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1 : : /* Basic IPA optimizations and utilities.
2 : : Copyright (C) 2003-2026 Free Software Foundation, Inc.
3 : :
4 : : This file is part of GCC.
5 : :
6 : : GCC is free software; you can redistribute it and/or modify it under
7 : : the terms of the GNU General Public License as published by the Free
8 : : Software Foundation; either version 3, or (at your option) any later
9 : : version.
10 : :
11 : : GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 : : WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 : : FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 : : for more details.
15 : :
16 : : You should have received a copy of the GNU General Public License
17 : : along with GCC; see the file COPYING3. If not see
18 : : <http://www.gnu.org/licenses/>. */
19 : :
20 : : #include "config.h"
21 : : #include "system.h"
22 : : #include "coretypes.h"
23 : : #include "backend.h"
24 : : #include "target.h"
25 : : #include "tree.h"
26 : : #include "gimple.h"
27 : : #include "alloc-pool.h"
28 : : #include "tree-pass.h"
29 : : #include "stringpool.h"
30 : : #include "cgraph.h"
31 : : #include "gimplify.h"
32 : : #include "tree-iterator.h"
33 : : #include "ipa-utils.h"
34 : : #include "symbol-summary.h"
35 : : #include "tree-vrp.h"
36 : : #include "sreal.h"
37 : : #include "ipa-cp.h"
38 : : #include "ipa-prop.h"
39 : : #include "ipa-fnsummary.h"
40 : : #include "dbgcnt.h"
41 : : #include "debug.h"
42 : : #include "stringpool.h"
43 : : #include "attribs.h"
44 : :
45 : : /* Return true when NODE has ADDR reference. */
46 : :
47 : : static bool
48 : 3357581 : has_addr_references_p (struct cgraph_node *node,
49 : : void *)
50 : : {
51 : 3357581 : int i;
52 : 3357581 : struct ipa_ref *ref = NULL;
53 : :
54 : 3459971 : for (i = 0; node->iterate_referring (i, ref); i++)
55 : 3365533 : if (ref->use == IPA_REF_ADDR)
56 : : return true;
57 : : return false;
58 : : }
59 : :
60 : : /* Return true when NODE can be target of an indirect call. */
61 : :
62 : : static bool
63 : 508 : is_indirect_call_target_p (struct cgraph_node *node, void *)
64 : : {
65 : 508 : return node->indirect_call_target;
66 : : }
67 : :
68 : : /* Look for all functions inlined to NODE and update their inlined_to pointers
69 : : to INLINED_TO. */
70 : :
71 : : static void
72 : 0 : update_inlined_to_pointer (struct cgraph_node *node, struct cgraph_node *inlined_to)
73 : : {
74 : 0 : struct cgraph_edge *e;
75 : 0 : for (e = node->callees; e; e = e->next_callee)
76 : 0 : if (e->callee->inlined_to)
77 : : {
78 : 0 : e->callee->inlined_to = inlined_to;
79 : 0 : update_inlined_to_pointer (e->callee, inlined_to);
80 : : }
81 : 0 : }
82 : :
83 : : /* Add symtab NODE to queue starting at FIRST.
84 : :
85 : : The queue is linked via AUX pointers and terminated by pointer to 1.
86 : : We enqueue nodes at two occasions: when we find them reachable or when we find
87 : : their bodies needed for further clonning. In the second case we mark them
88 : : by pointer to 2 after processing so they are re-queue when they become
89 : : reachable. */
90 : :
91 : : static void
92 : 143462903 : enqueue_node (symtab_node *node, symtab_node **first,
93 : : hash_set<symtab_node *> *reachable)
94 : : {
95 : : /* Node is still in queue; do nothing. */
96 : 143462903 : if (node->aux && node->aux != (void *) 2)
97 : : return;
98 : : /* Node was already processed as unreachable, re-enqueue
99 : : only if it became reachable now. */
100 : 79792098 : if (node->aux == (void *)2 && !reachable->contains (node))
101 : : return;
102 : 50261622 : node->aux = *first;
103 : 50261622 : *first = node;
104 : : }
105 : :
106 : : /* Return true if NODE may get inlined later.
107 : : This is used to keep DECL_EXTERNAL function bodies around long enough
108 : : so inliner can proces them. */
109 : :
110 : : static bool
111 : 792299 : possible_inline_candidate_p (symtab_node *node)
112 : : {
113 : 792299 : if (symtab->state >= IPA_SSA_AFTER_INLINING)
114 : : return false;
115 : 768847 : cgraph_node *cnode = dyn_cast <cgraph_node *> (node);
116 : 736942 : if (!cnode)
117 : : return false;
118 : 736942 : if (DECL_UNINLINABLE (cnode->decl))
119 : : return false;
120 : 734077 : if (opt_for_fn (cnode->decl, optimize))
121 : : return true;
122 : 2023 : if (symtab->state >= IPA_SSA)
123 : : return false;
124 : 1686 : return lookup_attribute ("always_inline", DECL_ATTRIBUTES (node->decl));
125 : : }
126 : :
127 : : /* Process references. */
128 : :
129 : : static void
130 : 36567325 : process_references (symtab_node *snode,
131 : : symtab_node **first,
132 : : hash_set<symtab_node *> *reachable)
133 : : {
134 : 36567325 : int i;
135 : 36567325 : struct ipa_ref *ref = NULL;
136 : 104370376 : for (i = 0; snode->iterate_reference (i, ref); i++)
137 : : {
138 : 67803051 : symtab_node *node = ref->referred;
139 : 67803051 : symtab_node *body = node->ultimate_alias_target ();
140 : :
141 : 48980942 : if (node->definition && !node->in_other_partition
142 : 116783907 : && ((!DECL_EXTERNAL (node->decl) || node->alias)
143 : 76767 : || (possible_inline_candidate_p (node)
144 : : /* We use variable constructors during late compilation for
145 : : constant folding. Keep references alive so partitioning
146 : : knows about potential references. */
147 : 36488 : || (VAR_P (node->decl)
148 : 31905 : && (flag_wpa
149 : 31905 : || flag_incremental_link
150 : : == INCREMENTAL_LINK_LTO)
151 : 0 : && dyn_cast <varpool_node *> (node)
152 : 0 : ->ctor_useable_for_folding_p ()))))
153 : : {
154 : : /* Be sure that we will not optimize out alias target
155 : : body. */
156 : 48944368 : if (DECL_EXTERNAL (node->decl)
157 : 57530 : && node->alias
158 : 48961619 : && symtab->state < IPA_SSA_AFTER_INLINING)
159 : 6558 : reachable->add (body);
160 : 48944368 : reachable->add (node);
161 : : }
162 : 67803051 : enqueue_node (node, first, reachable);
163 : : }
164 : 36567325 : }
165 : :
166 : : /* EDGE is an polymorphic call. If BEFORE_INLINING_P is set, mark
167 : : all its potential targets as reachable to permit later inlining if
168 : : devirtualization happens. After inlining still keep their declarations
169 : : around, so we can devirtualize to a direct call.
170 : :
171 : : Also try to make trivial devirutalization when no or only one target is
172 : : possible. */
173 : :
174 : : static void
175 : 185357 : walk_polymorphic_call_targets (hash_set<void *> *reachable_call_targets,
176 : : struct cgraph_edge *edge,
177 : : symtab_node **first,
178 : : hash_set<symtab_node *> *reachable)
179 : : {
180 : 185357 : unsigned int i;
181 : 185357 : void *cache_token;
182 : 185357 : bool final;
183 : 185357 : vec <cgraph_node *>targets
184 : : = possible_polymorphic_call_targets
185 : 185357 : (edge, &final, &cache_token);
186 : :
187 : 185357 : if (cache_token != NULL && !reachable_call_targets->add (cache_token))
188 : : {
189 : 230104 : for (i = 0; i < targets.length (); i++)
190 : : {
191 : 138228 : struct cgraph_node *n = targets[i];
192 : :
193 : : /* Do not bother to mark virtual methods in anonymous namespace;
194 : : either we will find use of virtual table defining it, or it is
195 : : unused. */
196 : 138228 : if (TREE_CODE (TREE_TYPE (n->decl)) == METHOD_TYPE
197 : 270030 : && type_in_anonymous_namespace_p
198 : 131802 : (TYPE_METHOD_BASETYPE (TREE_TYPE (n->decl))))
199 : 4774 : continue;
200 : :
201 : 133454 : n->indirect_call_target = true;
202 : 133454 : symtab_node *body = n->function_symbol ();
203 : :
204 : : /* Prior inlining, keep alive bodies of possible targets for
205 : : devirtualization. */
206 : 133454 : if (n->definition
207 : 133454 : && (possible_inline_candidate_p (body)
208 : 100133 : && opt_for_fn (body->decl, flag_devirtualize)))
209 : : {
210 : : /* Be sure that we will not optimize out alias target
211 : : body. */
212 : 100133 : if (DECL_EXTERNAL (n->decl)
213 : 2871 : && n->alias
214 : 100133 : && symtab->state < IPA_SSA_AFTER_INLINING)
215 : 0 : reachable->add (body);
216 : 100133 : reachable->add (n);
217 : : }
218 : : /* Even after inlining we want to keep the possible targets in the
219 : : boundary, so late passes can still produce direct call even if
220 : : the chance for inlining is lost. */
221 : 133454 : enqueue_node (n, first, reachable);
222 : : }
223 : : }
224 : :
225 : : /* Very trivial devirtualization; when the type is
226 : : final or anonymous (so we know all its derivation)
227 : : and there is only one possible virtual call target,
228 : : make the edge direct. */
229 : 185357 : if (final)
230 : : {
231 : 161 : if (targets.length () <= 1 && dbg_cnt (devirt))
232 : : {
233 : 14 : cgraph_node *target, *node = edge->caller;
234 : 14 : if (targets.length () == 1)
235 : 6 : target = targets[0];
236 : : else
237 : 8 : target = cgraph_node::get_create (builtin_decl_unreachable ());
238 : :
239 : 14 : if (dump_enabled_p ())
240 : : {
241 : 0 : dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, edge->call_stmt,
242 : : "devirtualizing call in %s to %s\n",
243 : 0 : edge->caller->dump_name (),
244 : : target->dump_name ());
245 : : }
246 : 14 : edge = cgraph_edge::make_direct (edge, target);
247 : 14 : if (ipa_fn_summaries)
248 : 2 : ipa_update_overall_fn_summary (node->inlined_to
249 : : ? node->inlined_to : node);
250 : 12 : else if (edge->call_stmt)
251 : 12 : cgraph_edge::redirect_call_stmt_to_callee (edge);
252 : : }
253 : : }
254 : 185357 : }
255 : :
256 : : /* Perform reachability analysis and reclaim all unreachable nodes.
