->callers; cs; cs = cs->next_caller) | |
3626 | { | |
3627 | isra_call_summary *csum = call_sums->get (cs); | |
3628 | gcc_checking_assert (csum); | |
3629 | if (csum->m_return_ignored) | |
3630 | continue; | |
3631 | if (!csum->m_return_returned) | |
3632 | return true; | |
3633 | ||
3634 | isra_func_summary *from_ifs = func_sums->get (cs->caller); | |
3635 | if (!from_ifs || !from_ifs->m_candidate) | |
3636 | return true; | |
3637 | ||
3638 | if (!ipa_edge_within_scc (cs) | |
3639 | && !from_ifs->m_return_ignored) | |
3640 | return true; | |
3641 | } | |
3642 | ||
3643 | return false; | |
3644 | } | |
3645 | ||
3646 | /* Push into NEW_PARAMS all required parameter adjustment entries to copy or | |
3647 | modify parameter which originally had index BASE_INDEX, in the adjustment | |
3648 | vector of parent clone (if any) had PREV_CLONE_INDEX and was described by | |
3649 | PREV_ADJUSTMENT. If the parent clone is the original function, | |
3650 | PREV_ADJUSTMENT is NULL and PREV_CLONE_INDEX is equal to BASE_INDEX. */ | |
3651 | ||
3652 | ||
3653 | static void | |
3654 | push_param_adjustments_for_index (isra_func_summary *ifs, unsigned base_index, | |
3655 | unsigned prev_clone_index, | |
3656 | ipa_adjusted_param *prev_adjustment, | |
3657 | vec<ipa_adjusted_param, va_gc> **new_params) | |
3658 | { | |
3659 | isra_param_desc *desc = &(*ifs->m_parameters)[base_index]; | |
3660 | if (desc->locally_unused) | |
3661 | { | |
3662 | if (dump_file) | |
3663 | fprintf (dump_file, " Will remove parameter %u\n", base_index); | |
3664 | return; | |
3665 | } | |
3666 | ||
3667 | if (!desc->split_candidate) | |
3668 | { | |
3669 | ipa_adjusted_param adj; | |
3670 | if (prev_adjustment) | |
3671 | { | |
3672 | adj = *prev_adjustment; | |
3673 | adj.prev_clone_adjustment = true; | |
3674 | adj.prev_clone_index = prev_clone_index; | |
3675 | } | |
3676 | else | |
3677 | { | |
3678 | memset (&adj, 0, sizeof (adj)); | |
3679 | adj.op = IPA_PARAM_OP_COPY; | |
3680 | adj.base_index = base_index; | |
3681 | adj.prev_clone_index = prev_clone_index; | |
3682 | } | |
3683 | vec_safe_push ((*new_params), adj); | |
3684 | return; | |
3685 | } | |
3686 | ||
3687 | if (dump_file) | |
3688 | fprintf (dump_file, " Will split parameter %u\n", base_index); | |
3689 | ||
3690 | gcc_assert (!prev_adjustment || prev_adjustment->op == IPA_PARAM_OP_COPY); | |
3691 | unsigned aclen = vec_safe_length (desc->accesses); | |
3692 | for (unsigned j = 0; j < aclen; j++) | |
3693 | { | |
3694 | param_access *pa = (*desc->accesses)[j]; | |
3695 | if (!pa->certain) | |
3696 | continue; | |
3697 | if (dump_file) | |
3698 | fprintf (dump_file, " - component at byte offset %u, " | |
3699 | "size %u\n", pa->unit_offset, pa->unit_size); | |
3700 | ||
3701 | ipa_adjusted_param adj; | |
3702 | memset (&adj, 0, sizeof (adj)); | |
3703 | adj.op = IPA_PARAM_OP_SPLIT; | |
3704 | adj.base_index = base_index; | |
3705 | adj.prev_clone_index = prev_clone_index; | |
3706 | adj.param_prefix_index = IPA_PARAM_PREFIX_ISRA; | |
3707 | adj.reverse = pa->reverse; | |
3708 | adj.type = pa->type; | |
3709 | adj.alias_ptr_type = pa->alias_ptr_type; | |
3710 | adj.unit_offset = pa->unit_offset; | |
3711 | vec_safe_push ((*new_params), adj); | |
3712 | } | |
3713 | } | |
3714 | ||
b90061c6 MJ |
3715 | /* Worker for all call_for_symbol_thunks_and_aliases. Set calls_comdat_local |
3716 | flag of all callers of NODE. */ | |
3717 | ||
3718 | static bool | |
3719 | mark_callers_calls_comdat_local (struct cgraph_node *node, void *) | |
3720 | { | |
3721 | for (cgraph_edge *cs = node->callers; cs; cs = cs->next_caller) | |
3722 | cs->caller->calls_comdat_local = true; | |
3723 | return false; | |
3724 | } | |
3725 | ||
ff6686d2 | 3726 | |
dfea3d6f | 3727 | /* Do final processing of results of IPA propagation regarding NODE, clone it |
ff6686d2 MJ |
3728 | if appropriate. */ |
3729 | ||
3730 | static void | |
3731 | process_isra_node_results (cgraph_node *node, | |
3732 | hash_map<const char *, unsigned> *clone_num_suffixes) | |
3733 | { | |
3734 | isra_func_summary *ifs = func_sums->get (node); | |
3735 | if (!ifs || !ifs->m_candidate) | |
3736 | return; | |
3737 | ||
3738 | auto_vec<bool, 16> surviving_params; | |
3739 | bool check_surviving = false; | |
3740 | if (node->clone.param_adjustments) | |
3741 | { | |
3742 | check_surviving = true; | |
3743 | node->clone.param_adjustments->get_surviving_params (&surviving_params); | |
3744 | } | |
3745 | ||
3746 | unsigned param_count = vec_safe_length (ifs->m_parameters); | |
3747 | bool will_change_function = false; | |
3748 | if (ifs->m_returns_value && ifs->m_return_ignored) | |
3749 | will_change_function = true; | |
3750 | else | |
3751 | for (unsigned i = 0; i < param_count; i++) | |
3752 | { | |
3753 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; | |
3754 | if ((desc->locally_unused || desc->split_candidate) | |
3755 | /* Make sure we do not clone just to attempt to remove an already | |
3756 | removed unused argument. */ | |
3757 | && (!check_surviving | |
3758 | || (i < surviving_params.length () | |
3759 | && surviving_params[i]))) | |
3760 | { | |
3761 | will_change_function = true; | |
3762 | break; | |
3763 | } | |
3764 | } | |
3765 | if (!will_change_function) | |
3766 | return; | |
3767 | ||
3768 | if (dump_file) | |
3769 | { | |
3770 | fprintf (dump_file, "\nEvaluating analysis results for %s\n", | |
3771 | node->dump_name ()); | |
3772 | if (ifs->m_returns_value && ifs->m_return_ignored) | |
3773 | fprintf (dump_file, " Will remove return value.\n"); | |
3774 | } | |
3775 | ||
3776 | vec<ipa_adjusted_param, va_gc> *new_params = NULL; | |
3777 | if (ipa_param_adjustments *old_adjustments = node->clone.param_adjustments) | |
3778 | { | |
3779 | unsigned old_adj_len = vec_safe_length (old_adjustments->m_adj_params); | |
3780 | for (unsigned i = 0; i < old_adj_len; i++) | |
3781 | { | |
3782 | ipa_adjusted_param *old_adj = &(*old_adjustments->m_adj_params)[i]; | |
3783 | push_param_adjustments_for_index (ifs, old_adj->base_index, i, | |
3784 | old_adj, &new_params); | |
3785 | } | |
3786 | } | |
3787 | else | |
3788 | for (unsigned i = 0; i < param_count; i++) | |
3789 | push_param_adjustments_for_index (ifs, i, i, NULL, &new_params); | |
3790 | ||
3791 | ipa_param_adjustments *new_adjustments | |
3792 | = (new (ggc_alloc <ipa_param_adjustments> ()) | |
3793 | ipa_param_adjustments (new_params, param_count, | |
3794 | ifs->m_returns_value && ifs->m_return_ignored)); | |
3795 | ||
3796 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3797 | { | |
3798 | fprintf (dump_file, "\n Created adjustments:\n"); | |
3799 | new_adjustments->dump (dump_file); | |
3800 | } | |
3801 | ||
3802 | unsigned &suffix_counter = clone_num_suffixes->get_or_insert ( | |
3803 | IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME ( | |
3804 | node->decl))); | |
3805 | vec<cgraph_edge *> callers = node->collect_callers (); | |
3806 | cgraph_node *new_node | |
3807 | = node->create_virtual_clone (callers, NULL, new_adjustments, "isra", | |
3808 | suffix_counter); | |
3809 | suffix_counter++; | |
b90061c6 MJ |
3810 | if (node->calls_comdat_local && node->same_comdat_group) |
3811 | { | |