257 : :
258 : : The algorithm is basically mark&sweep but with some extra refinements:
259 : :
260 : : - reachable extern inline functions needs special handling; the bodies needs
261 : : to stay in memory until inlining in hope that they will be inlined.
262 : : After inlining we release their bodies and turn them into unanalyzed
263 : : nodes even when they are reachable.
264 : :
265 : : - virtual functions are kept in callgraph even if they seem unreachable in
266 : : hope calls to them will be devirtualized.
267 : :
268 : : Again we remove them after inlining. In late optimization some
269 : : devirtualization may happen, but it is not important since we won't inline
270 : : the call. In theory early opts and IPA should work out all important cases.
271 : :
272 : : - virtual clones needs bodies of their origins for later materialization;
273 : : this means that we want to keep the body even if the origin is unreachable
274 : : otherwise. To avoid origin from sitting in the callgraph and being
275 : : walked by IPA passes, we turn them into unanalyzed nodes with body
276 : : defined.
277 : :
278 : : We maintain set of function declaration where body needs to stay in
279 : : body_needed_for_clonning
280 : :
281 : : Inline clones represent special case: their declaration match the
282 : : declaration of origin and cgraph_remove_node already knows how to
283 : : reshape callgraph and preserve body when offline copy of function or
284 : : inline clone is being removed.
285 : :
286 : : - C++ virtual tables keyed to other unit are represented as DECL_EXTERNAL
287 : : variables with DECL_INITIAL set. We finalize these and keep reachable
288 : : ones around for constant folding purposes. After inlining we however
289 : : stop walking their references to let everything static referenced by them
290 : : to be removed when it is otherwise unreachable.
291 : :
292 : : We maintain queue of both reachable symbols (i.e. defined symbols that needs
293 : : to stay) and symbols that are in boundary (i.e. external symbols referenced
294 : : by reachable symbols or origins of clones). The queue is represented
295 : : as linked list by AUX pointer terminated by 1.
296 : :
297 : : At the end we keep all reachable symbols. For symbols in boundary we always
298 : : turn definition into a declaration, but we may keep function body around
299 : : based on body_needed_for_clonning
300 : :
301 : : All symbols that enter the queue have AUX pointer non-zero and are in the
302 : : boundary. Pointer set REACHABLE is used to track reachable symbols.
303 : :
304 : : Every symbol can be visited twice - once as part of boundary and once
305 : : as real reachable symbol. enqueue_node needs to decide whether the
306 : : node needs to be re-queued for second processing. For this purpose
307 : : we set AUX pointer of processed symbols in the boundary to constant 2. */
308 : :
309 : : bool
310 : 1463587 : symbol_table::remove_unreachable_nodes (FILE *file)
311 : : {
312 : 1463587 : symtab_node *first = (symtab_node *) (void *) 1;
313 : 1463587 : symtab_node *snode;
314 : 1463587 : struct cgraph_node *node, *next;
315 : 1463587 : varpool_node *vnode, *vnext;
316 : 1463587 : bool changed = false;
317 : 1463587 : hash_set<symtab_node *> reachable;
318 : 1463587 : hash_set<tree> body_needed_for_clonning;
319 : 1463587 : hash_set<void *> reachable_call_targets;
320 : :
321 : 1463587 : timevar_push (TV_IPA_UNREACHABLE);
322 : 1463587 : build_type_inheritance_graph ();
323 : 1463587 : if (file)
324 : 700 : fprintf (file, "\nReclaiming functions:");
325 : 1463587 : if (flag_checking)
326 : : {
327 : 29783483 : FOR_EACH_FUNCTION (node)
328 : 28319997 : gcc_assert (!node->aux);
329 : 23705335 : FOR_EACH_VARIABLE (vnode)
330 : 22241849 : gcc_assert (!vnode->aux);
331 : : }
332 : : /* Mark functions whose bodies are obviously needed.
333 : : This is mostly when they can be referenced externally. Inline clones
334 : : are special since their declarations are shared with master clone and thus
335 : : cgraph_can_remove_if_no_direct_calls_and_refs_p should not be called on them. */
336 : 29783907 : FOR_EACH_FUNCTION (node)
337 : : {
338 : 28320320 : node->used_as_abstract_origin = false;
339 : 28320320 : node->indirect_call_target = false;
340 : 28320320 : if (node->definition
341 : 16738307 : && !node->inlined_to
342 : 14460908 : && !node->in_other_partition
343 : 42780979 : && !node->can_remove_if_no_direct_calls_and_refs_p ())
344 : : {
345 : 7764042 : gcc_assert (!node->inlined_to);
346 : 7764042 : reachable.add (node);
347 : 7764042 : enqueue_node (node, &first, &reachable);
348 : : }
349 : : else
350 : 20556278 : gcc_assert (!node->aux);
351 : : }
352 : :
353 : : /* Mark variables that are obviously needed. */
354 : 21631168 : FOR_EACH_DEFINED_VARIABLE (vnode)
355 : 20167581 : if (!vnode->can_remove_if_no_refs_p()
356 : 20167581 : && !vnode->in_other_partition)
357 : : {
358 : 10116660 : reachable.add (vnode);
359 : 10116660 : enqueue_node (vnode, &first, &reachable);
360 : : }
361 : :
362 : : /* Declarations or symbols in other partitions are also needed if referenced
363 : : from asm. */
364 : 52026176 : FOR_EACH_SYMBOL (snode)
365 : 50562589 : if (snode->ref_by_asm)
366 : 761 : enqueue_node (snode, &first, &reachable);
367 : :
368 : : /* Perform reachability analysis. */
369 : 51725209 : while (first != (symtab_node *) (void *) 1)
370 : : {
371 : 50261622 : bool in_boundary_p = !reachable.contains (first);
372 : 50261622 : symtab_node *node = first;
373 : :
374 : 50261622 : first = (symtab_node *)first->aux;
375 : :
376 : : /* If we are processing symbol in boundary, mark its AUX pointer for
377 : : possible later re-processing in enqueue_node. */
378 : 50261622 : if (in_boundary_p)
379 : : {
380 : 13694297 : node->aux = (void *)2;
381 : 13694297 : if (node->alias && node->analyzed)
382 : 3888 : enqueue_node (node->get_alias_target (), &first, &reachable);
383 : : }
384 : : else
385 : : {
386 : 36567325 : if (TREE_CODE (node->decl) == FUNCTION_DECL
387 : 36567325 : && DECL_ABSTRACT_ORIGIN (node->decl))
388 : : {
389 : 3111964 : struct cgraph_node *origin_node
390 : 3111964 : = cgraph_node::get (DECL_ABSTRACT_ORIGIN (node->decl));
391 : 3111964 : if (origin_node && !origin_node->used_as_abstract_origin)
392 : : {
393 : 369912 : origin_node->used_as_abstract_origin = true;
394 : 369912 : gcc_assert (!origin_node->prev_sibling_clone);
395 : 369912 : gcc_assert (!origin_node->next_sibling_clone);
396 : 531647 : for (cgraph_node *n = origin_node->clones; n;
397 : 161735 : n = n->next_sibling_clone)
398 : 161735 : if (n->decl == DECL_ABSTRACT_ORIGIN (node->decl))
399 : 130825 : n->used_as_abstract_origin = true;
400 : : }
401 : : }
402 : : /* If any non-external and non-local symbol in a comdat group is
403 : : reachable, force all externally visible symbols in the same comdat
404 : : group to be reachable as well. Comdat-local symbols
405 : : can be discarded if all uses were inlined. */
406 : 36567325 : if (node->same_comdat_group
407 : 1606247 : && node->externally_visible
408 : 38148532 : && !DECL_EXTERNAL (node->decl))
409 : : {
410 : 1581207 : symtab_node *next;
411 : 1581207 : for (next = node->same_comdat_group;
412 : 4799112 : next != node;
413 : 3217905 : next = next->same_comdat_group)
414 : 6435810 : if (!next->comdat_local_p ()
415 : 3151673 : && !DECL_EXTERNAL (next->decl)
416 : 3151670 : && !reachable.add (next))
417 : 753101 : enqueue_node (next, &first, &reachable);
418 : : }
419 : : /* Mark references as reachable. */
420 : 36567325 : process_references (node, &first, &reachable);
421 : : }
422 : :