3812 | new_node->add_to_same_comdat_group (node); | |
3813 | new_node->call_for_symbol_and_aliases (mark_callers_calls_comdat_local, | |
3814 | NULL, true); | |
3815 | } | |
ed649cda | 3816 | new_node->calls_comdat_local = node->calls_comdat_local; |
ff6686d2 MJ |
3817 | |
3818 | if (dump_file) | |
3819 | fprintf (dump_file, " Created new node %s\n", new_node->dump_name ()); | |
3820 | callers.release (); | |
3821 | } | |
3822 | ||
3823 | /* Check which parameters of NODE described by IFS have survived until IPA-SRA | |
3824 | and disable transformations for those which have not or which should not | |
3825 | transformed because the associated debug counter reached its limit. Return | |
3826 | true if none survived or if there were no candidates to begin with. */ | |
3827 | ||
3828 | static bool | |
3829 | disable_unavailable_parameters (cgraph_node *node, isra_func_summary *ifs) | |
3830 | { | |
3831 | bool ret = true; | |
3832 | unsigned len = vec_safe_length (ifs->m_parameters); | |
3833 | if (!len) | |
3834 | return true; | |
3835 | ||
3836 | auto_vec<bool, 16> surviving_params; | |
3837 | bool check_surviving = false; | |
3838 | if (node->clone.param_adjustments) | |
3839 | { | |
3840 | check_surviving = true; | |
3841 | node->clone.param_adjustments->get_surviving_params (&surviving_params); | |
3842 | } | |
3843 | bool dumped_first = false; | |
3844 | for (unsigned i = 0; i < len; i++) | |
3845 | { | |
3846 | isra_param_desc *desc = &(*ifs->m_parameters)[i]; | |
3847 | if (!dbg_cnt (ipa_sra_params)) | |
3848 | { | |
3849 | desc->locally_unused = false; | |
3850 | desc->split_candidate = false; | |
3851 | } | |
3852 | else if (check_surviving | |
3853 | && (i >= surviving_params.length () | |
3854 | || !surviving_params[i])) | |
3855 | { | |
3856 | /* Even if the parameter was removed by a previous IPA pass, we do | |
3857 | not clear locally_unused because if it really is unused, this | |
3858 | information might be useful in callers. */ | |
3859 | desc->split_candidate = false; | |
3860 | ||
3861 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
3862 | { | |
3863 | if (!dumped_first) | |
3864 | { | |
3865 | fprintf (dump_file, | |
3866 | "The following parameters of %s are dead on " | |
3867 | "arrival:", node->dump_name ()); | |
3868 | dumped_first = true; | |
3869 | } | |
3870 | fprintf (dump_file, " %u", i); | |
3871 | } | |
3872 | } | |
3873 | else if (desc->locally_unused || desc->split_candidate) | |
3874 | ret = false; | |
3875 | } | |
3876 | ||
3877 | if (dumped_first) | |
3878 | fprintf (dump_file, "\n"); | |
3879 | ||
3880 | return ret; | |
3881 | } | |
3882 | ||
3883 | ||
3884 | /* Run the interprocedural part of IPA-SRA. */ | |
3885 | ||
3886 | static unsigned int | |
3887 | ipa_sra_analysis (void) | |
3888 | { | |
3889 | if (dump_file) | |
3890 | { | |
3891 | fprintf (dump_file, "\n========== IPA-SRA IPA stage ==========\n"); | |
3892 | ipa_sra_dump_all_summaries (dump_file); | |
3893 | } | |
3894 | ||
3895 | gcc_checking_assert (func_sums); | |
3896 | gcc_checking_assert (call_sums); | |
3897 | cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count); | |
3898 | auto_vec <cgraph_node *, 16> stack; | |
3899 | int node_scc_count = ipa_reduced_postorder (order, true, NULL); | |
3900 | ||
3901 | /* One sweep from callees to callers for parameter removal and splitting. */ | |
3902 | for (int i = 0; i < node_scc_count; i++) | |
3903 | { | |
3904 | cgraph_node *scc_rep = order[i]; | |
3905 | vec<cgraph_node *> cycle_nodes = ipa_get_nodes_in_cycle (scc_rep); | |
3906 | unsigned j; | |
3907 | ||