423 : 50261622 : if (cgraph_node *cnode = dyn_cast <cgraph_node *> (node))
424 : : {
425 : : /* Mark the callees reachable unless they are direct calls to extern
426 : : inline functions we decided to not inline. */
427 : 28063100 : if (!in_boundary_p)
428 : : {
429 : 16442617 : struct cgraph_edge *e;
430 : : /* Keep alive possible targets for devirtualization. */
431 : 16442617 : if (opt_for_fn (cnode->decl, optimize)
432 : 16442617 : && opt_for_fn (cnode->decl, flag_devirtualize))
433 : : {
434 : 13536875 : struct cgraph_edge *next;
435 : 13536875 : for (e = cnode->indirect_calls; e; e = next)
436 : : {
437 : 1173226 : next = e->next_callee;
438 : 14710101 : if (usable_polymorphic_info_p (e->indirect_info))
439 : 185357 : walk_polymorphic_call_targets (&reachable_call_targets,
440 : : e, &first, &reachable);
441 : : }
442 : : }
443 : :
444 : : /* A reference to the default node implies use of all the other
445 : : versions (they get used in the function resolver made later
446 : : in multiple_target.cc) */
447 : 16442617 : cgraph_function_version_info *node_v = cnode->function_version ();
448 : 16442617 : if (node_v && is_function_default_version (node->decl))
449 : 963 : for (cgraph_function_version_info *fvi = node_v->next;
450 : 4108 : fvi;
451 : 3145 : fvi = fvi->next)
452 : 3145 : enqueue_node (fvi->this_node, &first, &reachable);
453 : :
454 : 72393657 : for (e = cnode->callees; e; e = e->next_callee)
455 : : {
456 : 55951040 : symtab_node *body = e->callee->function_symbol ();
457 : 55951040 : if (e->callee->definition
458 : 21993540 : && !e->callee->in_other_partition
459 : 77944443 : && (!e->inline_failed
460 : 19732005 : || !DECL_EXTERNAL (e->callee->decl)
461 : 687382 : || e->callee->alias
462 : 602466 : || possible_inline_candidate_p (e->callee)))
463 : : {
464 : : /* Be sure that we will not optimize out alias target
465 : : body. */
466 : 21984144 : if (DECL_EXTERNAL (e->callee->decl)
467 : 796534 : && e->callee->alias
468 : 22069060 : && symtab->state < IPA_SSA_AFTER_INLINING)
469 : 83711 : reachable.add (body);
470 : 21984144 : reachable.add (e->callee);
471 : : }
472 : 55951040 : enqueue_node (e->callee, &first, &reachable);
473 : : }
474 : :
475 : : /* When inline clone exists, mark body to be preserved so when removing
476 : : offline copy of the function we don't kill it. */
477 : 16442617 : if (cnode->inlined_to)
478 : 2261398 : body_needed_for_clonning.add (cnode->decl);
479 : :
480 : : /* For non-inline clones, force their origins to the boundary and ensure
481 : : that body is not removed. */
482 : 19575436 : while (cnode->clone_of)
483 : : {
484 : 3132819 : bool noninline = cnode->clone_of->decl != cnode->decl;
485 : 3132819 : cnode = cnode->clone_of;
486 : 3132819 : if (noninline)
487 : : {
488 : 836344 : body_needed_for_clonning.add (cnode->decl);
489 : 836344 : enqueue_node (cnode, &first, &reachable);
490 : : }
491 : : }
492 : :
493 : : }
494 : 11620483 : else if (cnode->thunk)
495 : 45 : enqueue_node (cnode->callees->callee, &first, &reachable);
496 : :
497 : : /* If any reachable function has simd clones, mark them as
498 : : reachable as well. */
499 : 28063100 : if (cnode->simd_clones)
500 : : {
501 : : cgraph_node *next;
502 : 0 : for (next = cnode->simd_clones;
503 : 0 : next;
504 : 0 : next = next->simdclone->next_clone)
505 : 0 : if (in_boundary_p
506 : 0 : || !reachable.add (next))
507 : 0 : enqueue_node (next, &first, &reachable);
508 : : }
509 : : }
510 : : /* When we see constructor of external variable, keep referred nodes in the
511 : : boundary. This will also hold initializers of the external vars NODE
512 : : refers to. */
513 : 50261622 : varpool_node *vnode = dyn_cast <varpool_node *> (node);
514 : 50261622 : if (vnode
515 : 22198522 : && DECL_EXTERNAL (node->decl)
516 : 2073563 : && !vnode->alias
517 : : && in_boundary_p)
518 : : {
519 : 2170933 : struct ipa_ref *ref = NULL;
520 : 5708081 : for (int i = 0; node->iterate_reference (i, ref); i++)
521 : 97372 : enqueue_node (ref->referred, &first, &reachable);
522 : : }
523 : : }
524 : :
525 : : /* Remove unreachable functions. */
526 : 29789152 : for (node = first_function (); node; node = next)
527 : : {
528 : 28325565 : next = next_function (node);
529 : :
530 : : /* If node is not needed at all, remove it. */
531 : 28325565 : if (!node->aux)
532 : : {
533 : 269104 : if (file)
534 : 91 : fprintf (file, " %s", node->dump_name ());
535 : 269104 : node->remove ();
536 : 269104 : changed = true;
537 : : }
538 : : /* If node is unreachable, remove its body. */
539 : 28056461 : else if (!reachable.contains (node))
540 : : {
541 : : /* We keep definitions of thunks and aliases in the boundary so
542 : : we can walk to the ultimate alias targets and function symbols
543 : : reliably. */
544 : 11613844 : if (node->alias || node->thunk)
545 : : ;
546 : 11609548 : else if (!body_needed_for_clonning.contains (node->decl))
547 : : {
548 : : /* Make the node a non-clone so that we do not attempt to
549 : : materialize it later. */
550 : 11248937 : if (node->clone_of)
551 : 0 : node->remove_from_clone_tree ();
552 : 11248937 : node->release_body ();
553 : : }
554 : 360611 : else if (!node->clone_of)
555 : 349280 : gcc_assert (in_lto_p || DECL_RESULT (node->decl));
556 : 11613844 : if (node->definition && !node->alias && !node->thunk)
557 : : {
558 : 144956 : if (file)
559 : 184 : fprintf (file, " %s", node->dump_name ());
560 : 144956 : node->body_removed = true;
561 : 144956 : node->analyzed = false;
562 : 144956 : node->definition = false;
563 : 144956 : node->cpp_implicit_alias = false;
564 : 144956 : node->alias = false;
565 : 144956 : node->transparent_alias = false;
566 : 144956 : node->thunk = false;
567 : 144956 : node->weakref = false;
568 : : /* After early inlining we drop always_inline attributes on
569 : : bodies of functions that are still referenced (have their
570 : : address taken). */
571 : 144956 : DECL_ATTRIBUTES (node->decl)
572 : 144956 : = remove_attribute ("always_inline",
573 : 144956 : DECL_ATTRIBUTES (node->decl));
574 : 144956 : if (!node->in_other_partition)
575 : 144773 : node->local = false;
576 : 144956 : node->remove_callees ();
577 : 144956 : node->remove_all_references ();
578 : 144956 : changed = true;
579 : : }
580 : : }
581 : : else
582 : 16442617 : gcc_assert (node->clone_of || !node->has_gimple_body_p ()
583 : : || in_lto_p || DECL_RESULT (node->decl));
584 : : }
585 : :
586 : : /* Inline clones might be kept around so their materializing allows further
587 : : cloning. If the function the clone is inlined into is removed, we need
588 : : to turn it into normal cone. */
589 : 29520048 : FOR_EACH_FUNCTION (node)
590 : : {
591 : 28056461 : if (node->inlined_to
592 : 2261398 : && !node->callers)
593 : : {
594 : 0 : gcc_assert (node->clones);
595 : 0 : node->inlined_to = NULL;
596 : 0 : update_inlined_to_pointer (node, node);
597 : : }
598 : 28056461 : node->aux = NULL;
599 : : }
600 : :
601 : : /* Remove unreachable variables. */
602 : 1463587 : if (file)
603 : 700 : fprintf (file, "\nReclaiming variables:");
604 : 23705856 : for (vnode = first_variable (); vnode; vnode = vnext)
605 : : {
606 : 22242269 : vnext = next_variable (vnode);
607 : 22242269 : if (!vnode->aux
608 : : /* For can_refer_decl_in_current_unit_p we want to track for
609 : : all external variables if they are defined in other partition
610 : : or not. */
611 : 22242269 : && (!flag_ltrans || !DECL_EXTERNAL (vnode->decl)))
612 : : {
613 : 43710 : struct ipa_ref *ref = NULL;
614 : :
615 : : /* First remove the aliases, so varpool::remove can possibly lookup
616 : : the constructor and save it for future use. */
617 : 43710 : while (vnode->iterate_direct_aliases (0, ref))
618 : : {
619 : 0 : if (file)
620 : 0 : fprintf (file, " %s", ref->referred->dump_name ());
621 : 0 : ref->referring->remove ();
622 : : }
623 : 43710 : if (file)
624 : 1 : fprintf (file, " %s", vnode->dump_name ());
625 : 43710 : vnext = next_variable (vnode);
626 : : /* Signal removal to the debug machinery. */
627 : 43710 : if (! flag_wpa || flag_incremental_link == INCREMENTAL_LINK_LTO)
628 : : {
629 : 41366 : vnode->definition = false;
630 : 41366 : (*debug_hooks->late_global_decl) (vnode->decl);
631 : : }
632 : 43710 : vnode->remove ();
633 : 43710 : changed = true;
634 : : }
635 : 22198559 : else if (!reachable.contains (vnode) && !vnode->alias)
636 : : {
637 : 2073639 : tree init;
638 : 2073639 : if (vnode->definition)
639 : : {
640 : 16686 : if (file)
641 : 0 : fprintf (file, " %s", vnode->dump_name ());
642 : : changed = true;
643 : : }
644 : : /* Keep body if it may be useful for constant folding. */
645 : 2068811 : if ((flag_wpa || flag_incremental_link == INCREMENTAL_LINK_LTO)
646 : 4142396 : || ((init = ctor_for_folding (vnode->decl)) == error_mark_node))
647 : 1990793 : vnode->remove_initializer ();
648 : : else
649 : 82846 : DECL_INITIAL (vnode->decl) = init;
650 : 2073639 : vnode->body_removed = true;
651 : 2073639 : vnode->definition = false;
652 : 2073639 : vnode->analyzed = false;
653 : 2073639 : vnode->aux = NULL;
654 : :
655 : 2073639 : vnode->remove_from_same_comdat_group ();
656 : :
657 : 2073639 : vnode->remove_all_references ();
658 : : }
659 : : else
660 : 20124920 : vnode->aux = NULL;
661 : : }
662 : :
663 : : /* Now update address_taken flags and try to promote functions to be local. */
664 : 1463587 : if (file)
665 : 700 : fprintf (file, "\nClearing address taken flags:");
666 : 17909835 : FOR_EACH_DEFINED_FUNCTION (node)
667 : 16446248 : if (node->address_taken
668 : 3286302 : && !node->used_from_other_partition)
669 : : {
670 : 3286158 : if (!node->call_for_symbol_and_aliases
671 : 3286158 : (has_addr_references_p, NULL, true))
672 : : {
673 : 23015 : if (file)
674 : 0 : fprintf (file, " %s", node->dump_name ());
675 : 23015 : node->address_taken = false;
676 : 23015 : changed = true;
677 : 23015 : if (node->local_p ()
678 : : /* Virtual functions may be kept in cgraph just because
679 : : of possible later devirtualization. Do not mark them as
680 : : local too early so we won't optimize them out before
681 : : we are done with polymorphic call analysis. */
682 : 23015 : && (symtab->state >= IPA_SSA_AFTER_INLINING
683 : 508 : || !node->call_for_symbol_and_aliases
684 : 508 : (is_indirect_call_target_p, NULL, true)))
685 : : {
686 : 517 : node->local = true;
687 : 517 : if (file)
688 : 0 : fprintf (file, " (local)");
689 : : }
690 : : }
691 : : }
692 : 1463587 : if (file)
693 : 700 : fprintf (file, "\n");
694 : :
695 : 1463587 : symtab_node::checking_verify_symtab_nodes ();
696 : :
697 : : /* If we removed something, perhaps profile could be improved. */
698 : 1463587 : if (changed && (optimize || in_lto_p) && ipa_call_summaries)
699 : 4127040 : FOR_EACH_DEFINED_FUNCTION (node)
700 : 4057928 : ipa_propagate_frequency (node);
701 : :
702 : 1463587 : timevar_pop (TV_IPA_UNREACHABLE);
703 : 1463587 : return changed;
704 : 1463587 : }
705 : :
706 : : /* Process references to VNODE and set flags WRITTEN, ADDRESS_TAKEN, READ
707 : : as needed, also clear EXPLICIT_REFS if the references to given variable
708 : : do not need to be explicit. */
709 : :
710 : : void
711 : 5388888 : process_references (varpool_node *vnode,
712 : : bool *written, bool *address_taken,
713 : : bool *read, bool *explicit_refs)
714 : : {
715 : 5388888 : int i;
716 : 5388888 : struct ipa_ref *ref;
717 : :
718 : 5388888 : if (!vnode->all_refs_explicit_p ()
719 : 5388888 : || TREE_THIS_VOLATILE (vnode->decl))
720 : 2935362 : *explicit_refs = false;
721 : :
722 : 4042878 : for (i = 0; vnode->iterate_referring (i, ref)
723 : 9431766 : && *explicit_refs && (!*written || !*address_taken || !*read); i++)
724 : 4042878 : switch (ref->use)
725 : : {
726 : 2765337 : case IPA_REF_ADDR:
727 : 2765337 : *address_taken = true;
728 : 2765337 : break;
729 : 697440 : case IPA_REF_LOAD:
730 : 697440 : *read = true;
731 : 697440 : break;
732 : 568011 : case IPA_REF_STORE:
733 : 568011 : *written = true;
734 : 568011 : break;
735 : 12090 : case IPA_REF_ALIAS:
736 : 12090 : process_references (dyn_cast<varpool_node *> (ref->referring), written,
737 : : address_taken, read, explicit_refs);
738 : 12090 : break;
739 : : }
740 : 5388888 : }
741 : :
742 : : /* Set TREE_READONLY bit. */
743 : :
744 : : bool
745 : 77336 : set_readonly_bit (varpool_node *vnode, void *data ATTRIBUTE_UNUSED)
746 : : {
747 : 77336 : TREE_READONLY (vnode->decl) = true;
748 : 77336 : return false;
749 : : }
750 : :
751 : : /* Set writeonly bit and clear the initalizer, since it will not be needed. */
752 : :
753 : : bool
754 : 25978 : set_writeonly_bit (varpool_node *vnode, void *data)
755 : : {
756 : 25978 : vnode->writeonly = true;
757 : 25978 : if (optimize || in_lto_p)
758 : : {
759 : 25978 : DECL_INITIAL (vnode->decl) = NULL;
760 : 25978 : if (!vnode->alias)
761 : : {
762 : 25978 : if (vnode->num_references ())
763 : 210 : *(bool *)data = true;
764 : 25978 : vnode->remove_all_references ();
765 : : }
766 : : }
767 : 25978 : return false;
768 : : }
769 : :
770 : : /* Clear addressale bit of VNODE. */
771 : :
772 : : bool
773 : 174493 : clear_addressable_bit (varpool_node *vnode, void *data ATTRIBUTE_UNUSED)
774 : : {
775 : 174493 : vnode->address_taken = false;
776 : 174493 : TREE_ADDRESSABLE (vnode->decl) = 0;
777 : 174493 : return false;
778 : : }
779 : :
780 : : /* Discover variables that have no longer address taken, are read-only or
781 : : write-only and update their flags.
782 : :
783 : : Return true when unreachable symbol removal should be done.
784 : :
785 : : FIXME: This cannot be done in between gimplify and omp_expand since
786 : : readonly flag plays role on what is shared and what is not. Currently we do
787 : : this transformation as part of whole program visibility and re-do at
788 : : ipa-reference pass (to take into account clonning), but it would
789 : : make sense to do it before early optimizations. */
790 : :
791 : : bool
792 : 301950 : ipa_discover_variable_flags (void)
793 : : {
794 : 301950 : if (!flag_ipa_reference_addressable)
795 : : return false;
796 : :
797 : 298427 : bool remove_p = false;
798 : 298427 : varpool_node *vnode;
799 : 298427 : if (dump_file)
800 : 73 : fprintf (dump_file, "Clearing variable flags:");
801 : 5687552 : FOR_EACH_VARIABLE (vnode)
802 : 5389125 : if (!vnode->alias
803 : 5389125 : && (TREE_ADDRESSABLE (vnode->decl)
804 : 2373564 : || !vnode->writeonly
805 : 25904 : || !TREE_READONLY (vnode->decl)))
806 : : {
807 : 5376798 : bool written = false;
808 : 5376798 : bool address_taken = false;
809 : 5376798 : bool read = false;
810 : 5376798 : bool explicit_refs = true;
811 : :
812 : 5376798 : process_references (vnode, &written, &address_taken, &read,
813 : : &explicit_refs);
814 : 5376798 : if (!explicit_refs)
815 : 2935362 : continue;
816 : 2441436 : if (!address_taken)
817 : : {
818 : 163464 : if (TREE_ADDRESSABLE (vnode->decl) && dump_file)
819 : 0 : fprintf (dump_file, " %s (non-addressable)",
820 : : vnode->dump_name ());
821 : 163464 : vnode->call_for_symbol_and_aliases (clear_addressable_bit, NULL,
822 : : true);
823 : : }
824 : 163464 : if (!address_taken && !written
825 : : /* Making variable in explicit section readonly can cause section
826 : : type conflict.