3908 | /* Preliminary IPA function level checks and first step of parameter | |
3909 | removal. */ | |
3910 | cgraph_node *v; | |
3911 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) | |
3912 | { | |
3913 | isra_func_summary *ifs = func_sums->get (v); | |
3914 | if (!ifs || !ifs->m_candidate) | |
3915 | continue; | |
3916 | if (!ipa_sra_ipa_function_checks (v) | |
3917 | || check_all_callers_for_issues (v)) | |
3918 | { | |
3919 | ifs->zap (); | |
3920 | continue; | |
3921 | } | |
3922 | if (disable_unavailable_parameters (v, ifs)) | |
3923 | continue; | |
3924 | for (cgraph_edge *cs = v->indirect_calls; cs; cs = cs->next_callee) | |
3925 | process_edge_to_unknown_caller (cs); | |
3926 | for (cgraph_edge *cs = v->callees; cs; cs = cs->next_callee) | |
3927 | if (!ipa_edge_within_scc (cs)) | |
3928 | param_removal_cross_scc_edge (cs); | |
3929 | } | |
3930 | ||
6b6a8065 JJ |
3931 | /* Look at edges within the current SCC and propagate used-ness across |
3932 | them, pushing onto the stack all notes which might need to be | |
3933 | revisited. */ | |
ff6686d2 MJ |
3934 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) |
3935 | v->call_for_symbol_thunks_and_aliases (propagate_used_to_scc_callers, | |
3936 | &stack, true); | |
3937 | ||
3938 | /* Keep revisiting and pushing until nothing changes. */ | |
3939 | while (!stack.is_empty ()) | |
3940 | { | |
3941 | cgraph_node *v = stack.pop (); | |
3942 | isra_func_summary *ifs = func_sums->get (v); | |
3943 | gcc_checking_assert (ifs && ifs->m_queued); | |
3944 | ifs->m_queued = false; | |
3945 | ||
3946 | v->call_for_symbol_thunks_and_aliases (propagate_used_to_scc_callers, | |
3947 | &stack, true); | |
3948 | } | |
3949 | ||
3950 | /* Parameter splitting. */ | |
3951 | bool repeat_scc_access_propagation; | |
3952 | do | |
3953 | { | |
3954 | repeat_scc_access_propagation = false; | |
3955 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) | |
3956 | { | |
3957 | isra_func_summary *ifs = func_sums->get (v); | |
3958 | if (!ifs | |
3959 | || !ifs->m_candidate | |
3960 | || vec_safe_is_empty (ifs->m_parameters)) | |
3961 | continue; | |
3962 | for (cgraph_edge *cs = v->callees; cs; cs = cs->next_callee) | |
3963 | if (param_splitting_across_edge (cs)) | |
3964 | repeat_scc_access_propagation = true; | |
3965 | } | |
3966 | } | |
3967 | while (repeat_scc_access_propagation); | |
3968 | ||
3969 | if (flag_checking) | |
3970 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) | |
3971 | verify_splitting_accesses (v, true); | |
3972 | ||
3973 | cycle_nodes.release (); | |
3974 | } | |
3975 | ||
3976 | /* One sweep from caller to callees for result removal. */ | |
3977 | for (int i = node_scc_count - 1; i >= 0 ; i--) | |
3978 | { | |
3979 | cgraph_node *scc_rep = order[i]; | |
3980 | vec<cgraph_node *> cycle_nodes = ipa_get_nodes_in_cycle (scc_rep); | |
3981 | unsigned j; | |
3982 | ||
3983 | cgraph_node *v; | |
3984 | FOR_EACH_VEC_ELT (cycle_nodes, j, v) | |
3985 | { | |
3986 | isra_func_summary *ifs = func_sums->get (v); | |
3987 | if (!ifs || !ifs->m_candidate) | |
3988 | continue; | |
3989 | ||
3990 | bool return_needed | |
3991 | = (ifs->m_returns_value | |
3992 | && (!dbg_cnt (ipa_sra_retvalues) | |
3993 | || v->call_for_symbol_and_aliases (retval_used_p, | |
3994 | NULL, true))); | |
3995 | ifs->m_return_ignored = !return_needed; | |
3996 | if (return_needed) | |
3997 | isra_push_node_to_stack (v, ifs, &stack); | |
3998 | } | |
3999 | ||
4000 | while (!stack.is_empty ()) | |
4001 | { | |
4002 | cgraph_node *node = stack.pop (); | |
4003 | isra_func_summary *ifs = func_sums->get (node); | |