827 : : See e.g. gcc.c-torture/compile/pr23237.c */
828 : 2507777 : && vnode->get_section () == NULL)
829 : : {
830 : 66311 : if (!TREE_READONLY (vnode->decl) && dump_file)
831 : 3 : fprintf (dump_file, " %s (read-only)", vnode->dump_name ());
832 : 66311 : vnode->call_for_symbol_and_aliases (set_readonly_bit, NULL, true);
833 : : }
834 : 2441436 : if (!vnode->writeonly && !read && !address_taken && written)
835 : : {
836 : 25978 : if (dump_file)
837 : 0 : fprintf (dump_file, " %s (write-only)", vnode->dump_name ());
838 : 25978 : vnode->call_for_symbol_and_aliases (set_writeonly_bit, &remove_p,
839 : : true);
840 : : }
841 : : }
842 : 298427 : if (dump_file)
843 : 73 : fprintf (dump_file, "\n");
844 : 298427 : return remove_p;
845 : : }
846 : :
847 : : /* Generate and emit a static constructor or destructor. WHICH must
848 : : be one of 'I' (for a constructor), 'D' (for a destructor).
849 : : BODY is a STATEMENT_LIST containing GENERIC
850 : : statements. PRIORITY is the initialization priority for this
851 : : constructor or destructor.
852 : :
853 : : FINAL specify whether the externally visible name for collect2 should
854 : : be produced. */
855 : :
856 : : static tree
857 : 4693 : cgraph_build_static_cdtor_1 (char which, tree body, int priority, bool final,
858 : : tree optimization,
859 : : tree target)
860 : : {
861 : 4693 : static int counter = 0;
862 : 4693 : char which_buf[16];
863 : 4693 : tree decl, name, resdecl;
864 : :
865 : : /* The priority is encoded in the constructor or destructor name.
866 : : collect2 will sort the names and arrange that they are called at
867 : : program startup. */
868 : 4693 : if (!targetm.have_ctors_dtors && final)
869 : : {
870 : 0 : sprintf (which_buf, "%c_%.5d_%d", which, priority, counter++);
871 : 0 : name = get_file_function_name (which_buf);
872 : : }
873 : : else
874 : : {
875 : : /* Proudce sane name but one not recognizable by collect2, just for the
876 : : case we fail to inline the function. */
877 : 4693 : sprintf (which_buf, "_sub_%c_%.5d_%d", which, priority, counter++);
878 : 4693 : name = get_identifier (which_buf);
879 : : }
880 : :
881 : 4693 : decl = build_decl (input_location, FUNCTION_DECL, name,
882 : : build_function_type_list (void_type_node, NULL_TREE));
883 : 4693 : current_function_decl = decl;
884 : :
885 : 4693 : resdecl = build_decl (input_location,
886 : : RESULT_DECL, NULL_TREE, void_type_node);
887 : 4693 : DECL_ARTIFICIAL (resdecl) = 1;
888 : 4693 : DECL_RESULT (decl) = resdecl;
889 : 4693 : DECL_CONTEXT (resdecl) = decl;
890 : :
891 : 4693 : allocate_struct_function (decl, false);
892 : :
893 : 4693 : TREE_STATIC (decl) = 1;
894 : 4693 : TREE_USED (decl) = 1;
895 : 4693 : DECL_FUNCTION_SPECIFIC_OPTIMIZATION (decl) = optimization;
896 : 4693 : DECL_FUNCTION_SPECIFIC_TARGET (decl) = target;
897 : 4693 : DECL_ARTIFICIAL (decl) = 1;
898 : 4693 : DECL_IGNORED_P (decl) = 1;
899 : 4693 : DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl) = 1;
900 : 4693 : DECL_SAVED_TREE (decl) = body;
901 : 4693 : if (!targetm.have_ctors_dtors && final)
902 : : {
903 : 0 : TREE_PUBLIC (decl) = 1;
904 : 0 : DECL_PRESERVE_P (decl) = 1;
905 : : }
906 : 4693 : DECL_UNINLINABLE (decl) = 1;
907 : :
908 : 4693 : DECL_INITIAL (decl) = make_node (BLOCK);
909 : 4693 : BLOCK_SUPERCONTEXT (DECL_INITIAL (decl)) = decl;
910 : 4693 : TREE_USED (DECL_INITIAL (decl)) = 1;
911 : :
912 : 4693 : DECL_SOURCE_LOCATION (decl) = input_location;
913 : 4693 : cfun->function_end_locus = input_location;
914 : :
915 : 4693 : switch (which)
916 : : {
917 : 3215 : case 'I':
918 : 3215 : DECL_STATIC_CONSTRUCTOR (decl) = 1;
919 : 3215 : decl_init_priority_insert (decl, priority);
920 : 3215 : break;
921 : 1478 : case 'D':
922 : 1478 : DECL_STATIC_DESTRUCTOR (decl) = 1;
923 : 1478 : decl_fini_priority_insert (decl, priority);
924 : 1478 : break;
925 : 0 : default:
926 : 0 : gcc_unreachable ();
927 : : }
928 : :
929 : 4693 : gimplify_function_tree (decl);
930 : :
931 : 4693 : cgraph_node::add_new_function (decl, false);
932 : :
933 : 4693 : set_cfun (NULL);
934 : 4693 : current_function_decl = NULL;
935 : 4693 : return decl;
936 : : }
937 : :
938 : : /* Generate and emit a static constructor or destructor. WHICH must
939 : : be one of 'I' (for a constructor) or 'D' (for a destructor).
940 : : BODY is a STATEMENT_LIST containing GENERIC
941 : : statements. PRIORITY is the initialization priority for this
942 : : constructor or destructor. */
943 : :
944 : : void
945 : 4685 : cgraph_build_static_cdtor (char which, tree body, int priority)
946 : : {
947 : : /* FIXME: We should be able to
948 : : gcc_assert (!in_lto_p);
949 : : because at LTO time the global options are not safe to use.
950 : : Unfortunately ASAN finish_file will produce constructors late and they
951 : : may lead to surprises. */
952 : 4685 : cgraph_build_static_cdtor_1 (which, body, priority, false,
953 : : optimization_default_node,
954 : : target_option_default_node);
955 : 4685 : }
956 : :
957 : : /* When target does not have ctors and dtors, we call all constructor
958 : : and destructor by special initialization/destruction function
959 : : recognized by collect2.
960 : :
961 : : When we are going to build this function, collect all constructors and
962 : : destructors and turn them into normal functions. */
963 : :
964 : : static void
965 : 103 : record_cdtor_fn (struct cgraph_node *node, vec<tree> *ctors, vec<tree> *dtors)
966 : : {
967 : 103 : if (DECL_STATIC_CONSTRUCTOR (node->decl))
968 : 78 : ctors->safe_push (node->decl);
969 : 103 : if (DECL_STATIC_DESTRUCTOR (node->decl))
970 : 29 : dtors->safe_push (node->decl);
971 : 103 : node = cgraph_node::get (node->decl);
972 : 103 : DECL_DISREGARD_INLINE_LIMITS (node->decl) = 1;
973 : 103 : }
974 : :
975 : : /* Define global constructors/destructor functions for the CDTORS, of
976 : : which they are LEN. The CDTORS are sorted by initialization
977 : : priority. If CTOR_P is true, these are constructors; otherwise,
978 : : they are destructors. */
979 : :
980 : : static void
981 : 75 : build_cdtor (bool ctor_p, const vec<tree> &cdtors)
982 : : {
983 : 75 : size_t i,j;
984 : 75 : size_t len = cdtors.length ();
985 : :
986 : 75 : i = 0;
987 : 174 : while (i < len)
988 : : {
989 : 99 : tree body;
990 : 99 : tree fn;
991 : 99 : priority_type priority;
992 : :
993 : 99 : priority = 0;
994 : 99 : body = NULL_TREE;
995 : 99 : j = i;
996 : 131 : do
997 : : {
998 : 131 : priority_type p;
999 : 131 : fn = cdtors[j];
1000 : 131 : p = ctor_p ? DECL_INIT_PRIORITY (fn) : DECL_FINI_PRIORITY (fn);
1001 : 131 : if (j == i)
1002 : : priority = p;
1003 : 32 : else if (p != priority)
1004 : : break;
1005 : 107 : j++;
1006 : : }
1007 : 107 : while (j < len);
1008 : :
1009 : : /* When there is only one cdtor and target supports them, do nothing. */
1010 : 99 : if (j == i + 1
1011 : 91 : && targetm.have_ctors_dtors)
1012 : : {
1013 : 91 : i++;
1014 : 91 : continue;
1015 : : }
1016 : : /* Find the next batch of constructors/destructors with the same
1017 : : initialization priority. */
1018 : 24 : for (;i < j; i++)
1019 : : {
1020 : 16 : tree call;
1021 : 16 : fn = cdtors[i];
1022 : 16 : call = build_call_expr (fn, 0);
1023 : 16 : if (ctor_p)
1024 : 8 : DECL_STATIC_CONSTRUCTOR (fn) = 0;
1025 : : else
1026 : 8 : DECL_STATIC_DESTRUCTOR (fn) = 0;
1027 : : /* We do not want to optimize away pure/const calls here.
1028 : : When optimizing, these should be already removed, when not
1029 : : optimizing, we want user to be able to breakpoint in them. */
1030 : 16 : TREE_SIDE_EFFECTS (call) = 1;
1031 : 16 : append_to_statement_list (call, &body);
1032 : : }
1033 : 8 : gcc_assert (body != NULL_TREE);
1034 : : /* Generate a function to call all the function of like
1035 : : priority. */
1036 : 16 : cgraph_build_static_cdtor_1 (ctor_p ? 'I' : 'D', body, priority, true,
1037 : 8 : DECL_FUNCTION_SPECIFIC_OPTIMIZATION (cdtors[0]),
1038 : 8 : DECL_FUNCTION_SPECIFIC_TARGET (cdtors[0]));
1039 : : }
1040 : 75 : }
1041 : :
1042 : : /* Helper functions for build_cxa_dtor_registrations ().
1043 : : Build a decl for __cxa_atexit (). */
1044 : :
1045 : : static tree
1046 : 0 : build_cxa_atexit_decl ()
1047 : : {
1048 : : /* The parameter to "__cxa_atexit" is "void (*)(void *)". */
1049 : 0 : tree fn_type = build_function_type_list (void_type_node,
1050 : : ptr_type_node, NULL_TREE);
1051 : 0 : tree fn_ptr_type = build_pointer_type (fn_type);
1052 : : /* The declaration for `__cxa_atexit' is:
1053 : : int __cxa_atexit (void (*)(void *), void *, void *). */
1054 : 0 : const char *name = "__cxa_atexit";
1055 : 0 : tree cxa_name = get_identifier (name);
1056 : 0 : fn_type = build_function_type_list (integer_type_node, fn_ptr_type,
1057 : : ptr_type_node, ptr_type_node, NULL_TREE);
1058 : 0 : tree atexit_fndecl = build_decl (BUILTINS_LOCATION, FUNCTION_DECL,
1059 : : cxa_name, fn_type);
1060 : 0 : SET_DECL_ASSEMBLER_NAME (atexit_fndecl, cxa_name);
1061 : 0 : DECL_VISIBILITY (atexit_fndecl) = VISIBILITY_DEFAULT;
1062 : 0 : DECL_VISIBILITY_SPECIFIED (atexit_fndecl) = true;
1063 : 0 : set_call_expr_flags (atexit_fndecl, ECF_LEAF | ECF_NOTHROW);
1064 : 0 : TREE_PUBLIC (atexit_fndecl) = true;
1065 : 0 : DECL_EXTERNAL (atexit_fndecl) = true;
1066 : 0 : DECL_ARTIFICIAL (atexit_fndecl) = true;
1067 : 0 : return atexit_fndecl;
1068 : : }
1069 : :
1070 : : /* Build a decl for __dso_handle. */
1071 : :
1072 : : static tree
1073 : 0 : build_dso_handle_decl ()
1074 : : {
1075 : : /* Declare the __dso_handle variable. */
1076 : 0 : tree dso_handle_decl = build_decl (UNKNOWN_LOCATION, VAR_DECL,
1077 : : get_identifier ("__dso_handle"),
1078 : : ptr_type_node);
1079 : 0 : TREE_PUBLIC (dso_handle_decl) = true;
1080 : 0 : DECL_EXTERNAL (dso_handle_decl) = true;
1081 : 0 : DECL_ARTIFICIAL (dso_handle_decl) = true;
1082 : : #ifdef HAVE_GAS_HIDDEN
1083 : 0 : if (dso_handle_decl != error_mark_node)
1084 : : {
1085 : 0 : DECL_VISIBILITY (dso_handle_decl) = VISIBILITY_HIDDEN;
1086 : 0 : DECL_VISIBILITY_SPECIFIED (dso_handle_decl) = true;
1087 : : }
1088 : : #endif
1089 : 0 : return dso_handle_decl;
1090 : : }
1091 : :
1092 : : /* This builds one or more constructor functions that register DTORs with
1093 : : __cxa_atexit (). Within a priority level, DTORs are registered in TU
1094 : : order - which means that they will run in reverse TU order from cxa_atexit.
1095 : : This is the same behavior as using a .fini / .mod_term_funcs section.
1096 : : As the functions are built, they are appended to the CTORs vector. */
1097 : :
1098 : : static void
1099 : 0 : build_cxa_dtor_registrations (const vec<tree> &dtors, vec<tree> *ctors)
1100 : : {
1101 : 0 : size_t i,j;
1102 : 0 : size_t len = dtors.length ();
1103 : :
1104 : 0 : location_t sav_loc = input_location;
1105 : 0 : input_location = UNKNOWN_LOCATION;
1106 : :
1107 : 0 : tree atexit_fndecl = build_cxa_atexit_decl ();
1108 : 0 : tree dso_handle_decl = build_dso_handle_decl ();
1109 : :
1110 : : /* We want &__dso_handle. */
1111 : 0 : tree dso_ptr = build1_loc (UNKNOWN_LOCATION, ADDR_EXPR,
1112 : : ptr_type_node, dso_handle_decl);
1113 : :
1114 : 0 : i = 0;
1115 : 0 : while (i < len)
1116 : : {
1117 : 0 : priority_type priority = 0;
1118 : 0 : tree body = NULL_TREE;
1119 : 0 : j = i;
1120 : 0 : do
1121 : : {
1122 : 0 : priority_type p;
1123 : 0 : tree fn = dtors[j];
1124 : 0 : p = DECL_FINI_PRIORITY (fn);
1125 : 0 : if (j == i)
1126 : : priority = p;
1127 : 0 : else if (p != priority)
1128 : : break;
1129 : 0 : j++;
1130 : : }
1131 : 0 : while (j < len);
1132 : :
1133 : : /* Find the next batch of destructors with the same initialization
1134 : : priority. */
1135 : 0 : for (;i < j; i++)
1136 : : {
1137 : 0 : tree fn = dtors[i];
1138 : 0 : DECL_STATIC_DESTRUCTOR (fn) = 0;
1139 : 0 : tree dtor_ptr = build1_loc (UNKNOWN_LOCATION, ADDR_EXPR,
1140 : : ptr_type_node, fn);
1141 : 0 : tree call_cxa_atexit
1142 : 0 : = build_call_expr_loc (UNKNOWN_LOCATION, atexit_fndecl, 3,
1143 : : dtor_ptr, null_pointer_node, dso_ptr);
1144 : 0 : TREE_SIDE_EFFECTS (call_cxa_atexit) = 1;
1145 : 0 : append_to_statement_list (call_cxa_atexit, &body);
1146 : : }
1147 : :
1148 : 0 : gcc_assert (body != NULL_TREE);
1149 : : /* Generate a function to register the DTORs at this priority. */
1150 : 0 : tree new_ctor
1151 : 0 : = cgraph_build_static_cdtor_1 ('I', body, priority, true,
1152 : 0 : DECL_FUNCTION_SPECIFIC_OPTIMIZATION (dtors[0]),
1153 : 0 : DECL_FUNCTION_SPECIFIC_TARGET (dtors[0]));
1154 : : /* Add this to the list of ctors. */
1155 : 0 : ctors->safe_push (new_ctor);
1156 : : }
1157 : 0 : input_location = sav_loc;
1158 : 0 : }
1159 : :
1160 : : /* Comparison function for qsort. P1 and P2 are actually of type
1161 : : "tree *" and point to static constructors. DECL_INIT_PRIORITY is
1162 : : used to determine the sort order. */
1163 : :
1164 : : static int
1165 : 96 : compare_ctor (const void *p1, const void *p2)
1166 : : {
1167 : 96 : tree f1;
1168 : 96 : tree f2;
1169 : 96 : int priority1;
1170 : 96 : int priority2;
1171 : :
1172 : 96 : f1 = *(const tree *)p1;
1173 : 96 : f2 = *(const tree *)p2;
1174 : 96 : priority1 = DECL_INIT_PRIORITY (f1);
1175 : 96 : priority2 = DECL_INIT_PRIORITY (f2);
1176 : :
1177 : 96 : if (priority1 < priority2)
1178 : : return -1;
1179 : 40 : else if (priority1 > priority2)
1180 : : return 1;
1181 : : else
1182 : : /* Ensure a stable sort. Constructors are executed in backwarding
1183 : : order to make LTO initialize braries first. */
1184 : 16 : return DECL_UID (f2) - DECL_UID (f1);
1185 : : }
1186 : :
1187 : : /* Comparison function for qsort. P1 and P2 are actually of type
1188 : : "tree *" and point to static destructors. DECL_FINI_PRIORITY is
1189 : : used to determine the sort order. */
1190 : :
1191 : : static int
1192 : 96 : compare_dtor (const void *p1, const void *p2)
1193 : : {
1194 : 96 : tree f1;
1195 : 96 : tree f2;
1196 : 96 : int priority1;
1197 : 96 : int priority2;
1198 : :
1199 : 96 : f1 = *(const tree *)p1;
1200 : 96 : f2 = *(const tree *)p2;
1201 : 96 : priority1 = DECL_FINI_PRIORITY (f1);
1202 : 96 : priority2 = DECL_FINI_PRIORITY (f2);
1203 : :
1204 : 96 : if (priority1 < priority2)
1205 : : return -1;
1206 : 40 : else if (priority1 > priority2)