4004 | gcc_checking_assert (ifs && ifs->m_queued); | |
4005 | ifs->m_queued = false; | |
4006 | ||
4007 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) | |
4008 | if (ipa_edge_within_scc (cs) | |
4009 | && call_sums->get (cs)->m_return_returned) | |
4010 | { | |
4011 | enum availability av; | |
4012 | cgraph_node *callee = cs->callee->function_symbol (&av); | |
4013 | isra_func_summary *to_ifs = func_sums->get (callee); | |
4014 | if (to_ifs && to_ifs->m_return_ignored) | |
4015 | { | |
4016 | to_ifs->m_return_ignored = false; | |
4017 | isra_push_node_to_stack (callee, to_ifs, &stack); | |
4018 | } | |
4019 | } | |
4020 | } | |
4021 | cycle_nodes.release (); | |
4022 | } | |
4023 | ||
4024 | ipa_free_postorder_info (); | |
4025 | free (order); | |
4026 | ||
4027 | if (dump_file) | |
4028 | { | |
4029 | if (dump_flags & TDF_DETAILS) | |
4030 | { | |
4031 | fprintf (dump_file, "\n========== IPA-SRA propagation final state " | |
4032 | " ==========\n"); | |
4033 | ipa_sra_dump_all_summaries (dump_file); | |
4034 | } | |
4035 | fprintf (dump_file, "\n========== IPA-SRA decisions ==========\n"); | |
4036 | } | |
4037 | ||
4038 | hash_map<const char *, unsigned> *clone_num_suffixes | |
4039 | = new hash_map<const char *, unsigned>; | |
4040 | ||
4041 | cgraph_node *node; | |
4042 | FOR_EACH_FUNCTION_WITH_GIMPLE_BODY (node) | |
4043 | process_isra_node_results (node, clone_num_suffixes); | |
4044 | ||
4045 | delete clone_num_suffixes; | |
ddf628e4 | 4046 | ggc_delete (func_sums); |
ff6686d2 | 4047 | func_sums = NULL; |
78cd68c0 | 4048 | delete call_sums; |
ff6686d2 MJ |
4049 | call_sums = NULL; |
4050 | ||
4051 | if (dump_file) | |
4052 | fprintf (dump_file, "\n========== IPA SRA IPA analysis done " | |
4053 | "==========\n\n"); | |
4054 | return 0; | |
4055 | } | |
4056 | ||
4057 | ||
4058 | const pass_data pass_data_ipa_sra = | |
4059 | { | |
4060 | IPA_PASS, /* type */ | |
4061 | "sra", /* name */ | |
4062 | OPTGROUP_NONE, /* optinfo_flags */ | |
4063 | TV_IPA_SRA, /* tv_id */ | |
4064 | 0, /* properties_required */ | |
4065 | 0, /* properties_provided */ | |
4066 | 0, /* properties_destroyed */ | |
4067 | 0, /* todo_flags_start */ | |
4068 | ( TODO_dump_symtab | TODO_remove_functions ), /* todo_flags_finish */ | |
4069 | }; | |
4070 | ||
4071 | class pass_ipa_sra : public ipa_opt_pass_d | |
4072 | { | |
4073 | public: | |
4074 | pass_ipa_sra (gcc::context *ctxt) | |
4075 | : ipa_opt_pass_d (pass_data_ipa_sra, ctxt, | |
4076 | ipa_sra_generate_summary, /* generate_summary */ | |
4077 | ipa_sra_write_summary, /* write_summary */ | |
4078 | ipa_sra_read_summary, /* read_summary */ | |
4079 | NULL , /* write_optimization_summary */ | |
4080 | NULL, /* read_optimization_summary */ | |
4081 | NULL, /* stmt_fixup */ | |
4082 | 0, /* function_transform_todo_flags_start */ | |
4083 | NULL, /* function_transform */ | |
4084 | NULL) /* variable_transform */ | |
4085 | {} | |
4086 | ||
4087 | /* opt_pass methods: */ | |
4088 | virtual bool gate (function *) | |
4089 | { | |
4090 | /* TODO: We should remove the optimize check after we ensure we never run | |
4091 | IPA passes when not optimizing. */ | |
4092 | return (flag_ipa_sra && optimize); | |
4093 | } | |
4094 | ||
4095 | virtual unsigned int execute (function *) { return ipa_sra_analysis (); } | |
4096 | ||
4097 | }; // class pass_ipa_sra | |
4098 | ||
4099 | } // anon namespace | |
4100 | ||
4101 | ipa_opt_pass_d * | |
4102 | make_pass_ipa_sra (gcc::context *ctxt) | |
4103 | { | |
4104 | return new pass_ipa_sra (ctxt); | |
4105 | } | |
4106 | ||
4107 | ||
4108 | #include "gt-ipa-sra.h" |