1207 : : return 1;
1208 : : else
1209 : : /* Ensure a stable sort - into TU order. */
1210 : 16 : return DECL_UID (f1) - DECL_UID (f2);
1211 : : }
1212 : :
1213 : : /* Comparison function for qsort. P1 and P2 are of type "tree *" and point to
1214 : : a pair of static constructors or destructors. We first sort on the basis of
1215 : : priority and then into TU order (on the strict assumption that DECL_UIDs are
1216 : : ordered in the same way as the original functions). ???: this seems quite
1217 : : fragile. */
1218 : :
1219 : : static int
1220 : 0 : compare_cdtor_tu_order (const void *p1, const void *p2)
1221 : : {
1222 : 0 : tree f1;
1223 : 0 : tree f2;
1224 : 0 : int priority1;
1225 : 0 : int priority2;
1226 : :
1227 : 0 : f1 = *(const tree *)p1;
1228 : 0 : f2 = *(const tree *)p2;
1229 : : /* We process the DTORs first, and then remove their flag, so this order
1230 : : allows for functions that are declared as both CTOR and DTOR. */
1231 : 0 : if (DECL_STATIC_DESTRUCTOR (f1))
1232 : : {
1233 : 0 : gcc_checking_assert (DECL_STATIC_DESTRUCTOR (f2));
1234 : 0 : priority1 = DECL_FINI_PRIORITY (f1);
1235 : 0 : priority2 = DECL_FINI_PRIORITY (f2);
1236 : : }
1237 : : else
1238 : : {
1239 : 0 : priority1 = DECL_INIT_PRIORITY (f1);
1240 : 0 : priority2 = DECL_INIT_PRIORITY (f2);
1241 : : }
1242 : :
1243 : 0 : if (priority1 < priority2)
1244 : : return -1;
1245 : 0 : else if (priority1 > priority2)
1246 : : return 1;
1247 : : else
1248 : : /* For equal priority, sort into the order of definition in the TU. */
1249 : 0 : return DECL_UID (f1) - DECL_UID (f2);
1250 : : }
1251 : :
1252 : : /* Generate functions to call static constructors and destructors
1253 : : for targets that do not support .ctors/.dtors sections. These
1254 : : functions have magic names which are detected by collect2. */
1255 : :
1256 : : static void
1257 : 11889 : build_cdtor_fns (vec<tree> *ctors, vec<tree> *dtors)
1258 : : {
1259 : 11889 : if (!ctors->is_empty ())
1260 : : {
1261 : 62 : gcc_assert (!targetm.have_ctors_dtors || in_lto_p);
1262 : 62 : ctors->qsort (compare_ctor);
1263 : 62 : build_cdtor (/*ctor_p=*/true, *ctors);
1264 : : }
1265 : :
1266 : 11889 : if (!dtors->is_empty ())
1267 : : {
1268 : 13 : gcc_assert (!targetm.have_ctors_dtors || in_lto_p);
1269 : 13 : dtors->qsort (compare_dtor);
1270 : 13 : build_cdtor (/*ctor_p=*/false, *dtors);
1271 : : }
1272 : 11889 : }
1273 : :
1274 : : /* Generate new CTORs to register static destructors with __cxa_atexit and add
1275 : : them to the existing list of CTORs; we then process the revised CTORs list.
1276 : :
1277 : : We sort the DTORs into priority and then TU order, this means that they are
1278 : : registered in that order with __cxa_atexit () and therefore will be run in
1279 : : the reverse order.
1280 : :
1281 : : Likewise, CTORs are sorted into priority and then TU order, which means that
1282 : : they will run in that order.
1283 : :
1284 : : This matches the behavior of using init/fini or mod_init_func/mod_term_func
1285 : : sections. */
1286 : :
1287 : : static void
1288 : 0 : build_cxa_atexit_fns (vec<tree> *ctors, vec<tree> *dtors)
1289 : : {
1290 : 0 : if (!dtors->is_empty ())
1291 : : {
1292 : 0 : gcc_assert (targetm.dtors_from_cxa_atexit);
1293 : 0 : dtors->qsort (compare_cdtor_tu_order);
1294 : 0 : build_cxa_dtor_registrations (*dtors, ctors);
1295 : : }
1296 : :
1297 : 0 : if (!ctors->is_empty ())
1298 : : {
1299 : 0 : gcc_assert (targetm.dtors_from_cxa_atexit);
1300 : 0 : ctors->qsort (compare_cdtor_tu_order);
1301 : 0 : build_cdtor (/*ctor_p=*/true, *ctors);
1302 : : }
1303 : 0 : }
1304 : :
1305 : : /* Look for constructors and destructors and produce function calling them.
1306 : : This is needed for targets not supporting ctors or dtors, but we perform the
1307 : : transformation also at linktime to merge possibly numerous
1308 : : constructors/destructors into single function to improve code locality and
1309 : : reduce size. */
1310 : :
1311 : : static unsigned int
1312 : 11889 : ipa_cdtor_merge (void)
1313 : : {
1314 : : /* A vector of FUNCTION_DECLs declared as static constructors. */
1315 : 11889 : auto_vec<tree, 20> ctors;
1316 : : /* A vector of FUNCTION_DECLs declared as static destructors. */
1317 : 11889 : auto_vec<tree, 20> dtors;
1318 : 11889 : struct cgraph_node *node;
1319 : 89722 : FOR_EACH_DEFINED_FUNCTION (node)
1320 : 77833 : if (DECL_STATIC_CONSTRUCTOR (node->decl)
1321 : 77833 : || DECL_STATIC_DESTRUCTOR (node->decl))
1322 : 103 : record_cdtor_fn (node, &ctors, &dtors);
1323 : 11889 : if (targetm.dtors_from_cxa_atexit)
1324 : 0 : build_cxa_atexit_fns (&ctors, &dtors);
1325 : : else
1326 : 11889 : build_cdtor_fns (&ctors, &dtors);
1327 : 11889 : return 0;
1328 : 11889 : }
1329 : :
1330 : : namespace {
1331 : :
1332 : : const pass_data pass_data_ipa_cdtor_merge =
1333 : : {
1334 : : IPA_PASS, /* type */
1335 : : "cdtor", /* name */
1336 : : OPTGROUP_NONE, /* optinfo_flags */
1337 : : TV_CGRAPHOPT, /* tv_id */
1338 : : 0, /* properties_required */
1339 : : 0, /* properties_provided */
1340 : : 0, /* properties_destroyed */
1341 : : 0, /* todo_flags_start */
1342 : : 0, /* todo_flags_finish */
1343 : : };
1344 : :
1345 : : class pass_ipa_cdtor_merge : public ipa_opt_pass_d
1346 : : {
1347 : : public:
1348 : 286437 : pass_ipa_cdtor_merge (gcc::context *ctxt)
1349 : : : ipa_opt_pass_d (pass_data_ipa_cdtor_merge, ctxt,
1350 : : NULL, /* generate_summary */
1351 : : NULL, /* write_summary */
1352 : : NULL, /* read_summary */
1353 : : NULL, /* write_optimization_summary */
1354 : : NULL, /* read_optimization_summary */
1355 : : NULL, /* stmt_fixup */
1356 : : 0, /* function_transform_todo_flags_start */
1357 : : NULL, /* function_transform */
1358 : 286437 : NULL) /* variable_transform */
1359 : 286437 : {}
1360 : :
1361 : : /* opt_pass methods: */
1362 : : bool gate (function *) final override;
1363 : 11889 : unsigned int execute (function *) final override
1364 : : {
1365 : 11889 : return ipa_cdtor_merge ();
1366 : : }
1367 : :
1368 : : }; // class pass_ipa_cdtor_merge
1369 : :
1370 : : bool
1371 : 565644 : pass_ipa_cdtor_merge::gate (function *)
1372 : : {
1373 : : /* Perform the pass when we have no ctors/dtors support
1374 : : or at LTO time to merge multiple constructors into single
1375 : : function. */
1376 : 565644 : return !targetm.have_ctors_dtors || in_lto_p || targetm.dtors_from_cxa_atexit;
1377 : : }
1378 : :
1379 : : } // anon namespace
1380 : :
1381 : : ipa_opt_pass_d *
1382 : 286437 : make_pass_ipa_cdtor_merge (gcc::context *ctxt)
1383 : : {
1384 : 286437 : return new pass_ipa_cdtor_merge (ctxt);
1385 : : }
1386 : :
1387 : : /* Invalid pointer representing BOTTOM for single user dataflow. */
1388 : : #define BOTTOM ((cgraph_node *)(size_t) 2)
1389 : :
1390 : : /* Meet operation for single user dataflow.
1391 : : Here we want to associate variables with sigle function that may access it.
1392 : :
1393 : : FUNCTION is current single user of a variable, VAR is variable that uses it.
1394 : : Latttice is stored in SINGLE_USER_MAP.
1395 : :
1396 : : We represent:
1397 : : - TOP by no entry in SIGNLE_USER_MAP
1398 : : - BOTTOM by BOTTOM in AUX pointer (to save lookups)
1399 : : - known single user by cgraph pointer in SINGLE_USER_MAP. */
1400 : :
1401 : : cgraph_node *
1402 : 3435965 : meet (cgraph_node *function, varpool_node *var,
1403 : : hash_map<varpool_node *, cgraph_node *> &single_user_map)
1404 : : {
1405 : 3435965 : struct cgraph_node *user, **f;
1406 : :
1407 : 3435965 : if (var->aux == BOTTOM)
1408 : : return BOTTOM;
1409 : :
1410 : 2453450 : f = single_user_map.get (var);
1411 : 2453450 : if (!f)
1412 : : return function;
1413 : 1001875 : user = *f;
1414 : 1001875 : if (!function)
1415 : : return user;
1416 : 979922 : else if (function != user)
1417 : : return BOTTOM;
1418 : : else
1419 : : return function;
1420 : : }
1421 : :
1422 : : /* Propagation step of single-use dataflow.
1423 : :
1424 : : Check all uses of VNODE and see if they are used by single function FUNCTION.
1425 : : SINGLE_USER_MAP represents the dataflow lattice. */
1426 : :
1427 : : cgraph_node *
1428 : 1785006 : propagate_single_user (varpool_node *vnode, cgraph_node *function,
1429 : : hash_map<varpool_node *, cgraph_node *> &single_user_map)
1430 : : {
1431 : 1785006 : int i;
1432 : 1785006 : struct ipa_ref *ref;
1433 : :
1434 : 1785006 : gcc_assert (!vnode->externally_visible);
1435 : :
1436 : : /* If node is an alias, first meet with its target. */
1437 : 1785006 : if (vnode->alias)
1438 : 16292 : function = meet (function, vnode->get_alias_target (), single_user_map);
1439 : :
1440 : : /* Check all users and see if they correspond to a single function. */
1441 : 5821634 : for (i = 0; vnode->iterate_referring (i, ref) && function != BOTTOM; i++)
1442 : : {
1443 : 8073256 : struct cgraph_node *cnode = dyn_cast <cgraph_node *> (ref->referring);
1444 : 4036628 : if (cnode)
1445 : : {
1446 : 616955 : if (cnode->inlined_to)
1447 : 87948 : cnode = cnode->inlined_to;
1448 : 616955 : if (!function)
1449 : : function = cnode;
1450 : 315552 : else if (function != cnode)
1451 : 24778 : function = BOTTOM;
1452 : : }
1453 : : else
1454 : 6839346 : function = meet (function, dyn_cast <varpool_node *> (ref->referring),
1455 : : single_user_map);
1456 : : }
1457 : 1785006 : return function;
1458 : : }
1459 : :
1460 : : /* Pass setting used_by_single_function flag.
1461 : : This flag is set on variable when there is only one function that may
1462 : : possibly referr to it. */
1463 : :
1464 : : static unsigned int
1465 : 231569 : ipa_single_use (void)
1466 : : {
1467 : 231569 : varpool_node *first = (varpool_node *) (void *) 1;
1468 : 231569 : varpool_node *var;
1469 : 231569 : hash_map<varpool_node *, cgraph_node *> single_user_map;
1470 : :
1471 : 3095398 : FOR_EACH_DEFINED_VARIABLE (var)
1472 : 2863829 : if (!var->all_refs_explicit_p ())
1473 : 1562276 : var->aux = BOTTOM;
1474 : : else
1475 : : {
1476 : : /* Enqueue symbol for dataflow. */
1477 : 1301553 : var->aux = first;
1478 : 1301553 : first = var;
1479 : : }
1480 : :
1481 : : /* The actual dataflow. */
1482 : :
1483 : 2016575 : while (first != (void *) 1)
1484 : : {
1485 : 1785006 : cgraph_node *user, *orig_user, **f;
1486 : :
1487 : 1785006 : var = first;
1488 : 1785006 : first = (varpool_node *)first->aux;
1489 : :
1490 : 1785006 : f = single_user_map.get (var);
1491 : 1785006 : if (f)
1492 : 29040 : orig_user = *f;
1493 : : else
1494 : : orig_user = NULL;
1495 : 1785006 : user = propagate_single_user (var, orig_user, single_user_map);
1496 : :
1497 : 1785006 : gcc_checking_assert (var->aux != BOTTOM);
1498 : :
1499 : : /* If user differs, enqueue all references. */
1500 : 1785006 : if (user != orig_user)
1501 : : {
1502 : 1307604 : unsigned int i;
1503 : 1307604 : ipa_ref *ref;
1504 : :
1505 : 1307604 : single_user_map.put (var, user);
1506 : :
1507 : : /* Enqueue all aliases for re-processing. */
1508 : 2629103 : for (i = 0; var->iterate_direct_aliases (i, ref); i++)
1509 : 13895 : if (!ref->referring->aux)
1510 : : {
1511 : 4185 : ref->referring->aux = first;
1512 : 13895 : first = dyn_cast <varpool_node *> (ref->referring);
1513 : : }
1514 : : /* Enqueue all users for re-processing. */
1515 : 5217386 : for (i = 0; var->iterate_reference (i, ref); i++)
1516 : 1301089 : if (!ref->referred->aux
1517 : 732366 : && ref->referred->definition
1518 : 2512723 : && is_a <varpool_node *> (ref->referred))
1519 : : {
1520 : 479268 : ref->referred->aux = first;
1521 : 479268 : first = dyn_cast <varpool_node *> (ref->referred);
1522 : : }
1523 : :
1524 : : /* If user is BOTTOM, just punt on this var. */
1525 : 1307604 : if (user == BOTTOM)
1526 : 1011005 : var->aux = BOTTOM;
1527 : : else
1528 : 296599 : var->aux = NULL;
1529 : : }
1530 : : else
1531 : 477402 : var->aux = NULL;
1532 : : }
1533 : :
1534 : 3095398 : FOR_EACH_DEFINED_VARIABLE (var)
1535 : : {
1536 : 2863829 : if (var->aux != BOTTOM)
1537 : : {
1538 : : /* Not having the single user known means that the VAR is
1539 : : unreachable. Either someone forgot to remove unreachable
1540 : : variables or the reachability here is wrong. */
1541 : :
1542 : 290548 : gcc_checking_assert (single_user_map.get (var));
1543 : :
1544 : 290548 : if (dump_file)
1545 : : {
1546 : 10 : fprintf (dump_file, "Variable %s is used by single function\n",
1547 : : var->dump_name ());
1548 : : }
1549 : 290548 : var->used_by_single_function = true;
1550 : : }
1551 : 2863829 : var->aux = NULL;
1552 : : }
1553 : 231569 : return 0;
1554 : 231569 : }
1555 : :
1556 : : namespace {
1557 : :
1558 : : const pass_data pass_data_ipa_single_use =
1559 : : {
1560 : : IPA_PASS, /* type */
1561 : : "single-use", /* name */
1562 : : OPTGROUP_NONE, /* optinfo_flags */
1563 : : TV_CGRAPHOPT, /* tv_id */
1564 : : 0, /* properties_required */
1565 : : 0, /* properties_provided */
1566 : : 0, /* properties_destroyed */
1567 : : 0, /* todo_flags_start */
1568 : : 0, /* todo_flags_finish */
1569 : : };
1570 : :
1571 : : class pass_ipa_single_use : public ipa_opt_pass_d
1572 : : {
1573 : : public:
1574 : 286437 : pass_ipa_single_use (gcc::context *ctxt)
1575 : : : ipa_opt_pass_d (pass_data_ipa_single_use, ctxt,
1576 : : NULL, /* generate_summary */
1577 : : NULL, /* write_summary */
1578 : : NULL, /* read_summary */
1579 : : NULL, /* write_optimization_summary */
1580 : : NULL, /* read_optimization_summary */
1581 : : NULL, /* stmt_fixup */
1582 : : 0, /* function_transform_todo_flags_start */
1583 : : NULL, /* function_transform */
1584 : 286437 : NULL) /* variable_transform */
1585 : 286437 : {}
1586 : :
1587 : : /* opt_pass methods: */
1588 : 231569 : unsigned int execute (function *) final override { return ipa_single_use (); }
1589 : :
1590 : : }; // class pass_ipa_single_use
1591 : :
1592 : : } // anon namespace
1593 : :
1594 : : ipa_opt_pass_d *
1595 : 286437 : make_pass_ipa_single_use (gcc::context *ctxt)
1596 : : {
1597 : 286437 : return new pass_ipa_single_use (ctxt);
1598 : : }
1599 : :
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